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Plural channels for transmission of a single pulse train

Subclass of:

375 - Pulse or digital communications

375259000 - SYSTEMS USING ALTERNATING OR PULSATING CURRENT

Patent class list (only not empty are listed)

Deeper subclasses:

Class / Patent application numberDescriptionNumber of patent applications / Date published
375267000 Diversity 776
375261000 Quadrature amplitude modulation 164
Entries
DocumentTitleDate
20130044833METHOD FOR FEEDING BACK PRECODING MATRIX INFORMATION AND MOBILE STATION THEREOF - A method for feeding back pre-coding matrix information and a mobile station thereof are provided. The method includes: determining multiple kinds of pre-coding matrix information corresponding to multiple multi-input multi-output (MIMO) modes; and feeding back multiple kinds of pre-coding matrix information. The present invention can feedback pre-coding matrix information adapting for multiple multi-input multi-output modes.02-21-2013
20130044832METHOD, DEVICE AND SYSTEM FOR COMMUNICATION BETWEEN DOUBLE CENTRAL PROCESSING UNITS - Embodiments of the present invention provide a method, a device and a system for communication between double central processing units, which relates to the field of mobile communications technologies. An embodiment of the present invention provides a method for communication between double central processing units, where the method includes: receiving, by a baseband function module, a baseband function invocation request message sent by an application function module through a service channel and a virtual channel, where the baseband function invocation request message carries a virtual channel identifier, and the virtual channel identifier corresponds to the virtual channel; and in response to the baseband function invocation request message, returning, by the baseband function module, a baseband function invocation response message to the application function module, where the baseband function invocation response message carries the virtual channel identifier.02-21-2013
20100067592OFDMA-BASED OPERATION OF A WIRELESS SUBSCRIBER TERMINAL IN A PLURALITY OF CELLS - A method for carrying out concurrent communications between a subscriber device and two base stations is disclosed. At least one OFDM/OFDMA sub-channel is selected for each of the two base stations which is associated with a communications sector belonging to one of the two base stations and comprises OFDM/OFDMA sub-carriers that are substantially different from sub-carries comprised in the OFDM/OFDMA sub-channel associated with a communications sector belonging to the other base station; establishing a communication path between the subscriber device and each of the two base stations along the respective sub-channel selected; receiving/transmitting control messages exchanged between the subscriber device and the two base stations, wherein at least one control message is exchanged between the subscriber device and one of the two base stations concurrently with at least one control message exchanged between the subscriber device and the other base station, and wherein the control messages are exchanged along different sub-channels comprised in the communication paths.03-18-2010
20080273607RANGING AND ROUND TRIP DELAY TIMING ADJUSTMENT IN A MULTI-POINT TO POINT BIDIRECTIONAL COMMUNICATION SYSTEM - A bidirectional communication system is provided. In one embodiment, a system comprises a host unit to communicate with a plurality of remote units using orthogonal frequency division multiplexing (OFDM), the plurality of remote units communicatively coupled to the host unit in a multipoint-to-point configuration; and wherein the host unit is configured to adjust a round trip path delay associated with at least one of the plurality of remote units.11-06-2008
20080273606Method For Signaling the Status of a Subcarrier in a Mc Network and a Method For Adaptively Allocating the Subcarrieres in a Mc Network - A fast method for allocating those channels or subcarriers of a multicarrier network to an ahead lying transmission is to let a transmitting terminal and a receiving terminal which intend to access the medium determine the status of the channels or subcarriers that are within their reception range and send a signal indicating the determined status to the corresponding terminal which will select those channels or subcarriers for the eventual transmission which fit best. Other terminals within the transmission range of the transmitting or the receiving terminal respect the reservation and wait for the current transmission to find out which channels or subcarriers are actually used.11-06-2008
20110200126CHANNEL ESTIMATION AND DATA DETECTION IN A WIRELESS COMMUNICATION SYSTEM IN THE PRESENCE OF INTER-CELL INTERFERENCE - Channel estimation and data detection in a wireless communication system in the presence of inter-cell interference is provided. In one embodiment, a method for channel estimation and data detection in a wireless communication system, comprising receiving a signal, wherein said signal is composed of a data signal, a desired reference signal and an interference reference signal; selecting a channel estimator using said desired reference signal, said interference reference signal or both; applying said selected channel estimator to said desired reference signal, said interference reference signal or both to generate one or more reference signal channel estimate weights; generating one or more data channel estimate weights using said reference signal channel estimate weights; selecting a data detector using said reference signal channel estimate weights, said data channel estimate weights or both; and detecting said data signal using said selected data detector, wherein said selected data detector uses said reference signal channel estimate weights, said data channel estimate weights or both.08-18-2011
20130028340CHANNEL STATUS INFORMATION FEEDBACK - The present invention provides a method and system for channel status information feedback based on a hierarchical codebook, the method comprising steps of: generating a hierarchical codebook; configuring the generated hierarchical codebook to a transmit end and a receive end, respectively; and feeding back channel state information from the receive end to the transmit end based on the hierarchical codebook, wherein the step of generating a hierarchical codebook further comprises the following steps: i) dividing each level of codeword in a to-be-generated codebook into a plurality of segments based on a basic codebook; ii) a module configured to generate each level of codeword in a first stage, wherein the each level of codeword is selected from the basic codebook; and iii) generating each level of codeword in other stages, wherein the each level of codeword is selected a pre-provided training sample matrix. And the feeding back the channel status information from the receiving end to the transmitting end based on the hierarchical codebook further comprises using a first bit and a second bit of the feedback bits to represent a signaling for performing tree search to the hierarchical codebook.01-31-2013
20090323844Codebook generation system and associated methods - A codebook generation system and associated methods are generally described herein.12-31-2009
20100061471CHANNEL ESTIMATION APPARATUS AND METHOD USING LINEAR/NONLINEAR AVERAGE IN WIRELESS TELECOMMUNICATION SYSTEM - Provided is a channel estimation apparatus and method using a linear/nonlinear average in a wireless communication system. The present research provides a channel estimation apparatus and method for estimating a channel between a transmitter and a receiver from a pilot-inserted OFDM signal and linearly or nonlinearly averaging the estimating channel, thereby preventing the equalizer performance from being degraded by noise component of the estimated channel and noise amplification caused by deep fading. The channel estimation apparatus includes: a channel estimation unit configured to estimate a channel coefficient of a channel between a transmitter and a receiver from a pilot-inserted carrier signal according to pilot arrangement; and a linear/nonlinear averaging unit configured to linearly or nonlinearly averaging the estimated channel coefficient, thereby preventing an equalizer performance from being degraded by noise component existing in the channel and noise amplification caused by deep fading.03-11-2010
20100020889ENCODED SIGNAL ARRANGEMENT METHOD IN MULTI-CARRIER COMMUNICATION AND COMMUNICATION DEVICE - Freedom for relationship between division of a signal processing unit and a pilot signal is improved in a multi-carrier communication system such as OFDM. An encoded signal is divided into resource blocks and the signals are arranged independently of the arrangement of a pilot signal. The signal arranged at the same position as the pilot signal causes a puncture upon transmission.01-28-2010
20130044831POWER ALLOCATION FOR OVERLAPPING TRANSMISSION WHEN MULTIPLE TIMING ADVANCES ARE USED - A method and apparatus for power allocation for overlapping transmissions is provided herein. During operation, user equipment will determine if transmissions to a single base station, on various frequencies, will be overlapping. If so, a determination is made to back off the power for at least one transmission on one frequency.02-21-2013
20090196361NON-BINARY SOURCE-TO-CHANNEL SYMBOL MAPPINGS WITH MINIMIZED DISTORTION - System and methodologies for low-distortion index assignment for quantization are provided herein. Various aspects described herein utilize a graph theoretic approach for determining an index assignment mapping between a quantization codebook and a signal constellation by employing a variation of the subgraph isomorphism problem. The graph theoretic index assignment algorithms described herein allow efficient determination of index assignment mappings for both binary and non-binary quantization schemes. Further, the topological structure of a signal constellation can be exploited to simplify the set of subgraphs to be searched in select cases. Various aspects described herein can additionally be utilized to determine index assignment mappings for space-time block codes in a multiple-input multiple-output wireless communication system.08-06-2009
20090196359METHODS AND SYSTEMS TO INSERT FILLER DATA IN UNALLOCATED RESOURCE REGIONS OF A FRAME - In at least some embodiments, a system comprises a first device that prepares a frame for transmission and a second device in communication with the first device. The first device is configured to identify unallocated resource regions in the prepared frame and insert filler data in the unallocated resource regions.08-06-2009
20090196369METHOD AND SYSTEM FOR OPTIMAL BITLOADING IN COMMUNICATION AND DATA COMPRESSION SYSTEMS - This invention provides a method and system for determining the number of bits to assign to a frequency range in a signal. The present invention is capable of bit allocation, with B total bits, among a plurality of N frequency ranges in time a time O(N log N), which is independent of the size of B. Embodiments of the present invention have many practical applications, including allocating bits among sub-channels in a multi-carrier communication system, and allocating bits among sub-bands in a signal representing digital multimedia, such as in JPEG or MPEG compressed files.08-06-2009
20090196368Radio transmission control method, radio receiver apparatus, and radio transmitter apparatus - Conventionally, if the number of transmission antennas is greater than that of reception antennas, different signals simultaneously transmitted from the transmission antennas cannot be separated from one another at the receiving end, resulting in a significant degradation of received-signal quality. A transmitter and a receiver each have a plurality of antennas. The transmitter transmits a pilot signal. The receiver receives the pilot signal, calculates transmission-related information corresponding to the pilot signal, selects, based on this calculated information, a transmission signal to be used by the transmitter, and notifies the transmitter of the selected signal. The transmitter selects, from the informed transmission signal, transmission antennas and uses the selected antennas to transmit information signals, so that a signal separation can be easily performed at the receiving end.08-06-2009
20090196365Wireless Communication Apparatus, Antenna Calibration Method and Program - A wireless communication apparatus includes a loopback transfer function acquisition section that, when a first path including all paths from each branch of the first set to each branch of the second set via the antenna is formed, acquires a loopback transfer function of each path included in the first path based on a reception status of a reference signal transmitted from each branch of the first set and received by each branch of the second set, and when a second path opposite to the first path is formed, acquires a loopback transfer function of each path included in the second path based on a reception status of a reference signal transmitted from each branch of the second set and received by each branch of the first set, and a calibration factor calculation section to calculate a calibration factor of each branch based on the acquired loopback transfer functions.08-06-2009
20090196364RADIO COMMUNICATION DEVICE, RADIO COMMUNICATION METHOD, AND PROGRAM - A radio communication method stores a plurality MAC frames for each of a plurality of destinations. The method decides the longest transmission time of transmission times needed to transmit the plurality of MAC frames to each of the plurality of destinations within a fixed period. The method generates a plurality of physical frames for the plurality of destinations to transmit them at the same time by connecting the plurality of MAC frames and adding additional information to each connected MAC frame so as to be a frame length equivalent to a transmission time equal to the longest transmission time.08-06-2009
20090196363RADIO COMMUNICATIONS APPARATUS AND COMMUNICATION METHOD - A radio communications apparatus transmitting data using multiple antennas is disclosed that includes a data link layer control information generation part configured to generate multiple data link layer control information items from generated data link layer control information; a data unit generation part configured to generate multiple data units to be transmitted through the corresponding antennas, based on the data link layer control information items generated by the data link layer control information generation part, so that the data units include the data link layer control information items; and a physical layer processing part configured to perform adaptive modulation and coding on the data units.08-06-2009
20090196362TRANSMISSION METHOD AND APPARATUS FOR ALLOCATING SUBCHANNEL AND FORMING STATIONARY BEAM TO MAXIMIZE TRANSMISSION EFFICIENCY IN ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING/MULTIPLE ACCESS BASED WIRELESS COMMUNICATION SYSTEM - Provided are a transmission method and apparatus for allocating a subchannel and forming a stationary beam to maximize transmission efficiency in an OFDMA based wireless communication system. The method includes determining the subchannel for the equipment of each user based on the channel state of the equipment of each user, determining a beam index for the equipment of each user, based on location information and direction of arrival information of the equipment of each user, generating an OFDM symbol by mapping a modulation symbol corresponding to the equipment of each user to the determined subchannel, and transmitting the generated OFDM symbol to a wireless space by forming a beam following the determined beam index. Using the method, the equipment of each user can be allocated with an advantageous subchannel, can remove an interference signal at low cost, and can increase total throughput of an OFDMA system downlink.08-06-2009
20090196366Transmission of Uplink Control Information with Data in Wireless Networks - Within a wireless network, feedback information from one node to another node is necessary to support various functions. The first node receives an allocation of resources for data transmission. The first node generates cyclic redundancy check (CRC) bits for a selected feedback control information type and encodes the selected feedback information and the CRC bits. The encoding of the feedback information and the CRC bits is adaptive based the amount of allocated resources. The encoded feedback information and CRC bits are then transmitted to the other node using a subset of the allocated resources on the physical shared channel that is normally used only for data transmissions.08-06-2009
20090092196Data Transmission Via Multi-Path Channels Using Orthogonal Multi-Frequency Signals With Differential Phase Shift Keying Modulation - A method and an apparatus relating to an OFDM data communications system where the sub-carriers are modulated using differential quadrature phase-shift keying (DQPSK). The multi-carrier transmitted signal is directly generated by means of summation of pre-computed sample points. As part of the multi-carrier signal generation, a signal for the guard interval is established. In an acoustic application of this approach, direct radiation of the sub-carrier approach is facilitated. Symbol synchronization in the receiver is based on signal correlation with the missed sub-carrier. Separation of the sub-carriers in the receiver by means of correlation of the received signal and reference signals that are derived from a table of pre-computed values. Optimal non-coherent processing of the sub-carriers without any phase tracking procedures is achieved.04-09-2009
20100046647Interpolation IIR filter for OFDM Baseband Processing - A filter for receiver and operative on a stream of OFDM symbols has a symbol timing identifier which indicates the time interval for each symbol and also indicates a non-truncation interval and a truncation interval of the stream of symbols. The stream of OFDM symbols is applied to an infinite impulse response (IIR) filter with a reset input for resetting internal registers such that during the non-truncation interval, the reset input is not asserted, and during the truncation interval of the stream of OFDM symbols, the reset input is asserted during the intervals between symbols, as identified by the symbol timing identifier.02-25-2010
20090213943TIME AND FREQUENCY DOMAIN BASED APPROACHES FOR FINE TIMING AND FREQUENCY ESTIMATIONS IN ISDB-T AND ISDB-TSB RECEIVER DESIGN - A method and apparatus for estimating timing and frequency offsets in an ISDB-T and ISDB-TSB receiver. In different embodiments, the method comprises estimating timing and frequency offsets by different estimation processes; assigning weights to the timing and frequency offsets according to the channel condition; and calculating timing and frequency offsets using the estimates of timing and frequency offsets and the weights.08-27-2009
20080205532Carrier Allocation Method In Ofdm System And Transmittting Apparatus Using The Method - The present invention relates to a method for allocating subcarriers in an orthogonal frequency division multiplex (OFDM) system, and a transmitter thereof. In the OFDM system according to an exemplary embodiment of the present invention, the subcarrier allocation is performed in the buffer (08-28-2008
20100086067SIGNAL SEPARATING DEVICE AND SIGNAL SEPARATING METHOD - A signal separating device the computational complexity of which is reduced and the communication quality of which is improved. A channel matrix interchanging section (04-08-2010
20100086066ADAPTIVE LOADING FOR ORTHOGONAL FREQUENCY DIVISION MULTIPLEX (OFDM) COMMUNICATION SYSTEMS - An orthogonal frequency division multiplex (OFDM) transmitter may adaptively load each sub-carrier, buffering less than an OFDM frame in order to reduce hardware requirements and latency. The transmitter may use feedback information from the receiver regarding the quality of the sub-carriers. In addition, combining repetition and puncturing to achieve a desired date rate per class further reduces hardware by simplifying or even eliminating an interleaver. Additional mitigation and even performance enhancement techniques are incorporated to address inter-class boundaries within an OFDM frame, such as introducing transition classes. Channel state information may be reported in various formats including full bitmap, changed subchannels, and reported bad subchannels.04-08-2010
20100080313APPARATUS AND METHOD FOR SUPPORTING IN-BAND VENUE-CAST ON A FORWARD LINK ONLY (FLO) NETWORK USING PILOT INTERFERENCE CANCELLATION - An apparatus and method for supporting in-band venue-cast comprising receiving a waveform with macro-cast contents introduced into a first symbol space in a superframe for wide area and local area services, at least one pilot signal introduced into a second symbol space in the superframe and venue-cast contents also introduced into the second symbol space, wherein the macro-cast contents and the at least one pilot signal are transmitted by a macro transmitter, and the venue-cast contents are transmitted by a venue transmitter; performing pilot interference cancellation to null the at least one pilot signal in the second symbol space; and extracting the venue-cast contents from the received waveform. In one aspect, the apparatus and method comprises determining a symbol space where pilots associated with macro transmission are scheduled for transmission; introduces venue-cast contents into the symbol space to form a waveform; and transmits the waveform to a predetermined venue site.04-01-2010
20100080312ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING (OFDM) COMMUNICATIONS DEVICE AND METHOD THAT INCORPORATES LOW PAPR PREAMBLE WITH CIRCUIT FOR MEASURING FREQUENCY RESPONSE OF THE COMMUNICATIONS CHANNEL - A communications device includes a demapping and demodulation circuit and processes an OFDM communications signal that includes modulated subcarriers carrying communications data forming a data payload and modulated subcarriers carrying a training sequence forming a preamble. Those OFDM subcarriers carrying the training sequence have a sample for each subcarrier at a frequency bin using evenly spaced, equal amplitude subcarriers that have a set phase of each sinusoid to a specific angle with quadratic phase to form a low peak-to-average power ratio (PAPR) preamble with about a PAPR value of 2.6 decibels (dB). A channel estimate circuit is operative for measuring fluctuations within a flat-top spectrum of the received OFDM communications signal corresponding to the preamble to reflect the frequency response of the communications channel.04-01-2010
20100080309LOW PEAK-TO-AVERAGE POWER RATIO (PAPR) PREAMBLE FOR ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING (OFDM) COMMUNICATIONS - A communications device includes communications data and a training sequence corresponding to a preamble. A modulation and mapping circuit modulates the communications data and training sequence into a plurality of multiple subcarriers that are orthogonal to each other to form an orthogonal frequency division multiplexing (OFDM) communications signal having modulated subcarriers carrying the communications data forming a data payload and modulated subcarriers forming the preamble. The modulation and mapping circuit applies a quadratic modulation to the subcarriers carrying the training sequences to produce a low peak-to-average power (PAPR) preamble of approximately 2.6 decibels (dB) independent of the number of subcarriers.04-01-2010
20110194636Broadband Network for Coaxial Cable Using Multi-carrier Modulation - A broadband local area data network uses coaxial cable wiring for interconnection of terminal devices. Orthogonal frequency division multiplexing (OFDM) with bit loading is used to overcome channel impairments and provide a path for terminal devices to transmit to and receive from other terminal devices. Probe messages are sent between devices to characterize the communication channel and determine optimum bit loading. The data network shares the cable spectrum with other services and uses frequency bands not used by other services. Adaptive power control can be used to maintain signal to noise ratio in a communication between terminal devices. Frequency coordination can be used to avoid interference between the LAN communications and other services transmitted on the cable.08-11-2011
20110194635SPECTRUM CODING APPARATUS, SPECTRUM DECODING APPARATUS, ACOUSTIC SIGNAL TRANSMISSION APPARATUS, ACOUSTIC SIGNAL RECEPTION APPARATUS AND METHODS THEREOF - A spectrum coding apparatus capable of performing coding at a low bit rate and with high quality is disclosed. This apparatus is provided with a section that performs the frequency transformation of a first signal and calculates a first spectrum, a section that converts the frequency of a second signal and calculates a second spectrum, a section that estimates the shape of the second spectrum in a band of FL≦k08-11-2011
20110194634BEARING DETERMINATION USING SIGNALS TRANSFORMED INTO FREQUENCY DOMAIN - An apparatus, a method and a computer program for determining a bearing. The apparatus may comprise a first transformer configured to transform a first signal formed from a set of multiple orthogonal subcarriers and received via a first path, from a time domain to a frequency domain and produce for each of a plurality of the multiple orthogonal subcarriers a respective first coefficient; a second transformer configured to transform a second signal formed from the set of multiple orthogonal subcarriers and received via a second path, different from the first path, from a time domain to a frequency domain and produce for each of a plurality of the multiple orthogonal subcarriers a respective second coefficient; and processing circuitry configured to process the plurality of first coefficients and the plurality of second coefficients to determine a bearing for the apparatus.08-11-2011
20110194633APPARATUS AND METHOD OF CALCULATING CHANNEL FREQUENCY DOMAIN CORRELATION - An apparatus and a method of calculating a channel frequency domain correlation are disclosed in the invention. The apparatus of calculating the channel frequency domain correlation includes: a pilot channel preliminary estimation unit configured to preliminarily estimate a frequency domain channel response at pilot subcarriers of a receiving signal to obtain a pilot channel preliminary estimation value; a determination unit configured to determine a channel frequency domain correlation value which can be reliably calculated; a first channel frequency domain correlation value calculation unit configured to calculate the channel frequency domain correlation value which can be reliably calculated using the pilot channel preliminary estimation value to obtain a reliably calculated channel frequency domain correlation value; and a second channel frequency domain correlation value calculation unit configured to calculate an other channel frequency domain correlation values using the reliably calculated channel frequency domain correlation value. The invention may also effectively apply to calculation of the channel frequency domain correlation and channel estimation.08-11-2011
20110194632MULTIPLE INPUT MULTIPLE OUTPUT COMMUNICATION METHOD AND SYSTEM EXCHANGING COORDINATED RANK INFORMATION FOR NEIGHBOR CELL - Provided is a multiple input multiple output (MIMO) communication method and system that may exchange information associated with a coordinated rank for a neighbor cell. In a MIMO communication system, a target terminal may feed back the information associated with the coordinated rank to a serving base station, and the serving base station may exchange the information associated with the coordinated rank with the neighbor base station. The serving base station may perform precoding based on the exchanged information associated with the coordinated rank.08-11-2011
20110194631UNIFIED FEEDBACK FRAME FOR SUPPORTING A PLURALITY OF FEEDBACK MODES AND A MULTIPLE-INPUT MULTIPLE-OUTPUT (MIMO) COMMUNICATION SYSTEM USING THE UNIFIED FEEDBACK FRAME - Provided is a multiple-input multiple-output (MIMO) communication system that may provide a plurality of feedback modes. A receiver may feed back, to a transmitter, a base codeword indicator indicating one of base codewords included in the base codebook, a differential codeword indicator indicating one of differential codewords included in the differential codebook, and/or a correlation codeword indicator indicating one of correlation codewords included in the correlation codebook. The transmitter may generate a precoding matrix using at least one of the base codeword indicator, the differential codeword indicator, and the correlation codeword indicator.08-11-2011
20110194630SYSTEMS AND METHODS FOR REPORTING RADIO LINK FAILURE - A mobile communications device is provided with a wireless module and a controller module. The wireless module receives a plurality of downlink signals from a service node and determines a plurality of status indicators respectively corresponding to the downlink signals. The controller module determines whether a radio link failure has occurred according to the status indicators, and transmits at least one uplink signal via the wireless module to indicate information of the radio link failure to the service node in response to the occurrence of the radio link failure.08-11-2011
20090296839 PILOT ALLOCATION IN MULTI-CARRIER SYSTEMS WITH FREQUENCY NOTCHING - The present invention relates to a transmitting apparatus (12-03-2009
20090122889Method and apparatus for decomposing channel in closed-loop multiple input multiple output communication system - An apparatus for decomposing a channel in a closed-loop Multiple Input Multiple Output (MIMO) communication system is provided. The channel decomposition apparatus includes a transmitter for preceding input symbols using a first matrix which is a product of a unitary matrix V, a diagonal matrix Φ and a blockwise Uniform Channel Decomposition (UCD) matrix P05-14-2009
20090122888RECEIVER - An exemplary aspect of an embodiment of the present invention is a receiver comprises a subcarrier unit combination section that performs weighting corresponding to quality of each subcarrier with respect to each subcarrier relating to a received symbol, a symbol unit combination section that performs common weighting based on quality of the symbol with respect to each subcarrier, and a combination system switching unit that switches between use of the symbol unit combination section and the subcarrier unit combination section.05-14-2009
20090122887CARRIER ALLOCATION METHOD IN MULTI CELL ORTHOGONAL FREQUENCY DIVISION MULTIPLE ACCESS SYSTEM - Provided is a carrier allocation method in a multi cell OFDMA system capable of improving the system capacity and the bit error rate performance. The method includes a step (S05-14-2009
20090122886TRANSMITTING/RECEIVING SYSTEM, TRANSMITTING APPARATUS, AND PILOT SIGNAL MULTIPLEXING METHOD USED IN THEM - At a transmitting side (05-14-2009
20090122884CLOSED-LOOP TRANSMISSION FEEDBACK IN WIRELESS COMMUNICATION SYSTEMS - A method in an OFDM wireless user terminal that communicates with a base unit is disclosed. The method comprises computing a transmit spatial covariance matrix, transforming the spatial covariance matrix, and transmitting the transformed spatial covariance matrix to a base unit.05-14-2009
20090122882METHOD AND APPARATUS FOR PREAMBLE TRAINING WITH SHORTENED LONG TRAINING FIELD IN A MULTIPLE ANTENNA COMMUNICATION SYSTEM - Methods and apparatus are provided for communicating data in a multiple antenna communication system having N transmit antennas. According to one aspect of the invention, a disclosed header format includes a legacy preamble having at least one legacy long training field and an extended portion having at least N additional long training fields on each of the N transmit antennas, wherein one or more of said at least N additional long training fields are comprised of only one OFDM symbol. The extended portion optionally comprises one or more repeated OFDM symbols for frequency offset estimation. In one implementation, the extended portion comprises a first high throughput long training field comprised of two repeated OFDM symbols and N−1 high throughput long training fields comprised of only one OFDM symbol. In another variation, the extended portion comprises N high throughput long training fields comprised of only one OFDM symbol.05-14-2009
20090122881FOLLOW-UP SYNCHRONIZATION TO MAINTAIN SYNCHRONIZATION THROUGHOUT TRANSMISSION - Method for an orthogonal frequency division multiplexing multipoint-to-point communications system are provided. In one embodiment, the method includes establishing communication between a first remote unit of a plurality of remote units and a host unit, the plurality of remote units communicatively coupled to the host unit in a multipoint-to-point configuration, transmitting up to a plurality of tones from the first remote unit, the up to a plurality of tones modulated with upstream information using orthogonal frequency division multiplexing, and adjusting the up to a plurality of tones transmitted from the first remote unit to maintain the up to a plurality of tones substantially orthogonal with respect to any tones transmitted from at least one other remote unit of the plurality of remote units as received at the host unit.05-14-2009
20090238295COMMUNICATING DATA USING WIDEBAND COMMUNICATIONS - This disclosure relates to varying load and modulation applied to each of multiple frequency subchannels based on anticipated attenuation experienced by those subchannels. Communicating data includes identifying a static component of a transmission medium for wideband communications having at least two subchannels determining a function of noise is attenuation versus frequency for the static component selecting wideband modulation schemes for the subchannels based on the function determined and communicating a data signal over the subchannels. The transmission medium includes a medium other than a copper telephone wire between and including a carrier facility and a termination of the copper telephone wire at an access point at a user premise and copper telephone wire in a cable riser in multitenant units and multi-dwelling buildings. Independent demodulation functions may be applied to at least two of the subchannels.09-24-2009
20090141817Method for Reducing Spectral Regrowth in a Spectrally Efficient Digital Modulation Scheme - A method that uses time-domain processing on a spectrally efficient digital modulation scheme to reduce the bandwidth expansion in envelope elimination and restoration (EER) amplifiers is disclosed. The method identifies and localizes sections of the signal responsible for the out of band emissions, or spectral regrowth, using a filter. The detected sections are flagged and extended to allow for introduction of a lower frequency transition in place of the extended section, thus reducing spectral regrowth from the output of an EER amplifier. The method is particularly useful for improving the quality of digital AM radio transmission.06-04-2009
20120177136WIRELESS COMMUNICATION DEVICE - According to one embodiment, a wireless communication device which comprises an automatic frequency controller configured to detect a radio frequency shift amount between a transmitting side and a receiving side, comprises a controller, a first weight multiplier, and an error correction decoder. The controller is configured to designate subcarrier that suffers interference caused by a DC component based on the radio frequency shift amount detected by the automatic frequency controller. The first weight multiplier is configured to multiply amplitude values of demodulated signals of signals carried by the subcarriers designated by the controller by a weighting coefficient in a range from 0 to 1. The error correction decoder is configured to perform error correction of the demodulated signals multiplied by the weighting coefficient by the first weight multiplier. The controller sets the weighting coefficient to be multiplied by the first weight multiplier based on the radio frequency shift amount.07-12-2012
20100002781TRANSMITTER IDENTIFICATION USING A CONTINUOUS WAVE TONE - A methodology for transmitter identification for a single frequency network is provided using a single CW tone. The tone can be transmitted outside the transmitter's active band. It is possible to arrive at significant overlap between the tone coverage area and the coverage area of a neighboring transmitter without disturbing the operations by picking the tone location and power appropriately.01-07-2010
20100118996METHODS AND SYSTEMS FOR LOCATION-BASED ALLOCATION OF MACRO CELL RESOURCES - Methods and systems for reusing macro cell resources in femto cell base stations or relay stations in a non-collaborative manner are disclosed. In addition, orthogonal resource allocation between a macro cell base station and femto cell base stations/relay stations may be dynamically adjusted by considering user-population variance. Moreover, an additional level of spatial reuse by femto cell base stations or relay stations can be provided by employing macro cell user location information.05-13-2010
20100118998METHOD AND DEVICE FOR ALLOCATING RESOURCES IN AN OFDM NETWORK - A radio station comprises means for allocating resources for communication with at least one other station, and including means for mapping data to be transmitted from at least the radio station to the at least one other station, and means for applying a cyclic shift to the data mapping, wherein this cyclic shift is adjusted depending on the number of data blocks to be mapped. A possible implementation concerns the mapping of the DVRB (Distributed Virtual Resource Block) in OFDM.05-13-2010
20100118990APPARATUS FOR SYNCHRONIZING OFDM SIGNAL USING OPEN-LOOP FREQUENCY SYNCHRONIZATION METHOD AND FREQUENCY OFFSET ESTIMATION SCHEME USING THE APPARATUS - There are provided an apparatus for synchronizing an OFDM signal using an open-loop frequency synchronization method, which can estimate and compensate for various types of frequency errors generated in a frequency modulation broadcasting/communication system to which the open-loop frequency synchronization method is applied, and a frequency offset estimation scheme using the apparatus. To this end, the apparatus for synchronizing an OFDM signal using the open-loop frequency synchronization method comprises a time offset estimator, a time offset compensator, a fractional frequency offset estimator, an integer frequency offset estimator, a frequency offset controller and a frequency offset compensator. Accordingly, in the OFDM demodulation broadcasting/communication system using the open-loop frequency synchronization method, a frequency offset, which is generated due to the carrier frequency difference between a transmitter and a receiver, a frequency shift generated due to the mobile environment of a receiver, the temperature characteristic of a local oscillator, and the like, can be estimated and compensated.05-13-2010
20100118993METHOD AND DEVICE FOR DETERMINING AN UNABBREVIATED CHANNEL-IMPULSE RESPONSE IN AN OFDM TRANSMISSION SYSTEM - A method and a device for determining an unabbreviated channel-impulse response in an OFDM transmission system, of which the duration is greater than the length of the guard interval, estimates the channel-transmission factor at frequency-time positions of a relatively-coarse frequency-time raster, interpolates the channel-transmission factor at frequency-time positions of a relatively-fine frequency-time raster and calculates the unabbreviated channel-impulse response by means of inverse Fourier transform from the estimated or interpolated values of the channel-transmission factor at the frequency-time positions of the relatively-fine frequency-time raster. In this context, estimated values of the channel-transmission factor optimized at the individual frequency-time positions of the relatively-fine frequency-time raster are determined from received symbols and from transmitted symbols estimated by means of decision from the received symbols.05-13-2010
20100118989EMPLOYING CELL-SPECIFIC AND USER ENTITY-SPECIFIC REFERENCE SYMBOLS IN AN ORTHOGONAL FREQUENCY-DIVISION MULTIPLE ACCESS - A method, a network base station, and a user communication device for transmitting data on an orthogonal frequency-division multiple access carrier are disclosed. A network base station 05-13-2010
20100158141METHODS AND SYSTEMS TO ESTIMATE CHANNEL FREQUENCY RESPONSE IN MULTI-CARRIER SIGNALS - Methods and systems to determine channel frequency responses corresponding to multi-carrier signals, such as OFDM signals, including to filter or mask noise from channel frequency response estimates in a time domain.06-24-2010
20100158149CHANNEL TRACKING WITH SCATTERED PILOTS - According to the disclosure, a system adapted to estimate and track a channel for wireless orthogonal frequency division modulation (OFDM) communication is disclosed. The system utilizes scattered pilot symbols being subject to channel conditions and estimates the channel value using the plurality of received pilot symbols and in accordance with correlation of the channel conditions over time.06-24-2010
20100158139Method and system for communication in a wireless orthogonal frequency division multiplexing (OFDM) Communication system - Method and system for wireless communication in an Orthogonal Frequency Division Multiplexing (OFDM) communication system is disclosed. The method involves receiving a plurality of receive-signals over a first set of antennas. Further, one or more of the plurality of receive-signals are cyclically delayed to generate one or more cyclically delayed receive-signal. Subsequently, one or more of the plurality of receive-signals are combined with one or more of the cyclically delayed receive-signals. In other words, the method involves performing receive Cyclic Delay Diversity (CDD).06-24-2010
20100074346CHANNEL ESTIMATION IN OFDM RECEIVERS - An OFDM receiver includes a fast Fourier transform processor that receives signal samples and outputs frequency domain samples corresponding to a received symbol. A delay element receives sets of frequency domain samples outputs each of the sets of frequency domain samples following a predetermined delay interval. A frequency domain channel estimator receives frequency domain samples and derives channel estimates from each of the sets of frequency domain samples. A channel estimate queue stores a sequence of channel estimates provided by the channel estimator and provides the sequence to a weighted averaging element that outputs an averaged channel estimate. A frequency equalizer outputs an equalized set of frequency domain samples responsive to the delayed set of frequency domain samples and to the averaged channel estimate.03-25-2010
20100074353METHOD OF DESIGNING CODEBOOK FOR NETWORK MULTIPLE INPUT MULTIPLE OUTPUT COMMUNICATION SYSTEM AND METHOD OF USING THE CODEBOOK - Provided herein is a method of designing a network codebook that may be shared by a plurality of base stations. Also provided herein is a feedback method of a terminal using the network codebook. The network codebook design method may design the network codebook by processing a pre-defined first codebook based on large scale fading of the base stations. The terminal may more effectively feed back a preferred matrix indicator with respect to the network codebook.03-25-2010
20100074352SPHERE DECODING METHOD APPLIED TO MULTI-INPUT MULTI-OUTPUT (MIMO) CHANNEL - A sphere decoding method applied to a MIMO channel is provided. Multiple constellation points of an n03-25-2010
20100074351METHOD AND APPARATUS FOR PROCESSING DATA FOR TRANSMISSION IN A MULTI-CHANNEL COMMUNICATION SYSTEM USING SELECTIVE CHANNEL INVERSION - Techniques to process data for transmission over a set of transmission channels selected from among all available transmission channels. In an aspect, the data processing includes coding data based on a common coding and modulation scheme to provide modulation symbols and pre-weighting the modulation symbols for each selected channel based on the channel's characteristics. The pre-weighting may be achieved by “inverting” the selected channels so that the received SNRs are approximately similar for all selected channels. With selective channel inversion, only channels having SNRs at or above a particular threshold are selected, “bad” channels are not used, and the total available transmit power is distributed across only “good” channels. Improved performance is achieved due to the combined benefits of using only the NS best channels and matching the received SNR of each selected channel to the SNR required by the selected coding and modulation scheme.03-25-2010
20100074348FINE SYMBOL TIMING SYNCHRONIZATION METHOD AND APPARATUS IN OFDM SYSTEM - A fine symbol timing synchronization method and apparatus in an orthogonal frequency-division multiplexing (OFDM) system are provided. The fine symbol timing synchronization method finds a path with a minimum mean square error (MMSE) as a first path among a plurality of paths, and a formula of the mean square error (MSE) used by the method is a simplified formula of the original MSE formula with low calculation complexity. Therefore, the time required by the fine symbol timing synchronization method is short, and a correct first path can be found, so as to lock a starting position of a fast Fourier transform (FFT) window on a starting position of a symbol signal of the correct first path.03-25-2010
20100074347METHOD AND APPARATUS OF SUBCHANNELIZATION OF WIRELESS COMMUNICATION SYSTEM - A method and apparatus to transmit pilot subcarriers over uplink channels. The pilot subcarriers includes symbols which hierarchically structured. The symbol includes a first split of at least two fractional frequency reuse (FFR) groups, a second split of a fractional frequency reuse (FFR) group to a distributed resource group and localized resource group and a third split of said distributed resource group and localized resource group into plurality of subchannels.03-25-2010
20100074354WIRELESS COMMUNICATIONS DEVICE INCLUDING A JOINT DEMODULATION FILTER FOR CO-CHANNEL INTERFERENCE REDUCTION AND RELATED METHODS - A wireless communications device may include a housing and a wireless transmitter and a wireless receiver carried by the housing. The wireless receiver may include a joint demodulation filter for reducing co-channel interference between a desired signal and a co-channel interfering signal which may include an input receiving samples of the desired signal and the co-channel interfering signal, a Viterbi decoder, and a first signal path between the input and the Viterbi decoder comprising a first filter. The joint demodulation filter may further include a second signal path between the input and the Viterbi decoder and comprising a linear finite impulse response (FIR) modeler for generating a channel impulse response estimate for the co-channel interfering signal. Additionally, a third signal path may be between the input and the Viterbi decoder and include a whitened matched filter for generating a channel impulse response estimate for the desired signal.03-25-2010
20100074349METHOD AND BASE STATION FOR ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING (OFDM) SIGNAL PROCESSING - A method and base station for forming an OFDM signal from a baseband signal includes a partitioning unit configured to partition a block of baseband signal samples into sub-blocks. A sub-carrier mapper maps the sub-blocks onto adjacent sub-carrier blocks of an OFDM multi-carrier to form corresponding unprefixed OFDM symbols. A cyclic prefix adder adds a cyclic prefix to each mapped sub-block to form prefixed OFDM symbols. Phase compensations force the unprefixed OFDM symbol part of all subsequently up-converted prefixed OFDM symbols to start at the same phase. Up-converters up-convert the phase compensated prefixed OFDM symbols to respective radio frequency bands having center frequencies and bandwidths that preserve the OFDM multi-carrier structure. A combiner combines the up-converted phase compensated prefixed OFDM symbols into an OFDM signal.03-25-2010
20100074350CODEWORD LEVEL SCRAMBLING FOR MIMO TRANSMISSION - Techniques for performing codeword level scrambling for a MIMO transmission are described. A transmitter station may perform channel encoding for multiple data streams being sent simultaneously for a MIMO transmission. The channel encoding may include forward error correction (FEC) encoding and/or rate matching. The transmitter station may perform scrambling for the multiple data streams with different scrambling codes after the channel encoding. The transmitter station may also perform channel interleaving, symbol mapping, and spatial processing for the multiple data streams after the channel encoding. A receiver station may receive the MIMO transmission, perform descrambling for the multiple data streams with the different scrambling codes, and then perform channel decoding for the multiple data streams. The scrambling may allow the receiver station to isolate each data stream by performing the complementary descrambling and to obtain randomized interference from the remaining data stream(s), which may improve performance.03-25-2010
20090310691METHODS AND SYSTEMS FOR CARRIER FREQUENCY OFFSET ESTIMATION AND CORRECTION OFDM/OFDMA SYSTEMS - Methods and apparatus for determining an accurate fractional carrier frequency offset (CFO) adjustment in an orthogonal frequency-division multiplexing (OFDM) or orthogonal frequency division multiple access (OFDMA) system in an effort to properly compensate for the actual CFO between a transmitter and a receiver are provided. This enhanced fractional CFO adjustment may be based on a history of estimated fractional CFOs and estimated carrier-to-interference-plus-noise ratios (CINRs) and may be statistically derived from this history, therefore leading to a more accurate fractional CFO adjustment when compared to conventional fractional CFO estimations. A more accurate fractional CFO adjustment may lead to increased physical layer performance and decreased decoding errors (i.e., lower bit error ratio, or BER).12-17-2009
20080317142SYSTEM AND METHOD FOR FREQUENCY DIVERSITY - A system and method for frequency diversity uses interleaving in a wireless communication system utilizing orthogonal frequency division multiplexing (OFDM) with various FFT sizes. Subcarriers of one or more interlaces are interleaved in a bit reversal fashion and the one or more interlaces are interleaved in the bit reversal fashion.12-25-2008
20130039435WIRELESS COMMUNICATION SYSTEM - A wireless communication method used by a wireless communication apparatus is disclosed. The wireless communication method transmits and receives control information divided into a second control information containing information related to the demodulation and decoding of traffic channel and a first control information containing information related to the MIMO separation of the second control information.02-14-2013
20100034302METHOD OF SYNCHRONIZING MULTI-CARRIER SYSTEMS AND MULTI-CARRIER SYSTEM - A method of synchronizing multi-carrier systems is provided, wherein the method comprises inserting a predefined frequency domain signal into a signal on a transmitter side of a multi-carrier system and multi-carrier modulating the signal. Furthermore, the method comprises transmitting the multi-carrier modulated signal via a carrier channel to a receiving side of the multi-carrier system, and synchronizing the multi-carrier modulated signal by using the predefined frequency domain signal portion of the multi-carrier modulated signal.02-11-2010
20090252237DOUBLE LAYER MAXIMUM RATIO COMBINING FOR OFDM RECEIVER DESIGN WITH INTER-CARRIER-INTERFERENCE CANCELLING - An apparatus, method, and system for reducing a C/N in an OFDM receiver using diversity combining techniques in the presence of ICI, wherein the apparatus comprises an encoded data estimator adapted to estimate data received in the OFDM receiver; a pair of ICI estimators operatively connected to the encoded data estimator and adapted to calculate an inter-carrier-interference term of the data; and a pair of diversity combining equalizers adapted to compensate multi-path interference of the data, wherein a first one of the diversity combining equalizers is operatively connected to the encoded data estimator, and a second one of the diversity combining equalizers is operatively connected to the pair of ICI estimators. The diversity combining equalizer may comprise a MRC diversity combining equalizer. Preferably, the encoded data estimator, the pair of ICI estimators, and the pair of diversity combining equalizers are implemented on a DVB-T/H diversity SoC.10-08-2009
20100061473METHOD AND APPARATUS FOR SELECTING MODULATION AND CODING SCHEME (MCS) INDEX BASED ON FREQUENCY SELECTIVITY - A method of selecting a modulation and coding scheme (MCS) index in a wireless communication system is disclosed. More specifically, the method includes measuring a frequency selectivity of a receiving channel, selecting a MCS index having a coding rate below a prescribed coding rate threshold value if the measured frequency selectivity is greater than or equal to a specified frequency selectivity threshold, and selecting the MCS index having the coding rate above or equal to the prescribed coding rate threshold value if the measured frequency selectivity is less than the specified frequency selectivity threshold.03-11-2010
20100027691METHOD AND SYSTEM FOR AN OFDM JOINT TIMING AND FREQUENCY TRACKING SYSTEM - Aspects of a method and system for an OFDM joint timing and frequency tracking system may include tracking carrier frequency and symbol timing in an Orthogonal Frequency Division Multiplexing (OFDM) signal based on at least a reference symbol set. A receiver frequency and timing may be adjusted based on the tracked carrier frequency and symbol timing. The carrier frequency may be tracked by generating an output signal as a function of a frequency offset Δf, and the symbol timing may be tracked by generating an output signal as a function of a guard time Δt02-04-2010
20100046650Method for Precoding Using a Block Diagonal Matrix - An objective problem of the invention is to provide a mechanism for improving the performance of a radio access network. According to a first aspect of the present invention, the object is achieved by a method in a first node for adapting a multi-antenna transmission to a second node over an effective channel. The first node and the second node are comprised in a wireless communication system. The method comprises the steps of obtaining at least one symbol stream and determining a precoding matrix having a block diagonal structure. The method comprises the further steps of precoding the at least one symbol stream with the determined precoding matrix, and transmitting the at least one precoded symbol stream over the effective channel to the second node.02-25-2010
20100046648Interpolation IIR filter for OFDM Baseband Processing - A filter for receiver and operative on a stream of OFDM symbols has a symbol timing identifier which indicates the time interval for each symbol and also indicates a non-truncation interval and a truncation interval of the stream of symbols. The stream of OFDM symbols is applied to an infinite impulse response (IIR) filter with a reset input for resetting internal registers such that during the non-truncation interval, the reset input is not asserted, and during the truncation interval of the stream of OFDM symbols, the reset input is asserted during the intervals between symbols, as identified by the symbol timing identifier.02-25-2010
20100046652RECEIVING DEVICE, SIGNAL PROCESSING METHOD, AND PROGRAM - A receiving device includes: a pilot extracting section; a first estimating section; a second estimating section; a third estimating section; a distortion correcting section; and a filter controlling section.02-25-2010
20100046651METHOD FOR DETECTING TRANSMISSION MODE IN A SYSTEM USING MULTIPLE ANTENNAS - A user terminal, a communication network, a computer readable medium and a method for selecting at the user terminal a reception and decoding of a transmission mode used by a base station, the user terminal receiving communicated information from the base station, which has multiple antennas, via plural channels, the plural channels including a primary broadcast channel and at least one control channel. The method includes receiving at the user terminal initiating data from the base station via the primary broadcast channel, detecting from the received initiating data whether a first or a second transmission mode is used by the base station for the primary broadcast channel, the first transmission mode indicating that a first number of antennas are used by the base station and the second transmission mode indicating that a second number, different than the first number, of antennas are used by the base station to communicate with the user terminal, and using the detected first or second transmission mode of the primary broadcast channel to decode the at least one control channel.02-25-2010
20100046649METHOD, ARRANGEMENT AND DEVICE FOR PRECOMPENSATION OF CROSSTALK IN A DSL MIMO SYSTEM - A method, an arrangement and a device for transmitting data via a plurality of channels. Additional data d are transmitted via at least one channel, and the transmission of the additional data d influences the transmission of the data in at least one of the further channels. The transmission of the data in the at least one of the further channels is influenced for example in such a way as to reduce interference, such as crosstalk, for instance, in the at least one of the further channels. The additional data d are advantageously transmitted during pauses in the useful data transmission of the at least one channel.02-25-2010
20100046654COMMUNICATIONS APPARATUS AND COMMUNICATIONS SYSTEM USING MULTICARRIER TRANSMISSION MODE - A communications system for communications by a multicarrier transmission mode between a plurality of communications apparatuses, wherein an overall frequency band assigned to the communications system is divided into a plurality of frequency bands each having a constant bandwidth and a specific band. The divided bands are used to transmit used frequency band information thereby indicating the assignment of the remaining bands used between said communications apparatuses. The specific band is defined as a main band for transmitting control channel information including used frequency band information and data channel information. The main band may be added with an extension band for transmitting further data channel information. The main band and extension band can be changed in the frequency band used along with time or can be changed in the number thereof. Both the main band and the extension bands are preferably used for multiplexing by some of communications apparatuses.02-25-2010
20100046653TIME REFERENCE IDENTIFICATION METHOD - In a method of identifying a time reference in signal received from a transmitter, a replica of a synchronization sequence is generated on the basis of at least one known transmission parameter and is compared to a sequence derived from the signal received from the transmitter to identify a reference point in the signal received from the transmitter.02-25-2010
20100046646Interpolation IIR filter for OFDM Baseband Processing - A filter for receiver and operative on a stream of OFDM symbols has a symbol timing identifier which indicates the time interval for each symbol and also indicates a non-truncation interval and a truncation interval of the stream of symbols. The stream of OFDM symbols is applied to an infinite impulse response (IIR) filter with a reset input for resetting internal registers such that during the non-truncation interval, the reset input is not asserted, and during the truncation interval of the stream of OFDM symbols, the reset input is asserted during the intervals between symbols, as identified by the symbol timing identifier.02-25-2010
20100046645Interpolation IIR filter for OFDM Baseband Processing - A filter for receiver and operative on a stream of OFDM symbols has a symbol timing identifier which indicates the time interval for each symbol and also indicates a non-truncation interval and a truncation interval of the stream of symbols. The stream of OFDM symbols is applied to an infinite impulse response (IIR) filter with a reset input for resetting internal registers such that during the non-truncation interval, the reset input is not asserted, and during the truncation interval of the stream of OFDM symbols, the reset input is asserted during the intervals between symbols, as identified by the symbol timing identifier.02-25-2010
20100046644SUPERPOSITION CODING - A transmitter and receiver communicate using a modified superposition coding scheme. The transmitter transits superposition symbols which include a near end symbol for a near receiver and a far end symbol for a far receiver. The transmitter modifies the near end symbol depending on the far end symbol prior to transmission. Specifically, the near end symbol may be mirrored around the real or imaginary axis. The near receiver generates mirrored superposition symbols by applying mirroring to each received superposition symbol around at least one of the real axis and the imaginary axis in response to the value of the received symbol. The mirroring may remove the uncertainty of the far end symbol value allowing a simpler decision for the near end symbol. The mirroring performed by the transmitter and the near receiver will negate each other for the near end symbol thereby allowing a simplified near end receiver operation.02-25-2010
20100046643FEEDFORWARD OF NON-QUANTIZED PRECODING WEIGHTS IN A WIRELESS COMMUNICATIONS SYSTEM - An apparatus and method to feedforward non-quantized precoding weights in an OFDM communication system includes a first step (02-25-2010
20130034176ROBUST LINEAR PRECODER DESIGNS FOR MULTI-CELL DOWNLINK TRANSMISSION - Methods and systems for optimizing the utilities of receiver devices in a wireless communication network are disclosed. Precoder design formulations that maximize a minimum worst-case rate or a worst-case sum rate are described for both full base station cooperation and limited base station cooperation scenarios. In addition, optimal equalizers are also selected to optimize the worst-case sum rate.02-07-2013
20130034175APPARATUS AND METHOD FOR ESTIMATING CHANNEL IN OFDM/OFDMA BASED WIRELESS COMMUNICATION SYSTEM - A method for transmitting pilots in a wireless communication system includes generating first two pilots for a first antenna. Second two pilots for a second antenna are generated by multiplying the first two pilots with two weight values respectively. The first two pilots are transmitted over two Orthogonal Frequency Division Multiplexing (OFDM) symbols via the first antenna. The second two pilots are transmitted over the two OFDM symbols via the second antenna, wherein each weight value is determined based on a value used to obtain a symbol index of a corresponding OFDM symbol of the two OFDM symbols within a slot. Symbol indexes for the two OFDM symbols are consecutive, and the two weight values are different with each other.02-07-2013
20090245399METHOD AND APPARATUS FOR INSERTING GUARD INTERVAL IN A MOBILE COMMUNICATION SYSTEM - A method for inserting a guard interval in an OFDM or OFDMA mobile communication system and a transmitting apparatus therefore are disclosed. The method for inserting a guard interval in an OFDM or OFDMA mobile communication system comprises rotating a phase of each symbol for a specific symbol stream, converting the phase-rotated symbol stream into a time-domain symbol stream, and performing at least one of copying a rear part of the time-domain symbol stream to insert the rear part of the time-domain symbol stream to the front of the time-domain symbol stream and copying a front part of the time-domain symbol stream to insert the front part of the time-domain symbol stream to the end of the time-domain symbol stream.10-01-2009
20080310525FFT-size detector and FFT-size detection method and cell search apparatus and cell search method in cellular system - An apparatus and method for cell acquisition and downlink synchronization acquisition in an OFDMA wireless communication system are provided. In an SS apparatus in a broadband wireless communication system, a preamble subcarrier acquirer extracts subcarrier values having a preamble code from an FFT signal. A multiplier code-demodulates the subcarrier values by multiplying the subcarrier values by a preamble code. A correlator calculates a plurality of differential correlations in the code-demodulated signal. An IFFT processor IFFT-processes the differential correlations by mapping the differential correlations to subcarriers. A maximum value detector detects a maximum value from the IFFT signal and calculates a timing offset using an IFFT output index having the maximum value.12-18-2008
20090175369MOBILE STATION AND A BASE STATION - A mobile station includes a control unit configured to change at least one parameter for a retransmission packet from that of a transmission packet, where the at least one parameter is selected from a data modulation scheme; a channel coding rate; a puncturing pattern; a spreading factor; a frequency bandwidth; a frequency allocation position; and transmission power. A base station includes a retransmission format determining unit configured to determine a pattern used for changing at least one parameter for a retransmission packet from that of a transmission packet to determine a format for the retransmission packet, where the at least one parameter is selected from a data modulation scheme; a channel coding rate; a puncturing pattern; a spreading factor; a frequency bandwidth; a frequency allocation position; and transmission power; and a control signal generating unit configured to generate a control signal based on the format for the retransmission packet determined by the retransmission format determining unit.07-09-2009
20100098180METHOD, APPARATUS AND TERMINAL DEVICE OF SYMBOL INTERLEAVING - A method and an apparatus of symbol interleaving are provided. A sequence S(i) is transformed to generate a symbol interleaving sequence. A numerical value of the sequence S(i) is corresponding to a serial number of a channel element (CE). The symbol interleaving sequence may also be obtained based on a Costas sequence. Therefore, the number of symbol groups in one CE that are mapped to the same physical resource position by different cells is effectively reduced, so that the effect of interference randomization between the cells is improved, the influence of the interference between the cells on the system performance is lowered, and the generation of the symbol interleaving sequence is simplified.04-22-2010
20100098178METHOD AND SYSTEM OF INTERLEAVING FOR A MULTIPLE-INPUT MULTIPLE-OUTPUT MULTI-BAND OFDM COMMUNICATION SYSTEM - A multiple-input multiple-output multi-band OFDM transmission system (04-22-2010
20090196367APPARATUS AND METHOD FOR TRANSMITTING/RECEIVING REFERENCE SIGNAL IN A COMMUNICATION SYSTEM - An apparatus and method for transmitting/receiving a reference signal in a communication system are provided, in which a transmitter determines first and second different transmit power values for first and second pilot tones residing in one of the substantially same time resource and the substantially same frequency resource among pilot tones included in a data area in a subframe having time and frequency resources, and transmits the first pilot tone with the first transmit power value and the second pilot tone with the second transmit power value. The first transmit power may be a reference transmit power value and the second transmit power may be a product between a weight and the reference transmit power value.08-06-2009
20090161780OPTIMUM BER ADJUSTMENT FOR ADAPTIVE MULTI-CARRIER MODULATION - The present invention relates to the fields of adaptive multi-carrier data transmission schemes. The present invention especially relates to a method of adapting transmission parameters of a group of subcarriers, a software program product and a communication device. The method of adapting transmission parameters of a group of subcarriers comprises steps of: determining a channel quality value for each subcarrier; establishing an order of assignment groups, each assignment group comprising one or more subcarriers, based on the channel quality values; assigning, in the order of the assignment groups, a transmission parameter to every assignment group, whereby assigning a transmission parameter to an assignment group comprises assigning the transmission parameter to all subcarriers of the assignment group; and calculating a link performance value based on previously assigned one or more transmission parameters; whereby the step of assigning a transmission parameter to every assignment group is based on the calculated link performance value.06-25-2009
20100111207TRANSMITTER AND METHOD FOR CONFIGURING TRANSMISSION FRAME - A transmitter which transmits information in transmission frame to a receiver, the transmission frame including multiple transmission symbols and guard intervals obtained by replicating a fixed time period of a transmission symbol, generates a transmission frame by making phases of one transmission symbol out of two transmission symbols and a guard interval thereof continuous with phases of the other transmission symbol and a guard interval thereof, when the two continuous transmission symbols are the same.05-06-2010
20100111206METHOD OF CONSTRUCTING AND TRANSMITTING PACKETS WITH MIMO CONFIGURATION IN A WIRELESS COMMUNICATION SYSTEM AND RELATED COMMUNICATION DEVICE - A method of constructing and transmitting packets with multiple-input multiple-output, hereinafter called MIMO, configuration in a radio link control layer of a wireless communication system includes, in a transmission opportunity, transforming at least an RLC service data unit into at least an RLC protocol data unit, hereinafter called PDU, according to an RLC PDU allowance of each of a plurality of transport blocks. Each of the at least an RLC PDU fits within at least an RLC PDU allowance of the plurality of transport blocks.05-06-2010
20100027688MULTI-INPUT MULTI-OUTPUT-ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING TRANSCEIVING METHOD AND APPARATUS - A multi-input multi-output orthogonal frequency division multiplexing (MIMO-OFDM) transceiving system is provided, in which an MIMO-OFDM receiver feeds back ordering information, such as the order of power intensities of reception signals of a plurality of reception antennas, to an MIMO-OFDM transmitter. The MIMO-OFDM transmitter arranges subcarriers, to which data symbols have been allocated, so that the subcarriers respectively correspond to a plurality of transmission antennas, according to the fed-back information. Thus, a specific substream can be transmitted via a transmission antenna having the greatest channel gain. Consequently, the probability of properly recovering the specific substream is greatly increased.02-04-2010
20100111205DATA TRANSMISSION SYSTEM AND METHOD - Continuous-phase high compaction multicarrier-modulation (CPPC/HC-MCM) according to the present application uses a continuous phase modulation (CPM) technique to prevent an amplitude gap between two continuous signals, thereby improving characteristics of the conventional PC/HC-MCM in terms of effective use of a frequency bandwidth. The CPPC/HC-MCM can achieve a lower bit error rate (BER) for a wide signal-to-noise ratio at a common spectral efficiency of about 0.33 or less, as compared to the conventional unmodulated PC/HC-MCM.05-06-2010
20100111204TRANSMISSION APPARATUS AND TRANSMISSION METHOD - The object is achieved by providing a transmission apparatus with: assignment means configured to assign, to each user, one of a frequency block that is obtained by dividing a system bandwidth into each block of continuous frequency subcarriers and a distributed type frequency block that include a frequency subcarrier that is discretely distributed in the system bandwidth; and mapping means configured to assign transmission data to one of the frequency block and the distributed type frequency block according to the assignment.05-06-2010
20100128808CARRIER FREQUENCY ESTIMATION METHOD AND APPARATUS IN WIRELESS COMMUNICATION SYSTEM - A carrier frequency estimation method and apparatus is provided for improving frequency estimation performance in an Orthogonal Frequency Division Multiplexing (OFDM) communication system. The frequency estimation method for a wireless communication system includes summing correlations of four pairs of reference symbols transmitted at different frequency-time resource blocks in a pattern, each pair including two closest reference symbols; calculating a statistical value (E) by accumulating the summed correlation in a frequency direction; and estimating a frequency offset using an angle extracted from the statistical value (E).05-27-2010
20080247473MULTIPLE SUB-BANDS TDS-OFDM TRANSMISSION SCHEME - An OFDM system is provided. The system comprises: a single symbol among a series of symbols comprising; and a series PN sequences interposed between the series of symbols, with at least one PN sequence comprising a set of PN sub-sequences, wherein each PN sub-sequence is respectively associated with an ordered sub-central frequency within the single symbol.10-09-2008
20120263247METHOD AND APPARATUS FOR SELECTING REFERENCE SIGNAL TONES FOR DECODING A CHANNEL - Methods and apparatuses are provided that include selecting reference signal (RS) or other tones to utilize in estimating a channel for decoding one or more channels. Where the RS tones are interfered by other base stations, interference cancelation can be performed over the RS tones. Since interference can vary over the tones, interference cancelation can yield RS tones of varying quality. Thus, a quality of each of the RS tones can be determined, and at least a subset of the RS tones can be selected for estimating a channel. Additionally or alternatively, the RS tones can be weighted or otherwise classified for performing channel estimation using the RS tones.10-18-2012
20100104033METHOD AND APPARATUS FOR SEPARABLE CHANNEL STATE FEEDBACK IN A WIRELESS COMMUNICATION SYSTEM - Systems and methodologies are described herein that facilitate the generation and use of separable, hierarchical channel state feedback in a wireless communication system. As described herein, in the event that multiple network nodes cooperate to conduct downlink transmissions to a network user, channel state feedback as reported by the network user can be separated into intra-node feedback relating to per-node channel conditions and inter-node feedback relating to relative phase and/or amplitude between channels corresponding to respective nodes. Further, a network user can select to report intra-node feedback and/or inter-node feedback based on network instructions, a cooperation strategy to be utilized by respective network nodes, or the like. As additionally described herein, respective codebooks on which inter-node and intra-node channel feedback is based can be configured to convey information relating to a partial channel description and/or to vary based on resource units (e.g., sub-bands, resource blocks, etc.) utilized for downlink communication.04-29-2010
20100104035Apparatus and method for clock synchronization in a multi-point OFDM/DMT digital communications system - A multi-point communications system is set forth herein. The communications system comprises a transmitter for transmitting OFDM/DMT symbols over a predetermined number of bins across a transmission medium. The OFDM/DMT symbols are generated using at least one timing signal. At least one of the predetermined number of bins includes a pilot tone sub-symbol having a frequency corresponding to the clock signal. The communications system also includes a receiver for receiving the OFDM/DMT symbols from the transmission medium. The receiver demodulates the received symbols using at least one timing signal. The receiver has a first pilot tone search mode of operation in which the receiver adjusts its timing signal to scan the frequency range of the predetermined number of bins looking for the pilot tone sub-symbol and identifies the bin including the pilot tone sub-symbol. The receiver further has a subsequent second pilot tone acquisition mode in which the receiver adjusts the timing signal to receive the identified bin containing the pilot tone sub-symbol and measures phase differences between successive pilot tone sub-symbols to thereby perform a further adjustment of the timing signal so that the pilot tone sub-symbol is received within a frequency range sufficient for subsequent phase locked loop processing thereof.04-29-2010
20100104036Contention-based access channel design in mimo OFDM/OFDMA systems - A contention-based multi-antenna access request transmission/receiving procedure in MIMO OFDM/OFDMA systems is provided to reduce access latency. A mobile station encodes and transmits an access request over a shared access channel using multiple transmitting antennas, while a base station receives and decodes a number of access requests using multiple receiving antennas. Each access request comprises an access indictor and an access message. In a first MIMO scheme, the mobile station transmits the access indicator as preambles, while the access message is encoded by SFBC/STBC to obtain spatial diversity. At the receive side, the access indicator is exploited as pilots for channel estimation. The access message is decoded using SFBC/STBC decoding algorithm. In a second MIMO scheme, the mobile station performs precoding/beamforming for each of the transmitting antenna to obtain beamforming gain, while the base station performs virtual beam matching based on the detection results of the access indicators.04-29-2010
201001040348-Transmit antenna reference signal design for downlink communications in a wireless system - Systems and methods are disclosed for mapping reference signals for antenna ports in a plurality of resource blocks among resource blocks in a subframe within an orthogonal frequency division multiplexing (OFDM) communication system. This method includes selecting at least one predetermined resource elements for transmitting in the plurality of resource blocks using a first number of antenna ports. This method also includes selecting a second number of antenna ports and mapping a plurality of reference signals relating to the second number of antenna ports using a second number of OFDM symbols.04-29-2010
20100104037Method And Device For Interference Suppression In User Terminal - A user terminal [04-29-2010
20100104032CODEBOOK DESIGN METHOD FOR MULTIPLE INPUT MULTIPLE OUTPUT SYSTEM AND METHOD FOR USING THE CODEBOOK - A multiple input multiple output (MIMO) communication method using a codebook is provided. The MIMO communication method may use one or more codebooks and the codebooks may change according to a transmission rank, a channel state of a user terminal, and/or a number of feedback bits.04-29-2010
20090154584APPARATUS AND METHOD FOR COMMUNICATION IN VARIABLE BANDS - A transmitter according to the present invention includes a mapping unit configured to convert transmitted data into data pieces associated with individual subcarriers, an inverse Fourier transform unit configured to convert the data pieces into a time-series signal, and a symbol generation unit configured to generate symbols for radio transmission from the time-series signal. The mapping unit associates the transmitted data with subcarriers different from predefined multiple subcarriers arranged at even intervals on a frequency axis. A demapping unit of a receiver according to the present invention supplies data comprising the data pieces associated with the subcarriers different from the predefined multiple subcarriers arranged at even intervals on a frequency axis as the data for restoration.06-18-2009
20090154581Discrete Multitone(DMT) Communications without Using a Cyclic Prefix - A Discrete Multitone (DMT) modulator modulates symbols with subcarriers for providing DMT symbols, wherein the subcarriers are divided into a number of subcarrier subsets such that adjacent DMT symbols formed from different subcarrier subsets06-18-2009
20090154580METHOD FOR RECEIVING CONTROL INFORMATION IN ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING SYSTEM OF MOBILE COMMUNICATION SYSTEM - The present invention relates to receiving control information in an orthogonal frequency division multiplexing (OFDM) system of a mobile communication system. The present invention includes receiving information related to a number of OFDM symbols in a subframe for receiving first control information, receiving information related to a number of OFDM symbols in the subframe for receiving second control information, decoding the first control information according to the received information related to the number of OFDM symbols in the subframe for receiving the first control information, and decoding the second control information according to the received information related to the number of OFDM symbols in the subframe for receiving the second control information, wherein the number of OFDM symbols for receiving the first control information is less than or equal to the number of OFDM symbols for receiving the second control information.06-18-2009
20090154579QR DECOMPOSITION APPARATUS AND METHOD FOR MIMO SYSTEM - Provided is a QR decomposition apparatus and method that can reduce the number of computers by sharing hardware in an MIMO system employing OFDM technology to simplify a structure of hardware. The QR decomposition apparatus includes a norm multiplier for calculating a norm; a Q column multiplier for calculating a column value of a unitary Q matrix to thereby produce a Q matrix vector; a first storage for storing the Q matrix vector calculated in the Q column multiplier; an R row multiplier for calculating a value of an upper triangular R matrix by multiplying the Q matrix vector by a reception signal vector; and a Q update multiplier for receiving the reception signal vector and an output of the R row multiplier, calculating an Q update value through an accumulation operation, and providing the Q update value to the Q column multiplier to calculate a next Q matrix vector.06-18-2009
20090154578METHOD AND APPARATUS FOR TRANSMITTING AND RECEIVING AN INITIALSETUPATTRIBUTE MESSAGE IN WIRELESS COMMUNICATION SYSTEMS - A method and apparatus of transmitting an InitialSetupAttribute message in a wireless communication system, comprising generating the InitialSetupAttribute message comprising an 8 bit AttributeID field, a 2 bit CQIReportingMode field, a 4 bit VCQIReportInterval field, a 2 bit VCQIMeasureInterval field, a 1 bit EnhancedPilotReportEnabled field, a 4 bit EnhancedPilotReportRatio field, a 4 bit EnhancedPilotReportThreshold field, a 2 bit MinReportInterval field, a 2 bit CQIReportInterval field, a 3 bit CQIReportPhase field, a 2 bit CQIPilotInterval field, a 3 bit CQIPilotPhase field, a 3 bit BFCHReportRate field, a 3 bit SFCHReportRate field, a 3 bit BFCHPowerOffset field, a 2 bit NumBFCHBits field, a 3 bit SFCHPowerOffset field, a 2 bit NumSFCHBits and a 3 bit MandatoryCQICHCTRLReportingPeriod field and transmitting the message over a communication link. A method and apparatus is further provided for receiving and processing the InitialSetupAttribute message.06-18-2009
20090154576MIMO/Transmit Diversity Channel Estimation - A receive station of the present invention despreads a received signal over both long and short despreading periods to determine individual channel estimates over each symbol period of an extended period for multiple pilot signals. As a result, the present invention provides channel estimates sufficient for both slow and fast fading conditions. The receive station determines an average channel estimate for each of the pilot signals over the extended period by despreading the received signal over the extended period using mutually orthogonal extended spreading sequences. The receive station further determines a combined channel estimate for the pilot signals over each symbol period of the extended period by despreading the received signal over each symbol period using a common spreading sequence. Based on the average and combined channel estimates, the receive station determines individual channel estimates for each pilot signal over each symbol period of the extended period.06-18-2009
20100040162TRANSMISSION METHOD, TRANSMISSION DEVICE, RECEIVING METHOD, AND RECEIVING DEVICE - A transmitting device and a receiving device wherein, on the transmitting side, a signal creation unit creates, as its output, a signal generated adding up the signals assuming that different data has passed through multiple virtual channels and, on the receiving side, oversampling is performed, the sampled data is distributed, and signals are detected assuming that the distributed data is the output of multiple virtual reception antennas.02-18-2010
20100040161WIRELESS TELECOMMUNICATION SYSTEM, TRANSMITTER AND RECEIVER - In a wireless telecommunication system for transmitting a plurality of streams from a base transmission station comprising a plurality of antennas to a mobile station comprising a plurality of antennas, the base transmission station respectively transmits, by way of a plurality of the antennas, each stream obtained by dividing data to be transmitted. The mobile station respectively receives each stream by utilizing the plurality of antennas. A measurement unit respectively measures a reception quality or received power from each antenna relating to a stream. A changeover unit carries out a handover for each stream according to a measurement result by the measurement unit.02-18-2010
20100040158EMBEDDING INFORMATION IN AN 802.11 SIGNAL FIELD - Techniques and apparatus for embedding one or more bits of 802.11 Very High Throughput (VHT) information in existing IEEE 802.11 preamble fields are provided. As will be described herein, because different combinations of modulation techniques, coding schemes, and transmission lengths result in the same transmit time (e.g., in terms of symbol length), a clever choice of modulation, coding, and length may allow some extra information to be embedded in a legacy field for use by VHT stations. In this manner, the total VHT preamble transmission time may potentially be reduced, thereby increasing the efficiency of the physical layer (PHY). Moreover, the embedded bits may most likely be invisible to legacy stations, since the transmission time that such stations compute will be independent of these bits by design.02-18-2010
20100040157Wireless communication method with air-interface encoder packets configured for more efficient use of network resources - A method is provided for communicating data belonging to at least one application flow (AF). In one aspect, the method involves mapping the data to payload bits of two or more encoder packets (EPs) such that each said EP carries a payload dedicated to only one AF, and transmitting the EPs concurrently. In a second aspect, the above said mapping is inverted at a receiver.02-18-2010
20100040156Dual-pass joint channel estimation and data demodulation for OFDM systems - The present invention provides architectures and methods which implement dual-pass joint channel estimation and data demodulation in communication systems to provide enhanced performance of the communication link. While not limited to any particular communication protocol, such architectures and methods are particularly beneficial in OFDM systems. Channel estimates may be performed using reference symbols and demodulated data symbols according to certain patterns of subcarriers for OFDM symbols. The channel estimates obtained from different patterns may be combined for dual-pass channel estimate which may have reduced estimation error. Such a procedure enables more accurate channel estimation and improved data demodulation, thereby enhancing system performance.02-18-2010
20100040155Method of multiple-antenna communication having improved utilization of channel correlations - A MIMO transmission scheme is provided which provides some advantages of the Alamouti code but which can be adapted so as to provide enhanced performance for a given amount of antenna correlation. A block of complex scalar input symbols is mapped to a block-code matrix which is transmitted as a spacetime signal matrix from an array of two or more antennas. The block-code matrix is assembled by combining input data with specified dispersion matrices. Each of the dispersion matrices is determined, in part, by an adjustable parameter which relates to a degree of beam-forming behavior by the transmission antenna array.02-18-2010
20100040154CHANNEL ESTIMATION - A method of channel estimation and a channel estimator for a multiple carrier radio transmission system is described. The method comprises receiving a signal comprising a symbol-carrier matrix, the symbol-carrier matrix comprising a pre-determined pattern of pilot symbols, and determining first channel estimates at pilot symbol positions of the pilot symbols in the symbol-carrier matrix. The method further comprises determining second channel estimates at intermediate positions of the symbol-carrier matrix, wherein the intermediate positions are separated from the pilot symbol positions of the pilot symbols by positions associated with non-determined channel estimates and determining third channel estimates at further positions of the symbol-carrier matrix.02-18-2010
20090135925TRANSMITTER, OFDM COMMUNICATION SYSTEM, AND TRANSMISSION METHOD - In a cellular system using an OFDM scheme, a transmitter multiplies subcarriers for channel estimation by codes and transmits them, the codes being such that a phase difference φ of the code multiplied with consecutive subcarriers for channel estimation is constant, and a code of every M consecutive subcarriers (M being 2 or an integer greater than 2) is mutually orthogonal with a code multiplied with same subcarriers of another transmitter.05-28-2009
20120183087METHOD AND APPARATUS FOR MULTIPLE FREQUENCY POINT MULTIPLE ACCESS - The present invention discloses a method and apparatus for multiple frequency point multiple access, which method comprises: in the situation that a system comprises a plurality of working frequency points, configuring a multi-access mode for the sending of uplink information and the sending of downlink information of each working frequency point in a plurality of working frequency points respectively; and each working frequency point performing the sending of the uplink information and the sending of the downlink information according to the configured multi-access modes. By way of the above technical solution, a simple multi-access mode is provided, which ensures the link performance of the working frequency point, improves the throughput of the entire network, and at the same time takes the problem of system peak average power ratio into account.07-19-2012
20120183086METHOD FOR TRANSMITTING SOUNDING REFERENCE SIGNAL IN MULTIPLE ANTENNA WIRELESS COMMUNICATION SYSTEM AND APPARATUS THEREFOR - A method for transmitting a sounding reference signal from a user equipment in a MIMO antenna wireless communication system is disclosed. The method comprises receiving sounding reference signal setup information from a base station, the sounding reference signal setup information including an initial cyclic shift value n07-19-2012
20080232494MIMO WIRELESS COMMUNICATION METHOD AND APPARATUS FOR TRANSMITTING AND DECODING RESOURCE BLOCK STRUCTURES BASED ON A DEDICATED REFERENCE SIGNAL MODE - The transmission and decoding of resource blocks (RBs) transmitted via a multiple-input multiple-output (MIMO) antenna having a plurality of transmit antennas is disclosed. Each RB includes a plurality of resource elements (REs). Each RE is reserved for one of a common reference signal (CRS) associated with one of the transmit antennas, a dedicated reference signal (DRS) including a single beamformed or precoded pilot, a DRS including a composite beamformed or precoded pilot, and a data symbol. Each RB may include a “control type” data symbol that indicates a DRS mode associated with the RB. In one DRS mode, each DRS includes a single beamformed or precoded pilot. In another DRS mode, each DRS includes a composite beamformed or precoded pilot. In yet another DRS mode, single beamformed or precoded pilots, and composite beamformed or precoded pilots, may coexist and be transmitted simultaneously within the same RBs or in different RBs.09-25-2008
20090202006MULTI-CARRIER TRANSMITTER - A multi-carrier transmitter and methods thereof are provided. For example, a multi-carrier transmitter comprises a processor operable to receive a plurality of baseband signals. Each of the plurality of baseband signals correspond to a separate data communication. A modulator is in communication with the processor. A non-linear device is in communication with the modulator. The processor is further operable to combine the plurality of baseband signals to generate a composite baseband signal. The modulator is operable to modulate a carrier signal with the composite baseband signal to generate a multi-carrier signal. The multi-carrier signal is provided to an input of the non-linear device.08-13-2009
20100142638MULTIPLEXING OF REAL TIME SERVICES AND NON-REAL TIME SERVICES FOR OFDM SYSTEMS - Transmitter and receiver units for use in an OFDM communications system and configurable to support multiple types of services. The transmitter unit includes one or more encoders, a symbol mapping element, and a modulator. Each encoder receives and codes a respective channel data stream to generate a corresponding coded data stream. The symbol mapping element receives and maps data from the coded data streams to generate modulation symbol vectors, with each modulation symbol vector including a set of data values used to modulate a set of tones to generate an OFDM symbol. The modulator modulates the modulation symbol vectors to provide a modulated signal suitable for transmission. The data from each coded data stream is mapped to a respective set of one or more “circuits”. Each circuit can be defined to include a number of tones from a number of OFDM symbols, a number of tones from a single OFDM symbol, all tones from one or more OFDM symbols, or some other combination of tones. The circuits can have equal size or different sizes. Different circuits can be used for full rate data (e.g., active speech) and low rate data (e.g., silence periods).06-10-2010
20100142634PILOT ALLOCATION IN SINGLE FREQUENCY NETWORK - The present invention relates to a distributed pilot scheme especially suited for single frequency networks used, for instance, for broadcasting digital TV. In current digital TV standards, e.g. DVB-T, the transmitters in the SFN transmit the exact same signal in the same frequency and at the same time. As a consequence the channel seen by the receiver is the channel created by the SFN characterized by a very long delay spread, which can be challenging to estimate. According to the present invention different, preferably orthogonal, pilot sequences are assigned to different transmitters in the same SFN so that the receiver can estimate the propagation channels from each transmitter to itself independently.06-10-2010
20100142635METHOD AND APPARATUS FOR CORRECTING LINEAR ERROR PHASE OF AN OFDM SIGNAL - The present invention relates to a method and an apparatus for correcting linear error phase of an OFDM signal. The method includes a step of offsetting a rotation corresponding to a back-off value of the signal. The apparatus of the present invention includes a correction module for offsetting the rotation of the signal corresponding to the back-off value.06-10-2010
20100329377RADIO COMMUNICATION SYSTEM - A radio communication system whereby one or a consecutive plurality of sub-carrier frequency intervals form sub-carrier groups each of which is assigned to a different user. The radio communication system includes a radio communication apparatus and a terminal configured to receive a control signal and a data signal from the radio communication apparatus. The terminal receives the control signal and the data signal according to a notified control signal position.12-30-2010
20100329369METHOD AND APPARATUS FOR FACILITATING MULTI-USER JOINT TRANSMIT-RECEIVE BEAMFORMING - A method of wireless communication is disclosed that includes receiving detected channel information from a plurality of access terminals; selecting a set of access terminals from the plurality of access terminals based on the received channel information; creating a beamforming vector for each access terminal in the set of selected access terminals; and transmitting a signal using at least one of the created beamforming vectors. An apparatus for performing the method is also disclosed herein.12-30-2010
20090220018TRANSMITTER AND METHOD FOR DIGITAL MULTI-CARRIER TRANSMISSION - The present invention relates to a transmitter and method employing a multi-carrier transmission method, especially utilizing real coefficient wavelet filter banks. The transmitter includes a preamble data generator, a modulator, and a ramp processor. The preamble data generator generates preamble bit data, and outputs the preamble data. The modulator modulates the preamble data, generates a plurality of subcarriers, and outputs a composite wave of the time waves of the plurality of subcarriers. Subsequently, the ramp processor performs ramp processing on the composite wave with a certain delay period from a reference position of the composite wave.09-03-2009
20100002780SIGNAL COMPONENT DEMULTIPLEXING APPARATUS, FILTER APPARATUS, RECEIVING APPARATUS, COMMUNICATION APPARATUS, AND COMMUNICATION METHOD - A communication apparatus, a signal component demultiplexing apparatus, and a filter apparatus to reduce a load of FFT processing in a receiver in multi-carrier communication. The receiving apparatus provides a signal component demultiplexing apparatus before an FFT circuit and extracts only the required symbol series. The signal component demultiplexing apparatus has hierarchically arranged branching circuits each including a symbol delay circuit, a phase offset adjustment circuit, an adder circuit, and a subtractor circuit, one symbol string being output from the adder circuit and another symbol string being output from the subtractor circuit.01-07-2010
20090316818RECEIVER - A receiver employing an OFDM system which uses a frequency band that is constituted by a plurality of subchannels, and receiving a signal added a phase rotation which is made to respectively differ for each transmission antennas of transmitter and transmitted from the transmission antennas, having an informing portion which informs the transmitter of an information in subchannel units for deciding a phase rotation which is added to the signal.12-24-2009
20090316810METHODS FOR TRANSMITTING AND RECEIVING A MULTICARRIER SIGNAL COMPRISING ISOLATED PILOTS, CORRESPONDING DEVICES AND COMPUTER PROGRAM PRODUCTS - A method is provided for receiving a received signal corresponding to a multicarrier signal transmitted by at least one transmitter via a transmission channel, the multicarrier signal being formed by a temporal succession of symbols including of a set of data elements with real values, including informative data elements, and reference data elements called pilots for at least some of the symbols. The reception method includes step of first estimation of the transmission channel. Due to at least one of the pilots being an isolated pilot in transmission, the reception method further includes a step of extracting the isolated pilot, and a step of locally refining the first estimation.12-24-2009
20090116565Method for selecting beams during initial synchronization process using switched beam, switched beam operation method and initial sychronization using the same - A method for selecting beams, a switched beam operation method during an initial synchronization process, and an initial synchronization method using it are provided for selecting beams to minimize the probability of occurrence of interferences between cells by considering a distance between beams within neighboring sectors during an initial synchronization process using switched beams, in an orthogonal frequency division multiplexing (OFDM) cellular system employing a smart antenna. The inventive method comprises the steps of dividing each cell into sectors, and counting the number of fixed beams per cell, and selecting a switched beam for minimizing probability of interference, from fixed beams presenting in a corresponding sector, based on distances between a selected beam and beams of all of adjacent cells and the number of cases to be selected in a subsequent time slot, according to the counted number of the fixed beams existing in each sector.05-07-2009
20090304102GENERATING SIGNALS FOR TRANSMISSION OF INFORMATION - A method for generating a signal is presented. The method includes selecting a first set of carrier frequencies that are integral multiples of a first frequency interval, and selecting a second set of carrier frequencies that are integral multiples of a second frequency interval. The second frequency interval is an integral multiple of the first frequency interval and the second set is a subset of the first set. The method includes, for each of one or more signal carrier frequencies in the second set, selecting a plurality of associated carrier frequencies in the first set including a peak carrier frequency having substantially the same value as the signal carrier frequency, and modulating waveform frequency components at each of the selected plurality of associated carrier frequencies according to the same data value.12-10-2009
20090110097DATA PROCESSING APPARATUS AND METHOD - A data processing apparatus maps input symbols to be communicated onto a predetermined number of sub-carrier signals of an Orthogonal Frequency Division Multiplexed (OFDM) symbol. The data processor includes an interleaver memory which reads-in the predetermined number of data symbols for mapping onto the OFDM sub-carrier signals. The interleaver memory reads-out the data symbols on to the OFDM sub-carriers to effect the mapping, the read-out being in a different order than the read-in, the order being determined from a set of addresses, with the effect that the data symbols are interleaved on to the sub-carrier signals. The set of addresses are generated from an address generator which comprises a linear feedback shift register and a permutation circuit. The linear feedback shift register has eleven register stages with a generator polynomial for the linear feedback shift register of R′04-30-2009
20090304101INTELLIGENT POWER SYSTEM AND METHODS FOR ITS APPLICATION - Methods and systems for injecting information into a power signal, and techniques to capture the injected information are disclosed. Various processes for using the information are also presented, which may relate to the type of device receiving the information. Moreover, techniques for determining the distance of a consumer device are disclosed, as have a specific implementation which relates to mobile consumer devices. Also various ways of encrypting both in-band and out-of-band transmission are disclosed.12-10-2009
20090304100INTERFERENCE REDUCTION BETWEEN OFDM CARRIERS BY FREQUENCY OFFSET OPTIMIZATION - Systems and methodologies are described that facilitate signal separation across different carriers within a wireless communications environment. The systems and methods can identify a carrier spacing that can be based upon a tone spacing associated with two or more carriers. Such carrier spacing can be employed within a network in order to mitigate signal separation with multiple carriers. The subject innovation can further evaluate a carrier raster associated with a network in order to identify a carrier spacing to ensure orthogonality between tones from different carriers.12-10-2009
20090304099DIGITAL SIGNAL TRANSMISSION AND RECEPTION - A digital signal transmitter in which multiple data streams are each transmitted by modulation of a respective frequency band within one of a group of frequency channels, the frequency bands each occupying no more than a predetermined maximum bandwidth less than or equal to the channel width; comprises means for transmitting at respective frequency positions within each frequency channel, one or more instances of band information defining the frequency bands corresponding to all of the data streams carried within that frequency channel, the one or more instances being arranged so that any portion of the frequency channel equal in extent to the predetermined maximum bandwidth includes at least one instance of the band information.12-10-2009
20090304098Method of transmitting control signals in wireless communication system - A method of transmitting control signals in a wireless communication system is provided. The method comprises allocating at least one control signal in a control channel region comprising a plurality of tiles, each tile consisting of a plurality of consecutive subcarriers in a frequency domain on a plurality of orthogonal frequency division multiplexing (OFDM) symbols in a time domain and transmitting the at least one control signal, wherein the number of the at least one control signal is determined based on the number of available sequences for the control channel region and the number of bit carried by each control signal.12-10-2009
20090304096SYSTEM AND METHOD FOR RANDOMIZED ANTENNA ALLOCATION IN ASYNCHRONOUS MIMO MULTI-HOP NETWORKS - A system and method for simultaneous and asynchronous transmissions in multi-antenna multi-hop networks. The system and method employ randomized and non-greedy resource allocation to counter starvation. The system and method define a class of asynchronous random access protocols subsuming MIMO systems via two components. Residual Capacity Estimation and Randomized Resource Allocation. The system and method realize the first asynchronous MIMO MAC protocol that counters flow starvation in multi-hop networks. Randomized and non-greedy antenna allocation coupled with local residual capacity estimation results in previously-starving nodes capturing a fair share of system resources while simultaneously exploiting throughput gains available to multi-antenna systems.12-10-2009
20090304095WIRELESS COMMUNICATION SYSTEM COMPENSATING FOR INTERFERENCE AND RELATED METHODS - A wireless communication system may include first and second wireless communications devices communicating with one another via a wireless communications link having a settable link characteristic. The first and second wireless communications devices may include respective first and second wireless transceivers and respective first and second controllers coupled thereto. The first controller may be for detecting received interference, for determining a type of the interference from among interference types comprising wideband interference and narrowband interference, and for setting the settable link characteristic to compensate for the interference based upon the interference type.12-10-2009
20090304094Dual Carrier Modulation Soft Demapper - An Orthogonal Frequency Division Multiplexing (OFDM) communication system with a transmitter and a receiver. The transmitter is arranged to transmit channel estimation sequences on each of a plurality of band groups, or bands, and to transmit data on each of the band groups or bands. The receiver is arranged to receive the channel estimation sequences for each band group or band to calculate channel state information from each of the channel estimation sequences transmitted on that band group or band and to form an average channel state information. The receiver receives the transmitted data, transforms the received data into the frequency domain, equalizes the received data using the channel state information, demaps the equalized data to re-construct the received data as soft bits and modifies the soft bits using the averaged channel state information.12-10-2009
20090110094DATA PROCESSING APPARATUS AND METHOD - A data processing apparatus maps input symbols to be communicated onto a predetermined number of sub-carrier signals of an Orthogonal Frequency Division Multiplexed (OFDM) symbol. The data processor includes an interleaver memory which reads-in the predetermined number of data symbols for mapping onto the OFDM sub-carrier signals. The interleaver memory reads-out the data symbols on to the OFDM sub-carriers to effect the mapping, the read-out being in a different order than the read-in, the order being determined from a set of addresses, with the effect that the data symbols are interleaved on to the sub-carrier signals. The set of addresses are generated from an address generator which comprises a linear feedback shift register and a permutation circuit. The linear feedback shift register has twelve register stages with a generator polynomial for the linear feedback shift register of R′04-30-2009
20090110090Wireless Communication Receiving System and Apparatus and Method for Deciding a Transmitted Signal Corresponding to a Received Signal Thereof - A wireless communication receiving system and an apparatus and a method for deciding a transmitted signal corresponding to a received signal thereof are provided. The transmitted signal comprises a plurality of sub-transmitted signals. The system selects at least one of the sub-transmitted signals as a reference signal group, wherein each of a plurality of candidate values of the reference signal group forms a candidate geometric space respectively. The received signal is projected to each of the candidate geometric spaces to generate a projection signal respectively. In each of the candidate geometric space, the corresponding projection signal is quantized to generate a quantized projection signal having a projection distance to the corresponding projection signal. Finally, the transmitted signal is decided according the quantized projection signal and the candidate signal value corresponding to the shortest projection distance.04-30-2009
20090103645DIGITAL MOBILE COMMUNICATION SYSTEM AND TRANSMISSION/RECEPTION METHOD THEREOF - A radio communication system in which a transmission station performs window function processing on a transmission symbol to which cyclic prefixes have been attached for each specified number of samples, then transmits the signal, and a receiving station extracts and demodulates effective signal portions from the received signal, wherein the transmission station uses a control channel to notify the receiving station of window width N04-23-2009
20090103644TRANSMITTING AND RECEIVING METHOD, AND RADIO APPARATUS UTILIZING THE SAME - A processing unit transmits, from at least one of a plurality of antennas, data corresponding respectively to the plurality of antennas. A control unit generates request signals with which to let a second radio apparatus supply information on rates at the second radio apparatus. When transmitting the request signal, the processing unit also transmits, from a plurality of antennas which includes antennas other than the antennas that transmit the data, known signals corresponding respectively to the plurality of antennas.04-23-2009
20100272194Channel Estimation Techniques for OFDM - An Orthogonal Frequency Division Multiplexing (OFDM) receiver comprises: a channel estimator receiving a signal that includes a plurality of symbols, each of the symbols including a plurality of pilots and a plurality of data subcarriers, wherein each symbol further includes at least one pilot subcarrier, the estimator using a first channel response estimate of the at least one pilot subcarrier in a first symbol to select a first weight matrix from a plurality of pre-generated weight matrices, and generating channel estimation information for data subcarriers in the first symbol using the selected first weight matrix.10-28-2010
20120219079RECEIVING DEVICE, RECEIVING METHOD, COMMUNICATION SYSTEM, AND COMMUNICATION METHOD - Provided is a receiving device including: a receiving unit that receives a multicarrier modulation signal; an interference cancelling unit that removes a modulation symbol replica generated using a decoding process result, from the signal received by the receiving unit, and outputs the resultant signal; and a signal detecting unit that decodes the signal outputted by the interference cancelling unit, and outputs the decoding process result. The interference cancelling unit generates the modulation symbol replica with the use of the decoding process result of part of data modulation symbols constituting the signal received by the receiving unit.08-30-2012
20120219078Subband Indexing Methods and Systems - Methods and systems for indexing subband selections are disclosed. The selected subbands can be represented as a binary sequence and the index can be determined by employing a choose function, where a choose function value for a particular selected bit position is defined by a selection occurrence count of the selected bit position that is chosen from a bit position count of the selected bit position. In particular, the index can be the summation of choose function values for each selected bit position.08-30-2012
20120219077METHOD AND APPARATUS FOR GENERATING/TRANSMITTING A FRAME FOR WIRELESS COMMUNICATION, AND SYNCHRONIZATION ESTIMATION METHOD FOR WIRELESS COMMUNICATION - Disclosed is a technique related to a method and apparatus for generating a preamble and a data frame for wireless communication, and to a synchronization estimation method using the preamble. According to the technique, a method for generating a frame for wireless communication is disclosed, wherein the method comprises: a step of generating a modified sequence using a first base sequence for synchronization estimation; and a step of allocating the first base sequence and the modified sequence to the frequency domain of a first timeslot to generate a preamble. The modified sequence includes a complex conjugated sequence of the first base sequence or a sequence having a code different from that of the first base sequence.08-30-2012
20090041141PILOT PATTERN DESIGN FOR AN OFDM SYSTEM - The present invention relates to a transmitting device and a receiving device in a wireless orthogonal frequency division multiplex (OFDM) communication system with space time transmit diversity (STTD). Further, the present invention relates to a channel estimation method for performing a channel estimation in such a wireless communication system, in which the transmitting device comprises a first and a second antenna for transmitting signals with space time transmit diversity. The first and the second antenna means are arranged spaced apart from each other in a space diversity arrangement, whereby first and second pilot symbols are transmitted via said first and said second antenna means, respectively. Some of the second pilot symbols are orthogonal to corresponding ones of the first pilot symbols, so that a channel estimation to separately determine the transmission quality of signals transmitted from the first and the second antenna means, respectively, can be performed in a receiving device which receives the signals with only one single antenna.02-12-2009
20090041144MULTI-USER MIMO RECEIVER AND METHOD FOR DECODING SIMULTANEOUS UPLINK TRANSMISSIONS FROM MOBILE STATIONS - Multicarrier receivers and methods for carrier frequency offset correction and channel estimation for receipt of simultaneous transmissions over a multi-user uplink are generally described herein. Other embodiments may be described and claimed.02-12-2009
20090041142PILOT PATTERN DESIGN FOR AN OFDM SYSTEM - A transmitting device for transmitting data symbols and pilot symbols in an OFDM transmission system; the device comprising symbol generating means for generating said data symbols and said pilot symbols, means for transmitting said data symbols and pilot symbols respectively by using a plurality of subcarriers of said OFDM transmission system, wherein said symbol generating means is designed to selectively generate a first type pilot symbol and a second type pilot symbol being orthogonal to said first type pilot symbol so that a pilot symbol pattern in the frequency dimension comprises at least said first type pilot symbol to be transmitted by using a predefined subcarrier and second type pilot symbol to be transmitted by using other predefined subcarrier, and wherein said pilot symbol pattern has a different pattern from a succeeding pilot symbol pattern in time dimension.02-12-2009
20090041136METHOD AND APPARATUS FOR RECOGNITION OF TRANSMISSION PARAMETER SIGNALING (TPS) AT FREQUENCY DOMAIN IN A TDS-OFDM RECEIVER - A receiver comprises a method is provided. The method has the step of: determining a transmission parameter signaling (TPS) parameter based a group of vectors inherent to a communication system.02-12-2009
20090041135NULL DETECTION IN DAB, T-DMB, AND DAB-IP SYSTEMS - Detecting Null symbols in a video data frame comprises sending OFDM symbols through a sliding windowed correlation process having a correlation window length proportional to a cyclic prefix length and a delay equal to a FFT size of the symbols, wherein output peaks of the process occur where two similar portions of the symbols coincide; checking peaks in windows sized equal to a duration of a symbol; determining whether the peaks are located in the middle of the windows; determining whether a shift has occurred in the location of the peak of a current window compared to in a second immediately previous window; determining whether the peak in a first immediately previous window is weak compared to that in a second immediately previous window; and declaring that a Null symbol exists in the first previous window when the shift has occurred and the determination of a weak peak exists.02-12-2009
20090003475METHOD AND SYSTEM FOR ADAPTATION BETWEEN DIFFERENT CLOSED-LOOP, OPEN-LOOP AND HYBRID TECHNIQUES FOR MULTIPLE ANTENNA SYSTEMS - Aspects of a method and system for adaptation between different closed loop, open loop and hybrid techniques for multiple antenna systems may include a transmitting station that enables generation of a plurality of signals that are concurrently transmitted via a communication medium based on a selected one of: full feedback information, reduced quantity feedback information, or no feedback information. The selection may be determined at the transmitting station based on a determined Doppler shift frequency.01-01-2009
20090316804METHOD AND APPARATUS TO IMPLEMENT OFDMA RANGING IN WIMAX SYSTEM - A communications processing device includes a rotor for rotating information associated with ranging subchannels in some symbols; and a single inverse fast Fourier transformer (IFFT), coupled to rotor, for subjecting the rotated information to a single IFFT along with information from all other channels. A method comprising the steps of: rotating information associated with ranging subchannels in some symbols; and subjecting the rotated information to a single IFFT along with information from all other channels.12-24-2009
20090092197OFDM DEMODULATION DEVICE AND METHOD - The present invention provides an OFDM demodulation device for demodulating an orthogonal frequency division multiplexed (OFDM) signal whose transmission unit is a transmission symbol produced by quadrature modulation in such a way that information is divided for a plurality of subcarriers in a predetermined band. The OFDM demodulation device includes a carrier frequency offset detecting circuit (04-09-2009
20090092195METHOD AND SYSTEM FOR ADAPTIVE PEAK TO AVERAGE POWER RATIO REDUCTION IN ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING COMMUNICATION NETWORKS - A method and system adaptively reduce a peak-to-average power ratio in a communication system. Energy is clipped from at least one peak of a modulated signal. The modulated signal includes a plurality of sub-carriers. At least one data sub-carrier is adaptively selected for peak-to-average power ratio reduction use based on known scheduling information. The clipped energy is distributed among at least one data sub-carrier.04-09-2009
20090092194ADAPTIVE PILOT DESIGN FOR MOBILE SYSTEM - A method, and device implementing the method, for adaptively allocating pilot signals in a wireless communication system. The method includes receiving channel data, including channel length (L) data, inter-carrier interference power (P04-09-2009
20090092193MULTI CARRIER TRANSMISSION DEVICE, MULTI CARRIER RECEPTION DEVICE, AND COMMUNICATION METHOD - Provided is a multi carrier transmission device capable of compensating the delay time and the imbalance and the orthogonal difference between the in-phase component and the orthogonal component of the amplitude at a low cost without increasing the circuit size. In this device, a coordinate conversion unit (04-09-2009
20090092192Multi-frequency data transmission channel power allocation - A method of controlling a communication device that is operable to transmit digital data over a plurality of frequency channels. The method includes selecting an initial transmission power and a corresponding data rate for each channel. The method also includes identifying in a first channel a first ratio of a first decrement in transmission power to a first data rate decrement that is greater than a second ratio of a second decrement in transmission power to a second data rate decrement. Then, the initial transmission power allocation of the first channel is reduced by the first decrement. The method also includes reallocating the decremented initial transmission power of the first channel to one or more other channels.04-09-2009
20130070866Multi-carrier Optical Communication Method and System Based on DAPSK - The present invention provides an optical communication method, comprising: performing modulation on the obtained bit stream data to generate modulated signals; performing differential encoding on the modulated signals to generate differentially encoded signals; converting the differentially encoded signals into electrical signals; and mapping the electrical signals onto optical carriers to generate optical signals for transmission. With the present invention, it is possible to enhance the system's capability of resisting inter-carrier interference without decreasing spectrum efficiency, hence improving the tolerance of existing optical communication systems towards laser linewidth, fast-changing PMD, optical fiber nonlinearity, inter-channel interference and other damages, greatly enhancing system performances.03-21-2013
20110058617METHOD FOR DECODING A SIGNAL TRANSMITTED IN A MULTI-ANTENNA SYSTEM, CORRESPONDING COMPUTER SOFTWARE PRODUCT AND DECODING DEVICE - A method is provided for decoding a signal received by a receiver including at least one reception antenna. The method includes: selecting, among at least two techniques available in the receiver, a decoding technique representative of a space/time encoding implemented upon transmission; and decoding the signal using the selected decoding technique. The selecting step takes into account at least one selection criterion.03-10-2011
20110013710System and Method for Information Feedback in a Wireless Communications System with Coordinated Multiple Point Transmission - A system and method for information feedback in a wireless communications system with coordinated multiple point (CoMP) transmission are provided. A method for operating in a communications system, the communications system having a first communications controller and a second communications controller participating in a CoMP cooperation set, the method includes selecting a CoMP processing technique, and reporting channel information to the first communications controller. The channel information is based on the preferred CoMP processing technique.01-20-2011
20110013709Cost and Resource Utilization Optimization in Multiple Data Source Transcoding - A plurality of input data streams, from a plurality of data sources, are identified. The input data streams are in a plurality of different formats. For each of the input data streams, one of a plurality of transcoders is selected, to obtain a transcoding plan. Each of the plurality of transcoders has an associated transcoding cost. A potential output for each of the plurality of transcoders has an associated storage cost, and the selecting step includes jointly reducing the overall cost, subject to appropriate constraints. The method can be employed, for example, for designing a new system or efficiently utilizing an existing system. The plurality of streams can be transcoded in accordance with the plan.01-20-2011
20110013708Signal Sequence Detection Techniques for OFDM/OFDMA Systems - Energy in a frequency band is received at a wireless communication device and data is generated representing samples of a received time domain waveform from the received energy. Data for groups of samples of the received time domain waveform is processed to transform the data for the received time domain waveform to produce data for an intermediate domain signal that is in neither the time domain nor the frequency domain. The data representing the intermediate domain signal is analyzed to determine whether a sequence having a predetermined pattern from a set of possible sequences is present in the received energy, and ultimately to determine a sequence of the predetermined pattern whose presence is detected in the received energy.01-20-2011
20090003471OFDM signal acquisition - In general, in one aspect, the disclosure describes a method defining order and means in which physical parameters of a received OFDM signal may be detected. A fractional frequency offset is determined for the OFDM signal and is used to determine a coarse location for received signal preamble. A symbol boundary is determined based on the coarse location and the course location is used to determine preamble location. A preamble sequence and integer frequency offset is determined based on the preamble location.01-01-2009
20090285315APPARATUS AND METHOD FOR ADAPTIVE CHANNEL ESTIMATION AND COHERENT BANDWIDTH ESTIMATION APPARATUS THEREOF - An apparatus and a method for adaptive channel estimation and a coherent bandwidth estimation apparatus are provided. The adaptive channel estimation apparatus includes a first channel estimator, a coherent bandwidth estimator and a second channel estimator. The first channel estimator uses a predetermined approach to calculate a first channel response of each tone of an orthogonal frequency-division multiplexing (OFDM) signal. The coherent bandwidth estimator is coupled to the first channel estimator for calculating a coherent bandwidth according to the first channel responses. The second channel estimator is coupled to the first channel estimator and the coherent bandwidth estimator. For each of the tones, the second channel estimator calculates a weighted average according to the coherent bandwidth and the first channel responses of several adjacent tones including the aforementioned tone. The second channel estimator outputs the weighted average as the second channel response of the aforementioned tone.11-19-2009
20090279627OFDM COMMUNICATION APPARATUS - An OFDM communication apparatus includes a determining section determine a number of known signals for transmission path estimation to be inserted in a transmit signal based on channel quality with respect to a communicating party, and a generating section performs inverse Fourier transform processing on an information signal and the number of known signals for transmission path estimation determined by the determining section and generates a transmit signal for the communicating party. The apparatus achieves both an improvement in demodulated signal error rate characteristics and an improvement in information signal transmission efficiency.11-12-2009
20090268832SYSTEMS AND METHODS FOR HIGH RATE OFDM COMMUNICATIONS - Messages transmitted between a receiver and a transmitter are used to maximize a communication data rate. In particular, a multicarrier modulation system uses messages that are sent from the receiver to the transmitter to exchange one or more sets of optimized communication parameters. The transmitter then stores these communication parameters and when transmitting to that particular receiver, the transmitter utilizes the stored parameters in an effort to maximize the data rate to that receiver. Likewise, when the receiver receives packets from that particular transmitter, the receiver can utilize the stored communication parameters for reception.10-29-2009
20090268831BACKWARD COMPATIBLE BANDWIDTH EXTENSION - A transmitter includes a bandwidth configuration unit configured to provide an increased system bandwidth corresponding to a bandwidth extension over multiple component carriers. Additionally, the transmitter also includes a transmit unit configured to employ the bandwidth extension.10-29-2009
20090268830SYSTEM AND METHOD FOR DETECTING TEMPORARILY UNUSED BANDWIDTH IN THE RF SPECTRUM10-29-2009
20090268827SYSTEM FOR FEEDING BACK INDEX OF CODEWORD MATRIX - A system is provided for performing downlink beamforming based on information fed back by a mobile station. The mobile station includes a channel matrix generation unit to generate a channel matrix with respect to channels ranging from a base station to a mobile station, the base station including multiple transmission antennas, a codebook updating unit to generate a second codebook including a plurality of second codeword matrixes based on the generated channel matrix and a first codebook including a plurality of first codeword matrixes, a codeword selection unit to select at least one transmission codeword matrix from among the plurality of second codeword matrixes, a transmission unit to transmit an index of the selected transmission codeword matrix to the base station, and a receiving unit to receive data transmitted from the base station via the multiple transmission antennas.10-29-2009
20090268825Receiver, Transmission Mehtod and Transmission System - To reduce the influence of inter-block interference even when the order number of the channel (physically corresponding to the impulse response length of the channel) is larger than the CP length. A receiver 10-29-2009
20090268826Time Domain Based Approach for Fast Fading Channel FFT Trigger Point Tracking in ISDB Receivers - A method of fast fading channel Fast Fourier Transform (FFT) trigger point tracking in an integrated services digital broadcasting (ISDB) receiver includes inputting a signal in a fading channel including N Orthogonal Frequency Division Multiplexing (OFDM) symbols, determining an average correlation result of a current time-domain sample of the signal and a previous time-domain sample taken previously of the signal, accumulating the average correlation result for at least one of the OFDM symbols, determining a peak of the average correlation result to obtain a peak position, and identifying the peak position as a trigger point of the input signal. The peak position may be compared with a first trigger point to generate a trigger point error signal. The first trigger point may be set at the middle of a guard of an OFDM symbol to generate the trigger point error signal.10-29-2009
20090268829Systems and Methods for Sampling Frequency Offset Estimation - A method comprises receiving a transmission including at least two Orthogonal Frequency Division Multiplexing (OFDM) symbols, estimating a sampling frequency offset associated with the OFDM symbols at least in part by employing a term representing a density of pilots in the OFDM symbols, and compensating for the sampling frequency offset using the estimated sampling frequency offset.10-29-2009
20090067525Apparatus and method for pilot transmission in a wireless communication system - An apparatus and method for pilot transmission in a wireless communication system are provided. The method includes generating a precode and a postcode for coordinated beamforming using channel information of one or more streams for transmitting signals to one or more receive ends, selecting one or more streams to be allocated pilots, updating the precode according to a reference point for representing an effective channel of non-selected streams orthogonal to an effective channel of the selected streams, and precoding signals transmitted through the streams.03-12-2009
20090067520METHOD AND APPARATUS FOR CHANNEL ESTIMATION IN COMMUNICATION SYSTEMS, AND RELATED COMPUTER PROGRAM PRODUCT - A method of channel estimation in orthogonal frequency-division multiplexing communication employing three or more subcarriers, wherein frequency correlation exists between the subcarriers. The method includes: 03-12-2009
20090060077WIRELESS COMMUNICATION BASE STATION APPARATUS AND PILOT SIGNAL DISPOSING METHOD - A base station device is provided with features in which multicast data can be prevented from deterioration in the accuracy of channel estimation due to interference of a unicast data pilot signal when multicast data and unicast data are multiplexed for transmission. In this device, a unicast pilot signal generating unit (03-05-2009
20100091898RECOVERY OF DATA FROM A MULTI CARRIER SIGNAL - In an embodiment, a multi-carrier signal (e.g., an OFDM signal) is received over a channel. First indicators of interference and channel response at a carrier frequency of the signal are determined and compared. If the first indicator of the interference has a relationship to the first indicator of the channel response, then a data value transmitted at the carrier frequency is recovered from a data value received at the carrier frequency according to a first algorithm. If, however, the first indicator of the interference does not have a first relationship to the first indicator of the channel response, then second indicators of interference and the channel response at the carrier frequency are determined and compared. If the second indicator of the interference has a second relationship to the second indicator of the channel response, then the data value transmitted at the carrier frequency is recovered from the data value received at the carrier frequency according to a second algorithm. Because first and second data-recovery algorithms may be faster than a conventional data-recovery algorithm, recovering one or more data values with the first or second algorithms may increase the speed at which data is recovered from a multicarrier signal as compared to using a conventional data-recovery algorithm exclusively.04-15-2010
20100091897WIRELESS COMMUNICATION SYSTEM, WIRELESS COMMUNICATION DEVICE, WIRELESS COMMUNICATION METHOD AND COMPUTER PROGRAM - There is provided a wireless communication system, including a first terminal equipped with N antennas, N being an integer of at least two, a second terminal equipped with M antennas, M being an integer of at least one, and a third terminal equipped with L antennas, L being an integer of at least one. The first terminal includes a matrix calculation portion that calculates a transmission weight matrix suitable for transmitting data from the first terminal to the second terminal, and a matrix multiplication portion that multiplies a first data stream and a second data stream by the transmission weight matrix, the first data stream being transmitted from the first terminal to the second terminal, and the second data stream being transmitted from the first terminal to the third terminal.04-15-2010
20100091896SIGNAL TRANSMISSION SYSTEM USING MULTIPLE ANTENNA AND SIGNAL TRANSMISSION METHOD THEREOF - The present invention relates to a multiple antenna transmission system and a signal transmission method In the signal transmission method using multiple antennas, a plurality of subcarrier symbols are grouped as a plurality of groups including first and second tiles that are basic resource management units including two or more subcarriers included in a set frequency domain, phases of subcarrier symbols included in a first tile are shifted to be a first phase shifting value, and phases of subcarrier symbols included in a second tile are shifted to be a second phase shifting value that is different from the first phase shifting value.04-15-2010
20100091895INTERFERING BASE STATIONS RECOGNITION METHOD AND SCHEME FOR 802.16E SYSTEMS - A method and apparatus for identifying the preamble for an unknown signal received in Orthogonal Frequency Division Multiplexing (OFDM) communications. In one embodiment, the preamble is identified from a set of known preambles using a detection statistic based on a generalized likelihood ratio (GLR) method. In another embodiment, the GLR detection statistic relies on a priori assumptions about a transfer function represented by the received signal.04-15-2010
20100091894CHANNEL QUALITY ASSESSMENT METHOD IN OFDM(A) COMMUNICATIONS AND A CORRESPONDING SYSTEM - A method and apparatus for determining a channel quality indicator (CQI) to be used in link adaptation for Orthogonal Frequency Division Multiplexing (OFDM) communications. In one embodiment of the invention, the CQI is based on a set of capacity values for subcarrier components in a received OFDM signal. In another embodiment, a minimum value from a running average of the set of capacity values is used to determine the CQI.04-15-2010
20100091893METHOD AND APPARATUS FOR CHANNEL FEEDBACK IN A WIRELESS COMMUNICATION SYSTEM - A communication system comprises evolved base nodes (eNBs) communicating via an over-the-air (OTA) link with low mobility user equipment (UE). A network can utilize the eNBs for cooperative beam shaping for interference nulling based upon a number of factors UE (e.g., coordinated multi-point (COMP) optimization for feedback, quality of service (QoS), fairness, etc.). The UE advantageously transmits adaptive rate and payload channel state feedback, trading accuracy versus delay based upon mobility of the UE. Channel coherence across a transmission interval (frequency and/or time invariance) provides an opportunity with sufficiently low mobility for transmitting a larger accuracy feedback report over one or more feedback reports for decoding at the eNB. Reduced quantization error can be realized via multi-level coding, one codebook multiple description coding (MDC), and use of N-best code representations from one codebook with MDC.04-15-2010
20100091892METHOD AND APPARATUS FOR CHANNEL FEEDBACK BY MULTIPLE DESCRIPTION CODING IN A WIRELESS COMMUNICATION SYSTEM - A communication system comprises evolved base nodes (eNBs) communicating via an over-the-air (OTA) link with low mobility user equipment (UE). A network can utilize the eNBs for cooperative beam shaping for interference nulling based upon a number of factors UE (e.g., coordinated multi-point (COMP) optimization for feedback, quality of service (QoS), fairness, etc.). The UE advantageously transmits multiple description coding (MDC) that supports a determination by the eNBs that coherent channel conditions (e.g., frequency and/or time invariance) exists for combining feedback reports to realize reduced quantization error. In addition, the MDC feedback reports still support incoherent channel states in which each report can be used individually for interference nulling/beamforming. MDC can be performed with one codebook or a plurality of codebooks.04-15-2010
20100091891LINK QUALITY METRIC BASED ANTENNA SELECTION FOR TRANSCEIVERS - A method and system for link quality metric based antenna selection for transceiver are disclosed. In one embodiment, a method for selecting an antenna from multiple antennas associated with a receiver, includes receiving multi-carrier modulated signals via a currently active antenna of the receiver, and estimating a predicted packet error rate (PER) associated with a current receive path of the receiver. The current receive path is used to process the multi-carrier modulated signals. The method further includes selecting a next antenna from the multiple antennas for forming a next receive path of the receiver based on the predicted PER and a packet error history associated with at least one previous receive path.04-15-2010
20120224648MULTIPLE-INPUT MULTIPLE-OUTPUT (MIMO) COMMUNICATION SYSTEM USING REGULARIZED BEAMFORMING - Provided are a beamforming vector determining method and an apparatus which may compute a normalization factor of each of a plurality of terminals by normalizing a predetermined reference value using noise power occurring in each of the terminals. A leakage channel of each of the terminals may be estimated, and a beamforming vector for each of the terminals may be determined with respect to a plurality of base stations based on the leakage channel of each of the terminals.09-06-2012
20130064316METHOD OF AND GENERATOR FOR GENERATING PREAMBLE SEQUENCES IN COMMUNICATION SYSTEMS - A method forms a preamble sequence in a wireless communication system. The method comprises determining a value K related to a time-domain characteristic of the wireless communication system so that a time-domain preamble sequence includes a number of K waveforms similar in shape to one another having a linear phase shift, identifying a first preamble sequence for a first band, the first preamble sequence having a first length not dividable by K, identifying at least one second preamble sequence each for a second band, the at least one second preamble sequence having at least one second length, identifying the length of a third preamble sequence, the length of the third preamble sequence equal to a sum of the first length and the at least one second length, determining whether the time-domain characteristic is maintained when the one or more of the at least one second preamble sequence is concatenated with the first preamble sequence, modifying one or more of the at least one second preamble sequence if the time-domain characteristic is not maintained when concatenated, and forming the third preamble sequence by concatenating the first preamble sequence and the at least one second preamble sequence having one or more second preamble sequence modified.03-14-2013
20130064315Progressive Feedback For High Resolution Limited Feedback Wireless Communication - A system and method is proposed for progressively quantizing channel state information for application in a MIMO (multiple input multiple output) communication system. A method includes computing an estimate of a communications channel between a subscriber unit and a base station, quantizing the estimate with a first codebook, thereby producing a first quantized estimate, quantizing an (n−1)-th quantized estimate with an n-th codebook, thereby producing an n-th quantized estimate, where n is an integer value ranging from 2 to R, R is a total number of quantizations of the estimate, wherein the n-th codebook is a localized codebook. The method also includes incrementing n, repeating the quantizing an (n−1)-th quantized estimate until n=R, and transmitting information based on the R quantized estimates to the base station.03-14-2013
20130064313METHOD FOR CHANNEL ESTIMATION, RELATED CHANNEL ESTIMATOR, RECEIVER, AND COMPUTER PROGRAM PRODUCT - An embodiment of a method for channel estimation for an Orthogonal Frequency Division Multiplexing communication system, including estimating a Time Domain Least Squares channel impulse response having a given maximum number of L taps based on a channel covariance matrix Q, and for each tap l=1, . . . , L a respective channel impulse response in the time-domain ĥ03-14-2013
20130064314APPARATUS FOR TRANSMITTING AND RECEIVING A SIGNAL AND METHOD OF TRANSMITTING AND RECEIVING A SIGNAL - According to one embodiment, a method of transmitting a broadcast signal includes: encoding physical layer pipe (PLP) data for delivering a service; mapping the encoded PLP data to symbols; building a signal frame based on the mapped symbols; modulating the signal frame according to an orthogonal frequency division multiplexing (OFDM) scheme; inserting a pilot symbol into a beginning part of the modulated signal frame; and transmitting the broadcast signal including the signal frame and the inserted pilot symbol. The pilot symbol comprises an effective portion, a cyclic prefix obtained by frequency-shifting a first portion of the effective portion, and a cyclic suffix obtained by frequency-shifting a second portion of the effective portion.03-14-2013
20090245405MIMO TRANSMITTER AND METHOD FOR TRANSMITTING A GROUP OF SEQUENTIAL OFDM SYMBOLS IN ACCORDANCE WITH AN IEEE 802.16 COMMUNICATION STANDARD - A multiple-input-multiple output (MIMO) transmitter for transmitting a group of sequential orthogonal frequency division multiplexed (OFDM) symbols on a time-division duplexed (TDD) channel in accordance with an IEEE 802.16 standard using a plurality of antennas. The MIMO transmitter comprises a spatial-frequency parser to parse a block of bits into spatial-frequency blocks of a variable number of coded bits, and subcarrier modulators to individually modulate OFDM subcarriers with the spatial-frequency blocks in accordance with spatial-frequency subcarrier modulation assignments to generate groups of symbol-modulated subcarriers. The TDD channel comprises a plurality of the groups of the OFDM subcarriers, and the OFDM subcarriers within each group of subcarriers and within each group of sequential OFDM symbols have the same spatial-frequency subcarrier modulation assignments.10-01-2009
20090238296MULTIPLE ACCESS SYSTEM AND METHOD FOR 60 GHZ WIRELESS COMMUNICATIONS SYSTEM - A control apparatus for use in wireless communications includes an antenna unit having antennas, the number of the antennas being equal to a maximum allowable number of connections in a specific frequency band; and a controller for receiving a connection request signal from each terminal attempting to connect to the control apparatus via the antenna unit, and transmitting and receiving a data signal to and from each terminal connected to the control apparatus by using a multiple-input-multiple-output scheme. The controller transmit and receive the data signal to and from each terminal connected to the control apparatus by obtaining a signal value of each antenna based on a predicted channel matrix and the number and types of terminals connected to the control apparatus via the antenna and separating the data signal for each terminal from the signal value according to the multiple-input-multiple-output scheme.09-24-2009
20090238294TRANSMISSION APPARATUS AND TRANSMISSION METHOD - An transmission apparatus includes a pseudo data addition section configured to add pseudo data into transmission data for a free subcarrier of a radio frequency, an OFDM modulator subjecting the transmission data added with the pseudo data to OFDM modulation, a power amplifier amplifying power of a transmission signal of the radio frequency, the transmission signal based on an OFDM signal subjected to the OFDM modulation, an antenna radiating the amplified transmission signal by using the radio frequency; and a distortion compensation circuit compensating for a distortion characteristic of the power amplifier by correcting the OFDM signal with a distortion compensation coefficient accumulated corresponding to the power value of the OFDM signal, outputting the corrected signal for the power amplifier, and monitoring the output of the power amplifier to update the distortion compensation coefficient.09-24-2009
20090238293OFDMA Based Medium Access Control and Frame Structure Design for Industrial Applications - A network includes a master and a set of slaves that communicate orthogonal frequency-division multiplexing (OFDM) and time division multiple access (TDMA) symbols on sub-carriers. A master broadcasts to the set of slaves using downlinks and all of the sub-carriers, a broadcast polling packet including data packets for each slave and sub-carrier assignments for the slaves. Each slave, in response to receiving the downlink polling packet, transmits simultaneously a response packet to the master using uplinks and the assigned sub-carriers. The master then transmits to the set of slave using the downlinks and all of the sub-carriers, a group acknowledgement packet, wherein the broadcast polling packet, the response packet, and the group acknowledgement packet comprise one superframe in one communication cycle, and wherein the broadcasting on the downlinks and the transmitting on the uplinks are disjoint in time.09-24-2009
20090238292MULTIPLE-INPUT MULTIPLE-OUTPUT COMMUNICATION SYSTEM CONTROL METHOD AND APPARATUS - A communication system control method, a communication system control apparatus and an apparatus for use in a communication system are provided. The communication system control apparatus includes an information collection unit to collect user set information about candidate user sets grouped by a plurality of base stations, and a scheduler to select target user sets corresponding to the plurality of base stations from among the candidate user sets based on an achievable sum data transmission rate of the plurality of base stations, and perform scheduling with respect to users included in the target user sets, the achievable sum data transmission rate being calculated based on the user set information.09-24-2009
20090238291COMMUNICATION APPARATUS, METHOD, AND TANGIBLE MACHINE-READABLE MEDIUM THEREOF FOR PROCESSING RANGING INTERFERENCE OF AN ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING SIGNAL - A communication apparatus, a method, and a tangible machine-readable medium thereof for processing ranging interference of an orthogonal frequency division multiplexing (OFDM) signal. The communication apparatus comprises a receiving unit, a processing unit, and a mask generating unit. The receiving unit receives the OFDM signal having a plurality of OFDM symbols. The processing unit estimates a delay value and an energy value of at least one ranging code according to the OFDM symbols. The mask generating unit generates a mask function according to the delay value and the energy value. Finally, the processing unit synthesizes the ranging interference in the OFDM signal and removes it according to the mask function.09-24-2009
20090238290TRANSMITTING DEVICE, RECEIVING DEVICE, TRANSMITTING METHOD, RECEIVING METHOD AND WIRELESS COMMUNICATION SYSTEM - Provided is a transmitting device which improves a data rate while maintaining channel estimation accuracy, or improves channel estimation accuracy while maintaining a data rate, in a MIMO-OFDM system. In the transmitting device, a transmitting antenna information adding section (09-24-2009
20090238289CHANNEL ESTIMATION IN WIRELESS SYSTEMS WITH IMPULSIVE INTERFERENCE - Systems and methodologies are described that facilitate detecting impulsive interference of pilot signals in wireless communications networks and accounting for such interference in estimating data channels to decode the pilot signals. Portions of a received pilot signal can be compared to other portions to create correlated subsets of similar portions. The number of portions in a subset can indicate a high likelihood of non-interference, and portions that are not in the subsets can be disregarded or weighted less in estimating channels for decoding. In cases of ambiguous subsets or portions, one or more subsets/portions can each be used to estimate the channel and data can be decoded multiple times. The decoding that results in a higher decoding metric can be selected. Additionally, systems and methodologies for inserting pilot signals within data are described.09-24-2009
20090232239METHOD AND APPARATUS FOR TRANSMITTING A PILOT IN MULTI-ANTENNA SYSTEM - A method of transmitting a pilot method in a multi-antenna system is provided. The method comprises generating a preceding matrix including a preceding vector, the preceding vector being applied to each of data streams to be transmitted, performing preceding procedure for a pilot by using the preceding matrix, and transmitting the precoded pilot, wherein transmission power of the precoded pilot is determined specifically to the each of the data streams. The transmission power of a precoded pilot can be controlled adaptively, individually and independently for each channel to improve channel estimation performance.09-17-2009
20090232237MODULATING DEVICE AND METHOD, DEMODULATING DEVICE AND METHOD, PROGRAM, AND RECORDING MEDIUM - A modulating device configured to perform modulation with the orthogonal frequency division multiplexing method, includes: a modulating unit configured to modulate main information with the orthogonal frequency division multiplexing method; and a determining unit configured to determine a subcarrier pattern employed when modulating the main information by the modulating unit based on additional information relating to the main information.09-17-2009
20090232234BANDWIDTH ASYMMETRIC COMMUNICATION SYSTEM - The present invention relates to a communication system comprising a plurality of terminals each having an uplink transmission unit (09-17-2009
20090232232Metric Computation for Lowering Complexity of MIMO Detection Algorithms - Included are embodiments of method for method for computing metrics. At least one embodiment includes searching a MIMO detection tree, the detection tree configuration being formed by a plurality of nodes and a plurality of leaves connected via a plurality of branches, the computational complexity associated with computing a node metric decreases with the node depth in the tree configuration and providing an estimate on a transmitted signal.09-17-2009
20090232230METHOD FOR OFDM AND OFDMA CHANNEL ESTIMATION - This invention discloses a method for OFDM and OFDMA channel estimation via phase-rotated polynomial interpolation and extrapolation (inter/extra-polation). For complexity reason, polynomial inter/extra-polation is an often considered method for channel estimation in orthogonal frequency-division multiplexing (OFDM) and orthogonal frequency-division multiple access (OFDMA) systems, in which the simplest choice is linear inter/extra-polation. But the performance of this method depends on the accuracy of symbol timing estimation as well as the channel delay spread. The invention mitigates the problem by adding a linear phase factor to polynomial inter/extra-polation, which corresponds to adding a delay (also called delay shift) in the time domain.09-17-2009
20090232229DEVICE, SYSTEM, AND METHOD OF RESOURCE ALLOCATION IN A WIRELESS NETWORK - Device, system, and method of resource allocation in a wireless network. Embodiments include optimal space-frequency architectures for very high peak rates in wireless systems. For example, an apparatus for wireless communication in a power-limited, very wideband system includes a wireless communication device having a media access controller (MAC) and a physical layer (PHY) that are adapted for a multiple-input-multiple-output (MIMO) orthogonal frequency-division multiple access (OFDMA) communication scheme; a plurality of antennas, operationally coupled to said device, to send and receive wireless communication signals according to the MIMO-OFDMA communication scheme; and a resource allocator, to allocate transmission resources of the device into desired MIMO channels optimized according to at least one of signal-to-noise ratio (SNR), bandwidth, number of users, and signal-to-noise-plus-interference ratio (SINR).09-17-2009
20090046794MULTI-INPUT MULTI-OUTPUT COMMUNICATION DEVICE, ANTENNA DEVICE AND COMMUNICATION SYSTEM - A multi-input multi-output communication device can communicate with other communication device. The multi-input multi-output communication device includes: an antenna device configured to perform communication using a plurality of polarized waves; a transmitting circuit configured to divide data to be transmitted into a plurality of data streams, and transmit the data by multiplexing signals corresponding to the data streams on the plurality of polarized waves from the antenna device; and a receiving circuit configured to receive data by separating signals multiplexed at the other communication device from a signal received by the antenna device via the plurality of polarized waves.02-19-2009
20090046793METHOD AND SYSTEM FOR SELECTIVE USE OF CONTROL CHANNEL ELEMENT BASED IMPLICIT POINTING - A method for selective use of control channel element (CCE)-based implicit pointing. The method includes the step of determining whether a number of multiple user elements (UE) within a multi-user multiple-input multiple-output (MU-MIMO) group is greater than the number of resource blocks allocated to the MU-MIMO group. If the number of UEs in the MU-MIMO group is greater than the number of resource blocks allocated to the MU-MIMO group, the method further includes transmitting to each of the UEs of the MU-MIMO group acknowledgements on acknowledgement channels within a first acknowledgement bank and acknowledgements on acknowledgement channels within a second acknowledgement bank. A first portion of the UEs of the MU-MIMO group receives the acknowledgements on the acknowledgement channels within the first acknowledgement bank and a second portion of the UEs of MU-MIMO group receives the acknowledgements on the acknowledgement channels within the second acknowledgement bank.02-19-2009
20090046791MULTICARRIER RECEIVING APPARATUS, MULTICARRIER COMMUNICATION SYSTEM AND DEMODULATION METHOD - To suppress effects produced on other terminals as much as possible, while obtaining the advantage of soft-combining. A multicarrier receiving apparatus that receives a packet comprised of at least a propagation path estimation symbol and a scrambled information symbol to demodulate, and has propagation path estimating sections 02-19-2009
20090046788Techniques for Reducing Precoding Overhead in a Multiple-Input Multiple-Output Wireless Communication System - A technique of operating a wireless communication device in a multiple-input multiple-output wireless communication system includes receiving, at a first wireless communication device, recommended precoder information from a second wireless communication device, which is associated with a recommended precoder. A precoded signal is then formed at the first wireless communication device based on the recommended precoder or an alternate precoder. The first wireless communication device, which is configured to not provide an indication of whether the recommended precoder or the alternate precoder was utilized to form the precoded signal, then transmits the precoded signal.02-19-2009
20090232231Frequency estimation - For estimating a difference between a frequency of a base station and a locally generated frequency of a mobile equipment in a mobile communications network, wherein at least a signal in a plurality of signals transmitted from the base station and received by the mobile equipment comprises a plurality of symbols each of which includes a cyclic prefix, a correlation between a symbol and its cyclic prefix is used for estimating the frequency difference.09-17-2009
20090310692CHANNEL ACCESS PROTOCOL FOR WIRELESS COMMUNICATION - Method, apparatus, and computer program product embodiments are disclosed to enable an access point in a wireless network to use Orthogonal Frequency-Division Multiple Access (OFDMA) reserve subcarriers of OFDM symbols for transmitting high priority voice data and video data to particular wireless devices, while the access point allocates the remaining available subcarriers for contention-based access by other wireless devices.12-17-2009
20100002788INTERPOLATING METHOD FOR AN OFDM SYSTEM AND CHANNEL ESTIMATION METHOD AND APPARATUS - The present invention provides an interpolating method for an OFDM system, a channel estimation method and apparatus, in which each OFDM symbol has scattered pilots inserted, and the interpolating method comprising: the step of inserting at least one copy of the first scattered pilot in each OFDM symbol before the first scattered pilot as virtual pilots, and inserting at least one copy of the last scattered pilot in each OFDM symbol behind the last scattered pilot as virtual pilots, after obtaining the channel state information on the sub-channels which propagate the scattered pilots in the OFDM symbols by linear filtering; and the step of performing interpolation by a FIR filter with the channel state information.01-07-2010
20090028255METHOD AND SYSTEM FOR COMMUNICATION - A method and a system for communication are presented. In one example embodiment, the method includes the step of receiving a first frame of a communication signal. The first frame includes a first plurality of constituents. One or more constituents of the first plurality of constituents of the first frame form a symbol of the first frame. The method includes the step obtaining a second frame. The second frame includes the first plurality of constituents. One or more constituents of the first plurality of constituents of the second frame form a symbol of the second frame. The symbols of the second frame are obtained by creating redundancies of the constituents of the first plurality of one or more symbols of the first frame. The first frame includes a second plurality of constituents. One or more constituents of the second plurality of the first frame form a preamble field of the first frame. The step of obtaining includes the step of creating redundancies of one or more constituents of the second plurality of constituents at the beginning and/or at boundary(ies) of one or more symbols of the second frame.01-29-2009
20090028253Tone-Interleaved Coded Modulation Scheme for MIMO OFDM Communication - A MIMO OFDM system for TICM is provided. The tone-level interleaver at the transmitter uses a block of N01-29-2009
20090010352CYCLIC REDUNDANCY IN OFDM SYSTEMS - Method, communication system, receiver, baseband processor and computer program for recovering data from a received OFDM-signal containing recurrent redundant information where part of the recurrent redundant information is used to maximize the SINR (Signal to Interference plus Noise Ratio) of the received OFDM-signal.01-08-2009
20090010351SIGNALING METHOD IN AN OFDM MULTIPLE ACCESS SYSTEM - A method for reducing the peak-to-average ratio in an OFDM communication signal is provided. The method includes defining a constellation having a plurality of symbols, defining a symbol duration for the OFDM communication signal, and defining a plurality of time instants in the symbol duration. A plurality of tones are allocated to a particular communication device, and a discrete signal is constructed in the time domain by mapping symbols from the constellation to the time instants. A continuous signal is generated by applying an interpolation function to the discrete signal such that the continuous signal only includes sinusoids having frequencies which are equal to the allocated tones.01-08-2009
20090010350APPARATUS AND METHOD FOR DETECTING SIGNAL USING MULTIVARIATE POLYNOMIAL IN MULTIPLE INPUT MULTIPLE OUTPUT COMMUNICATION SYSTEM - A signal detection apparatus and method in a Multiple Input Multiple Output (MIMO) wireless communication system are provided. The apparatus includes a receiver for receiving training symbol vectors and a data signal vector from a transmitting end through a plurality of receive (Rx) antennas and a detector for expanding the training symbol vectors into second- or higher-order polynomials, for generating a weighting parameter vector for multivariate polynomial expansion of the data signal vector by using the polynomials expanded from the training symbol vectors and thereafter for expanding the data signal vector into a second- or higher-order multivariate polynomial using the weighting parameter vector, and for detecting Transmit (Tx) values of the data signal vector from the multivariate polynomial. Therefore, signal detection performance in a Multiple Input Multiple Output (MIMO) wireless communication system resembles that of a non-linear scheme while complexity resembles that of a linear scheme.01-08-2009
20090010349APPARATUS AND METHOD FOR GENERATING EFFECTIVE SIGNAL TO NOISE RATIO PER STREAM IN A MULTIPLE INPUT MULTIPLE OUPUT WIRELESS COMMUNICATION SYSTEM - An apparatus and method for generating an effective Signal to Noise Ratio (SNR) per stream in a Multiple Input Multiple Output (MIMO) wireless communication system is disclosed. The apparatus includes a selector, a calculator, a generator, and a decider. The selector selects effective streams among whole streams. The calculator calculates a relative SNR rate between the effective streams. The generator generates an equation having as a solution an SNR of a first effective stream. The decider decides an SNR per effective stream using the solution of the equation and the relative SNR rate.01-08-2009
20090010348Decoding Apparatus and Decoding Method - Provided are a decoding apparatus, a decoding method and a receiving apparatus for decoding in a system supporting an OFDM/OFDMA scheme. The decoding method includes the steps of: receiving phase-modulated signal; performing subcarrier demodulation on the received signal and generating correlation metrics; generating decoding metrics using the correlation metrics; and determining a payload using the largest metric of the decoding metrics and at least one of an average metric and the second largest metric of the decoding metrics. The decoding apparatus includes: a receiving buffer for buffering received phase-modulated signal; a likelihood metric generator for generating decoding metrics corresponding to likelihoods of the received signal buffered in the receiving buffer being determined as respective potential payload values; a mean calculator for calculating an average metric; and a payload determiner for determining a payload using the largest metric of the decoding metrics and at least one of an average metric and the second largest metric of the decoding metrics.01-08-2009
20090010347TDS-OFDMA Communication Open-Loop Power Control - In a TDS-OFDM communications system, within a frame time, a transmitted signal comprising a preamble, a downlink sub-frame, and an uplink sub-frame. Within the downlink sub-frame, interposed between sub-frames are guard intervals comprising known sequences. The known sequences are used for an estimation of a received power. A method comprising the step of using a guard sequence in a guard interval of OFDM symbols of the received TDS-OFDM signals in the downlink to estimate a received signal power or an interference power is provided.01-08-2009
20090010345TDS-OFDMA COMMUNICATION CLOSED-LOOP POWER CONTROL - In a TDS-OFDMA communications system, a frame structure comprising: a frame such that within a frame time, a transmitted signal comprising a preamble, a downlink sub-frame, and an uplink sub-frame; and interposed between OFDM symbols are guard intervals comprising known sequences being used for an estimation of a received power.01-08-2009
20090010344METHOD AND SYSTEM FOR MANAGING COMMUNICATION IN AN OFDMA SYSTEM - The present invention provides methods and system for managing communication in an orthogonal frequency division multiple access (OFDMA) system. The method comprises setting at least a first segment as a high power segment for a plurality of base station in the OFDMA system. Further, communication is established between at least one base station and at least one communication device in the OFDMA system, in response to setting the at least first segment as a high power segment. The method further comprises assigning a region of the first segment to a set of base stations in the OFDMA system. The assigned region can be used by the set of base stations at high power level to communicate with communication devices located in overlapping areas. A method for coordinating uplink transmission in the OFDMA system for reducing uplink interference is also provided.01-08-2009
20100080311ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING (OFDM) COMMUNICATIONS DEVICE AND METHOD THAT INCORPORATES LOW PAPR PREAMBLE AND RECEIVER CHANNEL ESTIMATE CIRCUIT - A communications device includes a demapping and demodulation circuit that demaps and demodulates an OFDM communications signal as modulated subcarriers carrying communications data and modulated subcarriers carrying a training sequence forming a preamble that includes a long sync sequence for channel and frequency offset estimation having a extended guard interval (GI). The OFDM subcarriers carrying the training sequence have a quadratic modulation to produce a low peak-to-average power (PAPR) preamble with PAPR of approximately 2.6 decibels (dB). A channel estimate circuit is positioned to receive signals after processing within a FFT circuit and subcarrier demapper circuit and estimates the channel characteristics of the communications channel based on splitting the extended guard interval from the long sync sequence and processing into values that represent the low PAPR preamble as plus or minus one (±1) values in a real or imaginary component as adds and subtracts.04-01-2010
20100086068Communication System, Base Station, Terminal, and Communication Method - A communication system using an OFDM includes a data creation section for coding data to be transmitted and mapping the data, a null symbol insertion section for filling a null symbol into a no-data subchannel if the number of subchannels containing the mapped data is small for the band assignment, and a symbol interleave section for performing symbol interleave in the whole user assignment band and inserting a known training symbol and pilot symbol into the determined symbol position of the user assignment band are included and symbols are placed such that signal phase change is continuous in the same subcarrier between symbols and carrier sense is executed at the positions of the symbols where the signal phase change is continuous.04-08-2010
20100086070USER APPARATUS, BASE STATION APPARATUS, MOBILE COMMUNICATION SYSTEM AND COMMUNICATION CONTROL METHOD - A user apparatus that communicates with a base station apparatus in a mobile communication system includes: a plurality of antennas; a selection unit configured to select an antenna according to a frequency; and a reception unit configured to receive a signal using the antenna selected by the selection unit. The selection unit selects all of the plurality of antennas when the frequency is greater than a predetermined threshold (1 GHz, for example), and the selection unit selects one of the plurality of antennas when the frequency is not greater than a predetermined threshold.04-08-2010
20090154575METHOD AND SYSTEM FOR ADC CALIBRATION IN OFDM SYSTEMS - Aspects of a method and system for ADC calibration in OFDM systems may include receiving a plurality of Orthogonal Frequency Division Multiplexing (OFDM) tones at an OFDM receiver comprising a ping-pong Analog-to-Digital Converter (ADC) and a Fast-Fourier Transform (FFT). A transfer function of the ping-pong ADC may be calibrated via one or more adjustment coefficients at one or more corresponding outputs of the FFT, based on processing of the plurality of the OFDM tones. The plurality of OFDM tones may be received in an OFDM preamble, or the received plurality of OFDM tones may be generated in a calibration signal generator. The output levels of the outputs of the FFT may be equalized to achieve the calibration of the transfer function. The adjustment coefficients may be varied, and said calibrating may be performed dynamically.06-18-2009
20120236953Base Station - A base station of a mobile communication network is described comprising a first receiver configured to receive data transmitted by a communication terminal wherein the received data is to be processed according to a data reception processing for extracting, from the received data, data to be transmitted from the communication terminal; a forwarding circuit configured to forward the received data to a data processing device external to the base station of the mobile communication network for carrying out at least a part of the data reception processing of the received data; and a second receiver configured to receive the processed data from the data processing device.09-20-2012
20110026627METHOD OF TRANSMITTING MIDAMBLE - A method of transmitting a midamble for channel estimation of multiple antennas performed by a base station in a system having segregated uplink and downlink frequency bands is provided. The method includes transmitting midamble information indicating presence of the midamble within a downlink frame to a user equipment (UE), and transmitting the midamble on a single downlink subframe among at least one downlink subframe included in the downlink frame or on a common zone to the UE by using the multiple antennas. A scheduling overhead of a base station and other overheads can be reduced by decreasing the number of transmissions of a midamble on one downlink frame, and thus limited radio resources can be effectively used.02-03-2011
20110026616METHOD AND APPARATUS FOR DOPPLER ESTIMATION IN ORTHOGONAL FREQUENCY-DIVISION MULTIPLEXING (OFDM) - A method and apparatus for estimating Doppler channel in an Orthogonal Frequency-Division Multiplexor. The method includes selecting a continuation pilot, generating a channel estimation, filtering the continual pilot with at least one channel estimator, computing the error between the channel estimation and the filtered channel estimates, averaging the error across continual pilot carriers and over time, estimating noise variance, corrects average error utilizing the estimated noise variance to generate an estimate of the overall channel estimator error, and setting the filter cutoff to minimum estimation error.02-03-2011
20110033000METHOD AND DEVICE FOR MANAGING THE OPERATION OF AN APPARATUS, FOR EXAMPLE AN MB-OFDM APPARATUS, IN PRESENCE OF AN EVENTUAL INTERFERING SIGNAL - According to an embodiment, the method of managing the operation of a first apparatus belonging to a first communication system and adapted to exchange within said first communication system a multi-carriers modulated signal on several sub-carriers, comprises detecting (02-10-2011
20090052567SYNCHRONIZATION SEQUENCE WITH TONE NOTCHING IN OFDM SYSTEMS - The present invention is a system, apparatus, and method for current MB-OFDM systems to design a time-domain sync sequence regarding DAA that (1) minimizes change to the current sync sequence, and (2) maintains the robustness of synchronization. Two tone-notching embodiments are provided for sync sequence design in the preamble when OFDM systems require detect-and-avoid (DAA) ability. The receiver needn't be aware of the change of sync sequence at the transmitter and can still use the original sync sequence. The design can be used in both DAA and non-DAA transmission modes.02-26-2009
20090232236BASE STATION AND MOBILE STATION FOR OFDMA CELLULAR SYSTEM - In a cellular radio communication system, a base station or a mobile station has a TA (Time Alignment)-range-out detection function, so that when a TA-range-out state that is unable to compensate with a guard interval is detected, the transmission condition of an uplink signal at the mobile station is changed by the mobile station autonomously or by the base station and the mobile station cooperatively.09-17-2009
20120128084NETWORK OPTIMIZATION BASED ON USER EQUIPMENT TYPE - A network device may include a first set of components and a second set of components. The first set of components may manage, using a first set of parameters, at least one of uplink radio resources or downlink radio resources for a group of mobile user equipment. The second set of components may manage, using a second set of parameters, at least one of uplink radio resources or downlink radio resources for a group of fixed user equipment. The second set of parameters may be different than the first set of parameters.05-24-2012
20080273612Codebook Method for A Multiple Input Multiple Output Wireless System - A method for wireless encoding includes encoding wireless multiple input and multiple output signals in accordance with a codebook being one of a discrete codebook restricting elements of codebook entries to be within a predetermined finite set of complex numbers and a constant amplitude codebook including each entry in its codebook having equal column norm and equal row norm. In a preferred embodiment the digital codebook further includes restricting elements of a finite set in the discrete codebook to be in the form of k11-06-2008
20100034301METHOD FOR GENERATING AND TRANSMITTING DOWNLINK FRAME - A downlink frame generation device arrange a plurality of synchronization channel symbols and a plurality of broad-casting channel symbols in a common bandwidth of a system so that the symbols may neighbor each other on the time axis. The downlink frame generation device applies a precoding vector to the synchronization channel symbols and the broadcasting channel symbols to generate a plurality of downlink frames corresponding to a plurality of antennas. The precoding vector is variable by a sector for transmitting a plurality of downlink frames and a subframe in which a plurality of synchronization channel symbols are positioned. The precoding vector is independent of an index of a subcarrier.02-11-2010
20100034300Receiver and method for receiving digital signal - The present invention provides a receiver for receiving digital signals including frames with a binary modulated cyclic preamble, comprising: means for correlating at least part of a first cyclic preamble in a first frame and at least part of a second cyclic preamble in a second frame, and for determining a carrier frequency offset based on said correlation.02-11-2010
20100034303DOWNLINK GRANTS IN A MULTICARRIER WIRELESS COMMUNICATION SYSTEM - Aspects describe communicating grant information in a multicarrier wireless communication system. The grant information can be transmitted to mobile devices that have single carrier capability and/or mobile devices that have multicarrier capability. Grant information can be sent in a legacy control region and/or a non-legacy control region.02-11-2010
20080232493COMBINED PRECODING VECTOR SWITCH AND FREQUENCY SWITCH TRANSMIT DIVERSITY FOR SECONDARY SYNCHRONIZATION CHANNEL IN EVOLVED UTRA - A method of providing transmit diversity for a secondary synchronization channel (S-SCH) includes generating a S-SCH signal, performing a frequency switched transmit diversity (FSTD) process on the S-SCH signal to create a first processed signal, performing a precoding vector switching (PVS) process on the first processed signal to create a processed S-SCH signal, and transmitting the processed S-SCH signal.09-25-2008
20080232495METHOD FOR MAPPING PHYSICAL DOWNLINK CONTROL CHANNEL TO RESOURCES AND APPARATUS FOR TRANSMITTING/RECEIVING THE MAPPED PHYSICAL DOWNLINK CONTROL CHANNEL IN A WIRELESS COMMUNICATION SYSTEM - A method for mapping a Physical Downlink Control Channel (PDCCH) to resources and an apparatus for transmitting/receiving the mapped PDCCH in a wireless communication system are provided, in which if at least one PDCCH is scheduled to be transmitted in a subframe according to a predetermined scheduling scheme, the PDCCHs are concatenated, interleaved, and mapped to at least one Resource Element (RE).09-25-2008
20100284476COORDINATION OF PACKET AND ACKNOWLEDGMENT RETRANSMISSIONS - Techniques generally related to a multi-copy transmission scheme are described. A first wireless communication device may transmit X11-11-2010
20110280326METHOD FOR CLUSTERING MULTIPLE STATIONS - A method for clustering multiple stations for a MIMO communication system comprises the steps of: assigning a plurality of stations of a MIMO communication system to a plurality of clusters, wherein each station is assigned to at least one cluster, and at least one cluster is assigned with more than one station; and assigning the plurality of clusters to a plurality of sets, wherein each cluster is assigned to a set.11-17-2011
20110280327APPARATUS FOR TRANSMITTING AND RECEIVING A SIGNAL AND METHOD OF TRANSMITTING AND RECEIVING A SIGNAL - The present invention relates to a method of transmitting and a method of receiving signals, and corresponding apparatus. One aspect of the present invention relates to a method of obtaining a field for indicating a time de-interleaving depth from a layer 11-17-2011
20110280325SPECTRAL-TEMPORAL AVERAGING FOR IEEE 802.11p DYNAMIC CHANNEL EQUALIZATION - A system and method for providing dynamic channel equalization in V2V and V2I communications systems. The method includes separating the channel bandwidth of a message into a plurality of subcarriers having different subcarrier frequencies, where the subcarriers include data subcarriers and pilot subcarriers. The method demodulates the message in the receiver to extract symbols from the message and determines channel estimation frequency responses using a least-squares estimation process and the extracted symbols for the pilot subcarriers. The channel estimation frequency responses of either the pilot subcarriers, the pilot subcarriers and some data subcarriers, or the pilot subcarriers and all data subcarriers are used to generate updated channel estimation frequency responses, and a new channel estimation frequency response is generated for each extracted signal using a previous channel estimation frequency response and the updated channel estimation frequency response. The extracted symbols are equalized using the new channel estimation frequency response.11-17-2011
20100195748METHOD AND SYSTEM FOR REFERENCE SIGNAL PATTERN DESIGN IN RESOURCE BLOCKS - A base station is provided. The base station comprises a downlink transmit path comprising circuitry configured to transmit a plurality of reference signals in two or more resource blocks. Each resource block comprises S OFDM symbols. Each of the S OFDM symbols comprises N subcarriers, and each subcarrier of each OFDM symbol comprises a resource element. The base station further comprises a reference signal allocator configured to allocate the plurality of reference signals to selected resource elements of the two or more resource blocks according to a reference signal pattern. A same pre-coding matrix is applied across the two or more resource blocks.08-05-2010
20090074094BEACON SYMBOLS WITH MULTIPLE ACTIVE SUBCARRIERS FOR WIRELESS COMMUNICATION - Techniques for transmitting information using beacon symbols in a wireless communication system are described. In one design, a transmitter may map information to multiple subcarriers among a plurality of subcarriers, with the information being conveyed by the position of the multiple subcarriers. The transmitter may map the information to at least one non-binary symbol. The transmitter may then determine each of the multiple subcarriers based on one non-binary symbol or may determine all of the multiple subcarriers based on one non-binary symbol. The transmitter may generate a beacon symbol having the information mapped to the multiple subcarriers. The transmitter may use higher transmit power for the multiple subcarriers to allow receivers with low geometry to reliably receive the information. The use of multiple subcarriers may allow more information to be sent in the beacon symbol and may also improve frequency diversity.03-19-2009
20090154577Determination of Pre-Coding Matrix Indicators for Spatial Multiplexing in a Mobile Communications System - A pre-coding matrix is determined in an OFDMA, multiple transmit antenna communication system having a number of sub-carriers grouped into a number, M, of resource blocks. This involves determining a frequency selectivity of a channel through which received signals have propagated. A number N of selected resource blocks is then determined as a function of the frequency selectivity the N selected resource blocks being those for which pre-coding matrices will be determined, wherein N06-18-2009
20110026619 METHOD AND SYSTEM FOR DOPPLER SPREAD AND DELAY SPREAD MATCHING WITH CHANNEL ESTIMATION BY CIRCULAR CONVOLUTION IN OFDM COMMUNICATION NETWORKS - A mobile device in an OFDM system receives an OFDM signal comprising RS tones and data OFDM symbols. The received RS tones are extracted and utilized to perform channel estimation. The resulting raw channel estimates are time filtered by matching channel time variance measured in frequency domain and in time domain, respectively. The measured channel time variance comprises inter-carrier interference measurement and Doppler spread measurement. Mean of differences between neighbor adjacent subcarriers of the extracted RS tones is used for inter-carrier interference measurement. Autocorrelation functions of the raw channel estimates are evaluated for the Doppler spread measurement using, for example, level crossing and/or axis crossing based methods. The raw channel estimates are filtered through averaging and/or recursively filtering using time filter parameters determined based on the inter-carrier interference measurement and the Doppler spread measurement. The time filtered channel estimates are utilized for data demodulation.02-03-2011
20090060075OFDM Modem Using Pilot Sub-Carrier Structure - An OFDM modem is presented that uses a pilot sub-carrier signal structure for channel estimation to reduce link latency of the modem, or alternatively, a pseudo-random number sequence inserted into the OFDM signal for later detection for channel estimation. The OFDM signal includes multiple symbols, each symbol having a plurality of closely-spaced, orthogonal data sub-carrier signals carrying data. In some implementations, one or more pilot sub-carrier signals are inserted with the data sub-carrier signals. Each pilot sub-carrier signal is modulated with a predetermined pilot modulation scheme. Each pilot sub-carrier signal is placed at a different sub-carrier signal location for each successive symbol duration of the OFDM signal to form a sliding pilot sub-carrier signal.03-05-2009
20100008433METHOD AND APPARATUS FOR ADVANCED INTER-CARRIER INTERFERENCE CANCELLATION IN ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING (OFDM) CHANNELS - A method of estimating a time variant Orthogonal Frequency Division Multiplexing (OFDM) while eliminating Inter-carrier Interference (ICI) is disclosed, where the time variant channel matrix is estimated at channel taps using a Basis Expansion Model (BEM). The BEM method decomposes the time variant channel into a group of basis functions in the frequency domain. Coefficients are estimated using a sub-space tracking algorithm that decreases the dimensions of the coefficient matrix allowing for simpler calculation of the estimated signal. The coefficients matrix is estimated using a conjugate gradient iterative method that may be stopped after 6-8 iterations to arrive at an acceptable estimation. Finally, the transmitted data is estimated, again using the conjugate gradient method iteratively, wherein the conjugate gradient method is stopped after a small number of iterations.01-14-2010
20090003479Method and Device for Estimating Channel of Uplink Signal in Wireless Communication System - Provided are a method and device for estimating a channel in a wireless communication system, and more particularly, a method of estimating a channel of an uplink signal in an orthogonal frequency division multiplexing (OFDM)/orthogonal frequency division multiple access (OFDMA) communication system supporting the Institute of Electrical and Electronics Engineers (IEEE) 802.16d/e standards and a channel estimation device employing the method. The method includes the steps of: extracting pilot symbols included in the received signal and estimating linear phase values using the pilot symbols; interpolating the pilot symbols along a time axis and obtaining first channel responses; interpolating the pilot symbols along a frequency axis according to the first channel responses and obtaining second channel responses; and calculating channel estimation values using the second channel responses and the linear phase values.01-01-2009
20090022237SYMBOL INTERLEAVING AND CHANNEL MAPPING DEVICE AND METHOD AND MOBILE COMMUNICATION SYSTEM - The present invention discloses a symbol interleaving and channel mapping device and method as well as a mobile communication system. The symbol interleaving and channel mapping device is used in a transmitter of a mobile communication system, said transmitter receiving the channel state information fed back from a receiver of the mobile communication system; the symbol interleaving and channel mapping device comprises a symbol classification unit for classifying symbols according to their importance; a symbol sub-carrier mapping unit for performing a sub-carrier mapping according to the classification result of said symbol classification unit and the channel state information such that the important symbols correspond to the non deep fading sub-carrier as much as possible.01-22-2009
20090296834TIME DIVISION SYNCHRONOUS ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING SUPPORTING FREQUENCY DIVISION MULTIPLE ACCESS - A method of time domain synchronous orthogonal frequency division multiplexing (TDS-OFDM) communication, including the steps of: preparing OFDM-body 12-03-2009
20090310690METHODS AND SYSTEMS OF AGC AND DC CALIBRATION FOR OFDM/OFDMA SYSTEMS - Methods and apparatus for automatic gain control (AGC) and DC calibration for orthogonal frequency-division multiplexing (OFDM) or orthogonal frequency division multiple access (OFDMA) systems are provided in an effort to avoid saturation of the analog-to-digital converter (ADC) in a radio frequency (RF) front end of a receiver, to handle dynamic received signal power, or to avoid interruptions in a communication link for DC calibration. For certain embodiments, the quantization error in the RF front end may also be decreased.12-17-2009
20110142145METHOD FOR ESTIMATING FREQUENCY OFFSET IN ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING SYSTEM - Provided is a method for estimating a frequency offset. The method for estimating the frequency offset may include calculating autocorrelation values associated with a Cyclic Prefix (CP) for a reception signal, dividing the calculated autocorrelation values into first autocorrelation values associated with an interval where a signal exists and second autocorrelation values associated with an interval where a signal does not exist, determining whether to use the divided second autocorrelation values; and estimating the frequency offset using the second autocorrelation values determined to be used and the first autocorrelation values.06-16-2011
20090207926ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING USING SUBSYMBOL PROCESSING - In one embodiment, a transmitter converts digital input data into combined-OFDM signals and a receiver recovers data from the transmitted combined-OFDM signals. For transmission, digital data is mapped into data symbols using a commonly known modulation technique, such as QAM or DQPSK. The data symbols are subsequently divided into two or more groups according to a specified grouping pattern. Each group of data symbols is then converted into a separate OFDM subsymbol using IFFT processing. The OFDM subsymbols are then combined according to a specified combining pattern to create a combined-OFDM symbol. Combined-OFDM symbols are then prepared for transmission by affixing cyclic prefixes, converting the symbols to analog format, and performing spectral shaping of the analog signal. Upsampling may be employed to increase the signal bandwidth. In alternative embodiments, OFDM subsymbols may be combined using interleaving to create an interleaved-OFDM symbol.08-20-2009
20090207929COMMUNICATION METHOD, AND TRANSMITTING APPARATUS AND RECEIVING APPARATUS USING THAT COMMUNICATION METHOD - A transmission method for transmitting an orthogonal frequency division multiplexing signal. The method includes composing a plurality of carrier groups each including one or more subcarriers and assigning transmission data for a plurality of transmission destination terminals, to the plurality of carrier groups, on a basis of one carrier group for one transmission destination terminal basis. The method further includes selecting, for each of the carrier groups, one of a first frame configuration where the transmission data is transmitted using one modulated signal, and a second frame configuration where the transmission data is transmitted using a plurality of modulated signals and transmitting the assigned transmission data of the plurality of transmission destination terminals at a same time on a time axis.08-20-2009
20090207928Training symbol format for adaptively power loaded MIMO - Training symbol formats are provided for use in a MIMO based wireless communication system that uses adaptive power loading. In at least one embodiment, a training symbol format is used that is capable of enhancing training symbol signal to noise ratio (SNR).08-20-2009
20090207925Wireless communication system, OFDM communication apparatus and method thereof - A wireless communication system adapted for the IEEE 802.11 or IEEE 802.16 standard comprises a radio frequency (RF) receiver, an analog-to-digital converter (ADC), and an OFDM communication apparatus. The RF receiver receives a radio signal. The ADC converts the radio signal to a digital signal. The OFDM communication apparatus comprises a digital filter, a notch filter, a fast Fourier transform (FFT) processor, and a detection element. The digital filter processes the digital signal to generate a processed digital signal. The notch filter filters out interference of the processed signal to generate a notched signal according to a filter band. The FFT processor performs an FFT process on the notched signal to generate an FFT signal according to the processed digital signal. The detection element generates the filter band of the notch filter according to the FFT signal.08-20-2009
20090207924NON-INTRUSIVE METHOD AND SYSTEM FOR COUPLING POWERLINE COMMUNICATIONS SIGNALS TO A POWERLINE NETWORK - A powerline system including non-intrusive coupling for powerline communications. The system has a powerline module couple to a data connection. In a specific embodiment, the powerline module is configured to process a first data signal in a first format to a second data signal in a second format, which is an OFDM format capable of being configured for transmission through one or more powerline cables. The system has a physical socket coupled to the powerline module. In a specific embodiment, the physical socket has a female connector device, which includes at least a first connector and a second connector. In a specific embodiment, the first connector and the second connector are electrically coupled to the second data signal in the second format. The system also has a male connector device, which is inserted into the female connector device. The male connector includes at least a first male connector and a second male connector are coupled respectively to the first connector and the second connector. In a specific embodiment, a first wire coupled to the first male connector and a second wire coupled to the second male connector. In a preferred embodiment, the system includes a twisted pair of wires including at least the first wire and the second wire. Preferably, the twisted pair of wires extend from the male connector and have a length of no greater than fifty feet, but can be other lengths depending upon the specific embodiment.08-20-2009
20100158147UPLINK POWER HEADROOM REPORTING FOR CARRIER AGGREGATION - A method for reporting power headroom is disclosed. Power headroom may be reported across all carriers (wideband), for a specific carrier, or for a carrier group. The formula used to calculate the power headroom depends on whether the carrier (or a carrier in the carrier group) has a valid uplink grant. If the carrier or carrier group does not have a valid uplink grant, the power headroom may be calculated based on a reference grant. The power headroom is calculated by a wireless transmit/receive unit and is reported to an eNodeB.06-24-2010
20090213948ADAPTIVE TWO-DIMENSIONAL CHANNEL INTERPOLATION - A method and apparatus for improving channel estimation within an OFDM communication system. Channel estimation in OFDM is usually performed with the aid of pilot symbols. The pilot symbols are typically spaced in time and frequency. The set of frequencies and times at which pilot symbols are inserted is referred to as a pilot pattern. In some cases, the pilot pattern is a diagonal-shaped lattice, either regular or irregular. The method first interpolates in the direction of larger coherence (time or frequency). Using these measurements, the density of pilot symbols in the direction of faster change will be increased thereby improving channel estimation without increasing overhead. As such, the results of the first interpolating step can then be used to assist the interpolation in the dimension of smaller coherence (time or frequency).08-27-2009
20130022140TRANSMISSION DEVICE, RECEIVING DEVICE, INFORMATION TRANSMISSION METHOD, INFORMATION RECEIVING METHOD IN WIRELESS COMMUNICATION SYSTEM, AND RECORDING MEDIUM - The present invention relates to a transmission device, a receiving device, an information transmission method, and an information receiving method in a wireless communication system, and a recording medium in which data of a codebook used for transmitting and receiving information is recorded.01-24-2013
20120099666Method and Arrangement for Adapting a Signal in a Wireless Communications Network - According to an aspect of the present invention, the power efficiency of a precoded OFDM signal is improved by a method in a network node 04-26-2012
20120099665DATA PROCESSING APPARATUS AND METHOD - A data processor maps input symbols to be communicated onto a predetermined number of sub-carrier signals of an Orthogonal Frequency Division Multiplexed (OFDM) symbol. The data processor includes an interleaver memory which reads-in the predetermined number of data symbols for mapping onto the OFDM sub-carrier signals. The interleaver memory reads-out the data symbols on to the OFDM sub-carriers to effect the mapping, the read-out being in a different order than the read-in, the order being determined from a set of addresses, with the effect that the data symbols are interleaved on to the sub-carrier signals. The set of addresses are generated from an address generator which comprises a linear feedback shift register and a permutation circuit.04-26-2012
20110299613METHOD AND APPARATUS FOR PROVIDING A BIT MASKED HEARTBEAT SIGNAL - An apparatus and method of providing a bit masked heartbeat signal across a digital communication network to a plurality of managed devices, said method comprising the steps of: providing a state value for each one of said managed devices; generating a heartbeat packet comprising state data that incorporates said state value of each one of said managed devices; and transmitting said heartbeat packet to each one of said managed devices.12-08-2011
20110299615SYSTEMS FOR PROCESSING DIFFERENTIATED HIERARCHICAL MODULTATION USED IN RADIO FREQUENCY COMMUNICATIONS - The present invention employs hierarchical modulation to simultaneously transmit data over different modulation layers using a carrier RF signal. Each modulation layer may be of a higher or lower order than the other modulation layers. Certain embodiments of the present invention may transmit different information on the different modulation layers. Other embodiments of the present invention may use the different layers for processing information differently.12-08-2011
20110299614METHOD AND APPARATUS FOR TRANSMITTING AND RECEIVING SIGNAL FROM RELAY STATION IN RADIO COMMUNICATION SYSTEM - A method for a transmitting and receiving a signal from a relay station in a radio communication system is provided. The method comprises the steps of: receiving offset time information from a base station; configuring a time difference between an access downlink transmission subframe that transmits an access downlink signal to a relay station terminal according to the offset time information and a backhaul downlink reception subframe that receives a backhaul downlink signal from the base station; transmitting a control signal from the access downlink transmission subframe to the relay station terminal; and receiving the backhaul downlink signal from the base station in the backhaul downlink reception subframe.12-08-2011
20110299612UNCONTROLLED SPATIAL MULTIPLE ACCESS IN WIRELESS NETWORKS - An uncontrolled spatial multiple access system and method facilitating spatial multiple access for multiple devices in a wireless local-area network (WLAN). Embodiments of the system and method increase throughput of the wireless network by facilitating concurrent encoded frame transmission. Decoding of the quasi-overlapped frames is achieved using a chain decoding technique that takes data streams (or signals) containing the quasi-overlapping encoded frames and isolates each encoded frame so that the frame can be decoded. Quasi-overlapped frames means that the frames are overlapped in the body of the frame but not at the preamble (or headers) of the frames. Embodiments of the chain decoding also use interference nullifying and interference cancelation to enable concurrent quasi-overlapping transmission. A carrier counting multiple access technique of embodiments of the system and method allow wireless networks to retain their asynchronous nature while supporting spatial multiple access and maintain backwards compatibility with the IEEE 802.11 standard.12-08-2011
20080273611Equalization for Zero Prefix Ofdm Systems - The system, apparatus, and method (11-06-2008
20090175374Multiple-Input Multiple-Output Transmission System - In a multiple-input multiple-output transmission system (MIMO system), a receive station detects whether or not there is an error in each data stream, estimates the state of the propagation path of each transmit antenna and reports, to the transmitting side, re-transmission necessary/unnecessary information, for every data stream, created based upon whether or not there is an error, and the state of the propagation path of each transmit antenna. A transmit station decides a transmit antenna that transmits a data stream requiring re-transmission, based upon the reported state of the propagation path of each transmit antenna, and re-transmits the data stream requiring re-transmission from the transmit antenna decided.07-09-2009
20100215110PRECODING CODEBOOK DESIGN FOR SINGLE USER MIMO - A transmitter is for use with multiple transmit antennas and includes a precoder unit configured to precode data for a transmission using a precoding matrix selected from a codebook, wherein the codebook corresponds to the following three transmission properties for an uplink transmission: 1) all precoding elements from the precoding matrix have a same magnitude, 2) each precoding element from the precoding matrix is taken from a set of finite values and 3) there is only one non-zero element in any row of the precoding matrix. The transmitter also includes a transmit unit configured to transmit the precoded data.08-26-2010
20090202009WIRELESS COMMUNICATIONS APPARATUS - Allocation of subcarriers of a wireless communications channel to antennas for transmission of said subcarriers from a multi-antenna transmitter, comprises selecting, for each subcarrier, the antenna with the most effective transmission performance against a predetermined performance criterion; and determining if subcarriers are evenly distributed amongst said antennas. If even distribution does not arise, then a reallocation sequence is performed. This comprises identifying, for an antenna having excessive subcarriers allocated thereto, the subcarriers allocated thereto and reallocating one of said subcarriers as required, said reallocated subcarrier being selected for reallocation on the basis of its impact on transmission performance.08-13-2009
20090202010SUB-CARRIER ALIGNMENT MECHANISM FOR OFDM MULTI-CARRIER SYSTEMS - A method of aligning sub-carriers of radio signals of two adjacent frequency channels and devices therefor are described. The method comprises aligning a first plurality of sub-carriers of a first radio signal and a second plurality of sub-carriers of a second radio signal within an overlapped frequency region in-between the two adjacent frequency channels by shifting a center frequency of the first radio signal with a frequency offset. The first radio signal and the second radio signal are adapted for transmission over the two adjacent frequency channels and the first frequency channel is one of the two adjacent frequency channels.08-13-2009
20110135021CHANNEL STATE INFORMATION COMPRESSING APPARATUS AND METHOD, CHANNEL STATE INFORMATION EXPANDING APPARATUS AND METHOD, COMPUTER PROGRAMS, RECEIVER, AND TRANSMITTER - A channel state information compressing apparatus includes a time-to-frequency region converter that converts a region for channel state information which indicates a state of each communication channel from a time region to a frequency region; and an adaptive selector that selects each frequency component to be included in compressed data based on electric power of the frequency component from among frequency region data obtained by the time-to-frequency region converter. The channel state information compressing apparatus outputs the compressed data consisting of each selected frequency component, and information for identifying each frequency component which forms the compressed data.06-09-2011
20110293029Tone count selection - In a device or system, a total tone count is determined or selected for modulating a data payload. Two or more code words are interleaved into the data payload, and the data payload is transmitted on a channel of the device or system.12-01-2011
20120014467 Method of and Equipment For Compensating Carrier Frequency Offset in an Orthogonal Frequency Division Multiplexing Wireless Radio Transmission System - For compensating carrier frequency generation in communication equipment for radio transmission in an Orthogonal Frequency Division Multiplex, OFDM, based wireless radio communication system, in which reference signals known communication equipment are transmitted in a regular time repetitive manner, carrier frequency generation is compensated (01-19-2012
20120014466METHOD AND COMMUNICATION SYSTEM DEVICE FOR THE GENERATION OR PROCESSING OF FODM SYMBOLS IN A TRANSMISSION SYSTEM WITH SPREAD USSER DATA - OFDM symbols are generated using data from one or more users or from one or more data sources represented on a number of sub-carriers. To inhibit multiple-access interference on application of the CDMA principle, the data are transformed in a data-source specific manner and only subsequently allocated to the sub-carriers, independently of the transformation.01-19-2012
20110293028METHOD AND SYSTEM FOR REDUCED COMPLEXITY CHANNEL ESTIMATION AND INTERFERENCE CANCELLATION FOR V-MIMO DEMODULATION - A method and system for wireless communication in a wireless communication network. The wireless communication network has a first mobile terminal and a second mobile terminal arranged in virtual multiple input, multiple output (“V-MIMO”) communication with a base station. A first wireless communication uplink channel corresponding to the first mobile terminal is estimated. The estimate is based on a first reference symbol signal and the cancellation of interference from a second reference symbol signal received from the second mobile terminal. A second wireless communication uplink channel corresponding to the second mobile terminal is estimated. The estimate is based on the second reference symbol signal and the cancellation of interference from the first reference symbol signal received from the first mobile terminal. The estimated first wireless communication uplink channel is used to demodulate a first data signal received from the first wireless device, and the estimated second wireless communication uplink channel is used to demodulate a second data signal received from the second wireless device.12-01-2011
20110293027ADJUSTABLE OPERATIONAL STATE WIRELESS MIMO - Wireless devices capable of one or more of extended multiple input multiple output (MIMO), dual bonded, and dual concurrent operation are disclosed. Methods for switching between the operational states for wireless devices capable of multiple operational states are also disclosed.12-01-2011
20110293026METHOD FOR THE BLIND ESTIMATION OF OFDM MODULATION PARAMETERS ACCORDING TO A MAXIMUM LIKELIHOOD CRITERION - The present invention relates to a method for blind estimation of at least one parameter of an OFDM signal according to a maximum likelihood (ML) criterion. In one embodiment, the estimation method uses a deterministic maximum likelihood criterion. In another embodiment, the estimation method assumes that the modulation symbols modulating the sub-carriers of the OFDM multiplex are i.i.d. and Gaussian random variables. The estimation of said parameter is carried out while minimizing a cost function depending on the chosen criterion.12-01-2011
20110293025SYSTEMS AND METHODS FOR INTRA COMMUNICATION SYSTEM INFORMATION TRANSFER - Systems and methods which provide for reduced intra communication system information transfer by providing a compressed representation of a portion of intra communication system information are shown. An embodiment operates to provide intra communication system transfer of uncompressed received information while providing intra communication system transfer of a compressed representation of information ancillary to the received information. According to embodiments, ancillary information, such as CSI, associated with other transferred information is transferred with reduced data throughput requirements through application of compression techniques with respect to the transferred ancillary information. Embodiments additionally or alternatively reduce the intra communication system information transferred by reducing the received information transferred.12-01-2011
20110293024METHOD FOR INCREASING THE PERFORMANCE OF A COMMUNICATIONS SYSTEM ON A MEDIUM FORMED BY MULTIPLE CONDUCTORS - Method for increasing the performance of a communications system on a medium formed by multiple conductors which increases the performance of a communications system by means of the creation of numerous communication channels with a high degree of isolation between each other on the same physical medium formed by multiple conductors. The method can be extended to be used in various applications, such as the reuse of frequencies on the same channel, the increase of the capacity of the point-to-point links in a network and the improvement of performance and reliability when used with digital processing of signals for transmission or reception, among others.12-01-2011
20100322332Systems and Methods for Code Sequence Extension Over Transmission in Wireless Communication Environments - A transmitter for transmitting signals to a receiver is provided. The transmitter generates a padded code sequence comprising a plurality of symbols. The padded sequence is generated by padding the first symbol to the end of a code sequence. The padding method can be applied to Zadoff-Chu code, generalized chirp like code, CAZAC sequence to acquire extra code property, e.g. orthogonal in terms of differential detection. The padded code sequence can be allocated on sub-carriers of an OFDM symbol in frequency domain in increasing or decreasing order to resist linear phase shift due to time domain delay. If multiple OFDM symbols are used, the padded code sequence may be divided into multiple sections and each section may be padded in the same padding manner. Latter on, the transmitter transmits the padded code sequence to a receiver via an air interface. Upon receiving the padded code sequence via the air interface, the receiver may detect the padded sequence according to its structure, e.g. differential detection.12-23-2010
20090279626Method and System for Adaptive Orthogonal Frequency Division Multiplexing Using Precoded Cyclic Prefix - A method for adaptive signal communication on a wireless or wireline network is disclosed including detecting the communication environment or determining the communication requirements, for communication on the wireless or wireline network. The method may include determining system parameter information for adaptive Orthogonal Frequency Division Multiplexing (OFDM) based on the communication environment or communication requirements and encoding the system parameter information into at least one precoded cyclic prefix (PCP) sequence. The method further provides for generating an OFDM symbol transmission by combining at least one PCP, and an adaptive OFDM symbol, using the system parameters, then transmitting the signal from at least one OFDM transmitter to at least one OFDM receiver followed by demodulating the at least one PCP, and demodulate the OFDM signal using the system parameters recovered. A related OFDM system for implementing the method for a wireless or wireline network or platform is disclosed as are wireless or wireline devices operable with this method.11-12-2009
20090060066Communication system and method for transmitting signals to a plurality of different types of receivers - A communication system and method of communicating signals to a plurality of different types of receivers is provided. The communication system includes at least one transmitter that transmits high priority and low priority signals as a single frequency network. At least one satellite receives and re-transmits at least one of the high priority and low priority signals. At least one terrestrial repeater is in communication with the at least one transmitter, and receives from the at least one transmitter and re-transmits at least one of the high priority and low priority signals. A plurality of receivers includes at least a first receiver configured to process the high priority signal to emit an output signal based upon the high priority signal, and a second receiver configured to process the high priority and low priority signals to emit an output signal based upon the high priority and low priority signals.03-05-2009
20100135421APPARATUS AND METHOD FOR REDUCING PEAK TO AVERAGE POWER RATION IN ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING SYSTEM - An apparatus for reducing PAPR (Peack to Average Power Ratio) in an OFDM (Orthogonal Frequency Division Multiplexing) system includes: an IFFT (Inverse Fast Fourier Transform) unit for performing an IFFT on an input data stream modulated using a specific constellation to generate time-domain signals; a time-domain clipping unit for performing a time-domain clipping on the time-domain signals at a clipping level determined by characteristics of the time-domain signals; an FFT (Fast Fourier Transform) unit for performing an FFT on the clipped time-domain signals to generate frequency-domain signals; and a frequency-domain clipping unit for performing a frequency-domain clipping on the frequency-domain signals. The time-domain clipping reduces in the OFDM system, and the frequency-domain clipping reduces distortions generated by the time-domain clipping.06-03-2010
20090122885Low noise differential charge amplifier for measuring discrete charges in noisy and corrosive environments - A low noise differential charge amplifier circuit for measuring discrete (e.g., pico coulomb) charges in noisy, elevated temperature and corrosive environments. An input stage of a differential charge amplifier circuit includes a twisted and or untwisted two pair cable with a grounded shield. One twisted and or untwisted pair can be connected to a sensor and a first charge amplifier and a second twisted and or/untwisted pair can be connected to a sensor electrical equivalent impedance circuit and or kept open and a second charge amplifier. The output from the charge amplifiers can be directed to a differential amplifier in order to provide an amplified sensor signal without external noise signal mainly from power supply mains. The differential amplifier and the charge amplifiers can include an auto offset correction circuit to reduce errors due to offsets.05-14-2009
20090103643HUMAN BODY COMMUNICATION METHOD USING MULTI-CARRIER MODULATION METHOD - Provided is a human body communication method using a multi-carrier modulation method, in which users do not interfere with each other in an environment with several users, and stable communication is possible when users are exposed to strong interference generated at other electronic devices. Also, provided are a multi-carrier modulation method, in which data between communication devices connected to a human body used as a channel is divided into a plurality of sub-channels and the data is transmitted by loading it on each of a plurality of sub-carrier signals, and a multi-connection method using the multi-carrier modulation method. The plurality of sub-channels having a predetermined bandwidth include several sub-carriers, and by changing a modulation method applied to the sub-carriers, stable communication can be realized.04-23-2009
20090103641MAXIMUM LIKELIHOOD DECODING METHOD, EQUIPMENT, AND RECEIVER - Provided is a maximum likelihood decoding method of separating and estimating multiple transmitted signals transmitted by multiple transmitter antennas from multiple received signals received by multiple receiver antennas, comprising: a first step of generating a channel matrix based on channel impulse responses corresponding to the received signals; a second step of dividing the generated channel matrix into multiple sub-matrices, of identifying parts of the received signals corresponding to the sub-matrices obtained through the division, and of transforming the sub-matrices obtained through the division, by using inverse matrices of the sub-matrices obtained through the division; a third step of applying QR decomposition to the transformed sub-matrices to obtain triangular matrices, and of transforming the received signals of the parts by using the obtained triangular matrices; and a fourth step of determining one combination candidate for the parts of the transmitted signals corresponding to the transformed received signals.04-23-2009
20110286541Method for Transmitting a Midamble in a Radio Communication System - A method for transmitting a midamble in a radio communication system is provided. The method includes: allocating a radio resource of a carrier for the midamble, and transmitting the midamble by using the allocated radio resource, wherein the carrier includes a used band allocated for transmitting a signal and a guard band allocated for preventing interference from occurring in the used band, and the midamble is allocated to a radio resource including the guard band. Accordingly, a midamble which can be used in both a user equipment operating at a narrow band and a user equipment operating at a wide band can be transmitted when a radio communication system is in a multi-carrier mode. Further, the midamble can be transmitted also in a guard band, thereby improving accuracy of channel estimation.11-24-2011
20090003474CONSTANT MODULUS MIMO PRECODING FOR CONSTRAINING TRANSMIT ANTENNA POWER FOR DIFFERENTIAL FEEDBACK - A method and apparatus for constraining power amplifier (PA) imbalance includes using a constant modulus (CM) criterion to ensure PA balance when using differential feedback.01-01-2009
20090316806METHODS AND SYSTEMS FOR UTILIZING A MULTICAST/BROADCAST CID SCHEDULING MAC MANAGEMENT MESSAGE - Methods and systems for utilizing a multicast/broadcast connection identifier (CID) scheduling message in an orthogonal frequency-division multiplexing (OFDM) or orthogonal frequency division multiple access (OFDMA) frame in an effort to bypass at least a portion of the Media Access Control (MAC) protocol data unit (PDU) parsing of the frame are provided. By bypassing at least a portion of the MAC PDU parsing of the OFDM/OFDMA frame (which may be in accordance with one or more standards of the IEEE 802.16 family of standards), a particular user terminal need not spend a lot of overhead in the CID filtering process, determining which MAC PDUs are intended to be processed by the MAC of that particular user terminal. Furthermore, for certain embodiments, a user terminal may power down related circuitry during the terminal's bypassing time period(s) of the OFDM/OFDMA frame in an effort to save power.12-24-2009
20100142631PORTABLE COMMUNICATIONS DEVICE WITH DEMODULATION CORRECTION AND RELATED METHODS - A portable communications device communicates based upon constant envelope orthogonal frequency-division multiplexing (CE-OFDM). The portable communications device may include an antenna for receiving a CE-OFDM signal, and a receiver coupled to the antenna. The receiver may include a frequency domain equalizer (FDE) operating based upon a channel estimate of the received CE-OFDM signal, a non-linear function block coupled to and downstream from the FDE, and a demodulation correction block coupled to and downstream from the non-linear function block for correcting an output of the non-linear function block.06-10-2010
20100239032SYSTEM AND METHOD FOR PRECODING AND DATA EXCHANGE IN WIRELESS COMMUNICATION - A method for a first user terminal to receive data from a second user terminal, wherein the first and second user terminals communicate with a transmitting terminal. The method includes: transmitting a first message to the transmitting terminal; receiving a signal from the transmitting terminal, the received signal including information regarding the first message and a second message transmitted from the second user terminal to the transmitting terminal; and decoding, based on the first message, the received signal to receive the second message.09-23-2010
20080279292WIRELESS COMMUNICATION APPARATUS AND METHOD - The wireless transmission apparatus generates one or a plurality of Orthogonal Frequency Division Multiplexing (OFDM) symbols for channel estimation, each OFDM symbol including plural subcarriers and having a known signal sequence of known signals which are linearly independent between adjacent subcarriers, and transmits the OFDM symbols.11-13-2008
20110188586SCALABLE HIGH SPEED MIMO-SATELLITE COMMUNICATION SYSTEM - This invention provides satellite communication systems and methods that employ a satellite in MIMO communication with a geographically-distributed array of ground nodes. In an embodiment, the satellite communication system includes a MIMO satellite configured to receive first information at a higher bandwidth, process the first information into lower bandwidth signals, and relay the lower bandwidth signals using a satellite communication link. The geographically-separated ground nodes receive the lower bandwidth signals and transmit terrestrial signals using high-speed communication links. A central processing node receives the terrestrial signals over the high-speed communication links and combines the terrestrial signals to obtain the higher data rate signals.08-04-2011
20110007829OPTIMAL TRAINING SEQUENCE AND CHANNEL ESTIMATION METHOD AND SYSTEM FOR SUPERIMPOSED TRAINING BASED OFDM SYSTEMS - The present invention relates to a method for minimizing means square estimation error (MSEE) and bit error rate during channel estimation and equalization between a transmitter and a receiver of an orthogonal frequency division multiplexing (OFDM) systems. The method comprises transmitting from said transmitter to said receiver a training sequence for channel estimation being superimposed onto data at specific pilot to data power ratio (PDPR), receiving the OFDM signals along with the training sequence as an input, cross-correlating said received signal to a specific lag determined by the rms delay spread of the channel, with a specific known training sequence stored in a register, and which is also the sequence that is added to the data at the transmitter in the time domain having a prescribed pilot to data power ratio. The cross-correlated data being processed over a length of samples which can be extended to exploit the coherence time of the channel and processed along with the stored values of the inverse of autocorrelation values of superimposed training (ST) sequence so as to obtain a reliable least squares based channel estimate in a way the PDPR is limited or otherwise. The invention also relates to a system comprising means for computing a time domain least squares (LS) based channel estimate at the receiver.01-13-2011
20090190679METHOD FOR DETERMINING SYSTEM INFORMATION, AND DECODER, TERMINAL, AND COMPUTER PROGRAM - A method for a terminal of a cellular telecommunication system for determining system information about a node of a network of the telecommunication system is disclosed. The telecommunication system enables determination of the system information by the terminal from information transmitted from at least one cell operated by the node, where the telecommunication system employs Orthogonal Frequency Division Multiple Access. The method comprises receiving a transmission signal, comprising reference symbols and synchronisation symbols, from a network node of the at least one cell; estimating, for each transmit antenna of the network node, a preliminary channel estimate based on the received reference symbols; and estimating a pre-coding vector, being associated with transmission by at least one transmit antenna of the network node of the at least one cell, for the synchronisation symbols. Corresponding features for computer program, decoder and terminal are also disclosed.07-30-2009
20080240261METHOD AND SYSTEM FOR CHANNEL ESTIMATION IN BURST MODE - The present invention is directed to a system and method for channel estimation for a communication channel such as, for example, that found in a wireless communication network. One or more channel estimates or channel observables can be combined to compute a refined channel estimate, for example, when the channel estimates or channel observables are from the same channel.10-02-2008
20090190680MOBILE COMMUNICATION SYSTEM AND WIRELESS DEVICE - A base station transmits a control channel transmitted before information channels upon performing differential coding between control channels of adjacent frequencies. A terminal apparatus performs transmission path estimation on the basis of a pilot while decoding the control channel having undergone the differential coding. The information channels are decoded on the basis of information obtained by decoding the control channel and a transmission path estimation result on the pilot.07-30-2009
20110206147RESOURCE BLOCK MAPPING FOR SYMBOLS WITH REPETITION - In a mobile communication system with uncorrelated channel characteristics, transmission using modulation of data symbols with repetition can improve the performance. However, mapping of the original and the repeated symbols into the physical resources may on the other hand reduce a desired level of diversity when the original and the corresponding repeated symbols map on the physical resources close to each other. The present invention provides a method for transmission, a transmitter, a method for receiving, and a receiver capable of efficiently transmit/receive data symbols with an increased level of diversity. This is achieved by grouping of portions of the original and the corresponding data symbols and by mapping the portions of the original and the corresponding data symbols into the different physical resource blocks.08-25-2011
20080310522Sliding Map Detector for Partial Response Channels - An estimator of the noiseless output of a noisy partial response channel is described. The estimator operates recursively. In each iteration, the estimator processes a window of the N most recently received noisy channel outputs to compare subsequence metrics for all possible channel output subsequences of length N, and selects a noiseless subsequence with maximal posterior probability. One noiseless sample of the selected subsequence is output as an estimate of one of the channel outputs.12-18-2008
20080310529RADIO TRANSMITTING APPARATUS AND RADIO RECEIVING APPARATUS - A radio transmitting apparatus includes a calibration reference signal generator for generating a calibration reference signal for each of the subcarriers to be calibrated, a subcarrier modulator for modulating the calibration reference signal with the subcarrier, a radio transmitter for frequency-converting a baseband signal, which is the modulated signal, into a transmission signal in a radio frequency band, a radio receiver for frequency-converting the transmission signal in the radio frequency band supplied from the radio transmitter, into a baseband signal, a calibration coefficient measurer for calculating a calibration coefficient from the baseband signal output from the radio receiver, and a calibration coefficient multiplier for multiplying a transmission signal for each of the subcarriers and each of the antenna elements, by the calculated calibration coefficient.12-18-2008
20080310528METHOD AND SYSTEM FOR RESOURCE ALLOCATION FOR OFDM WIRELESS NETWORKS - According to an embodiment, the present invention provides a method for providing resource allocation in a wireless communication network. The method includes providing an access provider that is configured to perform orthogonal frequency division multiplexing (OFDM). The access provider is configured to allocate transmission resources. The method also includes providing a first plurality of terminals that are wirelessly connected to the access provider. The method further includes assigning the first plurality of terminals to a first scheduling group that is associated with a first plurality of resources. The first plurality of resources includes at least a first resource. The method additionally includes providing a second plurality of terminals that are wirelessly connected to the access provider. The method further includes assigning the second plurality of terminals to a second scheduling group that is associated with a second plurality of resources.12-18-2008
20080310524Methods and Systems For Varying Bus Frequencies - The present invention provides a method for receiving an instruction for varying the bus frequency from a current bus frequency to a new frequency. The method may include storing a group of parameters corresponding to a second frequency, disabling a link connected to the host bus at a first frequency while the host bus is being operated with parameters corresponding to the first frequency, updating the parameters for operating the host bus with the group of parameters, and enabling the link at the second bus frequency to operate the host bus with the group of parameters.12-18-2008
20100014601RETRANSMISSION OF DATA IN A MULTIPLE INPUT MULTIPLE OUTPUT (MIMO) SYSTEM - A method for retransmission of data in a multiple input multiple output (MIMO) system, the method comprising space-time block code (STBC) encoding multiple data streams including one or more retransmission data streams using a STBC matrix, the STBC matrix multiplying at least one of the retransmission data streams with respective variable weighting factors.01-21-2010
20100014602DETERMINING SYMBOL SYNCHRONIZATION INFORMATION FOR OFDM SIGNALS - The invention provides a method of detecting symbol synchronization information for an OFDM signal, the OFDM signal comprising at least one OFDM symbol and corresponding GI, the method comprising steps of: generating a correlated signal based on each OFDM symbol and its corresponding GI; processing the correlated signal to generate a first conditional signal comprising at least two local peaks; converting the first conditional signal into a second conditional signal comprising a global peak; and detecting the global peak to obtain the symbol synchronization information. The converting step further comprises delaying the first conditional signal by a predefined delay, and generating the second conditional signal by subtracting the delayed first conditional signal from the first conditional signal. With the method provided in the invention, detection of symbol synchronization information for an OFDM signal based on GI may be provided with improved precision, without being limited by the channel spread for the propagation channel.01-21-2010
20100014604TRANSMISSION APPARATUS, RECEPTION APPARATUS, COMMUNICATION APPARATUS, AND COMMUNICATION SYSTEM - A transmission apparatus divides transmission data according to spatial streams and transmits divided transmission data in parallel in an MIMO communication system. A control unit selects a modulation scheme for each of the spatial streams and determines a data allocation method for each of the spatial streams based on a selected modulation scheme. An allocating unit allocates the transmission data to each of the spatial streams based on the data allocation method determined by the control unit. A modulating unit modulates allocation data for each of the spatial streams by using the selected modulation scheme for each of the spatial streams.01-21-2010
20100014603GUARD INDEPENDENT SIGNAL MAPPING - Systems and methodologies are described that facilitate guard bandwidth independent mapping and de-mapping of bandwidth in a wireless communication system. Broadcast signals can be created as if all bandwidth were available, and guard bandwidth can be initialized over the utilized bandwidth such to puncture the data existing in the guard bandwidth. Upon decoding the broadcast signal, size of the guard bandwidth can be predetermined or estimated allowing a center portion of the signal to be decoded without decoding the guard bandwidth. In this regard, the decoder of the signal need not find exact positions of the guard bandwidth as transforming and decoding the center portion can provide a substantial portion of the signal to interpret the signal.01-21-2010
20100014600WINDOW POSITION OPTIMIZATION FOR PILOT-AIDED OFDM SYSTEM - A window position optimization for a pilot-aided OFDM system is disclosed. A method of reducing aliasing in an orthogonal frequency division multiplexing (OFDM) system, using window optimization and pilots comprises receiving an RF signal including a pilot, generating a channel frequency response estimate, interpolating the channel estimate to calculate a pilot carrier frequency response, and dynamically selecting a window to capture a channel impulse response to prevent aliasing.01-21-2010
20100014599APPARATUS AND METHOD FOR MODIFYING TRANSMISSIONS ON SPECIFIED WIRELESS CHANNELS TO REDUCE INTERFERENCE WITH HIGHER-PRIORITY TRANSMITTERS - A method includes obtaining data to be transmitted wirelessly and detecting if any transmitting devices having a higher priority are currently using at least one of multiple wireless channels. The method also includes transmitting the data wirelessly over the multiple wireless channels in a first specified manner when no transmitting devices having the higher priority are detected. The method further includes transmitting at least a portion of the data wirelessly over the multiple wireless channels in a second specified manner when at least one transmitting device having the higher priority is detected. The data could normally be transmitted using OFDM. When a higher-priority transmitting device is detected, at least a portion of the data could be transmitted using a reduced transmit power and a reduced constellation size and/or larger error correcting code. One or more wireless channels associated with one of two quadrature components could also be suppressed.01-21-2010
20100034304Configurable frequency band elimination for powerline network - A communication device for use in adapting an appliance to a computer network consistent with certain embodiments has a data transmitter that receives data to be transmitted and generates output signals carrying the data at a plurality of carrier frequencies. A user configurable notch filter, receives the output signals from the data transmitter, for reducing the amplitude of a user selected range of frequencies, and producing a filtered output. A network communication medium interface receives the filtered output and transmitting the filtered output over a network communication medium. This abstract is not to be considered limiting, since other embodiments may deviate from the features described in this abstract.02-11-2010
20100034299MAPPING AND SIGNALING OF COMMON REFERENCE SYMBOLS FOR MULTIPLE ANTENNAS - A method, a network base station, and a user communication device for transmitting data on an orthogonal frequency-division multiplexing carrier are disclosed. An antenna array may transmit a signal decodable by a legacy user communication device designed for compatibility with a legacy set of transmission antennas. A processor 02-11-2010
20090279619METHOD AND APPARATUS FOR CELL EDGE TRANSMISSION PERFORMANCE ENHANCEMENT FOR TDS-OFDM - In a communication system with multiple base stations having at least one base station with communications overlaps with at least another base station, a method is provided. The method comprising the steps of: characterizing the users into a first group and a second group, and adjusting some PN lengths of transmitted information for one group of users. The system includes users of a TDS-OFDM system,11-12-2009
20100027690APPARATUS AND METHOD FOR GENERATING A MULTICARRIER COMMUNICATION SIGNAL HAVING A REDUCED CREST FACTOR - An apparatus for generating a multicarrier communication signal having a reduced crest factor enables efficient power amplifier operation. The apparatus includes a plurality of shaping filters (02-04-2010
20100027689I/Q CALIBRATION OF TRANSMIT AND RECEIVE PATHS IN OFDM FDD COMMUNICATION SYSTEMS - I/Q gain and phase mismatches of both transmit and receive paths of an OFDM FDD transceiver are simultaneously estimated. An up-converted RF signal is generated when the transmit path performs IQ modulation on a reference signal having a single sideband tone. The up-converted RF signal is sent via a loop-back path to the receive path. A down-converted evaluation signal is generated when the receive path performs IQ demodulation on the up-converted RF signal. The single evaluation signal is used to determine the transmit path gain and phase mismatches and the receive path gain and phase mismatches. The four I/Q mismatches are estimated without using significant hardware nut otherwise used in the regular transmission of data signals. The I/Q mismatches in data signals are corrected by pre-processing the up-converted RF signals and post-processing the down-converted RF signals by adding attenuated components of the in-phase and quadrature-phase signals to each other.02-04-2010
20090110087Channel-Dependent Frequency-Domain Scheduling in an Orthogonal Frequency Division Multiplexing Communications System - Methods and apparatus are disclosed for scheduling sub-carriers in an Orthogonal Frequency Division Multiplexing (OFDM) communication system. In an exemplary method, channel quality metric values for each of a plurality of sub-channels are determined, in view of a selected mobile terminal. For each of two or more threshold levels for the channel quality metric, sub-carrier groups composed of sub-carriers corresponding to sub-channels having channel quality metric values superior to the threshold level are identified, and an estimated data throughput is calculated for each of the identified sub-carrier groups. One or more of the identified sub-carrier groups is allocated to the selected mobile terminal according to the estimated data throughputs.04-30-2009
20090279620Data communication - Embodiments related to communication of data in a first and second transmission mode are depicted and described herein.11-12-2009
20100027693Stream Weight Estimation and Compensation in SIMO/MIMO OFDM Receivers - A process for equalizing streams of OFDM subcarrier data computes the noise variance for each stream, and forms a stream weighting coefficient by equalizing the noise variance, such that for a first stream having a noise variance σ02-04-2010
20090232240MULTI-RESOLUTION BEAMFORMING IN MIMO SYSTEMS - Certain aspects of the present disclosure relate to methods for beamforming that achieve beamforming optimality criterions. Some proposed beamforming techniques are based on antenna directions with multiple resolutions.09-17-2009
20090220017TRANSMISSION APPARATUS AND RECEPTION APPARATUS - A transmission apparatus used in a mobile communication system adopting a single carrier scheme in an uplink includes: multiplexing means configured to multiplex a pilot channel, a control channel, and a data channel; and transmission means configured to transmit a transmission symbol including at least the pilot channel and the control channel using the uplink. A first pilot channel used for a reception apparatus to measure channel state of the uplink is transmitted using a frequency band over a plurality of resource blocks. A second pilot channel for compensating for a channel transmitted by the uplink is transmitted by a resource block assigned to the transmission apparatus. Control channels of the transmission apparatus and the apparatus other than the transmission apparatus are orthogonalized with each other by a FDM scheme.09-03-2009
20090220014BASE STATION, MOBILE STATION AND METHOD - A base station performs communication of an orthogonal frequency division multiplexing (OFDM) scheme with a mobile station by using any one of equal to or greater than two frequency bands. The base station includes means that transmits a synchronization channel and a control channel using a band that includes a center frequency f09-03-2009
20090161783PER STREAM RATE CONTROL (PSRC) FOR IMPROVING SYSEM EFFICIENCY IN OFDM-MIMO COMMUNICATION SYSTEMS - A method and apparatus for separating a user-data stream into a plurality of sub-streams. The apparatus determines channel conditions for each of a plurality of sub-carriers. Next, a plurality of sub-carriers are modulated and encoded with the sub-stream data according to the selected modulation schemes and coding rates. The modulated sub-carriers are each allocated to one or more transmit antennas for transmission. The adaptive modulation and coding function, the sub-carrier allocation function, and the power control function are jointly controlled to optimize throughput, signal quality, and system efficiency.06-25-2009
20080310527CORRELATION INTERVAL SYNCHRONIZATION APPARATUS AND METHOD - The present invention is directed to a correlation interval synchronization apparatus and method. Correlation is firstly performed on received data, followed by searching peaks in accordance with the output of the correlation. Subsequently, peak intervals are acquired according to the peaks, and the peak interval where the synchronization head position resides is determined. Finally, the synchronization head position is identified within the associated peak interval.12-18-2008
20080310523Method and Apparatus for Controlling Multi-Antenna Transmission in a Wireless Communication Network - Multi-antenna transmission control presented herein involves generating a set of virtual channel realizations at the transmitter that shares the same second-order statistics as the actual channel realizations observed for a targeted receiver. By making the control-related quantities of interest at the transmitter depend on the long-term statistics of the channel, the actual channel realizations are not needed for transmission control, e.g., for accurate Multiple-Input-Multiple-Output (MIMO) preceding. As such, the use of virtual channel realizations enables transmission control that approaches the “closed-loop” channel capacity that would be provided by full feedback of the (instantaneous) actual channel realizations, without requiring the overhead signaling burden that attends full feedback.12-18-2008
20080310526Method, device, and apparatus for multi-stream multi-band transmission - A transmitter may include a set of stream groups, each including two or more streams producing a set of orthogonal frequency division multiplexed (OFDM) stream-symbols and a coding unit interleaving the stream-symbols into an interleaved signal. An input bit multiplexer may route an input data signal to be divided among each of the streams. An inverse fast Fourier transform unit may operate on a combined signal formed from interleaving the interleaved signals from each stream group. Each stream may include for example a baseband signal processor producing the OFDM stream-symbols.12-18-2008
20080310535METHOD AND APPARATUS FOR SYMBOL TRANSMISSION IN AN OFDM MOBILE COMMUNICATION SYSTEM - A mapping method and an apparatus, which uniformly distribute bits included in transmission symbols to various resource blocks in mapping the transmission symbols to the resource blocks for transmission in an OFDMA mobile communication system. A sub-packet generator generates a sub-packet by selecting symbols from coded symbols including a first bit group and a second bit group, the first bit group having a different priority than the second bit group. A divider divides each bit group of the sub-packet into as many bit streams as previously allocated resource blocks. A resource block mapper maps the divided bit streams to the resource blocks, respectively, and outputs the bit streams for transmission.12-18-2008
20080310538Versatile System for Dual Carrier Transformation in Orthogonal Frequency Division Multiplexing - The present invention provides a versatile system for selectively spreading carrier data across multiple carrier paths within an Orthogonal Frequency Division Multiplexing (OFDM) system (12-18-2008
20080310536Adaptive joint channel estimation and data demodulation for OFDM systems - The present invention provides architectures and methods which implement adaptive joint channel estimation and data demodulation in wireless communication systems to provide enhanced performance of the communication link. While not limited to any particular air interface, such architectures and methods are particularly beneficial in OFDM systems. Channel estimates may be performed for pilot sub-carriers for a given OFDM symbol and filtering may then be performed for channel estimation of a given data subcarrier. Received symbols may be equalized and demodulated, and the channel estimate may be updated for the given data subcarrier. Such a procedure enables more accurate channel estimation and improved data demodulation, thereby enhancing system performance.12-18-2008
20080310530Wireless Communication Apparatus and Wireless Communication Method - A wireless communication apparatus and a wireless communication method wherein even when the permissible delay amount of data is small, the permissible delay thereof can be satisfied. A data type determining part (12-18-2008
20080310534WIRELESS COMMUNICATION METHOD AND WIRELESS COMMUNICATION APPARATUS - A wireless communication apparatus generates transmission signal including first and second pilot signal sequences allocated to first and second frequencies symmetrically located in relation to a center frequency, and third and fourth pilot signal sequences allocated to third and fourth frequencies symmetrically located in relation to the center frequency, quadrature-modulates the transmission signal, to obtain a quadrature modulation signal, quadrature-demodulates the quadrature modulation signal, to obtain a reception signal, extracts first to fourth pilot signal sequences from the reception signal, estimates a first transfer characteristic concerning first and second frequency by using first and second pilot signal sequences, estimates a second transfer characteristic concerning third and fourth frequencies using third and the fourth pilot signal sequences, generates a third transfer characteristic from which an influence of transmission IQ imbalance is removed by using first and second transfer characteristic, and estimates, from the third transfer characteristic, reception IQ imbalance characteristic.12-18-2008
20080310531ROBUST CHANNEL ESTIMATION IN COMMUNICATION SYSTEMS - An apparatus for archiving robust channel estimation in a communication system includes a training sequence generator to generate a training sequence. A formatter inserts the training sequence to a frame. A transmitting module is employed to transmit the frame. The training sequence generator further includes a symbol generator to generate a plurality of training symbols satisfying a predetermined constraint such that the training symbols are insensitive to synchronization error and a training sequence forming unit that forms the training sequence from the training symbols generated by the training symbol generator.12-18-2008
20090154582SYNERGETIC TRANSMITTING SYSTEM FOR DIGITAL BROADCAST SFN AND METHOD THEREOF - A cooperative transmission system for single frequency digital broadcasting network and method thereof are disclosed, said system includes a first double-layer cooperative transmission structure with same frequency and a second double-layer cooperative transmission structure with same frequency, which are vertically aggregated; wherein each of the double-layer cooperative transmission structures with same frequency is made up of a main transmission layer including several main transmitters with same transmitting frequency and an auxiliary transmission layer including several auxiliary transmitters with same transmitting frequency; the electromagnetic wave transmitted by the main transmitters in the first double-layer cooperative transmission structure with same frequency and the electromagnetic wave transmitted by the main transmitters in the second double-layer cooperative transmission structure with same frequency have different frequencies. The present invention makes up the disadvantage of the single frequency network, and can greatly improve the spectrum efficiency of broadcasting channel, the coverage (especially the indoor coverage) of broadcasting signal and the effect of mobile receiving of broadcasting signal.06-18-2009
20090316805ENERGY-EFFICIENT LINK ADAPTATION AND RESOURCE ALLOCATION FOR WIRELESS OFDMA SYSTEMS - An energy-efficient framework for active transmission in OFDMA-based long-range wireless networks is disclosed. This frame-work is based on using energy-aware metrics for resource allocation and link adaptation. By casting the optimal energy-efficient resource allocation problem as utility-based optimization problem, low-complexity utility-based resource allocation schemes developed here can be applied to reduce the complexity of resource allocation decisions.12-24-2009
20090185630METHOD AND APPARATUS FOR ESTIMATING THE CHANNEL IMPULSE RESPONSE OF MULTI-CARRIER COMMUNICATING SYSTEMS - An apparatus for estimating channel impulse response. The apparatus comprises an IFFT module, a tap selection module, a correlation module, a correlation module, and a decision module. The IFFT module receives and transforms a plurality of pilot tones into a periodic discrete-time series. The tap selection module selects two taps from the periodic discrete-time series and obtains time differences of the two selected taps Dt and Dt′. The correlation module receives a time-directional symbol having time index k r(k) and a time-directional symbol having time index (k+Dt) r(k+Dt) to correlate a first correlated result C(Dt) and receives the time-directional symbol having time index k r(k) and a time-directional symbol having time index (k+Dt′) r(k+Dt′) to correlate a second correlated result C(Dt′). The decision module compares the first and second correlated result and outputs a channel impulse response according to the first and second correlated results.07-23-2009
20090161774Apparatus and Method for Dynamic Frequency Selection in ofdm Networks - A wireless endpoint is a Wireless Regional Area Network (WRAN) endpoint, such as a base station (BS) or customer premise equipment (CPE). The WRAN endpoint can transmit an orthogonal frequency division multiplexed (OFDM) signal comprising 2048 subcarriers in a channel. The 2048 subcarriers are divided into 16 subcarrier sets, or subchannels, each subcarrier set comprising 128 subcarriers. However, upon detection of an incumbent narrowband signal in the channel, the WRAN endpoint forms the OFDM signal for transmission in such a way that the WRAN endpoint excludes use of those one, or more, of the subcarrier sets that would interfere with the incumbent narrowband signal.06-25-2009
20090147872METHOD OF RANGING SIGNAL DESIGN AND TRANSMISSION FOR MIMO-OFDMA INITIAL RANGING PROCESS - A mobile communication system uses a multiple-input-multiple-output (MIMO) technology with an orthogonal frequency division multiplexing access (OFDMA) scheme. Multiuser diversity, multiantenna diversity, and power control since the first ranging attempt are exploited in the initial ranging process. At network entry, an initial ranging method selects from multiple ranging signal designs to accomplish the initial ranging process. In one embodiment, three classes of ranging signal designs may be selected for use in generating ranging codes. The information on the ranging signal design to be used, which is selected by the base station based on the cell size of the communication system (i.e., the radio coverage area of the base station), is broadcast from the BS. The ranging signal designs are directly applicable to single-antenna systems, and they are applied to MIMO systems by using appropriate mapping across transmit antennas based on the adopted MIMO ranging transmission scheme. In a mobile communication system using MIMO technology with the OFDMA scheme, the ranging user selects from multiple ranging transmission schemes of different levels of computation complexity, power consumption and performance. In one example, optimum eigenmode and suboptimum eigenmode transmission schemes provide the best performance at high computational complexity and high power consumption. A simpler single-antenna selection transmission scheme provides significantly reduces computational complexity and achieves power saving at a marginal degradation in system performance.06-11-2009
20090147870METHOD FOR SOLVING HIGH PAPR PROBLEM OF MCM COMMUNICATION SYSTEM USING UNITARY TRANSFORM - The method contains the following steps. First, in a MCM system with N sub-carriers, the baseband signal blocks 06-11-2009
20090147868METHOD AND APPARATUS FOR TRANSMITTING PILOT SYMBOLS IN WIRELESS COMMUNICATION SYSTEM - A method of transmitting pilot symbols is disclosed. In a communication system performing communications using a plurality of antennas and multiple carriers, the present invention includes the steps of generating a plurality of pilot symbol sequences based on a basic code sequence, data-processing a plurality of the pilot symbol sequences by allocating each of a plurality of the pilot symbol sequences to the multiple carriers, and transmitting each of a plurality of the data-processed pilot symbol sequences via a corresponding one of a plurality of the antennas.06-11-2009
20090147867Communication conrol apparatus, communication terminal apparatus, wireless communication system, and transmitting method - To determine a length of a guard interval based on performance provided in a communication terminal apparatus. A communication control apparatus 06-11-2009
20100124291Receivers for Embedded ACK/NAK in CQI Reference Signals in Wireless Networks - Within a wireless network, uplink control information (UCI) transmitted by user equipment is received by a base station. The UCI includes a least two elements, a first set of symbols produced using a first information element and a second set of symbols produced using a second information element. At least a first metric is produced using the first set and the second set of received symbols. The first information element may then be detected using the first metric.05-20-2010
20100124296Method and System to Reduce Peak to Average Power Ratio in Multi-Carrier Modulation Receivers - Provided is a method for performing channel estimation in an Orthogonal Frequency Division Multiplexed (OFDM) signal. The method includes performing the channel estimation based upon use of reserved tone channel carriers.05-20-2010
20090147875RADIO TRANSMITTER AND RADIO RECEIVER - A radio transmitter includes a unit which generates a first instruction to instruct the transmission of a first transmission signal, a unit which generates the first transmission signal based on the first instruction, a unit which generates a second instruction to instruct the transmission of a second transmission signal to be selectively multiplied by an orthogonal code, a unit which generates the second transmission signal based on the second instruction, unit which transmits the first and the second transmission signals, a unit which predicts a collision of the first and second transmission signals, and a unit which stops the first transmission signal while the collision is predicted in a case where the second transmission signal is multiplied by the orthogonal code and which stops the second transmission signal while the collision is predicted in a case where the second transmission signal is not multiplied by the orthogonal code.06-11-2009
20090147871Compact Specification of Data Allocations - The subject matter disclosed herein provides a mechanism for numbering OFDMA symbols in data regions of OFDMA frames. The method may include assigning, based on a pattern vector, one or more numbers to one or more symbols of a time diversity interval. Moreover, the one or more numbered symbols may be assigned to one or more segments. The pattern vector is then provided to a client station to enable the client station to access, based on the numbered one or more symbols, at least one of the segments. Related systems, apparatus, methods, and/or articles are also described.06-11-2009
20090022233RADIO RECEIVING APPARATUS AND RADIO RECEIVING METHOD - A radio receiving apparatus wherein the interference can be minimized and the power and bands can be effectively used in the process of receiving a signal comprising a combination of an impulse signal and an OFDM signal. In this apparatus, a transmission path equalizing part (01-22-2009
20100128807METHOD FOR ESTIMATING CHANNEL IN RADIO COMMUNICATION SYSTEM AND DEVICE THEREFOR - Disclosed is a radio communication device, and more particularly to a method for estimating a channel and compensating for error occurring in the estimation procedure, for a device for performing a frequency domain signal processing, such as Orthogonal Frequency Division Multiplexing (OFDM) The channel estimation method in a radio communication system includes the steps of: transforming a received OFDM signal into a frequency domain; estimating a channel frequency response (CFR) value from a result value obtained through the transformation by using a pilot signal; transforming the estimated CFR value into a time domain through an extended Inverse Fast Fourier Transform scheme, and detecting a channel impulse response (CIR) value; detecting a delay path position of a channel; modifying a non-ideal autocorrelation function; and compensating the estimated CIR value for error, through use of the detected delay path position and the non-ideal autocorrelation function.05-27-2010
20110170623APPARATUS AND METHOD FOR CHANNEL INFORMATION FEEDBACK, BASE STATION RECEIVING THE CHANNEL INFORMATION, AND COMMUNICATION METHOD OF THE BASE STATION - Disclosed is a wireless communication system including an apparatus and a method for feeding back channel information of a User Equipment (UE); a Base Station (BS) for receiving channel information of a UE and for communicating with the UE; and a communication method of the BS which can dynamically switch between Single-User Multiple-Input Multiple-Output (SU-MIMO) and Multiple-User Multiple-Input Multiple-Output (MU-MIMO) access schemes.07-14-2011
20080304590METHOD AND APPARATUS FOR TRANSMISSION FROM MULTIPLE NON-COLLOCATED BASE STATIONS OVER WIRELESS RADIO NETWORKS - A method and apparatus is disclosed herein for wireless transmission from multiple non-colocated antennas. In one embodiment, a wireless communication system comprises a controller to control a set of antenna elements dispersed over multiple, non-collocated base stations to wirelessly transmit information-bearing signals to one or more receivers using OFDM transmission, wherein control unit includes an antenna selection control operable to select non-collocated antenna elements from the set of antenna elements to send at least one signal to a receiver in the wireless communication system from antenna elements located at different base stations, and further wherein the OFDM transmission uses a circular prefix long enough to accommodate a maximum possible relative delay in reception between arrivals of the transmitted signals.12-11-2008
20090310694APPARATUS AND METHOD FOR TRANSMITTING AND RECEIVING MAP INFORMATION IN A BROADBAND WIRELESS COMMUNICATION SYSTEM - A broadband wireless communication system and method are provided. The method includes allocating an orthogonal sequence to a MAP that requires ACKnowledge (ACK) transmission, transmitting the MAP that does not comprise allocation information of the orthogonal sequence, determining whether the orthogonal sequence is detected in an ACK channel allocated for a subframe that carries the MAP, and determining that the MAP is successfully received when the orthogonal sequence is detected.12-17-2009
20080285673Apparatus and method for reducing peak to average power ratio based on tile structure in broadband wireless communication system - A broadband wireless communication system is provided. A transmitting end of the broadband wireless communication system includes: a controller for receiving a plurality of Orthogonal Frequency Division Multiple Access (OFDMA) symbols, and for generating the same number of symbol sets corresponding to the OFDMA symbols wherein each symbol set includes a plurality of OFDMA symbols having various Peak to Average Power Ratios (PAPRs) according to several phase-shifting patterns, a selector for grouping the plurality of OFDMA symbols into symbol groups according to the same phase-shifting pattern of the several phase-shifting patterns, and for finding maximum peak value in each symbol group, and a transmitter for transmitting the symbol group having a minimum value selected from among the maximum peak values of the symbol groups.11-20-2008
20080247475METHOD FOR CODEBOOK DESIGN AND BEAMFORMING VECTOR SELECTION IN PER-USER UNITARY RATE CONTROL (PU2RC) SYSTEM - A base station includes a storage unit to store a codebook, wherein the codebook includes a plurality of matrices; a control unit to perform beamforming using the codebook to generate a signal; and a multi-antenna to transmit the signal. For all of the plurality of matrices, all column vectors of a same matrix of the plurality of matrices are orthogonal to each other. For all columns of the plurality of matrices, all column vectors of a same column of all of the plurality of matrices satisfy a Grassmannian line packing (GLP) criterion.10-09-2008
20080247480METHODS AND SYSTEMS FOR DETECTING A NARROW-BAND INTERFERER - Various embodiments of the systems and methods described herein may be used to compute a minimum variance unbiased estimator by receiving a first OFDM signal at a pilot tone, receiving a second OFDM signal sent in the same frequency band and determining a differential phase metric between the first OFDM signal and the second OFDM signal. In some embodiments, the differential phase metric may be used to diversity combine synchronization statistics. In various embodiments, the differential phase metric may be used to detect a narrow-band interference.10-09-2008
20080267304 METHOD AND SYSTEM FOR JOINT TIME-OF-ARRIVAL AND AMPLITUDE ESTIMATION BASED ON A SUPER-RESOLUTION TECHNIQUE - In a geolocation application, a method is provided to jointly estimate the time-of-arrival (TOA) and the amplitude of a received signal based on super-resolution technique. The super-resolution joint TOA-amplitude estimators are provided based on either the expectation-maximization (EM), parallel-interference-cancellation space-alternating generalized expectation maximization (PIC-SAGE) or serial-interference-cancellation SAGE (SIC-SAGE). The SIC-SAGE estimator minimizes the ranging estimation error especially under a non-line-of-sight (NLOS) condition. The SIC-SAGE estimator is a simplified version of the maximum likelihood estimator with more stable performance in a multipath rich environment, such as the ultra-wideband (UWB) based applications. These techniques provide the following benefits: 1) it is generic, so that signal processing can be deployed on both time-domain (e.g., UWB impulse-radio) and frequency-domain (e.g., multi-band orthogonal frequency-division multiplexing (MB-OFDM)) based transceiver schemes and applicable for both UWB and non-UWB systems; 2) it is robust especially under NLOS condition and multipath rich environment.10-30-2008
20080267302Method and System for Data-Driven, Variable-Rate, Channel Quality Indicator for LTE Non-Real-Time Bursty Traffic - A method and system, in a long term evolution architecture utilizing adaptive modulation and coding requiring periodic channel quality indication reports, the method having the steps of: waiting for an idle channel indication; and upon detection of the idle channel indication, decreasing the rate of periodic channel quality indication reports.10-30-2008
20100266055SYSTEM AND METHOD FOR ESTABLISHING A LOCALIZED SINGLE FREQUENCY NETWORK - A method, wireless communication network, and transmitting device that detects that one or more carrier frequencies have crossed a threshold, selects one or more helping transmitting devices to transmit the detected carrier frequencies, transmits the data assigned to the detected carrier frequencies to the selected helping transmitting devices, wherein the selected helping transmitting devices transmit the data over the detected carrier frequencies.10-21-2010
20080212700METHOD AND APPARATUS FOR TRANSMITTING AND RECEIVING CONTROL CHANNEL MESSAGE IN A MIMO MOBILE COMMUNICATION SYSTEM - A method and apparatus for transmitting and receiving a control channel message in a Multiple Input Multiple Output (MIMO) mobile communication system are provided, in which a control channel message generator generates a pilot/MIMO field indicating at least one of a pilot format, a MIMO transmission rank being a number of transmission layers for transmitting encoded packet streams, and precoding information for MIMO data transmission, and outputs a control channel message including the pilot/MIMO field, and a transmission module converts the control channel message to a radio signal and transmits the radio signal to an MS. In the case of using common pilots for data demodulation and at least one of knock-down precoding and ready-made precoding for the MIMO transmission, the pilot/MIMO field includes information about the at least one precoding. In the case of dedicated pilots for data demodulation, the pilot/MIMO field indicates a format of the dedicated pilots.09-04-2008
20100124295PSEUDO-DIFFERENTIAL INTERFACING DEVICE HAVING A TERMINATION CIRCUIT - The invention relates to an interfacing device for pseudo-differential transmission through interconnections used for sending a plurality of electrical signals. The interfacing device of the invention includes signal terminals and a common terminal distinct from the reference terminal (ground). A transmitting circuit receiving the input signals of the transmitting circuit coming from a source delivers, when the transmitting circuit is in the activated state, currents to the signal terminals. A receiving circuit delivers, when the receiving circuit is in the activated state, output signals of the receiving circuit determined each by the voltage between one of the signal terminals and the common terminal, to the destination. A termination circuit is such that, when it is in the activated state, it is approximately equivalent, for the signal terminals and the common terminal, to a network consisting of 4 branches, each branch being connected to the common terminal and to one of the signal terminals.05-20-2010
20100118995WIRELESS COMMUNICATION SYSTEM, BASE STATION, TERMINAL DEVICE, AND WIRELESS COMMUNICATION METHOD - In a communication system in which a communication is performed between a base station and one or more terminals by using one or more communication channels, a control element unit is defined by T OFDM symbols and F subcarriers. A second combination of T and F is determined for a first combination of T and F such that the number of modulation symbols (one OFDM symbol x one subcarrier) included in the control element unit defined by the second combination is closest to the number of modulation symbols included in the control element unit defined by the first combination.05-13-2010
20100118997Method of controlling in a wireless communication system having multiple antennas - A method of controlling interference in a wireless communication system is disclosed. A method for controlling interference by a transmitter of a wireless communication system with multiple antennas comprises generating a base codebook subset including at least one precoding matrix selected from a base codebook; transmitting a base codebook subset indication, which represents the at least one precoding matrix included in the base codebook subset, to a receiver; and precoding data using the base codebook subset or the base codebook.05-13-2010
20100118992COMMUNICATION PROCESSING SYSTEM, OFDM SIGNAL TRANSMITTING METHOD, OFDM TRANSMITTER, OFDM RECEIVER, AND CONTROL STATION - An OFDM signal transmitting method includes multiplying a first data channel signal multiplied by a scrambling code by a transmission power boost value notified in advance from one or more control stations that control OFDM transmitters included in the same service area to all the OFDM transmitters included in the service area; generating, in a time symbol based on time symbol information from one of the one or more control stations, an OFDM signal by OFDM-modulating a second data channel signal and a pilot channel signal multiplied by scrambling codes and the first data channel signal multiplied by the transmission power boost value, the OFDM signal being a signal in which a macro diversity signal and a non-macro diversity signal are frequency-division-multiplexed; and transmitting the OFDM signal.05-13-2010
20100119000METHOD AND APPARATUS FOR ADJUSTING POWER CONTROL MODE IN WIRELESS COMMUNICATION SYSTEM - A method and an apparatus for adjusting power control mode in a wireless communication system is provided. A mode change message is transmitted from a base station (BS) to a user equipment (UE) to request changing a power control mode from a base station (BS). The mode change message comprises a power control mode change (PMC) field which indicates the power control mode to be changed. The UE transmits a UE confirmation message to the BS, and receives a BS confirmation message from the BS. The UE changes the power control mode based on the mode change message.05-13-2010
20100118994DIGITAL TRANSMISSION SYSTEM FOR TRANSMITTING ADDITIONAL DATA AND METHOD THEREOF - A digital transmission system is disclosed. The system includes a transmission signal generation unit which generates a transmission signal in which data to be transmitted is carried by a carrier wave, and an additional data process unit which processes so that a low power signal to represent additional data is carried by the carrier wave. The system is embodied as an orthogonal frequency division multiplexing (OFDM) system such as a digital video broadcast-video (DVB-V), and a single carrier system such as a vestigial sideband modulation (VSB). Accordingly, additional data are efficiently transmitted without degrading transmission quality of main data.05-13-2010
20130022138METHOD FOR TRANSMITTING AND RECEIVING ADDITIONAL CONTROL SIGNALS - A method for transmitting/receiving an additional control signal without any loss of bandwidth and power in an original Tx signal is disclosed. If the additional control signal is transmitted via the Tx signal composed of at least one of data and control signals, at least one of the amplitude and phase of the Tx signal of the time- and frequency-resource domain is modulated according to the additional control signal to be transmitted. The modulated Tx signal is transmitted to the receiver, so that the additional control signal can be transmitted irrespective of the original Tx signal. According to a modulation status of at least one of an amplitude and a phase of the Rx signal contained in the time- and frequency-resource domain, the additional control signal can be acquired.01-24-2013
20080247472INTERFERENCE ESTIMATION CIRCUIT AND METHOD - The present application provides an interference estimation circuit which includes a signal generator, a first symbol extractor and a first mixer. The signal generator generates an orthogonal signal orthogonal to partial symbols of a plurality of pilot signals. The first symbol extractor extracts partial symbols of a first decoded signal decoded from a received signal wherein the first decoded signal contains one of the plurality of pilot signals, and includes an input node for receiving the first decoded signal and an output node for outputting a first extracted signal. The first extracted signal is substantially orthogonal to the orthogonal signal. The first mixer is coupled to the signal generator for receiving the orthogonal signal and to the first symbol extractor for receiving the first extracted signal, and outputs a first mixed signal of the orthogonal signal and the first extracted signal for interference estimation.10-09-2008
20080247478Orthogonal frequency division multiplexing communication system, multi-hop system, relay station, and spatially layered transmission mode - An apparatus and method for data transmission in an Orthogonal Frequency Division Multiplexing (OFDM) communication system are provided. An OFDM system includes a reference Relay Station (RS) and a cooperative relay station respectively for performing an Spatially Layered transmission Mode (SLM) process by modulating a phase and magnitude of a signal by using a predetermined modulation order suitable for the reference relay station to obtain a spatially-layered signal and for delivering the spatially-layered signal to a target Mobile Station (MS); a Base Station (BS) for selecting the reference relay station and the cooperative relay station among a plurality of relay stations; and an mobile station for detecting data through Maximum Likelihood (ML) detection in which a signal having the largest ML is detected by comparing the received spatially-layered signal with a signal which is converted through the SLM upon receiving the spatially-layered signal from the reference relay station and the cooperative relay station.10-09-2008
20080247474Apparatus and Method For Receiving Signals in Multi-Carrier Multi-Carrier Multiple Access Systems - A method for receiving signals in a multi-carrier multiple access system is disclosed. The method comprises receiving signals from at least one base station wherein each signal has a base station identifier, processing the signals to identify each base station by using the base station identifier, performing a channel estimation using the processed signals, combining the processed signals using an information obtained from the channel estimation and decoding the combined signals. Also, an apparatus for receiving signals in a multi-carrier multiple access system comprises a serial-to-parallel converter for converting a serial signal including a base station identifier from at least one base station to parallel signals, a Fast Fourier transformer for transforming the parallel signals, a parallel-to-serial converter for converting the parallel signals to a serial signal, a despreading processor for despreading frequency domain signals using the base station identifier from at least one base station, a channel estimiator for compensating a channel variation between the at least one base station and a mobile station, a signal combiner for combining signals from base stations and a decoder for decoding the combined signal.10-09-2008
20100086071BI-DIRECTIONAL COMMUNICATION SYSTEM, COMMUNICATION APPARATUS, AND CONTROL METHOD OF COMMUNICATION APPARATUS - Each of two communication apparatuses in a bi-directional communication system transmits to a partner communication apparatus as an OFDM signal at a predetermined carrier frequency an OFDM symbol having a guard interval length determined in advance and an effective symbol length determined in advance; receives the OFDM signal that has been transmitted by the partner communication apparatus; and carries out demodulation processing on the received OFDM signal in a period that does not include a symbol boundary of the received OFDM signal. A transmission timing of an OFDM signal in at least one of these communication apparatuses is controlled to a timing that precedes a symbol timing of the received OFDM signal by a predetermined time shorter than a total of transmission times of the bi-directional OFDM signal in the bi-directional communication.04-08-2010
20090310693EFFICIENT CQI SIGNALING IN MULTI-BEAM MIMO SYSTEMS - The present invention relates to the signaling of channel quality information in a multi-beam transmission system, wherein a plurality of beams are simultaneously transmitted and a plurality of sets of channel quality information are transmitted for controlling independently the transmission rate on the different beams. Determined are beams with a different quality resulting in different effects of errors in the transmissions of the channel quality information for the beams. Said different effects are exploited for reducing a signaling overhead of the channel quality information for the beams.12-17-2009
20090262847Orthogonal Frequency Division Multiplexing Receiver for Minimizing Inter-Symbol Interference - Techniques, apparatus, and systems are described for providing an orthogonal frequency division multiplexing (OFDM) receiving apparatus. An orthogonal frequency division multiplexing (OFDM) receiving apparatus includes a fast Fourier transform (FFT) start point estimating unit to detect a minimum symbol interference point of a received OFDM signal and identify a FFT start point. The apparatus includes a FFT operation performing unit to communicate with the FFT start point estimating unit and to perform a FFT operation at the FFT start point identified by the FFT start point estimating unit. The apparatus includes a phase modifying unit to communicate with the FFT start point estimating unit and to modify a phase of an output of the FFT operation performing unit. Also, the apparatus includes a decoding unit to communicate with the FFT operation performing unit and to decode the phase modified output of the FFT operation performing unit.10-22-2009
20100119001MIMO SYSTEM WITH MULTIPLE SPATIAL MULTIPLEXING MODES - A MIMO system supports multiple spatial multiplexing modes for improved performance and greater flexibility. These modes may include (1) a single-user steered mode that transmits multiple data streams on orthogonal spatial channels to a single receiver, (2) a single-user non-steered mode that transmits multiple data streams from multiple antennas to a single receiver without spatial processing at a transmitter, (3) a multi-user steered mode that transmits multiple data streams simultaneously to multiple receivers with spatial processing at a transmitter, and (4) a multi-user non-steered mode that transmits multiple data streams from multiple antennas (co-located or non co-located) without spatial processing at the transmitter(s) to receiver(s) having multiple antennas. For each set of user terminal(s) selected for data transmission on the downlink and/or uplink, a spatial multiplexing mode is selected for the user terminal set from among the multiple spatial multiplexing modes supported by the system.05-13-2010
20100118999COMMUNICATION APPARATUS AND OFFSET CANCELING METHOD - There is already disclosed a technique for an MB-OFDM communication system whereby an orthogonal demodulation section removes a DC offset generated in a received signal in a region where the received signal is an analog signal, but the removal of the DC offset in the analog region cannot prevent the DC offset from remaining, and therefore the DC offset needs to be effectively removed in a digital region. An offset canceling section 05-13-2010
20090296838DATA PROCESSING APPARATUS AND METHOD - A data processing apparatus is operable to map input data symbols to be communicated onto a predetermined number of sub-carrier signals of Orthogonal Frequency Division Multiplexed OFDM symbols. The predetermined number of sub-carrier signals is determined in accordance with one of a plurality of operating modes and the input data symbols include first sets of data symbols and second sets of input data symbols. The data processing apparatus includes a controller, an address generator and an interleaver memory. The controller is operable, when operating in accordance with an even interleaving process to read out a first set of the input data symbols from the interleaver memory on to the sub-carrier signals of an even OFDM symbol using read addresses generated by the address generator, and to write in a second set of the input data symbols into the interleaver memory using the addresses generated by the address generator. The controller is operable in accordance with an odd interleaving process, to read out a first set of input data symbols from the interleaver memory on to the sub-carrier signals of an odd OFDM symbol using read addresses determined in accordance with a sequential order of the first set of input data symbols, and to write in a second set of the input data symbols into the interleaver memory at write addresses determined in accordance with the sequential order of the first group of input data symbols. The controller is operable to determine before reading out the first input data symbols from the interleaver memory, whether the read address is valid for a previous OFDM symbol, and to determine before writing the second input data symbols into the interleaver memory, whether the write address is valid for a current OFDM symbol. As such, the interleaver memory size can be minimised to an amount which corresponds to a maximum number of sub-carriers, which are available for an OFDM symbol for any of the operating modes. Application can be found with DVB-T2, which includes a 32K mode.12-03-2009
20090296833APPARATUS FOR GENERATING A SET OF RADIO PARAMETERS, A TRANSMITTER AND A RECEIVER - A transmitter includes: a data modulation and channel coding unit configured to perform data modulation and channel coding for a data channel with a modulation level and a channel coding rate updated for each transmission time interval; a multiplexing unit configured to multiplex a control channel and the data channel for each transmission time interval; and an adjusting means configured to adjust a length of the transmission time interval. Increasing a unit of information transmission in the time direction and/or the frequency direction depending on communication conditions can reduce a frequency of inserting (allocating) the control channel, and can improve data transmission efficiency.12-03-2009
20120033750TRANSPORT BLOCK SIZE - Disclosed herein is a method, device, network and computer program product for transmitting data in transport blocks from the device on an uplink channel of the network. Information indicative of a current condition on the uplink channel is determined. Based on the determined information, a transport block size for use in transmitting data on the uplink channel is adapted and data is transmitted from the device on the uplink channel in transport blocks having the adapted transport block size.02-09-2012
20100080308VIRTUAL MULTICARRIER DESIGN FOR ORTHOGONAL FREQUENCY DIVISION ... - Embodiments of the present invention provide a virtual multicarrier design for orthogonal frequency division multiple access communications. Other embodiments may be described and claimed.04-01-2010
20100195749Radio Communication Device and Symbol Arrangement Method - Provided is a radio communication device which can reduce the affect of CDD channel fluctuation of an interference signal from other cell when using a CDD. In this device, an arrangement unit (08-05-2010
20100086069COMMUNICATION DEVICE AND COMMUNICATION SYSTEM - A communication device performing communications by an OFDMA system. The communication device includes a zone-boosting-amount calculating unit that obtains a segment number calculated in a synchronization process, obtains a sub-channel corresponding to the segment number by referring to a predetermined relationship between sub-channels and segment numbers, and calculates an amount of zone boosting based on an average power of a preamble and an average power of pilot sub-carriers included in the sub-channel. A demodulating unit estimates a transmission path after correcting a power value of a received signal based on calculated amount of zone boosting, and performs demodulation.04-08-2010
20100080310ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING (OFDM) COMMUNICATIONS DEVICE AND METHOD THAT INCORPORATES LOW PAPR PREAMBLE AND VARIABLE NUMBER OF OFDM SUBCARRIERS - A communications device includes communications data and a training sequence corresponding to a preamble. A modulation and mapping circuit modulates the communications data and training sequence into a plurality of multiple subcarriers that are orthogonal to each other to form an OFDM communication signal having modulated subcarriers carrying the communications data forming a data payload and modulated subcarriers forming the preamble. A circuit turns OFF and ON selected subcarriers based on an encryption algorithm to increase transmit power and signal-to-noise ratio and reduce the Inter-Carrier Interference (ICI). The modulation and mapping circuit applies a quadratic modulation to the subcarriers carrying the training sequences to produce a low peak-to-average power ratio (PAPR) preamble with a PAPR value of approximately 2.6 decibels (dB).04-01-2010
20090086836WIRELESS TRANSMISSION DEVICE - The invention provides a method and device for managing the use of antennas in a multiple antenna wireless transmission system for OFDM signals. The method includes defining a utility function which comprises a performance metric for transmission. Combinations of antenna and OFDM subcarriers are selected to optimise the utility function under two constraints. The first constraint is that the combinations of antenna and subcarrier include only one antenna for each subcarrier, the second constraint is that the combinations include the same number of subcarriers for each antenna.04-02-2009
20090086832PREAMBLE TECHNIQUES FOR COMMUNICATIONS NETWORKS - Techniques are disclosed involving preamble sequences. For instance, an apparatus includes a module to provide a preamble sequence having multiple values, where each of the values corresponds to an orthogonal frequency division multiplexing (OFDM) subcarrier. These multiple values may include multiple blocks of values based on a differentially encoded and scrambled row of a Hadamard matrix. The apparatus may further include a modulation module to produce an OFDM modulated signal from the preamble sequence. Further, techniques for the detection of such preambles are disclosed.04-02-2009
20090279628Transmission Power Control Method In Communication System Using Multiple Carriers And Radio Communication Device Using The Method - A transmission power control method is employed in a communication system, which uses multiple carriers. A plurality of different modulation systems are allocated to a plurality of different frequency subcarriers. A signal amplitude gain corresponding to a predetermined power offset from an average signal power is provided to a corresponding frequency subcarrier for each of the modulation systems allocated to the plurality of different frequency subcarriers. Therefore, service area can be expanded and signal quality can be maintained at a high transmission capacity.11-12-2009
20110026626METHOD OF AND A RADIO TRANSMISSION SYSTEM AND RADIO ACCESS EQUIPMENT FOR CELLULAR WIRELESS RADIO TRANSMISSION - Radio transmission in an Orthogonal Frequency Division Multiplex, OFDM, based cellular wireless radio transmission system, wherein radio access equipment of the system connects to multiple geographically spread radio antennas of a Distributed Antenna System, DAS, for transmitting to and receiving radio signals from user equipment. Transmit timings for radio transmission between the user equipment and the antennas of the DAS are established. The radio transmission is scheduled based on the established transmit timings.02-03-2011
20090080548OFDM DEMODULATION DEVICE - A delay indicator calculator calculates at least two of a first delay indicator indicating a delay time determined based on a correlation value having a predetermined difference from the maximum value of the correlation signal, a second delay indicator indicating a change of a delay time determined based on time during which the correlation signal has no less than a predetermined value, and a third delay indicator indicating a change of a time difference between main and delay path peaks. An estimator generates a state estimation of the transmission path based on the probabilities of the at least two delay indicator values exceeding respective reference values for a plurality of symbols.03-26-2009
20090296841METHOD FOR DETECTING AN OFDM SIGNAL - The present invention relates to a method for detecting the presence of an OFDM signal in a received signal wherein said received signal is down converted into baseband and subjected to a passband filtering corresponding to a band of interest before being sampled. The thus sampled signal is subjected to a second filtering for eliminating at least one interfering line in the band of interest. The presence of an OFDM signal is detected if the signal filtered by the second filtering is cyclostationary.12-03-2009
20090202005Method and Apparatus for Improved Channel Estimation for Communications Signal Processing - Teachings presented herein present a “whitening” channel estimation method and apparatus that produce high-quality net channel estimates for processing a received signal, such as a received CDMA signal. Processing includes forming an initial least squares problem (for medium channel estimates) using known pilot values and corresponding pilot observations for the received signal, transforming the initial least squares problem using a whitening transformation term, and solving the transformed least squares problem to obtain whitened medium channel estimates. The whitening transformation term may be determined, for example, by carrying out a Cholesky factorization of a (traffic) data correlation matrix, which can be obtained from traffic data values for the received signal. Processing further includes converting the whitened medium channel estimates into whitened net channel estimates, which consider the effects of transmit/receive filtering.08-13-2009
20090168912MULTI-CARRIER COMMUNICATIONS WITH ADAPTIVE CLUSTER CONFIGURATION AND SWITCHING - A method and apparatus for allocating subcarriers in an orthogonal frequency division multiple access (OFDMA) system is described. In one embodiment, the method comprises allocating at least one diversity cluster of subcarriers to a first subscriber and allocating at least one coherence cluster to a second subscriber.07-02-2009
20090168908APPARATUS AND METHOD FOR ESTIMATING DELAY SPREAD OF MULTI-PATH FADING CHANNEL IN OFDM SYSTEM - Provided is an apparatus for estimating a delay spread of a multi-path fading channel in an Orthogonal Frequency Division Multiplexing (OFDM) system. The apparatus is applied to an OFDM receiver including a channel equalization unit compensating channel distortion by estimating channel distortion at pilot locations with respect to output signals of an FFT unit.07-02-2009
20090097576OFDM RECEIVER APPARATUS HAVING A PLURALITY OF RECEIVER CIRCUITS AND OFDM RECEIVING METHOD - A receiver circuit in each branch has an FFT unit that performs Fourier transform on OFDM signals. A slave branch FFT window control unit determines whether an undesired wave is a preceding wave or a delay wave, and notifies a master branch of the result. In response to the notification from the slave branch, a master branch FFT window control unit controls a position of an FFT window that indicates a time range in which Fourier transform is performed on OFDM signals.04-16-2009
20110200129METHOD OF TRANSMITTING AND RECEIVING ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING (OFDM) SIGNAL USING MULTIPLE ANTENNAS, AND TRANSMITTER AND RECEIVER THEREOF - Provided is a transmitter for transmitting an orthogonal frequency division multiplexing (OFDM) signal using multiple antennas, including: a subgroup generator to divide data symbols of a frequency domain into a plurality of subgroups; an inverse fast Fourier transform (IFFT) unit to perform an IFFT with respect to each of the subgroups so as to generate partial signals of a time domain corresponding to the plurality of subgroups, respectively; a candidate OFDM signal generator to generate at least two candidate OFDM signals using a combination of the partial signals so that each of the partial signals is transmitted to one of transmit antennas; and a selector to select one of the at least two candidate OFDM signals.08-18-2011
20110200130METHOD AND APPARATUS FOR TRANSMITTING/RECEIVING DATA IN MU-MIMO SYSTEM - A method for transmitting, by a single transmitting station, data to a plurality of receiving stations includes: generating a plurality of data frames including the data and Ack order information; transmitting the plurality of data frames to the plurality of receiving stations; and sequentially receiving block Ack signals from the plurality of receiving stations according to the Ack order information.08-18-2011
20110200128APPARATUS FOR TRANSMITTING AND RECEIVING A SIGNAL AND METHOD OF TRANSMITTING AND RECEIVING A SIGNAL - The present invention relates to method of transmitting and receiving signals and a corresponding apparatus. One aspect of the present invention relates to a method of receiving a signal, which includes interleaving in an appropriate manner for a channel bonding system. The interleaving can allow decoding a user requested service at a random tuner window position.08-18-2011
20110200127Feedback Method and Apparatus for Multiple Base Stations in a Wireless Communication System Supporting Single Base Station MIMO Communication and Multiple Base Stations MIMO Communication - A feedback method for multiple base stations MIMO in a wireless communication system supporting a single base station MIMO (multiple input multiple output) communication and a multiple base stations MIMO communication is disclosed. The present invention includes the steps of transmitting feedback control information for the multiple base stations MIMO to a mobile station and receiving a multiple base stations MIMO feedback message for the multiple base stations MIMO feedback generated based on the feedback control information, wherein the feedback control information includes a target resource unit (TRU) indicating a frequency resource unit to be measured for a feedback.08-18-2011
20120106664Variable Symbol Period Assignment And Detection - Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for dynamically selecting symbol periods for communications signals and recovering symbols from the communications signals. In one aspect, a method includes receiving a plurality of communications signals over a plurality of different communications channels and determining symbol period end times for the communications signals. A determination is made that a present time is coincident with an end of a sample period for the communications signals and that an end of the symbol period for the communications signals received over at least one of the communications channels is coincident with the present time. In turn, data are provided that represent a symbol received over each communications channel for which an end of the symbol period is coincident with the present time.05-03-2012
20090168906Methods and arrangements in a mobile telecommunication network - The present invention relates to a first unit adapted to be used in a base station in a mobile telecommunication network adapted to use an identity for identifying a mobile terminal or for identifying a channel in the uplink. The first unit comprises means for managing information of at least one additional identity of a mobile terminal or a channel, belonging to at least a second base station, it should be aware of for interference mitigation purposes, preferably means for detecting whether the mobile terminal or channel identified by said additional identity is active and means for mitigating cell-interference caused by an active mobile terminal or a channel identified by the additional identity. The invention also relates to a second unit comprising means for reserving at least one identity for identifying a mobile terminal or for identifying a channel in order to make the at least one identity identifiable to at least a second base station.07-02-2009
20090274229WIRELESS COMMUNICATION APPARATUS, WIRELESS COMMUNICATION METHOD, COMPUTER PROGRAM, AND WIRELESS COMMUNICATION SYSTEM - There is provided a wireless communication apparatus including: a matrix estimating unit that estimates a channel matrix of N rows and M columns (N and M are natural numbers); a selecting unit that selects S rows (S is a natural number, and S11-05-2009
20090274227APPARATUSES AND METHODS FOR TRANSMISSION AND RECEPTION IN A CODEBOOK BASED CLOSED-LOOP (CL)-MULTIPLE INPUT MULTIPLE OUTPUT (MIMO) SYSTEM - Apparatuses and methods for transmission and reception in a Closed-Loop (CL)-Multiple Input Multiple Output (MIMO) system are provided. A codebook generation method includes determining weight vectors v11-05-2009
20090274224METHOD AND APPARATUS FOR CONFIGURING CHANNEL QUALITY FEEDBACK IN AN ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING COMMUNICATION SYSTEM - In an Orthogonal Frequency Division Multiplexing communication system wherein a frequency bandwidth is divided into multiple sub-bands, a method and a scheduler is provided for configuring channel quality feedback for a point-to-multipoint communication session involving multiple users equipment (UEs). The scheduler receives multiple channel quality measurements from the multiple UEs and, based on the multiple channel quality measurements, determines whether to implement a frequency selective channel quality feedback scheme or a non-frequency selective channel quality feedback scheme for the point-to-multipoint communication session. The scheduler then implements the determined channel quality feedback scheme. In another embodiment of the invention, the scheduler may determine whether to implement a frequency selective or non-frequency selective channel quality feedback scheme based on a number of UEs serviced by the scheduler.11-05-2009
20090274221METHOD, HARDWARE PRODUCT, AND COMPUTER PROGRAM PRODUCT FOR PERFORMING HIGH DATA RATE WIRELESS TRANSMISSION - A method, a hardware product, and a computer program product for performing high data rate wireless transmission and reception. Minimum shift-keyed (MSK) data is transmitted by multiplexing a first MSK data stream and a second MSK data stream wherein the first MSK data stream is substantially 90-degree phase-shifted with respect to the second MSK data stream. The transmitted MSK data is received by performing phase recovery and demodulation using an FM discriminator having a demodulation circuit for implementing a 45-degree phase shift prior to demodulation.11-05-2009
20090097578Methods for Decoding TPS Carriers in OFDM Systems - The present invention relates to methods for TPS demodulation, frame boundary detection, and TPS decoding. In particular, the present invention relates to a method for finding a frame boundary in demodulating an OFDM signal, comprising the steps of: differentially demodulating each symbol to generate differentially demodulated symbol bits; and finding a sync word position when the scatter pilot position equals zero, wherein the sync word position is set as the frame boundary.04-16-2009
20090202011Techniques to time vary pilot locations in wireless networks - An embodiment of the present invention provides an apparatus, comprising a receiver capable of selecting optimal pilot locations and providing feedback of the pilot locations to a transmitter in communication with the receiver. The optimal pilot locations may be selected by locations that avoid strong interference or platform noise at the receiver, by locations that avoid deep fading, by locations that maximize the spacing between pilot tones at the two ends of a wireless frequency band or by locations that equalize the interspacing between any two adjacent pilots.08-13-2009
20110170622WIRELESS COMMUNICATION APPARATUS AND WIRELESS COMMUNICATION METHOD - A wireless communication apparatus prevents deterioration of communication characteristics because of a transmission weight of a highest common factor and enhances the communication characteristics of feedback MIMO. A wireless communication apparatus having antennas includes a reception unit for obtaining channel state information of channels received from another wireless communication apparatus, a channel state information calculation unit for dividing a predetermined frequency band into regions, selecting a particular region based on the number of channels included in each of the regions and the channel state information of the channels, and calculating representative channel state information of the predetermined frequency band overall based on the channel state information of the channels included in the particular region, a transmission weight selection unit for selecting a transmission weight based on the representative channel state information, and a transmission unit for transmitting identification information of the transmission weight to the another wireless communication apparatus.07-14-2011
20110170621CODEBOOK DESIGN METHOD FOR MULTIPLE-INPUT MULTIPLE-OUTPUT (MIMO) COMMUNICATION SYSTEM AND METHOD FOR USING THE CODEBOOK - A multiple-input multiple-output (MIMO) communication system and method using a codebook, are provided. A transmitter and at least one receiver included in the MIMO communication system may use at least one codebook from among a plurality of codebooks. Codeword matrices included in one of the codebooks may correspond to vectors included in a block diagonal matrix, and another codebook may be configured by rotating the vectors. The codeword matrices of the remaining codebooks may include the rotated vectors and random vectors.07-14-2011
20080317146APPARATUS AND METHOD FOR CHANNEL-INTERLEAVING AND CHANNEL-DEINTERLEAVING DATA IN A WIRELESS COMMUNICATION SYSTEM - An interleaving and deinterleaving apparatus and method in a wireless communication system are provided, in which it is determined whether coded bits to be transmitted in one modulation symbol are selected from a plurality of code blocks. The coded bits are interleaved on a modulation symbol basis if the coded bits to be transmitted in the modulation symbol are selected from a plurality of code blocks.12-25-2008
20110268204MULTIPLE INPUT MULTIPLE OUTPUT COMMUNICATION SYSTEM OF SUPPORTING SEVERAL REPORTING MODES - A plurality of reporting modes used to report feedback information is provided. A transmitter and a receiver generate and share feedback information based on a corresponding reporting mode.11-03-2011
20090262850System and Method of Dynamically Optimizing a Transmission Mode of Wirelessly Transmitted Information - The present invention includes a method of optimizing a transmission mode of wirelessly transmitted data. The method includes selecting a first transmission mode based on a predetermined channel database and a first channel characterization. The first channel characterization can be based upon signals transmitted in an initial mode. An error factor is generated based on a difference between an estimated performance characteristic, and an expected performance characteristic. A subsequent transmission mode is selected based upon the predetermined channel database, the error factor and a subsequent channel characterization. The predetermined channel database can include a predetermined look-up-table that provides transmission mode selections based upon the channel characterizations. The look-up-table generally includes a plurality of quality parameter thresholds that determine the selection of a transmission mode. Another method includes receiving transmission signals that include data encoded in an initial transmission mode. A first quality parameter of the received transmission signals is measured. A subsequent transmission mode is selected based upon the quality parameter. Transmission signals are received having data encoded in the subsequent transmission mode. A second quality parameter is measured. A parameter is adjusted within selection criteria of another subsequent transmission mode based upon the second quality parameter.10-22-2009
20090262849Universal Blind Mode Detector, Guard Mode Detector of The Universal Blind Mode Detector, and Method of Detecting Universal Blind Mode - Provided are a universal blind mode detector capable of universally detecting not only various orthogonal frequency division multiplexing (OFDM) communication services but also non-OFDM communication services, and a fast Fourier transform (FFT) mode detector, a guard mode detector, and a memory sharing structure of the universal blind mode detector, and a method of detecting a universal blind mode. The universal blind mode detector includes a radio frequency (RF) tuner converting a received signal into a baseband frequency signal, an automatic gain control (AGC) unit which is connected to the RF tuner and determines existence of a communication service by referring to a received signal strength indication (RSSI), a communication service mode detection unit determining of which scheme a communication service mode signal is if the AGC unit determines that there is the communication service, and detecting the communication service mode signal, and a channel decoding unit detecting the detected signal.10-22-2009
20090262848METHOD OF DESIGNING A MULTIPLEXING STRUCTURE FOR RESOURCE ALLOCATION TO SUPPORT LEGACY SYSTEM - New multiplexing UL structures for supporting legacy system are provided. A 16m system of diversity mode can be multiplexed with 16e system in PUSC mode in FDM manner with the same tiles/permutation rules. A 16m system can be multiplexed with 16e system in AMC mode in FDM and/or TDM manner. The time length of multiplexed 16e PUSC packets and/or 16m packets can be extended to more than two sub-frames for UL coverage. A PRU for 16m system may consists of 16 sub-carriers by 6 OFDMA symbols, 18 sub-carriers by 6 OFDMA symbols, or 20 sub-carriers by 6 OFDMA symbols when FDM is used.10-22-2009
20090262846APPARATUS AND METHOD FOR TRANSMITTING PILOT SIGNAL IN WIRELESS COMMUNICATION SYSTEM - An apparatus and method for reducing pilot overhead in a multi-antenna system are provided. The method generates postcodes and pre-codes for streams used to transmit signals to at least two receivers. The method allocates a pilot signal to at least one of the streams, and allocates an additional pilot signal shared by at least one of the streams. The method precodes the pilot signal allocated to at least one of the streams, the additional pilot signal, and data to be transmitted to each of the receivers, based on the pre-code for each of the streams, prior to transmission.10-22-2009
20090262845Method for transmitting and receiving data using pilot structure - A method for efficiently transmitting and receiving data in a wireless access system and a pilot allocation structure for the same are provided. In the method, data is transmitted using a resource block constructed taking into consideration channel estimation capabilities and data transfer rate and data is received using the resource block. The resource block includes a predetermined number of pilot symbols constructed in a predetermined pattern and the pilot symbols are allocated to the resource block at a predetermined allocation rate taking into consideration the number of transmit antennas.10-22-2009
20090262844MOBILE STATION APPARATUS AND TRANSMISSION CHANNEL ESTIMATION METHOD - A disclosed mobile station apparatus, which receives a downlink signal including pilots, includes a first estimation unit configured to estimate a delay spread of a transmission channel and a Doppler frequency based on the downlink signal; a determination unit configured to determine, based on the delay spread and the Doppler frequency, an interpolation method to be applied to the pilots; and a second estimation unit configured to perform interpolation using the interpolation method to estimate the transmission channel.10-22-2009
20090262842Robust FFT Trigger Point Tracking for Echo Channels in OFDM Based Communication Systems - Identifying a trigger point of at least one OFDM decoder includes correlating a first time-domain sample of the at least one OFDM symbol with a second time-domain sample of the at least one OFDM symbol, processing the first time-domain sample and the second time-domain sample in the first moving average filter to determine a channel impulse response, comparing at least one correlation value of a first biggest path in the channel impulse response and a second biggest path in the channel impulse response, and determining a channel length of the channel impulse response based on a time duration of the channel impulse response. The OFDM decoder includes a first moving average filter and a second moving average filter.10-22-2009
20100086065BASE STATION, MOBILE STATION, AND COMMUNICATIONS METHOD - A base station carrying out communications with a mobile station with an Orthogonal Frequency Division Multiplexing (OFDM) method by using a predetermined frequency band out of a transmission band is disclosed. The base station includes an allocation portion that allocates, for a mobile station performing peripheral cell search, a band that includes a center frequency on a raster of a first band and has a bandwidth equal to or greater than a bandwidth of a second band with which a synchronization channel is transmitted.04-08-2010
20080240274PRECODING APPARATUS AND METHOD IN A WIRELESS COMMUNICATION SYSTEM USING MULTIPLE INPUT MULTIPLE OUTPUT - A transmission apparatus in a Multiple Input Multiple Output (MIMO)-based wireless communication system. The transmission apparatus includes at least two antenna groups each having at least two antennas, wherein the antenna groups are spaced apart by a first distance and transmit antennas in each antenna group are spaced apart by a second distance which is shorter than the first distance. A channel coding and modulation unit channel-codes and modulates a desired transmission data stream. A precoding unit precodes the channel-coded and modulated signal separately for each antenna group and each antenna in the same antenna group. Thereafter, a transmission processing unit transmission-processes the output signal from the precoding unit.10-02-2008
20090110091DATA PROCESSING APPARATUS AND METHOD - A data processing apparatus maps input symbols to be communicated onto a predetermined number of sub-carrier signals of an Orthogonal Frequency Division Multiplexed (OFDM) symbol. The data processor includes an interleaver memory which reads-in the predetermined number of data symbols for mapping onto the OFDM sub-carrier signals. The interleaver memory reads-out the data symbols on to the OFDM sub-carriers to effect the mapping, the read-out being in a different order than the read-in, the order being determined from a set of addresses, with the effect that the data symbols are interleaved on to the sub-carrier signals. The set of addresses are generated from an address generator which comprises a linear feedback shift register and a permutation circuit. A generator polynomial for the linear feedback shift register of R′04-30-2009
20090110102SIGNAL ROUTING METHOD - A signal routing method adapted to a DWA structure is provided. The signal routing method at least includes following steps. An M-bit input digital signal is provided. The odd bit in the input digital signal is routed into a low-bit signal of an output digital signal, and the even bit in the input digital signal is routed into a high-bit signal of the output digital signal, wherein the output digital signal has M bits.04-30-2009
20090110092DATA PROCESSING APPARATUS AND METHOD - A data processing apparatus is arranged to map input data symbols to be communicated onto a predetermined number of sub-carrier signals of Orthogonal Frequency Division Multiplexed OFDM symbols. The predetermined number of sub-carrier signals is determined in accordance with one of a plurality of operating modes and the input data symbols are divided into first sets of input data symbols and second sets of input data symbols. The data processing apparatus comprises an interleaver operable to perform an odd interleaving process which interleaves the first sets of input data symbols on to the sub-carrier signals of first OFDM symbols and an even interleaving process which interleaves the second sets of input data symbols on to the sub-carrier signals of second OFDM symbols, such that while the input data symbols from the first set are being read from locations in the interleaver memory, input data symbols from the second set can be written to the locations just read from and when input data symbols from the second set are being read from the locations in the interleaver memory, the input data symbols from a following first set can be written to the locations just read from. Furthermore, when the modulation mode is a mode which includes half or less than half a number of sub-carrier signals than a total number of sub-carriers in the OFDM symbols for carrying the input data symbols that can be accommodated by the interleaver memory, the data processing apparatus is operable to interleave the input data symbols from both first and second sets in accordance with the odd interleaving process on to the first and second OFDM symbols.04-30-2009
20090274222System and Method for Initial Ranging in Wireless Communication Systems - A system and method for initial ranging in wireless communication systems is provided. A plurality of orthogonal frequency division multiplexing (OFDM) blocks are received by an OFDMA base station transceiver from a plurality of remote user devices in wireless communication with the base station. A ranging subchannel is extracted from the OFDM blocks. The number of active codes in the ranging subchannel is determined, active codes are identified, and carrier frequency offsets (CFOs) are estimated for each active code. Timing delays and power levels for each active code are then estimated. The estimated CFOs, timing delays, and power levels are broadcasted by the base station to the remote user devices, so that the user devices can utilize same to adjust transmission parameters to optimize power levels and synchronize communication with the base station.11-05-2009
20090274231BASE STATION, SUBORDINATED STATION AND TRANSMISSION METHOD THEREOF - A base station (BS), a subordinated station (SS) and the transmission methods thereof for use in a multi-input multi-output (MIMO) network are provided. The BS stores resource allocation information about the MIMO network and an SS list, and generate a super frame according to the resource allocation information and the SS list. The super frame comprises a pilot pattern which comprises a plurality of pilots and data. The BS and SS both considers the pilot pattern as an identifier of the SS. When there are communications occurred between the BS and the SS, the BS/SS will confirm whether the pilot pattern of the super frame matches the identifier of the SS to reduce interference from other stations in the MIMO network.11-05-2009
20090274226SOUNDING CHANNEL BASED FEEDBACK IN A WIRELESS COMMUNICATION SYSTEM - An apparatus and method for providing sounding channel based feedback in an OFDM communication system includes a first step (11-05-2009
20090279622Unknown - In a method for sending communication signals, space-time block coding is performed by dividing a data stream of complex-value data symbols into a number K11-12-2009
20090296835Communication Control System, Radio Communication Terminal and Communication Control Method - A communication control system according to the present invention transmits and receives multiple data flows having different priorities to and from a radio communication terminal by a multicarrier using multiple carriers. The communication control system is provided with a carrier transmitter configured to transmit the multiple carriers to the radio communication terminal 12-03-2009
20090296842SOFT OUTPUT M-ALGORITHM RECEIVER STRUCTURES WITH GENERALIZED SURVIVOR SELECTION CRITERIA FOR MIMO SYSTEMS - A method and apparatus is disclosed herein for a modified soft output M-algorithm. In one embodiment, the soft output M-algorithm is employed by a receiver in a wireless communication system to receive information-bearing signals wirelessly transmitted from the transmitter wirelessly transmitted, the receiver comprising: an inner decoder structure having a multiple-in multiple-out (MIMO) joint demapper to perform joint inner demapping over each tone, the joint demapper being operable to apply a soft-output M-type algorithm to identify survivor candidates at each depth in a detection tree being searched for each tone, including surviving full-length candidates, based on at least one metric and at least one other criterion, where a number of best alternatives from every level of the tree are expanded along with one or more alternatives selected meeting the at least one other criterion and where soft-output related information is collected and stored for each bit, and an outer decoder operable with the inner decoder to perform iterative decoding.12-03-2009
20090279624METHOD AND APPARATUS FOR SPATIAL MAPPING MATRIX SEARCHING - A spatial mapping matrix searching apparatus may include a plurality of antennae configured to receive a plurality of transmission signals, a post-coding module configured to generate a post-coding information according to the received plurality of transmission signals and generate a received signal from the received plurality of transmission signals, and a pre-coding module configured to generate a pre-coding information according to the post-coding information.11-12-2009
20090279621Signal converter and multimedia system using the same - In a signal converter and a multimedia system using the same, the multimedia system includes an image capture device, a first signal converter, a second signal converter. The image capture device is configured for capturing images, converting the images into a first electronic signal, and transmitting the first electronic signal through a first type transmission interface. The first signal converter is configured for receiving the first electronic signal, modulating the first electronic signal by the orthogonal frequency-division multiplexing (OFDM) technology to obtain a second electronic signal suited for a second type transmission interface. The second signal converter is configured for receiving and modulating the second electronic signal through the second type transmission interface. The first type transmission interface is different from the second type transmission interface.11-12-2009
20090279623SYSTEM AND METHOD FOR PILOT DESIGN - A method for generating a pilot pattern for data to be transmitted in an orthogonal frequency-division multiplexing (OFDM) based communication system includes: allocating pilot symbols for a plurality of data streams to form a plurality of pilot clusters in the pilot pattern, wherein each of the pilot clusters includes ones of the pilot symbols, the ones of the pilot symbols being for respectively different ones of the data streams.11-12-2009
20090285319Efficient Physical Layer Preamble Format - A method for generating a preamble of a data unit for transmission via a communication channel includes generating a first field of the preamble using one of a first sequence or a second sequence, such that the first sequence and the second sequence are complementary sequences such that a sum of out-of-phase aperiodic autocorrelation coefficients of the first sequence and the second sequence is zero; generating, using the other one of the first sequence or the second sequence, an indicator of a start of a second field of the preamble, the second field associated with channel estimation information, such that the indicator of the start of the second field immediately follows the first field; and generating the second field of the preamble.11-19-2009
20090285318Digital Broadcast Receiver and Digital Broadcast Receiving Apparatus - An FFT unit generates a frequency-domain signal for one-segment broadcasting and a frequency-domain signal for full-segment broadcasting. Under a good reception environment, the frequency-domain signal for the full-segment broadcasting is extracted by a switching control unit and the transmitted data for the full-segment broadcasting are recovered. When the reception environment deteriorates, both the one-segment broadcasting and the full-segment broadcasting are temporary demodulated. After a delay time due to the demodulation process has passed, a reception mode is switched from the full-segment broadcasting to the one-segment broadcasting.11-19-2009
20090285316METHODS AND SYSTEMS FOR INITIAL FCH PROCESSING - Methods and apparatus for initially decoding a frame control header (FCH) in an orthogonal frequency-division multiplexing (OFDM) or orthogonal frequency division multiple access (OFDMA) system in an effort to accurately determine the downlink frame prefix (DLFP) such that the remainder of an OFDM/A frame may be properly decoded are provided. Used, for example, when boosting factors applied in the transmitter to various elements of the OFDM/A frame and/or available pilots for the FCH are unknown, such methods may utilize a preamble channel estimate, the FCH pilots, or a combination thereof.11-19-2009
20090290653METHOD FOR TRANSMITTING PILOT FOR MULTIPLE CARRIER SYSTEM - A method of transmitting pilot signals in a system which performs communication using two or more earners comprises transmitting first pilots and second pilots from at least one user equipment to a base station, the first and second pilots, which are transmitted from the at least one user equipment, being multiplexed by code division multiplexing, and the first and second pilots, which are transmitted from a specific user equipment, having different transmission powers, and transmitting data from the at least one user equipment to the base station depending on the first pilots and the second pilots. Since many UEs can transmit CQ pilots, exact channel estimation can be performed and thus communication efficiency can be improved.11-26-2009
20090103642COMMUNICATION APPARATUS, COMMUNICATION METHOD, CIRCUIT MODULE AND INTEGRATED CIRCUIT - In communication method for communicating via a transmission channel to which first communication apparatuses communicating based on a first communication system, second communication apparatuses communicating based on a second communication system, and third communication apparatuses communicating based on a third communication system are connected, a data transmission domain and a notification domain for notifying a data transmission within the data transmission domain are allocated to the first communication apparatuses, the second communication apparatuses, and the third communication apparatuses, respectively. In the communication method, notices of the data transmission for each of the first communication apparatuses, the second communication apparatuses and the third communication apparatuses are transmitted within the notification domain, and the data transmission domain is reallocated in accordance with the notices transmitted from the first, second and third communication apparatuses.04-23-2009
20090103640METHOD AND AN APPARATUS FOR TIMING CONTROL OF CHANNEL ESTIMATION - The present invention relates to a method and an apparatus for timing control of channel estimation. The method includes: sequentially shifting a channel estimation window in a power-delay profile in a specific time interval to obtain a plurality of candidate segments; sequentially calculating a metric corresponding to the candidate segments according to the delay paths and the channel power contained in the candidate segments; among the metrics, finding out an optimal segment with the maximum metric and deciding a timing of channel estimation based on the optimal segment.04-23-2009
20090296840DATA PROCESSING APPARATUS AND METHOD - A data processing apparatus is operable to map input data symbols to be communicated onto sub-carrier signals of Orthogonal Frequency Division Multiplexed OFDM symbols. The number of sub-carrier signals the available from each of the OFDM symbols being variable between OFDM symbols and the input data symbols include first sets of data symbols and second sets of input data symbols. The data processing apparatus includes a controller, an address generator and an interleaver memory. The controller is operable, when operating in accordance with an even interleaving process to read out a first set of the input data symbols from the interleaver memory on to the sub-carrier signals of an even OFDM symbol using read addresses generated by the address generator, and to write in a second set of the input data symbols into the interleaver memory using the addresses generated by the address generator. The controller is operable in accordance with an odd interleaving process, to read out a first set of input data symbols from the interleaver memory on to the sub-carrier signals of an odd OFDM symbol using read addresses determined in accordance with a sequential order of the first set of input data symbols, and to write in a second set of the input data symbols into the interleaver memory at write addresses determined in accordance with the sequential order of the first group of input data symbols. The controller is operable to determine before reading out the first input data symbols from the interleaver memory, whether the read address is valid for a previous OFDM symbol, and to determine before writing the second input data symbols into the interleaver memory, whether the write address is valid for a current OFDM symbol. As such, the interleaver memory size can be minimised to an amount which corresponds to a maximum number of sub-carriers, which are available for any of the OFDM symbols. Application can be found with Cable 12-03-2009
20090080554TONE ALLOCATION IN MULTIPOINT-TO-POINT COMMUNICATION USING ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING - Systems and methods for OFDM tone allocation are provided. In one embodiment, an end-user communication device comprises: a first remote unit for communicating with a host unit using orthogonal frequency division multiplexing (OFDM), the host unit communicatively coupled to a plurality of remote units in a multipoint-to-point configuration, wherein OFDM waveform from distinct remote units of the plurality of remote units combine to a unified OFDM waveform at the host unit. The first remote unit is configured to transmit up to a plurality of tones, the up to a plurality of tones modulated with upstream information using OFDM. The first remote unit is configured to determine when bandwidth is needed for upstream transmission to the host unit. The first remote unit is configured to transmit a request for bandwidth to the host unit on a first tone of the plurality of tones, wherein access to the first tone is contention-based.03-26-2009
20090296836CHANNEL ESTIMATION METHODS AND APPARATUS UTILIZING THE SAME - A channel estimation device and method for an orthogonal frequency division multiplexing (OFDM) system for receiving OFDM symbols to generate channel estimation information is provided. The channel estimation method includes: obtaining a portion of pilot signals from a plurality of pilot signals as a first pilot set according to corresponding positions of the pilot signals in the OFDM symbols; estimating a first estimation factor by calculating the pilot signals in the first pilot set in a first direction; estimating a second estimation factor by calculating the pilot signals in the first pilot set in a second direction; obtaining a pilot signal estimation result according to the first estimation factor and the second estimation factor; and obtaining the channel estimation information according to the pilot signal estimation result.12-03-2009
20100166090WIRELESS COMMUNICATION SYSTEM USING PILOT ALLOCATION, METHOD AND PILOT PATTERN THEREOF - A wireless communication system using pilot allocation, method and pilot pattern thereof are disclosed. The method is applied for allocating pilots for transmission of multiple pilot streams in a multiple-input-multiple-output (MIMO) antenna system using orthogonal frequency division multiplexing (OFDM) modulation. In embodiment, the pilot allocation are applied in contiguous frame structure, and two pilots are allocated for each pilot stream in frame structure comprising 18 subcarriers and 6 OFDM symbols. The 8 pilot streams are grouped into two pilot stream clusters, and pilots for each pilot stream cluster are grouped into two pilot clusters. Four pilot clusters are then allocated in first frame structure, and the allocation of the pilot clusters in second frame structure corresponds to those in first frame structure. Therefore, better transfer rate in such wireless communication system can be achieved.07-01-2010
20090041143MULTI-CARRIER TRANSMISSION SYSTEM - Multi-carrier transmission system comprises transmitter including acquisition unit configured to acquire 202-12-2009
20090041140METHOD FOR BLINDLY DETECTING A PRECODING MATRIX INDEX - A method for blindly detecting a precoding matrix index used to transmit a data or control signal is provided. The method includes receiving at a mobile station (02-12-2009
20090041139APPARATUS AND METHOD FOR TRANSMITTING/RECEIVING UPLINK CONTROL CHANNELS IN A WIRELESS COMMUNICATION SYSTEM - A method and apparatus for transmitting/receiving pilot symbols for demodulation of control channel information in the uplink of a wireless communication system are provided. When an Evolved Node B (ENB) expects to receive both the Channel Quality Information (CQI) and the Acknowledgement (ACK)/Negative ACK (NACK) from a User Equipment (UE) in a certain subframe, if the UE transmits only the CQI channel, the ENB is prevented to detect the nonexistent ACK/NACK information from the CQI channel, thereby avoiding false alarm.02-12-2009
20090041137INDIVIDUAL INTERLEAVING OF DATA STREAMS FOR MIMO TRANSMISSION - The present invention, generally speaking, provides interleavers and methods of interleaving that satisfy the need for backward compatibility while effectively addressing competing design objectives. In accordance with one aspect of the invention, data is transmitted using a number of transmit antennas greater than an expected number of receive antennas. At least one pair of transmit antennas (ant′_1, ant′_) is formed, and multiple second data streams (02-12-2009
20090041134Methods and Apparatus for Channel Estimation for Wideband Ofdm Communication Systems - Systems and methods according to the present invention provide channel estimation methods, systems and devices which determine a coarse channel estimate (02-12-2009
20100111210COMMUNICATION METHODS AND SYSTEMS HAVING PERMUTATION SCHEMES - A wireless communication method implemented in a communication system includes receiving a first data sequence, and processing the first data sequence to obtain information containing at least one of a first number and a sampling spacing associated with the first data sequence. The method also includes permuting the first data sequence to generate a permuted second data sequence. Permuting the first data sequence includes determining a first parameter based on at least one of the first number and the sampling spacing, determining a second parameter based on at least one of the first parameter, the first number, and the sampling spacing, and determining a mapping relationship between a j-th data item of the permuted second data sequence and an i-th data item of the first data sequence. The method further includes outputting the permuted second data sequence.05-06-2010
20100111212Decision Feedback Channel Estimation And Pilot Tracking for OFDM Systems - Current OFDM systems use a limited number of symbols and/or sub-channels to provide approximations for channel estimations and pilot tracking, i.e. phase estimations. For example, two training symbols in the preamble of a data packet are used to provide channel estimation. Four of the fifty-four sub-channels are reserved for providing phase estimation. However, noise and other imperfections can cause errors in both of these estimations, thereby degrading system performance. Advantageously, decision feedback mechanisms can be provided to significantly improve channel estimation and pilot tracking in OFDM systems. The decision feedback mechanisms can use data symbols in the data packet to improve channel estimation as well as data sub-channels to improve pilot tracking.05-06-2010
20100111208COMMUNICATION METHODS AND SYSTEMS HAVING PERMUTATION SCHEMES - A wireless communication method implemented in a communication system may include receiving a data sequence to be permuted, and obtaining information associated with the data sequence to be permuted, the information containing at least a length of the data sequence and a sampling spacing for permuting the data sequence. The method may also include identifying a first portion of the data sequence having a first number of adjacent data items, and a second portion of the data sequence having a second number of adjacent data items. The method may also include accessing the first number of data items from the first portion at the sampling spacing, and placing the accessed first number of data items into a predetermined number of sub-blocks included within a permuted data sequence to be generated based on the received data sequence. The method may further include inserting each of the second number of data items into an end position of one of the sub-blocks within the permuted data sequence, and outputting the permuted data sequence.05-06-2010
20080212693Transmitter and Receiver for Ultra-Wideland Ofdm Signals Employing a Low-Complexity Cdma Layer for Bandwidth Expansion - A method and apparatus for transmitting and receiving high-bandwidth OFDM signals, while limiting the complexity of the OFDM signal processing is described. Bandwidth expansion is achieved by repetition of whole OFDM symbols with the polarity of repetitions determined by a long PN code. This technique ensures a perfectly white spectrum. Use of zero-suffix OFDM symbols allows a large tolerance to multipath channels, even while maintaining a single, low-rate RAKE finger for despreading in the receiver.09-04-2008
20080212697Doppler Dependent Power Control and Sub-Carrier Allocation in ofdm Multiple Access Systems - Digital data Symbols from a transceiver are transmitted to at least two remote transceivers in a wireless Communications System employing Orthogonal Frequency Division Multiplexing, wherein a number of available sub-carriers are shared between said remote transceivers. Information about magnitudes of Doppler effect experienced by the remote transceivers is provided; sub-carriers are allocated to each remote transceiver in dependence of the information about magnitudes of Doppler effect; and a power level transmitted to each of said remote transceivers is controlled in dependence of the Information about magnitudes of Doppler effect. In this way the reception of OFDM Signals for transceivers moving at high speed and thus experiencing a high Doppler effect is improved without degrading the reception quality for transceivers with low or no Doppler effect. Thus the Performance of a System based on OFDM and multiple access is improved.09-04-2008
20080212701METHOD AND APPARATUS FOR TRANSMITTING CONTROL SIGNALING FOR MIMO TRANSMISSION - A method and apparatus for processing multiple-input multiple-output (MIMO) transmission are disclosed. A wireless transmit/receive unit (WTRU) receives downlink control information including WTRU-specific MIMO and transport format information and MIMO information for all other WTRUs assigned to the same resource. The WTRU processes received MIMO data based on the downlink control information. The downlink control information may also include transport format information for all other WTRUs assigned to the same RB. The downlink control information may be transmitted via WTRU-specific control signaling. All WTRUs' MIMO and/or transport format information may be transmitted via resource-specific common control signaling. The downlink control signaling format may include at least one of a number of streams for the WTRU, a number of active WTRUs assigned to the same resource, a spatial channel identity for the WTRU, a MIMO mode, a precoding matrix index and a precoding vector index.09-04-2008
20080212696Radio-Communication Device and Radio-Communication Method - The disclosed invention determines whether a reception packet is an MM packet or a GF packet with precision and avoids unnecessary decoding operations performed at the GF-packet-reception time and inefficient communications.09-04-2008
20080212705RADIO COMMUNICATION METHOD, RADIO TRANSMITTING APPARATUS, AND RADIO RECEIVING APPARATUS - A duplicating section duplicates a bit sequence to be input, and a 16QAM section modulates a bit sequence of a duplicating source to form a symbol, a 16QAM section modulates the duplicated bit sequence to form a symbol, an S/P section parallel converts the symbol sequence input in series, an S/P section parallel converts the symbol sequence input in series, and an IFFT section 09-04-2008
20080212704MIMO TRANSMISSION AND RECEPTION METHODS AND DEVICES - In a wireless transmitting device which performs transmission by an OFDM using a plurality of subcarriers orthogonal to each other, a plurality of preambles to which a plurality of different subcarrier groups selected from a plurality of subcarriers within an OFDM signal band are allocated are transmitted by using a plurality of transmit antennas, and data is transmitted by using the antennas after the preambles are transmitted.09-04-2008
20080212702PRECODED PILOT TRANSMISSION FOR MULTI-USER AND SINGLE USER MIMO COMMUNICATIONS - The disclosed method and apparatus include an WTRU-specific reference signal scheme that provides efficient precoded pilot transmission and effective channel estimation using dedicated pilot signals. The disclosed methods are efficient for both a single user (SU) and a multi user (MU) Multiple Input Multiple Output (MIMO) system.09-04-2008
20080212695Transmission Methods and Apparatus in Multi-Band Ofdm Wideband Systems - Methods and apparatus for use in a multi-band OFDM wideband transmission systems are disclosed. A frame of source data is mapped by a transmitter for transmission using a first mapping. The frame of source data is then mapped by the transmitter for retransmission using a second mapping to increase frequency diversity. A receiver may identify source data that experiences fading and communicate the tone/frequency on which the fading occurred to the transmitter so that the transmitter may map the source data that experienced fading during transmission to another tone/frequency for retransmission.09-04-2008
20080212692Method and apparatus for multimode, point to multipoint base station capable of supporting both OFDM and OFDMA subscribers - A method and system for providing multilingual wireless communications network are disclosed. The present invention discloses a mechanism of receiving and/or transmitting an OFDM data stream using IEEE 802.16-2004 standard and an OFDMA data stream using IEEE 802.16e standard. A timing division duplexing (“TDD”) frame is configured to contain data that has different standards. At least a portion of OFDM data is allocated in a portion of the TDD frame while a portion of OFDMA data is allocated in another portion of the TDD frame. The TDD frame is subsequently transmitted to both OFDM subscriber stations and OFDMA subscriber stations.09-04-2008
20110268206METHOD AND DEVICE OF CHANNEL ESTIMATION FOR OFDM SYSTEM - The present invention relates to the field of communication technology. A channel estimation device for an Orthogonal Frequency Division Multiplexing (OFDM) system is provided for performing channel estimation on data based on synchronization signal and pilot, which comprises: a synchronization signal based initial channel estimation module for performing initial channel estimation based on a synchronization signal in the data; a pilot channel tracking module for performing pilot channel tracking on the result of the initial channel estimation; a noise reduction module for performing noise reduction on the result of the pilot channel tracking; and an effective sub-carrier extraction module for extracting channel estimation values of effective sub-carriers from the result of the noise reduction. With the channel estimation method and device for OFDM system according to the present invention, the channel estimation is carried out jointly based on the synchronization signal and the pilot, such that the accuracy of channel estimation can be significantly improved and the performance requirements of the system can be satisfied without increasing the density of pilots and thus reducing the amount of system payload. Moreover, the synchronization signal can still be used for its original purpose of carrier and timing synchronization.11-03-2011
20090274230Progressive Feedback For High Resolution Limited Feedback Wireless Communication - A system and method is proposed for progressively quantizing channel state information for application in a MIMO (multiple input multiple output) communication system. A method includes computing an estimate of a communications channel between a subscriber unit and a base station, quantizing the estimate with a first codebook, thereby producing a first quantized estimate, quantizing an (n−1)-th quantized estimate with an n-th codebook, thereby producing an n-th quantized estimate, where n is an integer value ranging from 2 to R, R is a total number of quantizations of the estimate, wherein the n-th codebook is a localized codebook. The method also includes incrementing n, repeating the quantizing an (n−1)-th quantized estimate until n=R, and transmitting information based on the R quantized estimates to the base station.11-05-2009
20120294380METHOD FOR SELECTING USER - Disclosed herein is a method for selecting a user. A method for selecting a user in a communication system including a base station having M antennas and K users having one receive antenna includes: (a) calculating channel orthogonality between each of the possible users and previously selected users; and (b) selecting users having the largest channel orthogonality calculated at the step (a) among the possible users.11-22-2012
20110206146CHANNEL ESTIMATION USING REPLICAS ZERO FORCING - Channel estimation for a wireless Orthogonal Frequency Division Multiplexed (OFDM) link having pilots on at least some carriers in at least some symbols may be implemented by performing first and second channel estimation processes. The first channel estimation process uses only frequency domain interpolation of the pilots to obtain a first candidate channel estimate for the OFDM link, and the second channel estimation process uses both time domain interpolation and frequency domain interpolation of the pilots to obtain a second candidate channel estimate for the OFDM link. One of the first and second candidate channel estimates is selected for processing a communication received via the OFDM link.08-25-2011
20110268203Techniques for Decoding Transmitted Signals Using Reactive Taboo Searches (RTS) - Techniques for enabling an estimate of a transmitted signal vector, given a received signal vector and a channel matrix to be computed, are provided. An initial solution signal vector for the estimate is calculated, and based on the initial estimate, a pool of possible solutions is generated. Methods described herein may be iterative in nature, and may cycle through possible estimates of the transmitted signal vector so as to continually improve the estimates and the pool of possible estimates. The methods may terminate once stopping criteria are reached. In some example methods, solutions may be marked at taboo and a taboo period can be established that indicates a number of subsequent iterations for which the current solution signal vector cannot be considered.11-03-2011
20100061472METHOD AND ARRANGEMENT FOR PILOT PATTERN BASED CONTROL SIGNALLING IN MIMO SYSTEMS - The present invention relates to control signaling in wireless communication systems. In particular, the present invention relates to control signaling in MIMO based communication systems. In the method according to the invention control information is transferred from a base station to at least one user equipment, via a plurality of common pilot channels. A set of unique pilot sequences has been pre-defined, and the base station assigns specific pilot sequences from the set of pilot sequences to specific common pilot channels, forming a pilot sequence assignment pattern representing a specific control information. The user equipment, having knowledge of the relations between pilot sequence assignment patterns and control information, interprets the received pilot sequence assignment pattern as specific control information. The method is particularly well suited for broadcast type control information.03-11-2010
20090168911APPARATUS AND METHOD FOR CHANNEL INFORMATION FEEDBACK IN MULTIPLE ANTENNA SYSTEM - An apparatus and method for channel information feedback in a multiple antenna system are provided. The method includes selecting at least one code for at least one Eigen vector based on channel information with a serving node from a codebook including at least one code, constructing a set of codes orthogonal to a first code including the at least one selected code, and indicating the first code using an amount of information that enables expression of the codes of the codebook, indicating codes, other than the first code, in the constructed set using an amount of information that enables expression of the codes included in the set and performing feedback to the serving node.07-02-2009
20090168910TRANSMITTING DEVICE, TRANSMITTING/RECEIVING DEVICE, TRANSMITTING METHOD AND TRANSMITTING/RECEIVING METHOD - A transmitting device according to the present invention comprises: a coding unit which encodes a transmission information bit string to a code bit string; a low-order modulating unit which conducts low-order modulation on the code bit string outputted from the encoding unit; a first frequency domain converting unit which converts the low-order modulated signal outputted from the low-order modulating unit to a frequency domain signal; a partial spectrum selecting unit which selects a central 1/M portion (M is an integer greater than or equal to two) of a spectrum from the frequency spectrum outputted from the first frequency domain converting unit; and a first time domain converting unit which converts the spectrum selected signal outputted from the partial spectrum selecting unit to a time domain signal.07-02-2009
20080225961APPARATUS AND METHOD TO ESTIMATE SAMPLING OFFSET - A sampling offset estimation apparatus including a pilot sub-carrier refiner, an information sub-carrier refiner, a data sub-carrier refiner, and a sampling offset estimator. The pilot sub-carrier refiner to refine a pilot sub-carrier extracted from a differential demodulated signal, and to generate a reference pilot sub-carrier. The information sub-carrier refiner to refine an information sub-carrier extracted from the differential demodulated signal, and to generate a reference information sub-carrier. The data sub-carrier refiner to refine a data sub-carrier extracted from the differential demodulated signal, and to generate a reference data sub-carrier. The sampling offset estimator to estimate a sampling offset included in the differential demodulated signal, on a basis of the reference pilot sub-carrier, the reference information sub-carrier, and the reference data sub-carrier.09-18-2008
20090296837SIGNALING METHOD IN AN OFDM MULTIPLE ACCESS SYSTEM - A method for reducing the peak-to-average ratio in an OFDM communication signal is provided. The method includes defining a constellation having a plurality of symbols, defining a symbol duration for the OFDM communication signal, and defining a plurality of time instants in the symbol duration. A plurality of tones are allocated to a particular communication device, and a discrete signal is constructed in the time domain by mapping symbols from the constellation to the time instants. A continuous signal is generated by applying an interpolation function to the discrete signal such that the continuous signal only includes sinusoids having frequencies which are equal to the allocated tones.12-03-2009
20100135424COMMUNICATION APPARATUS - A communication apparatus includes: a plurality of antennas; a pre-processing unit that, according to an instruction from a higher-level layer, performs processing on each zone generated by time-division of a transmission frame and generates a transmitting signal; and post-processing units that transmit the transmitting signal generated corresponding to each zone via one or more of the antennas. Each post-processing unit includes transmission of a preamble via each of the antennas. Thus, each post-processing unit transmits the preamble in a format that enables a receiving side to correctly determine AGC power control amount.06-03-2010
20110206150UWB SYSTEM EMPLOYING GAUSSIAN MINIMUM SHIFT KEY MODULATION, COMMON MODE SIGNALING, AND BEAMFORMING - A multi-mode transmission system supporting OFDM and single-carrier signals is configured to perform interpolation and decimation such that the ratio of the interpolation factor to the decimation factor equals the ratio between the OFDM sampling rate and the single-carrier chip rate. A constant-envelope modulator comprises a π/4 fixed rotator, a π/2 continuous rotator, and in-phase and quadrature-phase analog Bessel filters. Frame formats and signaling protocols are provided for signal acquisition, synchronization, and tracking between wireless devices that employ different antenna configurations. Spreading gains are selected to compensate for different antenna gains such that the total gain (antenna gain plus spreading gain) is substantially equal for transmissions employing different beam patterns.08-25-2011
20110206149METHOD AND SYSTEM FOR EFFICIENT TRANSMISSION AND RECEPTION OF RF ENERGY IN MIMO SYSTEMS USING POLAR MODULATION AND DIRECT DIGITAL FREQUENCY SYNTHESIS - A first oscillating signal may be generated via a first direct digital frequency synthesizer of a communication device. One or more second oscillating signals may be generated via one or more second direct digital frequency synthesizers of the communication device. Signals received via a plurality of antennas may be processed utilizing the first oscillating signal. Signals to be transmitted via the plurality of antennas may be processed utilizing the first oscillating signal and the one or more second oscillating signals. The communication device may comprise a plurality of receive channels, a plurality of transmit channels, and a multiplexer. The first oscillating signal may be coupled, via the multiplexer, to the plurality of receive paths and one of the transmit paths. During time intervals in which the communication device is configured to receive signals via the plurality of antennas, the multiplexer may route the first oscillating signal to the first one or more direct digital frequency synthesizers.08-25-2011
20110206148METHOD FOR MITIGATING INTERFERENCE IN OFDM COMMUNICATIONS SYSTEMS - The method for mitigating interference in Orthogonal Frequency Division Multiplexing (OFDM) communications systems uses comb-type pilot signals in a doubly selective channel where the pilot signals are calculated to have zero correlation sequences in order to maintain orthogonality where there is a high Doppler effect to mitigate intercarrier interference. The pilot signals may be precomputed, stored in a look-up table, and selected based upon total power constraints of the pilot signals. The steps of the method may be performed by a Finite Impulse Response (FIR) equalizer.08-25-2011
20110206145Methods and Apparatus for Secure Distribution and Storage of Data Using N Channels - Methods and apparatus are provided for secure distribution and storage of data using N channels. An input data sequence, X, is distributed using a plurality, N, of channels. In one embodiment, the input data sequence, X, is split into N subsequences; and the N subsequences are encoded into N bit streams using a set of Slepian-Wolf codes with N separate encoders and a joint decoder. The Slepian-Wolf codes can be selected to ensure a computational complexity to obtain a portion of the input data sequence grows exponentially with respect to a length of the input data sequence unless all of the N bit streams are compromised. In another embodiment, the input data sequence, X, is compressed using a lossless data compressing techniques; and the compressed input data sequence is split into N subsequences that are distributed.08-25-2011
20100135426MODULATION SCHEME FOR ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING SYSTEMS OR THE LIKE - Briefly, in accordance with one embodiment of the invention, bit and power loading may be utilized to select a modulation rate and subcarrier power scaling based on channel state information. As a result, a higher data rate may be utilized for a given signal-to-noise ratio while maintaining a constant bit error rate.06-03-2010
20100135423Determining a Frequency Error in a Receiver of a Wireless Communications System - A frequency error of received signals in an OFDM receiver of a wireless communications system is determined. Symbols of a given duration are transmitted as cells on sub-carrier frequencies; and some of the cells are pilot cells modulated with reference information. The method comprises the steps of selecting at least three pilot cells (p06-03-2010
20100135420ANTENNA MULTIPLEXING SYSTEM AND METHOD OF SMART ANTENNA AND MULTIPLE-INPUT MULTIPLE-OUTPUT ANTENNA - An antenna multiplexing system and a method of a smart antenna and a Multiple-Input Multiple-Output antenna are provided, wherein the system includes a MIMO antenna array and a smart antenna array, the smart antenna array includes several groups of antenna array elements in which the distance between neighbor antenna array elements is less than or equal to one half of wavelength, and the smart antenna array comprises at least two groups of antenna array elements with the coherence sufficient for the requirement of the MIMO applications. The method includes: in accordance with the type of the data to be transmitted, determining a transmitting mode and processing the data to be transmitted accordingly, and in accordance with the transmitting mode, controlling the MIMO antenna array or smart antenna array, so as to transmitting the data to the mobile terminal. With the premise that the actual coverage of TD-SCDMA system should be further improved, the requirement of higher user throughout could be met, and the MIMO antenna system could satisfy the requirement of the future system evolution. Both of the applications of the MIMO and the smart antenna could be met with the use of the same antenna feeding system, and the adaptive switching of the MIMO and the smart antenna with respect to the user could be achieved.06-03-2010
20090097580Apparatus and Method For Modulating Data Message By Employing Orthogonal Variable Spreading Factor (OVSF) Codes In Mobile Communicating System - A method for converting source data to a channel-modulated signal having a plurality of pairs of in-phase (I) and quadrature-phase (Q) data in a mobile station, wherein the mobile station uses at least one channel, includes the steps of: a) encoding the source data to generate at least one data part and a control part; b) generating at least one spreading code to be allocated to the channel, wherein each spreading code is selected on the basis of a data rate of the data part and the control part and spreading codes are selected so that two consecutive pairs of the I and Q data are correspondent to two points located on same point or symmetrical with respect to a zero point on a phase domain; and c) spreading the control part and the data part by using the spreading code, to thereby generate the channel-modulated signal. The method is capable of improving a power efficiency of a mobile station by reducing a peak-to-average power ratio in a mobile communication system.04-16-2009
20100128806METHOD FOR PLANNING A DIGITAL VIDEO BROADCASTING NETWORK - A method and a system for planning a digital video broadcasting network in a geographic area of interest includes simulating an electromagnetic field propagation in a plurality of area elements of the area of interest; for at least one area element of the plurality, performing a decoding of the simulated radio signals which, as a result of the simulating, are received at that area element, and based on a result of the decoding, determining a service coverage in the area of interest, wherein the network is a digital video broadcasting-handheld network and performing a decoding of the radio signals includes changing a position in time of a decoding time window, in particular, for determining the position wherein the ration signal/noise is maximum.05-27-2010
20100128805TRANSMITTER, RECEIVER AND COMMUNICATION METHOD - A transmission device includes: system information generation means for generating system information; multiplexing means for multiplexing system information required for cello search among the system information with a report channel and multiplexing system information other than the system information required for the cell search with a common data channel; and transmission means for transmitting the report channel and the common data channel.05-27-2010
20090046792METHOD AND SYSTEM OF TIME-OF-ARRIVAL ESTIMATION FOR ULTRA WIDEBAND MULTI-BAND ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING SIGNALS - A time-of-arrival (TOA) estimation method for multi-band orthogonal frequency division multiplexing (MB-OFDM) signals uses a simple equally-spaced channel model to recover the impulse response of the wireless channel, and locates the delay of the first channel path by minimizing the energy leakage from the first channel path. The TOA is estimated based on the delay. Such a method does not require channel information for TOA estimation at the receiver and does not require modification of the receiver structure. The method also avoids a sub-optimal solution known to occur in maximum likelihood (ML) estimation.02-19-2009
20090168909TRANSMITTING APPARATUS AND METHOD, AND RECEIVING APPARATUS AND METHOD - A method of transmitting data symbols via an Orthogonal Frequency Division Multiplexed (OFDM) symbols, includes forming data symbols into pairs, generating a first pair of modulation symbols for each of the pairs of data symbols, the first pair of modulation symbols forming first and second modulation symbols of an Alamouti cell, forming a first version of the OFDM symbols by modulating the sub-carriers allocated for carrying the data with the first and second modulation symbols of the Alamouti cells, and modulating the one or more pilot carriers of the first version of the OFDM symbol according to a predetermined pattern. The method also comprises generating a second pair of modulation symbols for each of the pairs of data symbols, the second pair of modulation symbols forming third and fourth modulation symbols of the Alamouti cell formed for the pair of data symbols in the first version of the OFDM symbol, forming a second version of the OFDM symbol by modulating the sub-carriers allocated for carrying the data with the third and fourth modulation symbols of the Alamouti cell, modulating the one or more pilot carriers of the second version of the OFDM symbols according to the predetermined pattern, and transmitting the first version of the OFDM symbol via a first antenna, and the second version of the OFDM symbol via a second antenna. For at least one of the pairs of data symbols, the sub-carriers, on which each of the first and second modulation symbols and the third and fourth modulation symbols forming the Alamouti cells, are separated within the first and second versions of the OFDM symbol by at least one other data bearing sub-carrier or one or more of the pilot carriers.07-02-2009
20090168913Apparatus And Method For Transmitting Signal Using Multicarrier System - A transmitter which transmits transmission symbols using a multicarrier system is used. The transmitter has a part configured to adjusted a phase rotation amount for each of N data symbols; a part configured to carry out inverse Fourier transform on the data symbols having undergone the phase adjustment and generating the transmission symbols; and a phase calculating part configured to determine the phase rotation amount with the use of a complex neural network. The phase calculating part has N neurons which derive, from N complex input signals to which a temporarily determined phase rotation has been carried out, one complex output signal after inverse Fourier transform, and use the complex output signal as the complex input signal for a next time; and a state updating part configured to update the phase rotation amount according to a value of an objective function calculated from the complex output signal.07-02-2009
20090168907OFDMA based communication system - In an Orthogonal Frequency Division Multiple Access communication system, the location of one- and two-dimensional bursts may be specified by specifying the starting location of the plurality of bursts. The length of a burst may then be determined by subtracting starting locations of successive bursts. In some embodiments, the number of bits needed to specifying the location of bursts may be reduced.07-02-2009
20080273614SYSTEM, METHOD, AND COMPUTER-READABLE MEDIUM FOR MULTILEVEL SHAPING FOR WIRELESS COMMUNICATION SYSTEMS - A system, method and computer-readable medium for encoding and decoding digital information over a channel is provided. Type Mapping is employed and is based on the partitioning of vectors over an alphabet into “types” and using enumeration for the encoding and decoding process. Type mapping allows for signal alphabets of arbitrary size and date rate flexible coding. Tradeoffs between optimal rate versus Signal to Noise Ratio are provided and works as a compliment to the Forward Error Control that may be employed in communications products.11-06-2008
20080273615CHANNEL PROFILE ESTIMATION FOR OFDM-BASED COMMUNICATION SYSTEM - A device and method for performing a channel profile estimation for an OFDM-based wireless communication system uses an averaged frequency coherence metric to select a particular channel profile, which is a current channel profile estimate. The averaged frequency coherence metric is derived using correlations between pilot subcarriers of an OFDM-based signal at predefined subcarrier locations for multiple frames of the OFDM-based signal. The selected channel profile may be used for channel estimation, as well as for link adaptation, to improve the performance of these processes.11-06-2008
20080273608Method and Apparatus for Correcting IQ Imbalance in an OFDM Receiver - Methods and apparatus for processing received OFDM signals to compensate for distortions caused by IQ imbalances are disclosed. Receiver circuits may be configured to demodulate symbols from a first logical channel, using an uncompensated received OFDM signal that includes the effects of those distortions. Receiver circuits may be further configured to calculate an IQ imbalance parameter, using the demodulated symbols, for use in compensating the received OFDM signal to reduce the effects of the IQ imbalances. The compensated signal produced thereby may be used for demodulating symbols from a second logical channel, perhaps corresponding to a user data channel.11-06-2008
20080273617STEERING DIVERSITY FOR AN OFDM-BASED MULTI-ANTENNA COMMUNICATION SYSTEM - A transmitting entity uses different steering vectors for different subbands to achieve steering diversity. Each steering vector defines or forms a beam for an associated subband. Any steering vector may be used for steering diversity. The steering vectors may be defined such that the beams vary in a continuous instead of abrupt manner across the subbands. This may be achieved by applying continuously changing phase shifts across the subbands for each transmit antenna. As an example, the phase shifts may change in a linear manner across the subbands for each transmit antenna, and each antenna may be associated with a different phase slope. The application of linearly changing phase shifts to modulation symbols in the frequency domain may be achieved by either delaying or circularly shifting the corresponding time-domain samples.11-06-2008
20080273613MULTIPLE INPUT, MULTIPLE OUTPUT (MIMO) COMMUNICATION SYSTEM OVER IN-PREMISES WIRES - A multiple input, multiple output (MIMO) communications unit includes a multiplicity of analog front ends and a MIMO processor. Each analog front end is connectable to a different two of the wires in a subscriber premises and each handles data of one channel. The MIMO processor processes together the data of the channels. In one embodiment, the wires are the power line wires in a subscriber premises, including the phase, neutral and ground power line wires. In another embodiment, the wires are pairs of telephony wires.11-06-2008
20080273609RECEIVING APPARATUS, TRANSMITTING APPARATUS, AND RECEPTION METHOD - Channel fluctuation values on propagation paths of modulated signals transmitted from a plurality of antennas are estimated, an eigenvalue of a channel fluctuation matrix created with the above-mentioned channel fluctuation values as elements is found in order to relate antenna received signals to modulated signals, and using that eigenvalue, receiving antenna selection, combining of modulated signals, and weighting processing on soft decision decoded values, are performed, and modulated signals are demodulated. By this means, it is possible to perform demodulation processing based on the effective reception power of a modulated signal (that is to say, the essential reception power, of the reception power obtained by a receiving apparatus, that can be effectively used when demodulating a modulated signal), enabling the precision of demodulation of modulated signals to be improved.11-06-2008
20080279297Method and Apparatus for Decoding Transmission Signals in a Wireless Communication System - Disclosed is a method and an apparatus for decoding transmission signal. The method includes the steps of: receiving transmission signal including repeated symbols; deinterleaving the received signal; mutually combining the repeated symbols in the deinterleaved signal; and decoding the combined symbols. According to the method, reception performance is improved as compared to a conventional decoding method, and system performance is improved by reducing the loss of frame information included in an FCH.11-13-2008
20080279294TDS-OFDMAA COMMUNICATION SYSTEM UPLINK FREQUENCY SYNCHRONIZATION - TDS-OFDM can be applied to uplink wireless communication multiple accesses through sub-channelization, which means that each user uses a portion of available bandwidth to achieve orthogonal multiple access, where the sub-carriers in each sub-band may be contiguous or distributed. Inside the bandwidth for each user, at least one random or known sequence is used as the guard interval between transmitted symbols, where the sequence is limited inside the sub-band.11-13-2008
20080279293Coded Orthogonal Frequency Division Multiplexing Method and Apparatus - A method and apparatus for transmitting and receiving data via guard tones are described. The information bits are coded by convolutional encoder (11-13-2008
20080279291OFDM transmission and reception for non-OFDMA signals - Methods and apparatuses for Orthogonal Frequency-Division Multiplexing (OFDM) communication of non-OFDM radio signals are disclosed. The non-OFDM radio signals are force-modulated into OFDM signals. In one example, a non-OFDM signal is received and is processed into an OFDM signal to produce a created OFDM signal. An actual OFDM signal is also received and is processed together with the created OFDM signal.11-13-2008
20080285664MODE AND RATE CONTROL FOR MIMO TRANSMISSION - Techniques for performing mode and rate control for a MIMO transmission are described. For mode selection, the use of an eigensteering mode is permitted if a first set of at least one criterion is satisfied. The eigensteering mode is selected for data transmission if a second set of at least one criterion is satisfied, and an unsteered mode is selected otherwise. For rate selection, SNR estimates are derived for data streams to potentially transmit, e.g., based on channel estimates and/or data symbol estimates. The number of data streams to transmit as well as at least one rate for at least one data stream to transmit are selected based on the SNR estimates and at least one backoff factor. The backoff factor(s) are adjusted based on status of received packets. The at least one rate may be adjusted based on the age of rate information.11-20-2008
20080285667METHOD AND APPARATUS FOR FEEDBACK IN CLOSED LOOP TRANSMITTING - A method an apparatus is described for providing feedback for closed-loop transmitting with multiple transmit and receive antennas. The method includes a first step 11-20-2008
20080285672APPARATUS AND METHOD FOR EVALUATING JPROPAGATION PATH CONDITIONS - A measurement indicator, “transfer efficiency,” is provided for evaluating conditions of propagation paths of wireless communication systems having a plurality of transmitting and receiving antennas. Transfer functions of signal paths are calculated from data of received signals that are obtained with receiving antennas by receiving OFDM signals transmitted by transmitting antennas. A demodulation matrix is calculated for demodulating a transmitting vector from a receiving vector concerning a desired subcarrier of the received signals. A noise amplification factor is calculated as a square root of a sum of second powers of components of the demodulation matrix of the receiving antennas concerning the desired transmitting antenna. The noise amplification factor or the inverse is displayed as a value or as a graph that has an axis concerning the subcarrier and an axis concerning the noise amplification factor or the inverse.11-20-2008
20080285668Method for Processing Control Information in a Wireless Mobile Communication System - In a wireless mobile communications system, a method for processing control information allows the operations of a mobile terminal to be simplified and permits efficient use of resources for the mobile terminal. The network instructs in advance, the transmission of control information, such as system information and the like, via a single indicator channel. The mobile terminal receives this single indicator channel and uses the indicator information that was transmitted via the indicator channel in order to receive the control information.11-20-2008
20080285665Methods and Systems for Providing Feedback for Beamforming - Methods and systems for providing feedback for beamforming are provided. In some embodiments, methods for providing feedback for beamforming are provided, the methods comprising: initializing a weighting vector; determining a perturbation vector; determining a plurality of weighting vectors to be applied to data based on the weighting vector and the perturbation vector; applying the plurality of weighting vectors to the data to provide weighted data; transmitting the weighted data to a receiver; receiving from the receiver a feedback signal based on at least one of the plurality of weighting vectors; and updating the plurality of weighting vectors based on the feedback signal.11-20-2008
20080285666Methods and Systems for Digital Wireless Communication - Methods and systems for digital wireless communication are provided.11-20-2008
20080292009MULTIPLE-INPUT-MULTIPLE-OUTPUT WIRELESS TRANSMISSION SYSTEM AND TRANSMISSION METHOD THEREOF - The present invention relates to a multiple-input-multiple-output (MIMO) wireless transmission system and a transmission method thereof. A wireless transmitting system thereof receives encoded data via a first processing unit, which processes the encoded data and outputs the encoded data to a plurality of modulation units for modulating the encoded data to produce a plurality of modulated data. A plurality of first conversion units converts the plurality of modulated data to a plurality of transmitting signals. A plurality of radio-frequency (RF) circuits receives the plurality of transmitting signals and transmits RF signals according to the frequency-hopping sequence of a piconet. A plurality of receiving processing units of a wireless receiving system according to the present invention receives the RF signals, respectively, according to the frequency-hopping sequence of the piconet and transmits to a plurality of second conversion units for converting the RF signals to received data. A switching circuit switches the received data according to the frequency-hopping sequence of the piconet. A plurality of demodulation units demodulates the switched received data to produce demodulated data. A second processing unit received the demodulated data, and processes the demodulated data to output demodulated data. A decoding unit decodes the demodulated data output by the second processing unit to produce output data.11-27-2008
20080292013NESTED PRECODING CODEBOOK STRUCTURES FOR MIMO SYSTEMS - Embodiments of the present disclosure provide a transmitter, a receiver and methods of operating a transmitter and a receiver. In one embodiment, the transmitter is for use with N11-27-2008
20080292011METHOD AND SYSTEM FOR IMPLEMENTING TRANSMITTING DIVERSITY AND RECEIVING DIVERSITY - The method for implementing transmitting diversity includes receiving a symbol from a destination mobile terminal, by a mobile terminal which is in the same mobile terminal group with the destination mobile terminal, wherein the symbol is also sent from the destination mobile terminal to a base station; and processing, by the mobile terminal, the symbol and transmitting the symbol processed to the base station. The method for implementing receiving diversity includes receiving, by a mobile terminal, a symbol from a base station; finding a destination mobile terminal which is in the same mobile terminal group with the mobile terminal if the mobile terminal is not the destination of the symbol; and forwarding the symbol to the destination mobile terminal. Embodiments of the present invention solve the problem of excessive size of a mobile terminal used for implementing transmitting diversity and receiving diversity, and also reduces bit error rate (BER).11-27-2008
20080292008Channel-Estimating Apparatus and Mimo Communication System - A channel-estimating apparatus according to the present invention, including: an input unit (11-27-2008
20080304582Multi-Carrier Transmission Device and Multi-Carrier Transmission Method - There is provided a multi-carrier transmission device capable of improving a packet error ratio in a system where transmission data is repeatedly multi-carrier-transmitted. In this device, the transmission data is subjected to error correction encoding in an error correction encoding unit (12-11-2008
20080304586Reduced Lattice Demodulation Method and Apparatus - RAKE-based receivers utilize lattice reduction for improving symbol estimation accuracy. Channel response estimates and received signal streams are transformed from a constellation lattice basis to an integer lattice basis to increase the orthogonality of symbol estimation decision regions. In one embodiment, received signal streams are processed by generating despread signal samples from received signal streams transmitted using different spreading codes. Channel response associated with the different received signal streams is estimated and transformed from a first lattice basis to a second lattice basis having greater orthogonality between decision regions than the first lattice basis. The despread signal samples are aligned to the second lattice and combining weights generated based on the transformed channel response estimate. Symbol estimation decision statistics are generated based on the combining weights and the aligned despread signal samples. Soft bit values are generated for decoding based on the symbol estimation decision statistics.12-11-2008
20080304583Radio Transmission Device, Radio Reception Device, Radio Transmission Method, and Radio Reception Method - A radio transmission device capable of improving channel estimation precision for each frequency. In this device, an FFT unit (12-11-2008
20080304588Methods and apparatus for mapping control channels to resources in OFDM systems - A method for data transmission. The method including the steps of generating at least one resource tree, mapping a plurality of resource elements into respective leaf nodes in the at least one resource tree according to a certain mapping scheme, with each node in the at least one resource tree representing a resource allocation scheme for data transmission, and transmitting data using a resource allocation scheme selected from among the plurality of resource allocation schemes represented by respective nodes in the at least one resource tree. In response to reception of the data, a receiver decodes the data by recursively applying the plurality of resource allocation schemes represented by respective nodes in the at least one resource tree until the data is decoded.12-11-2008
20080304587Ofdm Reception Device - An OFDM reception device detects a time at which impulse noise occurs in a received OFDM signal, and specifies a start position candidate period that does not have intersymbol interference and is estimated to have a guard interval signal in a symbol. When setting a FFT window of an effective symbol length in a symbol duration of each symbol, if the impulse noise occurrence time is included in the symbol, the OFDM reception device determines a start position of the FFT window within a range of the start position candidate period so as to exclude the impulse noise occurrence time as much as possible.12-11-2008
20080304584Radio Transmission Device and Radio Reception Device - There is disclosed a radio transmission device capable of improving the throughput. The radio transmission device (12-11-2008
20080304581Method and System for Multicarrier Communication Between a Base Station and Subscribers of Different Bandwidths - A multicarrier base station communicates with subscriber stations of different bandwidth profiles by allocating time slots in downlink and uplink frames and subcarriers of a single multicarrier communication channel to various bandwidth subchannels.12-11-2008
20100002783Blind Channel Estimation for PSK and D-PSK Modulated Multicarrier Communication Systems - An apparatus and method is described that provide an efficient blind channel estimation approach for PSK and DPSK modulated multicarrier communication systems. With the requirement that the channel phase difference between any two adjacent carriers is smaller than one half of the minimum phase difference between two symbols of the PSK or DPSK constellation, a low-complexity deterministic approach to channel estimation is devised. This approach is highly effective, robust, and particularly useful for time varying channels with low AWGN noise.01-07-2010
20080212699COMMUNICATION CONTROL APPARATUS AND CONTROL METHOD THEREOF, COMMUNICATION APPARATUS AND CONTROL METHOD THEREOF, WIRELESS COMMUNICATION SYSTEM, PROGRAM, AND STORAGE MEDIUM - A communication control apparatus that performs wireless communication with a plurality of communication apparatuses, the communication control apparatus comprises: a grouping unit adapted to group the plurality of communication apparatuses based on the relative positions of each of the plurality of communication apparatuses; a notification unit adapted to notify each of the plurality of communication apparatuses of the group to which that communication apparatus belongs and of a communication slot allocated to that group; and a transmission unit adapted to transmit transmission data at a predetermined timing.09-04-2008
20080285670MIMO WLAN SYSTEM - A multiple-access MIMO WLAN system that employs MIMO, OFDM, and TDD. The system (1) uses a channel structure with a number of configurable transport channels, (2) supports multiple rates and transmission modes, which are configurable based on channel conditions and user terminal capabilities, (3) employs a pilot structure with several types of pilot (e.g., beacon, MIMO, steered reference, and carrier pilots) for different functions, (4) implements rate, timing, and power control loops for proper system operation, and (5) employs random access for system access by the user terminals, fast acknowledgment, and quick resource assignments. Calibration may be performed to account for differences in the frequency responses of transmit/receive chains at the access point and user terminals. The spatial processing may then be simplified by taking advantage of the reciprocal nature of the downlink and uplink and the calibration.11-20-2008
20080292014Communication equipment - Communication equipment for transmitting signals of an OFDM system while effectively suppressing peaks in the transmission. Forming means form a plurality of OFDM signals, peak-suppressing means of a base band suppresses peaks of the OFDM signals based on these signals, IF converter means convert OFDM signals of which the peaks are suppressed into intermediate-frequency signals, peak-suppressing means of the intermediate frequency suppresses the peaks of the intermediate-frequency signals based on these signals, synthesizing means synthesizes a plurality of intermediate-frequency signals of which the peaks are suppressed, and amplifier means amplifies the signals after having been synthesized. Peak-suppressing means of the base band suppresses the peaks with the synthesized value of absolute values of the OFDM signals as an estimated peak value, and the peak-suppressing means of the intermediate frequency suppresses the peaks with the absolute value of the result of synthesizing the plurality of intermediate-frequency signals as an estimated peak value.11-27-2008
20080212694Signal decoding systems - We describe a method of decoding a DCM (dual carrier modulation) modulated OFDM signal, the method comprising: inputting first received signal data representing modulation of a multibit data symbol onto a first carrier of said OFDM signal using a first constellation; inputting second received signal data representing modulation of said multibit data symbol onto a second, different carrier of said OFDM signal using a second, different constellation; determining a combined representation of said first and second received signal data, said combined representation representing a combination of a distance of a point representing a bit value of said multibit data from a constellation point in each of said different constellations; and determining a decoded value of a data bit of said multibit data using said combined representation.09-04-2008
20080219362Diversity wireless systems - Diversity wireless system, processor, cross-correlator, transmit baseband filter and modulator for processing, cross-correlating, filtering, modulating and providing a first and a second bit rate signal to a transmission system for transmission of the processed, filtered, modulated signal. Transmission system having two transmitters for transmission of the modulated signal. Diversity receiver system with two receivers for receiving the transmitted modulated signal and for providing received signal to a demodulator. Demodulator, receive baseband filter and receive processor for demodulation, filtering and processing received signal. Receive baseband filter for filtering is mismatched to the transmit baseband filter for filtering of the first bit rate signal and receive processor for processing first bit rate demodulated baseband filtered signal provides received baseband mis-match filtered cross-correlated in-phase and quadrature-phase signal. Processor and transmit baseband filter for processing and filtering a signal into a cross-correlated filtered and into a cross-correlated spread spectrum in-phase and quadrature-phase baseband signal. Processor, first and second modulator for processing and baseband filtering a signal into time division multiplexed (TDM) filtered signal and into Orthogonal Frequency Division Multiplexed (OFDM) signal and for providing processed TDM filtered and processed OFDM signal to two modulators for modulation, transmission and diversity reception.09-11-2008
20080317147METHOD FOR TRANSMITTING SCATTERED PILOT SIGNALS IN MULTI-CARRIER SYSTEM - A method for transmitting scattered pilot signals in a multi-carrier system is disclosed. The method includes: in each time slot, in time dimension, putting each 4 OFDM symbols into a group according to the order of the OFDM symbols; in each group of OFDM symbols, in frequency dimension, selecting, for each OFDM symbol, a plurality of valid sub-carriers to transmit scattered pilots, wherein for a same OFDM symbol, between each 2 valid sub-carriers selected, there are 7 valid sub-carriers; for different OFDM symbols in a same group, the valid sub-carriers selected are interleaving in frequency domain; and transmitting scattered pilot signals on the valid sub-carriers selected. The solution helps the multi-carrier system to handle multi-path channel with large delay spread, to obtain more accurate channel estimation and to achieve better receiving performance.12-25-2008
20080317151Apparatus and method for forming subchannel in a communication system - A method for forming a subchannel in a communication system where a first communication system and a second communication system coexist. The method includes determining a first tile set by arranging first tiles remaining after forming at least one first subchannel for the first communication system among frequency resources, including a plurality of tiles, available for the first communication system; determining a second tile set by inserting second tiles which are independent of the frequency resources and are available for the second communication system into the determined first tile set at predetermined positions; forming at least one second subchannel for the second communication system by selecting a predetermined number of tiles from the second tile set; and performing communication using at least one of the first subchannel and the second subchannel.12-25-2008
20080317148WIRELESS COMMUNICATIONS APPARATUS AND WIRELESS COMMUNICATION METHOD - The invention performs orthogonal frequency division multiplex processing on a transmission signal to form an OFDM modulation signal (daubed in FIG.) and performs orthogonal frequency division multiplex processing and code division multiple access processing on a transmission signal to form an OFDM-CDM modulation signal (shaded in FIG.) to transmit the OFDM modulation signal and the OFDM-CDM modulation signal, which makes it possible to transmit data in a very high rate using the OFDM modulation signal while making it possible to transmit data in a higher quality using the OFDM-CDM modulation signal than using the OFDM-modulation signal, although it is slightly inferior to OFDM modulation in terms of high rate transmission.12-25-2008
20110007830BASE STATION APPARATUS AND RECEPTION BAND CONTROL METHOD - A mobile station (01-13-2011
20110007828TECHNIQUES FOR MULTIPLE-SUBCARRIER JOINT PRECODING01-13-2011
20090190678Estimating Channel In Orthogonal Frequency Division Multiplexing Communication System - Among others, techniques, systems and apparatus are described for estimating a channel in an orthogonal frequency division multiplexing (OFDM) communication system. A method of estimating a channel in an orthogonal frequency division multiplexing (OFDM) communication system includes sequentially receiving symbols. Each symbol includes pilots and data. The pilots included in each of first n symbols of the sequentially received symbols are placed in first areas of a memory component used for channel estimation. Data in second areas disposed between the first areas of the memory component are estimated. The pilots of at least one symbol after the nth symbol of the sequentially received symbols are placed in the first areas and the estimated data is updated in the second areas.07-30-2009
20080292016SIGNAL DECODING METHODS AND APPARATUS - This invention is generally concerned with methods, apparatus and processor control code for decoding a signal received over a MIMO (multiple input-multiple output) channel.11-27-2008
20080292015Channel Estimation Method of Mobile Terminal in Wireless Communication System and Channel Estimator Employing the Method - Provided is a mobile terminal of a wireless communication system, and more particularly, a channel estimation method performed in a mobile terminal of a wireless communication system supporting the IEEE 802.16e standard and a channel estimator of the mobile terminal to which the method is applied. The channel estimation method includes the steps of: extracting a preamble included in a received signal and obtaining a preamble estimation value based on the preamble; extracting a pilot included in the received signal and obtaining a pilot estimation value based on the pilot; and obtaining a channel estimation value based on calculating the preamble estimation value and the pilot estimation value according to a predetermined algorithm.11-27-2008
20100135427COFDM DEMODULATOR WITH AN OPTIMAL FFT ANALYSIS WINDOW POSITIONING - The invention relates to a method for the COFDM demodulation of a signal received from a transmission channel. The inventive method includes performing the fast Fourier transform of the signal received in a window corresponding to a symbol, each symbol being associated with a guard time reproducing one part of the symbol; supplying a set of estimated values for the module impulse response; determining coefficients, each coefficient being obtained from the product of the aforementioned set and a filtering function (FE) for a determined relative position of the filtering function in relation to the set; determining the maximum coefficient and the corresponding relative position; and positioning the window as a function of the relative position, the filtering function including a central part (LMAX) which has a constant amplitude and a duration equal to the duration of the guard time and which is surrounded by non-zero decreasing edges.06-03-2010
20100135422PREAMBLE TRANSMISSION AND RECEPTION METHOD AND APPARATUS FOR OFDM SYSTEM - A method and apparatus for transmitting and receiving a preamble having sequence information for an OFDM system is provided. The preamble transmission method includes generating a preamble block including at least one frame having a header with a known sequence and a code block containing control information and transmitting the preamble block mapped to Orthogonal Frequency Division Multiplexing (OFDM) cells by repeating in frequency axis direction.06-03-2010
20100135425TURBO CHANNEL ESTIMATION FOR OFDM SYSTEMS - A system and method for estimating a channel in a wireless receiver is disclosed. The method preferably applies to a communication system using the OFDM standard. The method comprises receiving a block of “n” transmitted symbols, the symbols including pilot symbols and “d” data symbols, estimating a channel using the pilot symbols to create a channel estimate, choosing a group of “m” strongest symbols from the “d” received symbols, compensating the “m” strongest symbols using the channel estimate to create a group of “m” compensated symbols, re-estimating the channel using the group of “m” compensated symbols and pilot symbols; and either (1) repeating the steps of choosing a group of “m” strongest symbols, compensating the group of “m” strongest symbols and re-estimating the channel, or (2) using a latest channel estimate to compensate all symbols within the block. The system comprises a wireless receiver having an estimator programmed, for example, using DSP or ASIC and imbedded into the wireless system design software for accomplishing the steps set forth according to the method.06-03-2010
20100272198Method of Detecting Transmission Channel and Related Wireless Communication System - A method and related system of transmission channel detection condition in a wireless communication system are disclosed. The method includes receiving a symbol, performing a channel estimation operation to generate a channel estimation result according to the symbol, performing a cross correlation operation on the channel estimation result and an initial channel estimation result to generate an operation result, and determining whether the condition of the transmission channel have changed or not.10-28-2010
20090147866COMMUNICATION APPARATUS, COMMUNICATION SYSTEM, AND COMMUNICATION METHOD - A communication apparatus capable of improving the spectrum usage rate of a system, especially, the spectrum usage rate in connection with both a fast fading and a channel estimation error as compared with the conventional sub-band adaptive method, while reducing the degree of the difficulty in achieving the adaptation, and further reducing the feedback overhead. In this apparatus, a sub-band group AMC parameter selecting part (06-11-2009
20100142633METHOD AND SYSTEM FOR COMMUNICATION CHANNEL OPTIMIZATION IN A MULTIPLE-INPUT MULTIPLE-OUTPUT (MIMO) COMMUNICATION SYSTEM - A transmission method in a multiple-input multiple-output (MIMO) communication system, a transmitter in a MIMO communication system and a MIMO communication system are provided. The method comprises the steps of: receiving feedback data representing channel state information from respective receivers of the MIMO communication system; grouping the receivers into one or more groups based on the received feedback data; obtaining a precoding matrix for each group of receivers based on the received feedback data such that precoding vectors or sub-matrices in the precoding matrix associated with respective receivers of said each group of receivers are orthogonal to each other; and applying the precoding matrix to input signals for transmission to said each group of receivers.06-10-2010
20090097577OFDM RECEIVING APPARATUS HAVING PLURALITY OF OFDM BRANCHES - An OFDM signal is demodulated to generate a frequency domain signal in each of a plurality of branches. A diversity combining unit combines the demodulated signals respectively obtained in each of the branches. A clock recovery unit recovers the clock for the OFDM signal. A guard correlation unit detects the phase error of the OFDM signal. A decision unit identifies a branch having high reliability. A clock error correction unit generates a correction instruction, in accordance with the average value of the phase errors in the branch having high reliability. The clock recovery unit in each of the branches respectively corrects the error of the clock in accordance with the correction instruction.04-16-2009
20100142630MULTICARRIER TRANSMITTING APPARATUS, MULTICARRIER RECEIVING APPARATUS, AND THEIR METHODS - A multicarrier transmitting apparatus capable of improving the data symbol error rate characteristic to improve the reception quality. In this apparatus, a replacement position deciding part (06-10-2010
20090080549Efficient MIMO precoding feedback scheme - Methods and apparatus for efficiently feeding back preceding information in a multiple input multiple output (MIMO) system. A codebook including a plurality of codebook entries is constructed. A plurality of subsets of codebook entries are defined for the codebook. Each subset includes a plurality of codebook entries. A subset of codebook entries is selected for precoding data in dependence upon a channel condition, and a codebook entry is selected from the subset. Then, a subset index corresponding to the selected subset, and a codebook entry index corresponding to the selected codebook entry within the selected subset, is transmitted as feedback information.03-26-2009
20080240269METHOD AND APPARATUS FOR MULITPLEXING CONTROL AND DATA CHANNEL - An approach is provided for performing control signaling. Data and control information are received. The control information is orthogonalized using block-level spreading. The data and the orthogonalized control information are multiplexed at a symbol-level.10-02-2008
20080240275Scalable OFDM and OFDMA bandwidth allocation in communication systems - Techniques for bandwidth allocation in communication systems such as OFDM, OFDMA, or SC-FDMA systems to improve spectral efficiency and increase flexibility and adaptability with scalable single or multiple-carrier bandwidth allocation characteristics.10-02-2008
20080240273RADIO TRANSMITTING APPARATUS AND RADIO RECEIVING APPARATUS USING OFDM - A radio transmitting apparatus includes an attacher to attach an error-detecting bit to a bit sequence, a coder to perform systematic coding on a bit sequence to which the error-detecting bit is attached to generate an information bit sequence and a parity bit sequence, a first modulator to modulate the information bit sequence to generate a first modulation symbol, a second modulator to modulate the parity bit sequence to generate a second modulation symbol, an allocator to allocate the first modulation symbols to first subcarriers by dispersing the first modulation symbols in the frequency/time direction, and allocate the second modulation symbols to second subcarriers different from the first subcarriers, an modulator to perform OFDM modulation on the first and second modulation symbols by using the first and the second subcarriers to generate an OFDM signal, and a transmitting unit to transmit the OFDM signal.10-02-2008
20080240264METHODS AND SYSTEMS FOR TRANSMITTING AND PROCESSING PILOT SIGNALS - A system and method of transmitting and processing pilot signals includes decorrelating a pilot tone that conveys a pilot signal, performing a channel estimation based on the decorrelated pilot tone to calculate estimated channel values and positioning the estimated channel values consistent with their order in subsequent transmission units. In one embodiment, the decorrelation comprises an interleaving operation. In another embodiment, the decorrelation occurs during a channel estimation stage. The decorrelation can be performed during a channel estimation stage by interleaving and deinterleaving pilot signals in the receiver.10-02-2008
20080240272SYSTEMS AND METHODS FOR N-DIMENSIONAL LEAF-NODE PREDICTION FOR MIMO DETECTION - Embodiments achieve favorable performance-complexity trade-offs in MIMO detection for three or more channel inputs. Some embodiments describe systems and methods comprising a leaf node predictor for receiving a processed communications stream, determining at least one channel metric corresponding to the communications stream for a given channel realization, and generating at least three instructions to output, which at least one instruction corresponds to at least one predicted best leaf node candidate for the given channel realization. Further embodiments alternatively describe systems and methods which enumerate N10-02-2008
20080240270INTERFERENCE DETECTION AND AVOIDANCE SIGNALLING AND PROCESSING - The present invention relates to a method of generating a signal for transmission over a channel subject to transmission conditions. A corresponding signal and a method of receiving a signal over a channel subject to transmission conditions are also disclosed. The invention further relates to a transmitter and a receiver.10-02-2008
20080240268METHOD AND SYSTEM FOR TRANSMITTING/RECEIVING DATA IN COMMUNICATION SYSTEM - Disclosed is a data transmission/reception method and system for minimizing intercarrier interference (ICI) in a communication system using a multicarrier. The data transmission method by a transmitter includes grouping transmission signals in units of a predetermined number of transmission signals when the transmitter has received the transmission signals, multiplying each group of the transmission signals by a transmission coding matrix, and transmitting the transmission signals multiplied by the transmission coding matrix to a receiver.10-02-2008
20080240266Arrangements for monitoring and controlling a transmission path - In one embodiment of the present disclosure, a method for improving communication between a transmitter and a receiver is disclosed. The method can include receiving a first signal having a first power level over a first path, receiving a second signal having a second power level over a second path wherein the first path is different than the second path. The method can compare the first power level with the second power and determine a difference between the first power level and the second power level. The method can also adjusting a parameter in the system to reduce the difference in power levels between the first and second signals compensating for interference cause by many sources.10-02-2008
20080240263OFDM/OFDMA TIMING SYNCHRONIZATION USING NON-CONSECUTIVE PILOT SUBCARRIER ASSIGNMENT - Systems and methods which are adapted determine timing with respect to an orthogonal frequency division (OFD) channel, such as may be used with respect to an OFDM or OFDMA systems through reliably identifying timing of a first arriving signal path. Embodiments use deconvolution to construct the channel impulse response associated with a received signal. The first arriving path for the received signal may readily and reliably be determined using the channel impulse response information.10-02-2008
20080240260ADAPTIVE CHANNEL PREDICTION SYSTEM AND METHOD - A method and system for predicting channel fading, particularly in a mobile wireless environment, that is accurate for long-range predictions. The method comprises estimating a model parameters based on a current channel estimate, and recursively adapting the model parameters to predict future channel fading coefficients until a predetermined re-acquisition condition is satisfied. Once the re-acquisition condition has been satisfied, the model parameters are again estimated based on a current channel estimate. The acquired model parameters are adaptively updated and used in a Kalman filter.10-02-2008
20090190676Enhanced MIMO detection method and apparatus - A multiple-input-multiple-output (MIMO) wireless communication enhanced detection method and apparatus are proposed whereby quasi optimal link performance is achieved, at low complexity for MIMO systems including those of high dimension and those operating at very high SNR.07-30-2009
20090080555GUARD INTERVAL LENGHT SELECTION IN AN OFDM SYSTEMS BASED ON COHERENCE BANDWIDTH OF THE CHANNEL - A system, apparatus and methods are described that select a guard interval length (03-26-2009
20090080546LIMITATION FEEDBACK METHOD FOR MULTIANTENNA SYSTEM, CHANNEL PARAMETER GENERATING METHOD, AND WIRELESS RECEIVER - A channel parameter generating method realizing limited feedback of a MIMO system. In this method, a channel parameter of a MIMO channel fed from a wireless receiver back to a wireless transmitter is generated. Channel estimation is carried out by using a signal received through a MIMO channel, the ranks of the space domain correlation matrix and the time domain correlation matrix of the MIMO channel are derived from the channel matrix obtained by the channel estimation, an operation to decrease the number of dimensions of the column of the estimated channel matrix is carried out if the rank of the derived space domain correlation matrix is smaller than that of the derived time domain correlation matrix, thereby a channel parameter is obtained, an operation to decrease the number of dimensions of the row of the estimated channel matrix is carried out if the rank of the derived time domain correlation matrix is smaller than that of the derived space domain correlation matrix, and a channel parameter is obtained.03-26-2009
20090161779METHOD FOR INTER-CARRIER INTERFERENCE CANCELLATION AND EQUALIZATION METHOD, APPARATUS, AND OFDM RECEIVER USING THE METHOD - An inter-carrier interference ICI cancellation method of a k06-25-2009
20090180563Turbo HSDPA System - A method of power saving for a wireless transceiver (FIGS. 07-16-2009
20090161776SYSTEM AND METHOD FOR FREQUENCY DIVERSITY - A system and method for frequency diversity uses interleaving in a wireless communication system utilizing orthogonal frequency division multiplexing (OFDM) with various FFT sizes. Subcarriers of one or more interlaces are interleaved in a bit reversal fashion and the one or more interlaces are interleaved.06-25-2009
20090129495ALLOCATION OF RADIO RESOURCE IN ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING SYSTEM - An uplink capacity is increased by a method in which more than two mobile stations simultaneously use a radio resource allocated to one mobile station. A method of allocating a radio resource in an orthogonal frequency division multiplexing system comprises receiving data associated with a radio resource allocation map from a base station, wherein the radio allocation map comprises control parameters for transmitting uplink data to the base station. The control parameters comprises orthogonal pilot pattern indicator for using orthogonal pilot patterns associated with supporting at least concurrent dual transmission by at least one mobile station, and for use in the same frequency band and same time duration. The orthogonal pilot patterns comprises at least a minus pilot being used for an uplink basic allocation unit. The mobile station then transmits uplink data to the base station by using the orthogonal pilot patterns.05-21-2009
20090129490Method and a Device for Dynamically Selecting Orthogonal Functions of an Orthogonal Transmission System - An interleaving method (05-21-2009
20090129494APPARATUS AND METHOD FOR CANCELING DC OFFSET IN BROADBAND WIRELESS ACCESS COMMUNICATION SYSTEM - An apparatus and method for canceling a Direct Current (DC) offset in a Broadband Wireless Access (BWA) communication system are provided. The method includes canceling a DC offset by performing self-calibration in a modulator/demodulator (modem), attempting initial synchronization acquisition in the modem, and if the initial synchronization acquisition succeeds, canceling a DC offset by performing DC offset trace and cancellation.05-21-2009
20090141818WIRELESS COMMUNICATION APPARATUS AND WIRELESS COMMUNICATION METHOD IN MULTICARRIER COMMUNICATION - A wireless communication apparatus capable of performing an efficient communication even in a case of frequency multiplexing a plurality of OFDM symbols having GIs the lengths of which are different from each other in a multicarrier communication. In this wireless communication apparatus (06-04-2009
20090161778Transmitter and Carrier Leak Detection Method - It is intended to compensate for a carrier leak for any carrier arrangement. There are provided a carrier leak compensating means 06-25-2009
20090161772Downlink channel transmission device and method thereof - A transmission device able to improve signal quality in a downlink channel is disclosed. The transmission device is for transmitting a control channel, a pilot channel, and a data channel, and includes a unit for transmitting the data channel by using a multi-beam or a variable directional beam, and a unit for transmitting a known signal as the pilot channel by using the multi-beam or the variable directional beam. The multi-beam includes plural fixed directional beams having respective fixed directions different from each other, and the variable directional beam is of a direction changing along with a position of a mobile terminal.06-25-2009
20090161771Fft carrier frequency offset estimation for ofdm signal - There is being disclosed an OFDM signal receiver for detecting carrier frequency offset. When FFT transform of the signal is processed in the receiver, an estimator applies the spectrum shape of the FFT transform for estimating the carrier frequency offset.06-25-2009
20090161777Overlay Modulation Technique for COFDM Signals Based on Amplitude Offsets - Systems and methods are presented for transmitting additional data over preexisting differential COFDM signals by changing the amplitude of the legacy data symbols. In exemplary embodiments of the present invention, additional data capacity can be achieved for a COFDM signal which is completely backwards compatible with existing legacy satellite broadcast communications systems. In exemplary embodiments of the present invention, additional information can be overlaid on a legacy COFDM signal by applying an amplitude offset to the legacy symbols. In exemplary embodiments of the present invention, special receiver processing can be implemented to extract this additional information, which can include performing channel equalization across frequency bins to isolate the amplitude modulated overlay signal. For example, at each FFT symbol time, average power across neighboring active data bins can be used to determine the localized power at the corresponding FFT bins, and a channel inversion can then, for example, be performed on the data bins to restore, as best as possible, the original transmitted symbol amplitude.06-25-2009
20090161782Characterizing channel response based on composite gain determination - Characterizing channel response based on composite gain determination. Based on tracked amplitude modulation (e.g., which may be hum modulation), compensation for amplitude modulation is applied across all orthogonal signal components of a non-time based orthogonal coded signal. Some examples of such non-time based orthogonal coded signals include an orthogonal frequency division multiplexing (OFDM) signal, a synchronous code division multiple access (S-CDMA) signal, or a code division multiple access (CDMA) signal, etc. The compensation may be applied to the signal across multiple frames, on a frame by frame basis, or intra-frame (i.e., changing and compensating differently within a frame). This compensation for amplitude modulation may be applied in conjunction with adaptive equalization in which different filter taps are applied to each respective orthogonal signal component of the signal. Also, automatic gain control (AGC) may be performed (e.g., before digital sampling) of a received signal in conjunction with the amplitude modulation compensation.06-25-2009
20090161781Characterizing channel response using data tone decision feedback - Characterizing channel response using data tone decision feedback. In addition, to pilot tones which may be existent within an orthogonal frequency division multiplexing (OFDM) signal, one or more date tones within that same signal may be employed to assist with channel estimation (alternatively, detection). Once a data tone qualifies as a pseudo-pilot tone, it may be used with the pilot tones for channel estimation. A qualifier considers slicer error associated with hard decisions for a data tone to determine if it is a candidate for assistance within channel estimation. A frame within an OFDM signal may, in one situation, include no pilot tones at all, and a previously calculated channel estimate may be used to process that frame. In addition, fewer pilot tones than needed to perform accurate channel estimation (based on the channel delay spread) may be employed by using one or more pseudo-pilot tones (e.g., qualified data tones).06-25-2009
20090161775METHOD AND APPARATUS OF ASSIGNING IN WIRELESS COMMUNICATION SYSTEMS - A method and apparatus of assigning selected interlace mode, the method comprising generating SelectedInterlaceAssignment message comprising SelectedInterlaceAssignment message comprising an 8 bit Message ID field, a 12 bit PilotPN field, a 1 bit SelectedInterlacesEnabled field, a 4 bit NumAssignedInterlaces field, and a 3 bit InterlaceID field, wherein, the PilotPN field is set to a PilotPN of the sector that sends SelectedInterlace Assignment message, the NumAssignedInterlaces field is set to the number of assigned interlaces, the InterlaceID field is set to an interlace assigned to the access terminal for SelectedInterlace operation and transmitting the generated SelectedInterlaceAssignment message over an OFDM communication link.06-25-2009
20090161773Channel Estimation Of Orthogonal Frequency Division Multiplexed Systems - Methods and apparatus, including computer program products, are provided for channel estimation. In one aspect, there is provided a receiver including a demodulator for decoding a signal including at least one of a transmission parameter signaling (TPS) carrier and a data carrier. The receiver further includes a channel estimator, coupled to the demodulator, for determining a channel estimate for the TPS carrier. Moreover, the receiver includes an interpolator, coupled to the channel estimator, for determining, based on the determined channel estimate for the TPS carrier, another channel estimate for the data carrier. Related systems, methods, and articles of manufacture are also disclosed.06-25-2009
20090185631Method and apparatus for detecting transmission symbol using lattice-reduction matrix in multiple input multiple output (MIMO) system - Provided are a method and apparatus for detecting a transmission symbol using a lattice-reduction matrix in a Multiple Input Multiple Output (MIMO) system. The transmission symbol detection method includes: restoring an original transmission symbol from a reception signal received through the plurality of antennas; and obtaining at least one noise component included in the reception signal from a constellation changed due to applying the lattice-reduction matrix, exchanging a position of the at least one noise component under a predetermined condition which depends on a state of the restored transmission symbol, and processing the at least one noise component whose position is changed, together with the restored transmission symbol, thereby providing a soft output. Therefore, it is possible to obtain a performance gain in channel decoding.07-23-2009
20090129491INSERTING METHOD OF DOWNLINK COMMON PILOT - The present invention discloses a method for inserting a downlink common pilot in a TDD system and more particularly to a method for inserting a downlink common pilot in a TDD system based on OFDMA technology and the method includes two steps. A: data to be transmitted are divided into several segments to be transmitted in several continuous time periods, wherein each time period includes several slots with at least one downlink slot; B: a common pilot is inserted in one downlink slot in the time period. Therefore, the scheduling based on the frequency domain can be achieved by measuring the common pilot channel.05-21-2009
20100002791APPARATUS AND METHOD FOR OPERATING VALID BIT IN A WIRELESS COMMUNICATION SYSTEM - An apparatus and method for processing a valid bit operation in a wireless communication system are provided. The method includes analyzing input data and generating valid bit information representing a start position of valid bits, generating operation data comprised of the valid bits and valid bit information by eliminating extra bits from the input data, and, after performing an operation process using the generated operation data, restoring the operation data to data that is the same data as the input data.01-07-2010
20090129493RECEIVER FOR DIFFERENTIALLY MODULATED MULTICARRIER SIGNALS - The invention relates to receivers and methods for receiving multi-carrier differentially modulated signals utilizing iterative decision-directed differential detection. The receiver includes a decision feedback loop including a channel estimator for estimating inter-symbol channel variations, and a differential equalizer for correcting channel-induced errors in a differentially detected signal based on the estimated inter-symbol channel variations.05-21-2009
20090129492TRANSMITTER, COMMUNICATION SYSTEM AND TRANSMISSION METHOD - A transmitter employing an OFDM system, including a phase rotating portion which gives a same phase rotation amount to each group configured with a plurality of consecutive subcarriers modulated by a data symbol or a known symbol, a rotation amount determining portion which sets a phase rotation for each antenna set or each transmitter, and a scheduling portion which determines an existence of phase rotation.05-21-2009
20090129489RECEIVER AND A METHOD FOR CHANNEL ESTIMATION - A receiver and a method for channel estimation, the method includes calculating at least one initial channel estimate; characterized by calculating an estimate of the channel based upon a mathematical relationship between a first group of pilot subcarriers and a second group of pilot subcarriers;05-21-2009
20090086834MULTICARRIER TRANSMITTING APPARATUS AND MULTICARRIER TRANSMITTING METHOD - To narrow the dynamic range of multicarrier signals and prevent both the increment of cost and the degradation of power efficiency. A modulating part (04-02-2009
20100002787WIRELESS COMMUNICATION SYSTEM WITH MULTIPLE TRANSMISSION ANTENNAS USING PILOT SUBCARRIER ALLOCATION - A method for allocating pilot subcarriers in a resource block for a wideband wireless mobile communication system having four (4) transmission antennas using orthogonal frequency division multiplexing (OFDMA) modulation is disclosed. In this method, pilot subcarriers are allocated in the resource block so that a group of consecutive data subcarriers separated from adjacent other group of consecutive data subcarriers by the pilot subcarriers has even number of subcarriers within an OFDMA symbol.01-07-2010
20090129488METHOD OF REDUCING INTERFERENCE - Various schemes for reducing effects of interference within communication systems are disclosed. A transmitter transmits a signal in a first time interval and a scrambled version of the signal in a second time interval, which does not overlap with the first time interval. A receiver receives a composite signal including a signal transmitted from the desired transmitter as well as signals from interferers in the first or the second time interval. The receiver determines a dominant interferer and obtains knowledge of signal scrambling done by the interferer as well as the desired transmitter by sensing an identification associated with the interferer or the desired transmitter. This knowledge is employed to determine coefficients for combining the received composite signals received in the first and the second time interval in order to recover the desired signal in a manner that maximizes the SNR associated with the desired signal or completely cancels the dominant interference.05-21-2009
20090135933COMMUNICATION TERMINAL DEVICE AND COMMUNICATION RELAY METHOD - There is provided a mobile station device in a multi-hop system capable of realizing relay of communication of another station while suppressing increase of power consumption of the local station. In this device, at timing t05-28-2009
20120140835CHANNEL ESTIMATION IN AN OFDM TRANSMISSION SYSTEM - A method of channel estimation in an OFDM transmission system having a transmitter and a receiver according to standard IEEE 802.11x. The method includes: in the transmitter, setting an identifier in a reserved bits section of the header following the preamble in a physical layer frame; attaching a postamble at the end of said frame without altering the length information in the header; transmitting said frame over the channel, in the receiver, receiving a frame over the channel and checking a reserved bits section in the header of the received frame for the presence of the identifier; and if the identifier is detected, using the postamble and the preamble of the received frame to estimate the channel.06-07-2012
20120069923METHOD AND APPARATUS FOR NEW CELL IDENTIFICATION IN A WCDMA NETWORK WITH A GIVEN NEIGHBOR SET - In a WCDMA network, a communication system may include a baseband processor that enables determination of a primary synchronization position and a plurality of scrambling codes based on received configuration information from at least one base station. The baseband processor may also determine a slot boundary in at least one signal received from the at least one base station based on the determined primary synchronization position. The baseband processor may concurrently apply segments of the plurality of scrambling codes to the received at least one signal. The segments of the plurality of scrambling codes are generated from a plurality of time shifted versions of one of the plurality of scrambling codes. The system may also include a multipath detector that enables unscrambling of the received at least one signal based on the determined slot boundary and at least a portion of the one or more scrambling codes.03-22-2012
20120069922DATA PROCESSING APPARATUS AND METHOD - A data processing apparatus maps input symbols to be communicated onto a predetermined number of sub-carrier signals of an Orthogonal Frequency Division Multiplexed (OFDM) symbol. The data processor includes an interleaver memory which reads-in the predetermined number of data symbols for mapping onto the OFDM sub-carrier signals. The interleaver memory reads-out the data symbols on to the OFDM sub-carriers to effect the mapping, the read-out being in a different order than the read-in, the order being determined from a set of addresses, with the effect that the data symbols are interleaved on to the sub-carrier signals. The set of addresses are generated from an address generator which comprises a linear feedback shift register and a permutation circuit.03-22-2012
20090003476METHOD AND APPARATUS FOR DECODING USING COMPLEX LATTICE REDUCTION IN A MULTIPLE ANTENNA SYSTEM - A method and apparatus for Multiple-Input Multiple-Output (MIMO) signal decoding using complex Lattice Reduction (LR) in a multiple antenna system is provided. The method provides MIMO signal decoding with increased operating speed using a transformation of reducing the lattice basis directly to a complex channel matrix that has a smaller size in comparison with a conventional matrix, which decreases the computational complexity of the LR transformation, as well as using a procedure of permutating columns of the channel matrix only twice without binding to the procedure of reducing off-diagonal elements of the matrix R, namely prior and after the procedure of reducing. Moreover, the new method for MIMO signal decoding has its output soft decisions.01-01-2009
20090003468SYSTEM AND METHOD TO OPTIMIZE MULTICARRIER COMMUNICATION - A system and method for allocating transmitter power to subcarriers of a multicarrier signal is provided. First, the subcarriers are transmitted with an initial set of power levels and an initial set of constellation assignments. Next, quantized SNR metric values are measured at the receiver for each subcarrier. Following, the measured subcarrier quantized SNR metric is compared with the respective allocated constellation quantized SNR metric, for determining the excess SNR per subcarrier. The transmitter power of the subcarriers whose excess SNR is above a predetermined threshold is adjusted, while keeping the total transmitter power constant. The process may be repeated until a set of predefined expectations is met. The transmitter power may be adjusted for increasing throughput or robustness of the system. For increased accuracy of SNR measurements via BER estimation, several training frames may be used. Advantageously, only constellations equally spaced, such as square or cross constellations, are used. According to a preferred embodiment, OFDM/DMT multicarrier system use IFFT prescalers in the transmitter power adjustment.01-01-2009
20090003472METHOD AND APPARATUS FOR COMMUNICATING WITH ROOT-NYQUIST, SELF-TRANSFORM PULSE SHAPES - A communication system (01-01-2009
20090003473METHOD AND APPARATUS FOR TRANSMITTING AND RECEIVING COMMON CONTROL CHANNELS IN A MOBILE COMMUNICATION SYSTEM - A method and apparatus for transmitting and receiving a common control channel in an Orthogonal Frequency Division Multiplexing (OFDM) mobile communication system. In the transmission apparatus, when a plurality of bursts are transmitted during a Transmission Time Interval (TTI) of the common control channel, an Inverse Fast Fourier Transform (IFFT) mapper generates bursts that are shifted in a frequency domain by applying a predetermined cyclic shift offset between the bursts, and maps the generated bursts in a resource block. A transmission unit transmits the bursts to a receiver. In the reception apparatus, a reception unit receives a burst, and a combining unit combines the received burst with a burst stored in a buffer. A decoder decodes each of the combined bursts, and upon a successful decoding, detects a TTI start timing of the common control channel from the successfully decoded burst.01-01-2009
20090003469Frequency Offset Correction When Decoding A Packet Encoded In A Frequency Modulated Signal - Frequency offset correction when decoding a packet encoded in a frequency modulated signal. Different symbols encoded in the packet may be corrected by different frequency offsets. In an embodiment, the frequency modulated signal is received on one of the signals of a multi-carrier signal (e.g., based on Orthogonal Frequency Domain Multiplexing, OFDM) and each packet is encoded according to 802.11(a) having the same long sequence repeating multiple times in a header portion. The repetitive sequence is used to compute the different offsets for different symbols.01-01-2009
20090003466System and Method for Mapping Symbols for Mimo Transmission - Methods and devices are provided for MIMO OFDM transmitter and receivers having odd and/even numbers of transmit antennas. Various methods for pre-coding information bits before space time coding (STC) are described for enabling transmission of information bits over all antennas. Methods of decoding received signals that have been pre-coded and STC coded are also provided by embodiments of the invention. Pilot patterns for downlink and uplink transmission between a base station and one or more wireless terminals for three transmit antenna transmitters are also provided. Variable rate codes are provided that combine various fixed rate codes in a manner that results in codes whose rates are dependent on all the various fixed rate codes that are combined.01-01-2009
20090046789SYSTEMS AND METHODS FOR CONSERVING THE POWER SUPPLY OF A COMMUNICATIONS DEVICE - A method for conserving the power supply of an Orthogonal Frequency Division Multiplexing (OFDM) communications device is described. The location of a bit of information within one of a plurality of symbols is obtained. A sleep mode is entered into. The one symbol that includes the bit of information is monitored. A return to the sleep mode is executed.02-19-2009
20090141821PROCEDURE FOR SIMULTANEOUS TRANSMISSION IN TIME AND FREQUENCY OF MULTIPLE COMMUNICATIONS OF DATA BY MEANS OF OFDM MODULATIONS - Which permits to solve the problems relating to the interference produced among communications equipment of the same technology but belonging to different communications and which simultaneously use the same communications channel in time and frequency. It comprises modifying one of the parameters of the starting signal. The main advantage of the invention is that, in a simple way, it allows equipment to be correctly synchronised with the signals reaching it from its own network while ignoring signals of lesser power received from other networks using the same or different technology, without any need to carry out a complex and costly processing on reception.06-04-2009
20090185633Method and System for Specifying the Location of Data Bursts - A system and method for locating data subbursts in a data transmission is provided. A preferred embodiment comprises receiving data subbursts with different MCIDs at a mobile station. The mobile station also receives an indicator message which indicates the location of the data subbursts with MCIDs associated with the mobile station, and the mobile station selectively decodes the data subbursts with the MCIDs associated with the mobile station without decoding the remaining data subbursts.07-23-2009
20100002792SYSTEM, APPARATUS AND METHOD FOR INTERLEAVING DATA BITS OR SYMBOLS - A data transmission system respectively encodes successive bits representing information to be transmitted. An interleaver receives the bits from the encoder and interleaves the bits. The interleaver includes a memory and a memory read write controller configured to write the bits to the memory in accordance with a diagonal write pattern and to read the bits from the memory in a diagonal read pattern. A symbol mapper receives the interleaved bits and maps the encoded interleaved bits into symbols using a transmission format.01-07-2010
20080317141Method for Calculating Functions of the Channel Matrices in Linear Mimo-Ofdm Data Transmission - The present application describes a method for transmitting data through a MIMO-OFDM system which requires the computation of a function f(H(sk)), where H is the channel matrix and sk=exp(j*2*pi*k/N). The method splits function f into a first, nonpolynomial part, which is in turn a function of one or more polynomial functions in sk.12-25-2008
20080317143Apparatus and Method for Correcting Iterative Residual Frequency and Phase in Turbo Coded Ofdm System - Provided is an iterative residual frequency and phase compensation apparatus for an OFDM system and a method thereof. The apparatus includes: a first classifying unit for classifying symbol sequences by each subcarrier wave; a soft-decision calculating unit for calculating a soft-decision value of a data symbol using a soft-decision reliability obtained from iterative decoding performed by the iterative decoder; a classifying unit for classifying the soft-decision values by a carrier wave; a frequency estimating unit for estimating a residual frequency error of each carrier wave using the soft-decision value; a phase estimating unit for estimating an average residual phase error using the soft-decision value; a frequency and phase compensating unit for compensating frequencies and phases for input symbols of each carrier wave using the estimated frequency error and the estimated phase error; and a buffer for temporally storing the compensated symbols to provide it to the first classifying unit.12-25-2008
20090252241Spectral shaping for multiband OFDM transmitters with time spreading - A method of shaping an orthogonal frequency division multiplexing (OFDM) signal spectrum of a transmitted signal is disclosed. An input signal including an input component is received and a first instance of the input component is generated. The method also includes determining that a second instance of the input component is to be different than the first instance. The second instance of the input component that is different from the first instance is generated. An output signal to be transmitted is generated and includes the first instance and the second instance of the input component.10-08-2009
20090252245TRANSMISSION METHOD AND APPARATUS FOR CANCELLING INTER-CARRIER INTERFERENCE - The present invention provides a transmission method and apparatus for cancelling inter-carrier interference in wireless communication systems. Particular carriers are not used for data transmission but carry weighted data to cancel the ici interference of a first group of interfering sub-carriers onto a second group of victim sub-carriers. The weights are inversely proportional to the frequency offset between the interfering sub-carriers and the victim sub-carriers.10-08-2009
20090252244WIRELESS COMMUNICATION DEVICE, WIRELESS COMMUNICATION METHOD, PROGRAM AND WIRELESS COMUNICATION SYSTEM - A wireless communication device is provided that includes: a plurality of receiving portions that respectively receive wireless signals that are transmitted based on frequency-use methods set from among a plurality of frequency-use methods; and a setting portion that sets one of the plurality of frequency-use methods on each of the plurality of receiving portions respectively. The setting portion changes the frequency-use method of the plurality of receiving portions, based on a receiving result of a wireless signal in each of the plurality of receiving portions.10-08-2009
20090252243Method and apparatus for transmitting signals in a multi-hop wireless communication system - A method and apparatus for transmitting signals in a multi-hop wireless communication system are provided. A first BS transmits a signal including a first common information codeword and a first private information codeword. A second BS transmits a signal including a second common information codeword and a second private information codeword. A first RS joint-decodes the first common information codeword and the second common information codeword and decodes the first private information codeword. A second RS joint-decodes the first common information codeword and the second common information codeword and decodes the second private information codeword.10-08-2009
20090252242Apparatus and method for detecting signal based on lattice reduction to support different coding scheme for each stream in multiple input multiple output wireless communication system - An apparatus and method for detecting signals based on a Lattice Reduction (LR) algorithm in a Multiple Input Multiple Output (MIMO) wireless communication system are provided. The apparatus includes a plurality of operators for determining soft-decision values for respective streams by performing a soft modulo operation on respective symbol values included in a Receive (Rx) signal block multiplied by a lattice transformation matrix T, a plurality of inner decoders for determining Log Likelihood Ratio (LLR) values of codewords according to coding schemes for the respective streams by decoding the soft-decision values for the respective streams according to identical decoding scheme, a passer for restoring the LLR values representing the codewords generated in a transmitting end using the LLR values, and a plurality of outer decoders for determining LLR values of Transmit (Tx) bitstreams for the respective streams by decoding the LLR values representing the codewords generated in the transmitting end for the respective streams according to decoding schemes for the respective streams.10-08-2009
20090252240TRANSMITTING APPARATUS AND METHOD, AND RECEIVING APPARATUS AND METHOD IN MULTPLE ANTENNA SYSTEM - Respective codewords of quantization codebooks corresponding to a number of data streams are selected based on channel information estimated by a received training symbol. A stream mode is selected among stream modes to determine a modulation method applied to each data stream. The data stream is detected by using the codeword corresponding to the quantization codebook of the data stream corresponding to the selected stream mode as a precode matrix, and the detected data stream is modulated. In this case, a receiving apparatus performs a feedback operation so that indexes of the selected stream mode and the codeword used as the precode matrix may be transmitted to the transmitting apparatus. The transmitting apparatus selects the number of transmitted data streams and the modulation method based on the transmitted index of feedback streams by the feedback operation.10-08-2009
20090252238RE-ACQUISITION OF SYMBOL INDEX IN THE PRESENCE OF SLEEP TIMER ERRORS FOR MEDIAFLO SYSTEMS - A technique for re-acquiring a symbol index in the presence of sleep timer errors in a MediaFLO™ (Forward Link Only) mobile multimedia multicast system comprising a receiver and a transmitter, wherein the method comprises receiving a digital signal comprising a superframe comprising one or more Orthogonal Frequency Division Multiplexing (OFDM) symbols in the receiver comprising a timer; waking up the receiver from a sleep mode of operation by an amount of time equal to a maximum error introduced by the timer plus a time to reacquire a beginning of each OFDM symbol plus a time to reacquire a symbol index; and reacquiring the symbol index.10-08-2009
20090252236RETRANSMITTING METHOD AND TRANSMITTING METHOD IN MULTI-ANTENNA TRANSMISSION - A transmitting apparatus capable of enhancing the certainty of data transmission of MIMO system, improving the system throughput, and providing a retransmission technique adaptive to the multi-antenna transmission. In this apparatus, a serial/parallel converting part (10-08-2009
20100002786SIGNAL DETECTING METHOD AND RECEIVER USING THE SAME - A signal detecting method and a receiver using the same are provided. The method includes the following steps. A receiving signal vector y is received through a number of channels, wherein the receiving signal vector y corresponds to a transmitting signal vector x transmitted by at least one of the channels. A channel matrix H is determined, wherein the channel matrix H represents at least one of the channels. A factorization matrix D is chosen, wherein D is invertible to make the channel matrix H expressed as H={tilde over (H)}D, and {tilde over (H)} is a corresponding channel matrix. The factorization matrix D is determined to make an expected value of the signal estimate error become smaller. The receiving signal vector y is detected to estimate the transmitting signal vector x according to the corresponding channel matrix {tilde over (H)} and the factorization matrix D.01-07-2010
20100002785ADAPTIVE THRESHOLDING FOR OFDM CHANNEL ESTIMATION - An adaptive thresholding technique eliminates suboptimum threshold values by adjusting for varying channel conditions to eliminate interference where no channel energy is present, without discarding viable taps having useful channel energy. The adaptive thresholding technique adaptively optimizes receive threshold values for both wide and local area channels based only on measured C/I ratios 300. Thresholds are calculated based on instantaneous C/I estimates and/or weighted average C/I estimates calculated from WID/LID energies obtained from the current superframe WIC/LIC symbols respectively. In alternate embodiments, thresholds are calculated based on instantaneous C/I estimates and/or weighted average C/I estimates calculated from WTPC and LTPC symbols for the wide and local area channels, respectively The present adaptive thresholding technique dynamically reduces the threshold as the C/I estimate increases to mitigate performance degradation due to removal of weak signal taps. There is a separate threshold for each of the 12 coding and modulation modes supported by an exemplary receiver.01-07-2010
20090052566METHOD FOR CHANNEL ESTIMATION USING RECURSIVE FILTERING AND MULTICARRIER RECEIVER WITH INTERFERENCE-AWARE DEMODULATION - Embodiments of a multicarrier receiver with interference-aware demodulation and methods for channel estimation using recursive filtering in wireless networks are generally described herein. Other embodiments may be described and claimed. In some embodiments, orders of a recursive filter are allocated to track a main channel and one or more interfering channels to generate channel estimates.02-26-2009
20090141819METHOD AND APPARATUS OF RECURSIVE TIME-FREQUENCY CHANNEL ESTIMATION - An approach is provided for estimating a channel of a multi-carrier transmission by splitting an interpolation or extrapolation or smoothing of estimates into a frequency domain part and a time domain part, wherein the channel estimation unit is configured to use for both the frequency domain part and the time domain part respective recursive filters, and wherein at least one of the recursive filters is adapted to channel conditions of the multi-carrier transmission.06-04-2009
20090141823Power Reduction For Digital Subscriber Line - An apparatus comprising a transmitter configured to transmit a low power mode Discrete Multi-Tone (DMT) signal using a plurality of DMT tones, wherein a subset of the DMT tones are used for transmitting data, and wherein at least some of the remaining DMT tones are used for a Peak-to-Average Ratio (PAR) reduction is disclosed. Included is a network component comprising at least one processor configured to implement a method comprising promoting transmission of a plurality of data streams using a plurality of first digital tones, and promoting transmission of at least one second digital tone that reduces a peak of a signal generated by at least one of the first digital tones.06-04-2009
20090141820Apparatus, computer program and method for determining a symbol estimate - An apparatus for determining a symbol estimate includes a detection unit, an information storage, a channel decoder, and an estimator. One or more detectors of the detection unit is configured to detect a first data stream and the one or more detectors or one or more other detectors are configured to detect a second data stream when interference cancellation is carried out and when interference cancellation is not carried out parallel to detection of a first data stream to obtain results of detection. The information storage is configured to store the results of the detection of the second data stream, and the channel decoder is configured to channel decode a detected first data stream. The estimator is configured to determine a symbol estimate by using the stored results of the detection of the second data stream and based on the success of the channel decoding of the first data stream.06-04-2009
20100002782RADIO COMMUNICATION SYSTEM AND RADIO COMMUNICATION METHOD - In an OFDM cellular system, a power density of a phase reference signal of a time frame used in an initial synchronization process (time frame including a system information notification signal, or a time frame in the vicinity thereof), in a channel band for initial synchronization, is more increased than that of the other time frame.01-07-2010
20100002784Method for Reducing Peak-To-Average Power Ratio in an Ofdm Transmission System - The Peak-to-Average Power Ratio in an OFDM transmission system is reduced based on a complementary parity coding in which the coding rules are derived from an appropriate auto-correlation property of transmitted symbol sequences.01-07-2010
20110222616MIMO Transmission with Rank Adaptation for Multi-Gigabit 60 GHz Wireless - A wireless system includes a transmitter with a baseband processor responsive to groups of transmitter antenna arrays for communicating over directional beams; and a receiver with a baseband processor responsive to groups of receiver antenna rays for communicating with the transmitter over the directional beams, the receiver including both a rank adaptation providing a transmit mode feedback to the transmitter and a blind beamforming providing a transmit beamformer index feedback to the transmitter and receiver groups of antenna arrays.09-15-2011
20110222617METHOD FOR PERFORMING WIRELESS SWITCHING - A wireless communication system includes an infrastructure device for transmitting and receiving communications to and from a plurality of user terminals. Each user terminal includes a receiver and a controller that receives a first orthogonal frequency division multiplexing (OFDM) signal on a first carrier frequency that has assignment information indicating a second carrier frequency to transmit uplink data and beam forming information. In response to the assignment information, a transmitter of the user terminal transmits a second OFDM signal on the second carrier frequency using a beam indicated in the beam forming information.09-15-2011
20090080553SYNCHRONIZATION TECHNIQUES IN MULTIPOINT-TO-POINT COMMUNICATION USING ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING - Systems and methods for synchronization techniques in multipoint-to-point communication using orthogonal frequency division multiplexing are provided. In one embodiment, a method for multipoint-to-point communication comprises: receiving at a host a plurality of upstream symbols transmitted from a plurality of remote units, the upstream symbols transmitted on a plurality of orthogonal carriers modulated using an inverse Fourier transform; and determining respective round trip path delay values associated with each of at least two of the plurality of remote units.03-26-2009
20090080551Bandwidth Efficient Coding for an Orthogonal Frequency Multiplexing OFDM System - A method for encoding an OFDM signal includes pairing two adjacent subcarriers of an OFDM signal as a group, changing a modulated symbol set of the OFDM signal to a modified symbol set for coding the OFDM signal, and providing a modified baseband OFDM signal with an increased frequency separation between the subcarriers and reducing the total number of subcarriers being used for transmission over each OFDM symbol interval.03-26-2009
20090046786SYSTEM AND METHOD OF OPERATING A MIMO SYSTEM - A MIMO system comprising a transmitting station (02-19-2009
20090046790MULTI-BANDWIDTH COMMUNICATION SYSTEM USING A SHARED BASEBAND PROCESSOR - Systems and methods are provided for transceiving information via alternate bandwidths using a shared baseband processor. The transmission method selects clock sampling frequencies, for example a first clock frequency (l×F1), or a second clock frequency (k×F1), where k>l. Digital information is processed using the selected clock sampling frequency and a baseband signal is generated. Regardless of the clock sampling frequency selected, the baseband signal may have the same number of subcarrier frequencies. The baseband signal is converted into a radio frequency (RF) signal having a data rate responsive to a selected clock frequency, and transmitted. More explicitly, a first baseband signal is generated having a first data rate in response to selecting the first clock frequency. A second baseband signal having a second data rate greater than the first data rate, may be generated in response to selecting the second clock frequency.02-19-2009
20090060074WIRELESS COMMUNICATIONS APPARATUS - Precoding a plurality of subcarriers in preparation for MIMO transmission is carried out by deriving preceding matrices from available information. When the number of data streams borne by the subcarriers equates to the number of transmit antennas employed in the MIMO transmission, the method comprises deriving, from respective acquired unitary precoder matrices for two of said subcarriers, interpolated precoder matrices for data streams intermediate the two subcarriers. The acquired and interpolated precoder matrices are then applied, as the case may be, at the respective subcarriers. The step of deriving the interpolated precoder matrices comprises determining an overall rotation matrix representing a transformation between the acquired precoder matrices, determining from the overall rotation matrix a further rotation matrix representing a step transformation for interpolation steps between said two subcarriers, and recursively applying said further rotation matrix to derive said interpolated precoder matrices. In the event that the number of data streams is less than the number of transmit antennas employed in said MIMO transmission, the rectangular precoder matrices should first be converted into square unitary matrices.03-05-2009
20090052563DECODING APPARATUS AND DECODING METHOD - Provided are a decoding apparatus and method for a system supporting an Orthogonal Frequency Division Multiple Access (OFDMA) scheme, the apparatus and method compensating received signals according to a wireless channel estimation result and thereby simply performing decoding by a coherent method. The decoding method includes the steps of: receiving a Quadrature phase shift keying (QPSK) modulated signal; compensating the received signals by applying a result of channel estimation based on pilot signals to the received signals; performing subcarrier demodulation to generate correlation metrics on the basis of the compensated received signals; and performing decoding using a decoding metric derived from the correlation metrics. The decoding apparatus and method compensate a received wireless signal according to a channel estimation result of a wireless channel through which a signal is transmitted, thereby performing decoding by a coherent method having a simple structure.02-26-2009
20090052565TURBO CHANNEL ESTIMATION FOR OFDM SYSTEMS - A system and method for estimating a channel in a wireless receiver is disclosed. The method preferably applies to a communication system using the OFDM standard. The method comprises receiving a block of “n” transmitted symbols, the symbols including pilot symbols and “d” data symbols, estimating a channel using the pilot symbols to create a channel estimate, choosing a group of “m” strongest symbols from the “d” received symbols, compensating the “m” strongest symbols using the channel estimate to create a group of “m” compensated symbols, re-estimating the channel using the group of “m” compensated symbols and pilot symbols; and either (1) repeating the steps of choosing a group of “m” strongest symbols, compensating the group of “m” strongest symbols and re-estimating the channel, or (2) using a latest channel estimate to compensate all symbols within the block. The system comprises a wireless receiver having an estimator programmed, for example, using DSP or ASIC and imbedded into the wireless system design software for accomplishing the steps set forth according to the method.02-26-2009
20090052564RECEIVING APPARATUS AND RECEIVING METHOD - An average power indicating channel characteristics is outputted from a reference value calculation unit as a reference value. An interference level corresponding to the degree of influence by frequency selective interference is outputted from an interference detection unit. A reliability determination unit determines a carrier that has been subjected to interference on the basis of the reference value and the interference level, to decide a reliability level. An error correction unit performs error correction of a demodulation signal on the basis of the reliability level.02-26-2009
20090052562CORRELATION CALCULATION UNIT AND CORRELATION CALCULATION APPARATUS - A correlation calculation unit includes: four arithmetic units each including a first differential arithmetic section calculating a difference between an OFDM (orthogonal frequency division multiplexing) signal and a first delay signal, a second differential arithmetic section calculating a difference between a second delay signal and a third delay signal, and a multiplication section multiplying arithmetic results of the first and second differential arithmetic sections; four polarity conversion units converting arithmetic results of the multiplication sections of the corresponding arithmetic units into polarity signals indicating polarities of the arithmetic results, respectively; four integrating units integrating the polarity signals obtained by the corresponding polarity conversion units, respectively; and an addition unit adding up integrating results of the four integrating units, and outputting an addition result as a correlation signal indicating a correlation between the OFDM signal and the second delay signal.02-26-2009
20090080550Communications device - A communications device for generating a Zadoff-Chu sequence includes a storage unit storing real and imaginary part values of exp{−j·(2π/N)·(m/2)} for the Zadoff-Chu sequence of the sequence length N, wherein m is an integer (0≦m<(N+1)/2); a parameter acquisition unit acquiring a sequence number u, data number k, cyclic shift amount Δ and cyclic shift number Ncs; a phase position detecting unit detecting a phase position of the Zadoff-Chu sequence with acquired parameters; and a sequence determination unit determining m to read a real and an imaginary part value in the storage unit based on the phase position and determining a plus/minus sign of each of the real and the imaginary part value. The device further includes a sequence acquisition unit acquiring the Zadoff-Chu sequence by using the real and the imaginary part values according to m determined by the sequence determination unit and the signs thereof determined.03-26-2009
20120069921APPARATUS AND METHOD FOR ENCODING/DECODING A MULTICHANNEL SIGNAL - An apparatus for encoding/decoding a multichannel signal. The apparatus for encoding/decoding a multichannel signal processes phase parameters for phase information among a plurality of channels constituting the multichannel signal in consideration of the characteristics of the multichannel signal. The apparatus generates an encoded bit stream for the multichannel signal using the processed phase parameters and the mono signal extracted from the multichannel signal.03-22-2012
20090080544Method and apparatus for an OFDMA parallel architecture scheduler - A method and apparatus for calculating an optimal sub-channel allocation of Orthogonal Frequency Division Multiple Access (OFDMA) from a first bipartite graph that may map users, to a second bipartite graph that may map additional users, including original users. A calculation of each bipartite graph may include a calculation of maximum weight paths and matchings. Using a bipartite graph method for OFDMA sub-channel allocation may improve the time and complexity when establishing an OFDMA wireless system.03-26-2009
20090080545Reducing data stream jitter during deinterleaving - In one embodiment, the present invention includes a deinterleaver having an input interface to receive orthogonal frequency division multiplexing (OFDM) symbols from a demodulator, a memory coupled to the input interface to store the OFDM symbols, an output interface coupled to the memory to receive the OFDM symbols stored in the memory, and a digital phase lock loop (PLL) to control and adjust a reading rate of data from the memory responsive to dynamic and static channel conditions.03-26-2009
20090080543ADAPTIVE CYCLIC DELAY DIVERSITY FOR MOBILE DEVICES - Embodiments of the present invention provide for adaptive cyclic delay diversity to be used in wireless transmissions to mobile devices. The cyclic delay diversity may be adapted through cyclic delay parameters determined based at least in part on a determined speed of the mobile device. Other embodiments may be described and claimed.03-26-2009
20090080552SYSTEM FOR MULTIPLE USE SUBCHANNELS - Systems for multiple use subchannels are provided. In one embodiment, a bidirectional communication system comprises: a first remote unit for communicating with a host using OFDM, the host communicatively coupled to a plurality of remote units in a multipoint-to-point configuration. The first remote unit is configured to transmit up to a plurality of tones, the up to a plurality of tones modulated with upstream information using OFDM, the first remote unit including a modulator for modulating the up to a plurality of tones using OFDM. The modulator is configured to adjust a carrier frequency and timing of the plurality of tones such that when any tones are transmitted from the first remote unit and at least one other remote unit, the orthogonality of the tones when received at the host unit is improved. Both control data and payload data are transmitted on a first tone of the plurality of tones.03-26-2009
20090080547BASE STATION APPARATUS AND MOBILE STATION APPARATUS - A base station apparatus that transmits frames in accordance with a communication format, and a mobile station apparatus that uses the frames to determine the communication format of the base station apparatus, and then performs an adaptive cell search in accordance with the determined communication format. The base station apparatus (03-26-2009
20090022231COMMUNICATION APPARATUS - A communication apparatus associated with a system that uses two or more discontinuous frequency bands. The communication apparatus includes a BPF (band pass filter) including a plurality of BPFs associated with signals having respective frequency bands; a controller that controls each unit to transmit/receive the signals having the respective frequency bands; a down-converter that down-converts a filtered signal into a baseband signal while switching frequencies under control of the controller; a receiver that performs predetermined reception processing under control of the controller; and a transmitter that performs predetermined transmission processing under control of the controller, and common hardware is used in communication in all frequency bands with respect to processing of the baseband signal.01-22-2009
20090067521BLIND ESTIMATION METHOD OF OFDM MODULATION PARATMETERS - The present invention concerns a blind estimation method of at least one temporal modulation parameter of an OFDM signal, in which a plurality of demodulation attempts of said OFDM signal are carried out using a plurality of respective values of this temporal parameter and, for each demodulation attempt, a cost function representative of the entropy of the demodulated signal is calculated, the estimate of said temporal parameter then being obtained as the value of this parameter minimising said cost function.03-12-2009
20090052561METHODS AND APPARATUS FOR GENERATING AND COMMUNICATING WIRELESS SIGNALS HAVING PILOT SIGNALS WITH VARIABLE PILOT SIGNAL PARAMETERS - An embodiment for wirelessly communicating a signal includes a transmitter generating and transmitting a wireless signal over a wireless communication channel. The wireless signal includes a guard band, data represented within a plurality of data-bearing subcarriers, and a plurality of pilot signals represented within a plurality of pilot subcarriers. In an embodiment, the plurality of pilot signals have variable pilot signal parameters selected from a group of parameters that includes pilot power and pilot spacing with respect to adjacent pilots. An embodiment further includes a receiver receiving a channel-affected version of the wireless signal, and producing a corrected signal by applying corrections to the received signal based on estimated channel perturbations within the received signal, where the estimated channel perturbations are determined based on the plurality of pilot signals. The receiver also produces an output data symbol from the corrected signal.02-26-2009
20110142148Orthogonal Frequency Division Multiplex Transmission Method - A communications system includes a first reception device and a transmission device. The transmission device includes a modulator operable to modulate a plurality of subcarriers using a signal series obtained by multiplexing a first signal series to be transmitted to the first reception device and a second signal series to be transmitted to a plurality of reception devices including the first reception device in a communications area of the transmission device and a transmitter operable to transmit the modulation signals. The first reception device includes a demodulator operable to regenerate the first signal series and the second signal series.06-16-2011
20110142147MULTI-RANK PRECODING MATRIX INDICATOR (PMI) FEEDBACK IN A MULTIPLE-INPUT MULTIPLE-OUTPUT (MIMO) SYSTEM - In at least some embodiments, a system includes a multiple-input multiple-output (MIMO) base station and a plurality of MIMO user equipment (UE) devices in communication with the MIMO base station. The MIMO base station is configured to switch between a single-user (SU)-MIMO mode and a multiple-user (MU)-MIMO mode during communications with the plurality of MIMO UE devices based on multi-rank precoding matrix indicator (PMI) feedback received from at least one of the MIMO UE devices.06-16-2011
20090274223ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING RECEIVER - In one aspect, an orthogonal frequency division multiplexing (OFDM) receiver includes an offset compensator, a fast Fourier transform (FFT) block, a control unit, a channel impulse response estimation block, and a sampling offset estimation block. The offset compensator is configured to receive a digital input signal and a sampling offset, and to convert the digital input signal into a baseband signal in accordance with the sampling offset. The fast Fourier transform (FFT) block is configured to perform an FFT operation of the base band signal output from the offset compensator and to output a corresponding FFT result. The control unit is configured to generate OFDM symbol information and a plurality of control signals based on the FFT result. The channel impulse response estimation block is configured to periodically generate receiving channel impulse response information of a receiving channel based on the FFT result. The sampling offset estimation block is configured to generate the sampling offset based on the FFT result, the receiving channel impulse response information, the OFDM symbol information, and the plurality of control signals.11-05-2009
20110142150USER SPECIFIC DOWNLINK POWER CONTROL CHANNEL Q-BIT - Systems and methodologies are described that facilitate controlling transmission power of a wireless terminal. A downlink power control channel segment may include an Orthogonal Frequency Division Multiplexing (OFDM) tone-symbol that may comprise a first component and a second component. The first component may be an in-phase (I) component and the second component may be a quadrature (Q) component, for example. A power command may be transmitted in the first component. Further, information associated with a wireless terminal may be transmitted in the second component. The information associated with the wireless terminal may be, for instance, a portion of a scrambling mask associated with the wireless terminal.06-16-2011
20110142149METHOD AND APPARATUS OF CODEBOOK TRANSFORMATION FOR INTERFERENCE MITIGATION IN CODEBOOK-BASED PRECODING - When a transmitter communicating with a first receiver interferes with an adjacent second receiver, the transmitter receives a reference signal from the second receiver in order to transform a codebook to mitigate interference in the second receiver. A channel with the second receiver is estimated through the received reference signal, and a receiving correlation matrix is calculated based on the estimated channel. The inverse of the receiving correlation matrix is calculated from the calculated receiving correlation matrix, and the codebook is transformed using the calculated inverse of the receiving correlation matrix.06-16-2011
20090232235User scheduling method in multiple antenna system - A user scheduling method includes: determining a maximum temporary user set of a maximum capacity among temporary user sets obtained from combinations of M number of active users; and transmitting data to users belonging to the maximum temporary user set via multiple antennas by using a preceding matrix and a weight matrix with respect to the maximum temporary user set. Users to actually receive data can be selected from among active users in a multi-antenna system, and a corresponding precoding matrix and a weighting matrix can be obtained.09-17-2009
20090097581METHOD AND APPARATUS FOR ADAPTIVELY CONTROLLING SIGNALS - A signal processing system according to various aspects of the present invention includes an excursion signal generator, a scaling system and a filter system. The excursion signal generator identifies a peak portion of a signal that exceeds a threshold and generates a corresponding excursion signal. The scaling system applies a real scale factor to contiguous sets of excursion samples in order to optimize peak-reduction performance. The filter system filters the excursion signal to remove unwanted frequency components from the excursion signal. The filtered excursion signal may then be subtracted from a delayed version of the original signal to reduce the peak. The signal processing system may also control power consumption by adjusting the threshold. The signal processing system may additionally adjust the scale of the excursion signal and/or individual channel signals, such as to meet constraints on channel noise and output spectrum, or to optimize peak reduction. The magnitude threshold, excursion signal and/or individual channel signals may also be adaptively adjusted based on, for example, a channel signal quality such as a noise level specification.04-16-2009
20110228868CHANNEL ESTIMATION METHOD OF AN ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING SYSTEM AND RECEIVING APPARATUS - A channel estimation method of an Orthogonal Frequency Division Multiplexing (OFDM) system and a corresponding receiving apparatus are provided. The technical solutions use the receiving apparatus to firstly perform channel estimation in time dimension on received signals, obtain channel information of pilot points from an effective sub-carrier frequency band on a frequency domain of each OFDM symbol, obtain information of the pilot points on frequency bands outside the effective sub-carrier frequency band by adding the information of the pilot points, and then perform Inverse Fast Fourier Transform (IFFT), windowing, zero-padding, and Fast Fourier Transform (FFT) to obtain a channel frequency response, so as to obtain a channel estimation result. The technical solutions can achieve goals of restraining an edge effect and improving accuracy of the channel estimation.09-22-2011
20090202013WIRELESS COMMUNICATION NETWORK AND METHOD FOR EXTENDED-RANGE UPLINK COMMUNICATIONS - Embodiments of a wireless network and method for extended-range communications are generally described herein. In some embodiments, an RF bandwidth of an uplink communication channel is established for a plurality of subscriber units. A desired channel quality is also established for uplink communications from each subscriber unit to a base transceiver station over the uplink communication channel. The RF bandwidth of the uplink communication channel is reduced and additional time-slots are allocated to the uplink communication channel of some subscriber units to achieve the desired channel quality for the uplink communications to provide extended-range uplink communications for subscriber units that are further from the base transceiver station.08-13-2009
20090086837Interfering stream identification in wireless communication systems - An exemplary embodiment in accordance with this invention is a method for determining the number of interfering streams. The method includes calculating statistical information based on one or more received OFDM signals. The number of interfering streams is estimated from the statistical information in this method. The OFDM signal(s) are received via a plurality of antennas. Storing the OFDM signal(s) in a square matrix may be included in the method. A covariance matrix of the square matrix can be determined; and a noise subspace and a signal plus interference subspace can be determined based on a SVD of the covariance matrix. The statistical information may be based on the signal plus interference subspace. Apparatus, computer programs and computer-readable media are also disclosed.04-02-2009
20090097579APPARATUS AND METHOD FOR REDUCING PAPR IN AN OFDM SYSTEM - An apparatus and method for reducing a Peak-to-Average Power Ratio (PAPR) are provided. The apparatus includes a gain processor for multiplying time signals in paths by gains set for respective paths, a delay processor for delaying gain-multiplied signals in second to last paths except for a first path by time delays set for respective second to last paths, a summer for summing the gain-multiplied signal for the first path received from the gain processor and the delayed signals received from the delay processor, a PAPR processor for measuring a PAPR of the summed signal received from the summer, for comparing the measured PAPR with a target PAPR, and for requesting one or more changes of at least one of the gain and time delay of each path, and a gain delay controller for changing the at least one of the gain and the time delay of each path according to the request received from the PAPR processor and for controlling the gain processor and the delay processor according to the change.04-16-2009
20090003480Method And Apparatus For Multi-Antenna Transmitting Based On Spatial-Frequency Encoding - The present disclosure relates to communication technologies and discloses a method and apparatus for multi-antenna transmitting based on spatial-frequency encoding. The method includes: performing spatial-frequency encoding on input data and outputting encoded data; mapping the encoded data to the same sub-carrier of each antenna in an antenna group; adding a phase shift to the encoded data on different sub-carriers of each antenna; OFDM-modulating the phase-shifted encoded data on each antenna; and transmitting the OFDM-modulated data by transmit antennas.01-01-2009
20090003465Method of Keying for Broadcast Using Ofdm - A method of modulation, which is applied to a communication system transmitting data in one frequency band using at least two orthogonal subcarriers, is disclosed. The present invention includes the steps of adding information bits indicating an amplitude reference and a phase reference to an input bit sequence by a specific time interval unit and carrying out differential amplitude phase shift keying (DAPSK) on the input bit sequence using the amplitude and phase references. The present invention prevents the waste of power and bandwidth due to insertion of a plurality of pilot toes in the related art 1β-QAM system.01-01-2009
20090003467POWER PROFILE RESHAPING IN ORTHOONAL FREQUENCY DIVISION MULTIPLE ACCESS SYMBOLS - A method, information processing system, and base station for reshaping power profiles in Orthogonal Frequency Division Multiple Access (OFDMA) symbols. The method includes monitoring a scheduler (01-01-2009
20090207927RECEIVING APPARATUS - There is provided a receiving apparatus (08-20-2009
20090245403METHODS AND APPARATUS FOR USE IN REDUCING RESIDUAL PHASE ERROR IN OFDM COMMUNICATION SIGNALS - Methods and apparatus for use in reducing residual phase error (RPE) in orthogonal frequency division multiplexed (OFDM) communication signals are described. In at least one embodiment of the invention, an apparatus includes a residual phase error estimator configured to estimate a residual phase error at least partially based on a plurality of phases of a first channel-compensated received signal and a plurality of phases of a sliced version of the first channel-compensated received signal. The residual phase error estimator is configured to correct a channel estimate at least partially based on the residual phase error estimate to thereby generate a corrected channel estimate. The apparatus includes a channel compensator configured to generate a second channel-compensated received signal at least partially based on a received signal and the corrected channel estimate.10-01-2009
20090220016INTERFERENCE REDUCTION IN A COMMUNICATION SIGNAL - The invention concerns the reduction of interference in a communication signal sent through a communication channel, where this interference is a performance limiting factor. The communication channel is any channel that can be described with memory elements. A Soft Input Soft Output receiver of a communication signal receives the communication signal and a priori information about the communication signal. Next creating candidate vectors having 1 to K samples by iteratively drawing samples using Gibbs sampling and using the a priori information. If a drawn kth sample of a candidate vector has not changed value for a predetermined number of created candidate vectors, then the value of the drawn kth sample is changed.09-03-2009
20090257517WIRELESS COMMUNICATION METHODS AND RECEIVERS FOR RECEIVING AND PROCESSING MULTIPLE COMPONENT CARRIER SIGNALS - A wireless communication system receiver receives and processes a signal comprising at least two component carriers carrying data scheduled to the receiver and having center frequencies spaced apart by at least one component carrier frequency difference. Each component carrier comprises a number of subcarriers spaced apart by a system subcarrier frequency spacing. A common divisor is obtained for the at least one component carrier frequency difference and the system subcarrier frequency spacing. A symbol is received on the subcarriers of the component carriers and downconverted to baseband to produce a baseband symbol. A block of padding values is inserted in the baseband symbol to produce a padded symbol. The length of the block of padding values is such that intermediate subcarriers are inserted to yield a subcarrier frequency spacing for the padded symbol equal to the common divisor. Finally the padded symbol is Fast Fourier Transform, FFT, processed.10-15-2009
20090257516SYSTEM AND METHOD FOR PILOT DESIGN FOR DATA TRANSMITTED IN WIRELESS NETWORKS - A method for pilot design for data to be transmitted by an orthogonal frequency-division multiplexing (OFDM) based communication system, the data being represented by a plurality of OFDM symbols. The method includes allocating pilot symbols for a data stream to be included in ones of the OFDM symbols; and performing a frequency shift on at least one of the OFDM symbols, to reduce frequency distance disparities among the pilot symbols.10-15-2009
20090257521Method and System for Channel Estimation in a Spatial Multiplexing MIMO System - Aspects of a method and system for channel estimation in a SM MIMO communication system may comprise receiving a plurality of spatially multiplexed communication signals from a plurality of transmit antennas. A plurality of baseband combined channel estimates based on phase rotation may be generated in response to the received plurality of spatially multiplexed communication signals. An estimate of the channel matrix may be determined based on the baseband combined channel estimates. A plurality of amplitude and phase correction signals may be generated in response to receiving the estimate of the channel matrix. An amplitude and a phase of at least a portion of the received plurality of spatially multiplexed communication signals may be adjusted based on the generated plurality of amplitude and phase correction signals, respectively.10-15-2009
20090245404OFDM TRANSMISSION/RECEPTION APPARATUS - Modulation section 10-01-2009
20090245401MULTIDIMENSIONAL CONSTELLATIONS FOR CODED TRANSMISSION - Techniques for rotating and transmitting multidimensional constellations are disclosed. A method for rotating a multidimensional constellation may include constructing a first rotation matrix, constructing a second rotation matrix, applying orthogonality constraints to the first and second rotation matrices; selecting an optimizing rotation matrix from the first and second rotation matrices; and rotating the multidimensional constellation using the optimizing rotation matrix. Constructing the first rotation matrix and second rotation matrices may include constructing a first column that includes first matrix elements based on the number of axes in the multidimensional constellation, and additional columns that include permutations of the first matrix elements.10-01-2009
20090245398Method of Processing a Signal and Apparatus for Processing a Signal - The present invention relates to a method and apparatus for processing a signal. An object of the present invention devised to solve the problem lies on a method and apparatus for processing a signal, which allows a signal having optimized signal transmission efficiency to be transmitted/received. According to an aspect of the present invention, there is provided A method for processing a signal, the method including receiving a broadcasting signal including data coded using a group reference value corresponding to a plurality of data included in one of groups formed according to data grouping and a difference value corresponding to the group reference value, demodulating the broadcasting signal in consideration of a scattered pilot which varies over time and a continual pilot which is fixed over time in a frame of the received broadcasting signal and decoding the demodulated signal to obtain a broadcasting transmission stream, demultiplexing the broadcasting transmission stream to obtain data coding identification information and decapsulating Internet protocol (IP) packets having the coded data, obtaining the group reference value corresponding to the plurality of data and the difference value corresponding to the group difference value through grouping from the decapsulated data and obtaining the data using the group reference value and the difference value.10-01-2009
20090245396ORTHOGONAL RESOURCE BLOCK HOPPING MULTIPLEXING METHOD AND APPARATUS - The present invention relates to an orthogonal resource block hopping multiplexing(ORBHM) method and apparatus in a wired/wireless communication system in which a plurality of communication channels coexist in a single medium.10-01-2009
20090245402APPARATUS AND METHOD FOR TILE PROCESSING IN WIRELESS COMMUNICATIONS - An apparatus and method for tile processing using a plurality of tile descriptors comprising defining the plurality of tile descriptors in a time-frequency plane; preparing the plurality of tile descriptors to be sent to a receiver for storage; allocating at least one tile associated with the plurality of tile descriptors to a user; and notifying the allocated at least one tile to a transmitter for transmitting a wireless signal to the user using the allocated at least one tile. In one aspect, the apparatus and method further comprise receiving the wireless signal, wherein the wireless signal comprises an encoded user message; retrieving the plurality of tile descriptors from a memory unit; and demodulating the wireless signal using the plurality of tile descriptors to obtain the encoded user message.10-01-2009
20080260060METHOD OF CONTROLLING SIGNAL TRANSMISSION IN MULTI-INPUT/MULTI-OUTPUT SYSTEM - A method of controlling signal transmission in a Multiple Input Multiple Output (MIMO) communication system including selecting a modulation and code set (MCS) for each of M data streams transmitted via M transmitting antennas in a transmitting side of the MIMO system, and selectively selecting M−1 or fewer transmitting antennas from the M transmitting antennas for transmitting the data streams based on channel quality information indicative of a transmission performance of the selected MCS corresponding to each of the M transmitting antennas. In another example, the present invention provides a novel method of controlling signal transmission in a MIMO communication system including selecting M weight vectors for streams transmitted by each of M transmitting antennas in a transmitting side of the MIMO system, and selectively selecting M−1 or fewer streams and weight vectors from the M weight vectors for transmitting data streams based on channel quality information indicative of transmission performance of the selected weight vectors corresponding to each of the M vector spaces.10-23-2008
20080260058METHOD AND APPARATUS FOR PRECODING VALIDATION IN WIRELESS COMMUNICATIONS - A method and apparatus for precoding validation in wireless communications with reduced error probability is disclosed. Error probability is reduced by applying phase rotations to precoding matrices, dedicated pilot symbols, or both to maximize a minimum pairwise distance.10-23-2008
20080260057METHOD AND APPARATUS FOR GENERATING TRAINING SEQUENCE CODES IN A COMMUNICATION SYSTEM - A method for generating a training sequence code (TSC) in a communication system. The method includes obtaining a full set of training sequence code candidates through joint channel estimation with consideration of a symbol delay of an interfering signal; optimizing cross-correlation properties for the full set; obtaining a subset for necessary training sequence codes among the training sequence code candidates; defining each of training sequence codes in the obtained subset as a reference sequence; and generating optimized training sequence codes by copying symbols of a predetermined number of bits located in the front of the reference sequence, arranging the copied symbols in Most Significant Positions (MSPs) as a guard sequence, copying symbols of a predetermined number of bits located in the rear of the reference sequence, and arranging the copied symbols in Least Significant Positions (LSPs) as a guard sequence.10-23-2008
20080260056Methods for Selecting a Coarse Frequency Offset Estimation for an Orthogonal Frequency Division Multiplexing Modulated Signal - The present invention provides methods for selecting the coarse frequency offset estimation in an orthogonal frequency division multiplexing system that may include: searching within a predefined subset for a set of frequency offset candidates; selectively searching outside the predefined subset for additional frequency offset candidates; and combining one or more ICDC method and CIR based method to select the coarse frequency offset.10-23-2008
20080260055Apparatus for Creating, Demodulating, Transmitting and Receiving Othorgonal Frequency Division Multiplexing Symbol - The present invention relates to an orthogonal frequency division multiplexing (OFDM) signal transmitting and receiving device, in which a peak to average power ratio characteristic is improved without reducing a data D transmission speed. The OFDM signal transmitting device separates a digital modulated symbol as a real part and an imaginary part, and performs discrete cosine transform (DCT) and discrete sine transform (DST) operations respectively for real and imaginary part symbols, performs an inverse fast Fourier transform operation, and generates an OFDM symbol. The OFDM signal receiving device performs a fast Fourier transform operation for the OFDM symbol, and performs an inverse DCT operation and an inverse DST operation, performs a digital demodulating operation, and generates a final binary data symbol.10-23-2008
20080260054METHOD AND APPARATUS FOR REDUCING A PEAK-TO-AVERAGE POWER RATIO IN A MULTIPLE-INPUT MULTIPLE-OUTPUT SYSTEM - A method and apparatus for reducing a peak-to-average power ratio (PAPR) in a multiple-input multiple-output (MIMO) wireless communication system are disclosed. Transmit beamforming or precoding is performed on transmit symbols based on a channel matrix. For feedback, channel matrices may be averaged over multiple subcarriers and the averaged channel matrices may be further quantized. In order to reduce the PAPR, amplitude clipping may be performed on the symbols after the transmit processing. The amplitude clipping may be performed by hard clipping, soft clipping, or smooth clipping.10-23-2008
20080260053Apparatus and method for transmitting and receiving data using space-time block coding - An STFBC coding apparatus for a transmitter with four Tx antennas is provided. In the transmitter, an encoder generates a code symbol vector by encoding an input symbol sequence in a predetermined coding method. A grouping block permutes the elements of the code symbol vector by multiplying the code symbol vector by a permutation antenna grouping pattern selected among predetermined permutation antenna grouping patterns according to a predetermined order and outputs the permuted code symbol vector as a grouping symbol vector. OFDM (Orthogonal Frequency Division Multiplexing) modulators OFDM modulate the grouping symbol vectors and transmit OFDM modulated symbols through the four transmit antennas.10-23-2008
20080260052Ofdm Reception Apparatus and Ofdm Reception Method - A degree of an influence of interference on an OFDM received signal is estimated with high precision even under various interference conditions. An OFDM reception apparatus for receiving and demodulating an OFDM signal is provided, comprising a fast Fourier transform section for converting a received OFDM signal into a frequency-domain OFDM signal, a channel response calculation section for obtaining a channel response with respect to a carrier transmitting a pilot signal, from the frequency-domain OFDM signal, an interpolation section for interpolating the channel response, and outputting the result, a power calculation section for calculating the square of a magnitude of the interpolated channel response, as a carrier power, for each carrier corresponding to the channel response, an interference calculation section for calculating a degree of an influence of interference on the received OFDM signal, as an interference power, for each carrier corresponding to the interpolated channel response, and a carrier quality calculation section for calculating a ratio of the carrier power obtained to the interference power corresponding thereto, for each carrier.10-23-2008
20100166091MULTICARRIER TRANSMITTER AND MULTICARRIER REVEIVER - Provided are a multicarrier transmitter and a multicarrier receiver which accelerate cell search and reduce a circuit scale by reducing the operation quantity for cell search. The transmitter (07-01-2010
20090316815METHODS AND SYSTEMS FOR OVERHEAD REDUCTION IN A WIRELESS COMMUNICATION NETWORK - Methods and apparatus are provided for increasing throughput in a wireless communication system by reducing the amount of overhead transmitted to certain user terminals. Overhead due to control information may be reduced for these certain user terminals by selecting a low repetition factor. Overhead may be further reduced for these certain user terminals by selecting a modulation/coding scheme with a higher data rate for transmitting the control information. The selection may be based on channel conditions associated with the user terminals, such as signal-to-interference-plus-noise ratios (SINRs).12-24-2009
20090316808RADIO RECEPTION DEVICE, RADIO TRANSMISSION DEVICE, RADIO BASE STATION, RECEPTION METHOD, AND TRANSMISSION METHOD - An OFDM radio reception device 12-24-2009
20090252239ROBUST FINE FREQUENCY AND TIME ESTIMATION IN MEDIALFLO SYSTEM RECEIVERS - A technique for estimating a carrier frequency offset and a timing offset in a MediaFLO™ (Forward Link Only) system, wherein the method comprises receiving Orthogonal Frequency Division Multiplexing (OFDM) symbols; interpolating pilots on odd or even symbols of the received OFDM symbols; determining a phase difference between two successive symbols using the interpolated pilots; obtaining an estimate of the carrier frequency offset and the timing offset from the determined phase difference between two successive symbols; and correcting a sampling frequency in accordance with the estimated carrier frequency offset and timing offset.10-08-2009
20090257515TRANSMISSION METHOD OF WIRELESS SIGNAL AND TRANSMITTER USING THE SAME - A transmission method of a wireless signal including the following steps is provided. Multiple orthogonal frequency division multiplexing (OFDM) symbols carried by multiple subcarriers are generated according to a data signal. A scrambling pattern including multiple scrambling symbols is generated, wherein the scrambling symbols respectively correspond to the subcarriers in the frequency domain. The scrambling symbols corresponding to two contiguous subcarriers are correlated. The scrambling symbols are utilized to encode the OFDM symbols carried by the corresponding subcarriers.10-15-2009
20090257520Pilot pattern design for small size resource block in OFDMA systems - In OFDMA wireless communications systems, pilot pattern design is optimized based on predefined resource block size. The number of pilots and the spacing between pilots within a resource block is determined based on a set of system requirements. In one novel aspect, if resource block size is smaller than three in either frequency or time domain, then the pilots are allocated such that average pilot-to-data distance is minimized and that pilot-to-pilot distance is as large as possible. In one example, m pilots are allocated in an i×j resource block. The resource block is partitioned into n equal sub blocks, where m is a multiple of n. Within each sub block, m/n pilots are positioned such that average pilot-to-data distance is minimized. On the other hand, if resource block size is larger than or equal to three in both frequency and time domain, then pilots are allocated to avoid channel extrapolation.10-15-2009
20090257519Pilot pattern design for high-rank MIMO OFDMA systems - In OFDMA wireless communications systems, pilot pattern design is optimized based on predefined resource block size. The number of pilots and the spacing between pilots within a resource block is determined based on a set of system requirements. In one novel aspect, in a high-rank MIMO system, pilots are allocated within a resource block to avoid channel extrapolation in frequency domain only. Because high-rank MIMO only supports low-mobility environment, time-domain extrapolation is no longer a dominant factor. For uplink transmission, one or more frequency tones at one or more edges of the resource block are reserved to be pilot-free to reduce multiuser synchronization error effect. When continuous resource blocks are jointly used for channel estimation, the upper and lower edges of each resource block are left with blanks such that edge pilots of adjacent resource blocks are not too close to each other to improve channel estimation.10-15-2009
20120195390Processing method and system of demodulate reference signal, base station, user equipment - The present disclosure discloses a processing method and system, configuring method, and demodulating method of demodulate reference signal, a base station and a UE. The base station configures common reference signals on control symbols and user-dedicated reference signals on service symbols; the UE demodulates control information by using the common reference signals and demodulates service data and broadcast data by using the user-dedicated reference signals, wherein the control symbols are OFDM symbols carrying the control information, and the service symbols are OFDM symbols without carrying the control information. With the application of the present disclosure, the purpose of reducing the overhead of reference signals can be achieved.08-02-2012
20120140836PEAK-TO-AVERAGE POWER RATIO REDUCTION IN A MULTICARRIER SIGNAL - A method and apparatus for multicarrier transmission of a signal representing a source signal. The source signal includes symbols including a set of subcarriers, transmitted simultaneously and having pilot subcarriers intended for at least one processing operation for assisting and/or improving decoding in at least one receiver, and data subcarriers, the location in time-frequency space and a reference value of the pilot subcarriers being known to the at least one receiver. The method of transmission includes: a phase of modifying, for a given symbol, the reference value of at least one subset of the pilot subcarriers, by correction data configured to correct phase and/or amplitude for each of the pilot subcarriers of the subset, so as to minimise peak-to-average power ratio, the correction data taking at least three distinct values, a transition between the values of two successive pilot subcarriers of the subset on a frequency axis being constant.06-07-2012
20090279625LEGACY-COMPLIANT BURST FORMATS FOR MULTIPLE USERS REUSING ONE SLOT (MUROS) OPERATION - A burst may include a three-bit tail sequence derived from a four-bit Enhanced General Packet Radio Service (EGPRS)-2 tail sequence. A legacy wireless transmit/receive unit (WTRU) may be multiplexed onto an Orthogonal Sub-channel (OSC) resource, and may receive a burst including four-bit Quadrature Phase Shift Keying (QPSK)-type tail sequences that decode to legacy three-bit Gaussian Minimum Shift Keying (GMSK)-type or 8PSK-type tail sequences. The legacy WTRU processes the tail sequences, unaware that the burst was received on an OSC sub-channel or that the tail sequences were encoded as QPSK-type tail sequences. An OSC QPSK tail sequence may be chosen such that it corresponds to the legacy GMSK tail sequence format when decoded on an OSC sub-channel, but also so that a power-versus-time mask, power constraint, or other criteria on the other MUROS sub-channel may be optimized. Different tail sequences may be used in OSC bursts, depending upon whether the WTRUs multiplexed onto a timeslot are legacy WTRUs or include OSC-specific features.11-12-2009
20090262843MIMO Slow Precoding Method and Apparatus - Pre-coder techniques disclosed herein are based on long-term statistical channel information for reducing channel feedback overhead and transmitter complexity. In an embodiment, a receiver includes two or more receive antennas spaced approximately λ/2 apart and a baseband processor. The baseband processor computes channel correlations for different combinations of transmit antennas and each receive antenna and averages the channel correlations over the different receive antennas to form a frequency-independent channel correlation matrix. The baseband processor also computes a scalar representing noise variance at the receive antennas and feeds back the frequency-independent channel correlation matrix and the scalar for use in performing transmitter pre-coding computations.10-22-2009
20100150256SELECTIVE PEAK POWER REDUCTION - The present invention provides a technique for reducing the peak power of a combined signal that has a first signal of a first modulation type and a second signal of a second modulation type. Based on the combined signal, peak reduction distortion is determined. The peak reduction distortion is configured such that, if applied to the entirety of the combined signal, excessive peaks throughout the combined signal would be reduced. However, instead of applying the entirety of the peak reduction distortion, a selected portion of the peak reduction distortion is applied to a corresponding portion of the combined signal to reduce the peak power of the combined signal.06-17-2010
20090122883FOLLOW-UP SYNCHRONIZATION TO MAINTAIN SYNCHRONIZATION THROUGHOUT TRANSMISSION - Method for an orthogonal frequency division multiplexing multipoint-to-point communications system are provided. In one embodiment, the method includes establishing communication between a first remote unit of a plurality of remote units and a host unit, the plurality of remote units communicatively coupled to the host unit in a multipoint-to-point configuration, transmitting up to a plurality of tones from the first remote unit, the up to a plurality of tones modulated with upstream information using orthogonal frequency division multiplexing, and adjusting the up to a plurality of tones transmitted from the first remote unit to maintain the up to a plurality of tones substantially orthogonal with respect to any tones transmitted from at least one other remote unit of the plurality of remote units as received at the host unit.05-14-2009
20090316819TRANSMITTER - A transmitter employing an OFDM system, having a phase rotating portion which gives a same phase rotation amount to each group configured with a plurality of consecutive subcarriers modulated by data or a known signal, a rotation amount determining portion which sets a phase rotation for each antenna set or each transmitter; and, and an allocating portion which allocates a plurality of groups to a receiver.12-24-2009
20090316813Transmitter, Receiver, Transmission Method and Reception Method - A phase relationship between signal sequences obtained by space-time-coding transmission signals is controlled so as to give a difference in peak power between the signal sequences to be transmitted from separate transmission antennas, and either one or both of the signal sequences are controlled so as to minimize a rate of a peak power of one of the signal sequences to an average transmission power of the signal sequences.12-24-2009
20090316817CHANNEL ESTIMATION FOR WIRELESS SYSTEMS WITHOUT MATRIX INVERSION - In various embodiments, techniques are provided to determine channel characteristics of various communication systems such as OFDM systems or systems using a plurality of transmit antennas by using various sets of training symbols that produce zero cross-correlation energy. Channel communication can accordingly be simplified as the zero cross-correlation property allows for channel estimation without a matrix inversion.12-24-2009
20090316812OFDM Communication Device and Guard Interval Length Determining Method - An OFDM communication device (12-24-2009
20090316809Method for transmitting channel quality information - There is provided a method for transmitting channel quality information in a wireless communication system. Over-all band of the wireless communication system is divided by a plurality of sub-bands. The method includes selecting a first sub-band having the highest CQI among the plurality of sub-bands, transmitting CQI of the first sub-band and transmitting CQI of a second sub-band, the second sub-band having the CQI lower than the first sub-band, wherein the number of CQI levels of the second sub-band is less than that of CQI levels of the first sub-band. Overheads incurred by CQI feedback can be reduced.12-24-2009
20090316803MIMO RECEIVER - In a MIMO receiver, initial solutions using sub-optional decoding algorithm are determined for the symbols transmitted from each of a number of transmit antennas at a given time (12-24-2009
20090316802MULTI-USER MIMO SYSTEMS AND METHODS - A method is provided for scheduling data transmission in a Multiple-Input Multiple-Output (MIMO) Orthogonal Frequency Division Multiplexing (OFDM) system. The MIMO-OFDM system may comprise at least one MIMO-OFDM transmitter and at least one MIMO-OFDM receiver Feedback from one or more receivers may be used by a transmitter to improve quality, capacity, and scheduling in MIMO-OFDM communication systems. The method may comprise generating or receiving information pertaining to a MIMO channel metric and information pertaining to a Channel Quality Indicator (CQI) in respect of a transmitted signal; and sending a next transmission to a receiver using a MIMO mode selected in accordance with the information pertaining to the MIMO channel metric, and an adaptive coding and modulation selected in accordance with the information pertaining to the CQI.12-24-2009
20090316801Radio Device, Electronic Device, and Imaging Device - A radio device for transmitting or receiving desired information through an MIMO transmission line, and an electronic device and an imaging device which have the radio device and supplied with drive power together with the radio device may realize to implement a desired radio transmission flexibly in the form suitable for the battery residual amount and power consumption, in which plural antenna sections for performing radio communication by a spatial division multiplexing method on an MIMO transmission line, and a controller for increasing or decreasing the number of the antenna portions used for the radio transmission.12-24-2009
20090086835APPARATUS AND METHOD FOR BLOCK INTERLEAVING USING MIXED RADIX SYSTEM IN MB-OFDM - A block interleaving apparatus for block interleaving M-bit input streams to be transferred with a modulus k using a mixed radix system in a multi-band orthogonal frequency division multiplexing communication system, including an array processor having an array including M cells in which the number of columns is k and the number of rows is M/k. The array processor inputs the input streams from the bottom-right cell up to the top-left last cell in the horizontal direction, and, after the first bit of the input streams reaches the last cell, generates interleaved output streams by changing the output of the array processor from horizontal direction to vertical direction.04-02-2009
20090074090SYSTEMS AND METHODS FOR RESTRICTING THE LOCATION OF CONTROL INFORMATION IN PHYSICAL LAYER SIGNALING - A method for conserving the power supply of an Orthogonal Frequency Division Multiplexing (OFDM) communications device is described. The location of control information within one or two of a plurality of symbols is obtained. A sleep mode is entered into. The one or two symbols that include the control information are monitored. A return to the sleep mode is executed.03-19-2009
20100183084 METHOD, A TRANSMITTING STATION AND A RECEIVING STATION FOR ANALOG BEAM FORMING - The present invention relates to a method for communicating a signal to a first station from a second station, the stations having antenna array. For communication in bands like 60 GHz, it is advisable to carry out analog beam steering. But it is needed to compute all the beam forming weights in a single message. Then, the invention proposes that for each signal, in the preamble, a plurality of training symbols are included, wherein during each training symbol repetition, the receiving station adjusts at least one antenna parameter of the plurality of antennas and measuring the combined signal for computing a set of antenna weights to be applied for an analog beam forming on the antenna array for receiving the data field.07-22-2010
20090116570METHOD AND APPARATUS FOR GENERATING CHANNEL QUALITY INDICATOR, PRECODING MATRIX INDICATOR AND RANK INFORMATION - A method and apparatus for generating channel quality indicator (CQI), precoding matrix indicator (PMI) and rank information are disclosed. The method and apparatus reduces feedback overhead and defines differential CQI information in an orthogonal frequency division multiplex (OFDM) symbol.05-07-2009
20090116567Channel estimation method and apparatus for long range signals in bluetooth - The present invention discloses a channel estimation method for Bluetooth signals through a multipath propagation channel, using a SYNC sequence as a preamble sequence. It mainly comprises the steps of: use of SYNC sequence as input to LS-based channel impulse response estimation, precomputation of local frequency domain preamble, precomputation of local inverted frequency domain preamble and shortening of estimated channel impulse response for further equalization purposes. The proposed channel estimation method and apparatus according to the present invention enables use of efficient equalization algorithms, therefore mitigating ISI and very successfully estimates propagation conditions while being very implementation-friendly.05-07-2009
20100183085BASE STATION APPARATUS, USER EQUIPMENT, AND COMMUNICATION CONTROL METHOD IN MOBILE COMMUNICATION SYSTEM - A disclosed base station apparatus is capable of communicating with a user equipment terminal in a multi-input multi-output (MIMO) mobile communication system using Pre-coding. The base station apparatus includes a receiving unit receiving a Pre-coding Matrix Indicator (PMI) indicating a specific Pre-coding matrix, a determination unit determining a value of a flag indicator indicating whether the Pre-coding matrix specified in the PMI is to be used for downlink communications, a control signal generation unit generating a downlink control signal including at least the flag indicator, and a transmission unit transmitting a signal including the downlink control signal in downlink.07-22-2010
20100183083OFDM SIGNAL TRANSMITTING APPARATUS AND OFDM SIGNAL RECEIVING APPARATUS - An OFDM signal receiving apparatus (07-22-2010
20090116569Bi-Directional Beamforming Multiple-Input Multiple-Output Wireless Communication - Techniques are provided herein to configure first and second wireless communication devices in order to perform bi-directional beamformed multiple-input multiple-output (MIMO) communication. Each device uses received signals from the other device to compute beamforming weight vectors for application to a plurality of signal streams to be simultaneously beamformed transmitted to the other device.05-07-2009
20090116566DELTA WRITING SCHEME FOR MIMO SIGNAL PATHS - Techniques for writing to registers associated with MIMO signal paths are disclosed. In are embodiment, a controller writes a common value to all registers corresponding to the same operational parameter or parameters, for all signal paths in the MIMO transmitter or receiver. The controller then updates the register in any signal path whose operational paramater differs from the common value, by accumulating a value to the value already in the register, or by replacing the value already in the register with a different value.05-07-2009
20090046787TRANSMITTING APPARATUS, RECEIVING APPARATUS, AND WIRELESS COMMUNICATION METHOD - A transmitting apparatus, a receiving apparatus and a wireless communication method for suppressing interference between codes, while further reducing the ratio of redundant components occupying a signal to improve the transmission efficiency. The transmitting apparatus (02-19-2009
20100260278COMMUNICATION APPARATUS AND COMMUNICATION METHOD - Modulated signal A is transmitted from a first antenna, and modulated signal B is transmitted from a second antenna. As modulated signal B, modulated symbols S10-14-2010
20090016457Apparatus and method for generating effective signal to noise ratio (SNR) per stream in multiple-input multiple-output (MIMO) wireless communication system - A multiple-input multiple-output (MIMO) wireless communication system includes a first calculator for calculating pairwise error rates (PERs) for each modulation scheme combination which comprise elements smaller than or equal to receive antennas in number; a second calculator for calculating symbol error rates (SERs) for the each modulation scheme combination using the PERs; a converter for converting the SERs to effective signal to noise ratios (SNRs); and a determiner for determining one among sets of effective SNR per stream acquired from the modulation scheme combinations, as a final effective SNR per stream.01-15-2009
20100177833SYSTEMS AND METHODS FOR DETERMINING THE NUMBER OF CHANNEL ESTIMATION SYMBOLS BASED ON THE CHANNEL COHERENCE BANDWIDTH - Various systems and methods are provided for channel estimation. These systems and methods (a) determine a coherence bandwidth for the channel, (b) adapt the channel estimation based on the coherence bandwidth, and (c) perform channel estimation by transmitting a channel estimation symbol over a channel. In some embodiments, the channel estimation is adapted based on the coherence bandwidth. This may include selecting a number of channel estimation symbols to transmit in a packet. Additionally, the number of channel estimation symbols transmitted in a packet can be selected by increasing the number of channel estimation symbols when the coherence bandwidth of the channel is high or decreasing the number of channel estimation symbols when the coherence bandwidth of the channel is low.07-15-2010
20100183086METHOD OF TRANSMITTING FEEDBACK DATA IN MULTIPLE ANTENNA SYSTEM - A method of transmitting feedback data in a multiple antenna system includes generating feedback data based on the channel information and transmitting the feedback data at transmission periods, wherein the feedback data is transmitted in a plurality of report types respectively having a different control signal type contained depending on the transmission periods.07-22-2010
20100226452METHOD AND SYSTEM FOR REDUCING FEEDBACK INFORMATION IN MULTICARRIER-BASED COMMUNICATION SYSTEMS BASED ON FREQUENCY GROUPING - Systems and methods for decreasing the amount of information sent on a feedback channel are disclosed. Various forms of spectral binning may be used to reduce the amount of information sent on the feedback channel. The systems and methods may be applicable to wideband communication systems, ultra-wideband communication systems, and/or other communication system using multiple carrier frequencies (e.g., tones).09-09-2010
20100226451APPARATUS AND METHOD FOR CHANNEL ESTIMATION IN WIRELESS COMMUNICATION SYSTEM - An apparatus and method for regulating arrangement of pilot subcarriers to improve a channel estimation throughput in a wireless communication system using an Orthogonal Frequency Division Multiplexing (OFDM) scheme are provided. The apparatus includes a pilot pattern manager for providing control such that pilots are non-uniformly generated according to a distance of a preamble in order to provide a constant link throughput of the frame when the downlink frame is generated.09-09-2010
20100177834SYSTEMS AND METHODS FOR IMPROVING REFERENCE SIGNALS FOR SPATIALLY MULTIPLEXED CELLULAR SYSTEMS - A method for using a numerical method to design reference signals for multiple input multiple output (MIMO) systems is described. An input multiple input multiple output signal is determined. A nearest tight frame to one or more given structured vectors is obtained. One or more structured vectors from the nearest tight frame are obtained. The one or more structured vectors are projected onto the space of circulant matrices. One or more classes of matrices associated with reference signals are outputted.07-15-2010
20100254469REPORTING CHANNEL QUALITY INFORMATION - A method and corresponding receiver for transmitting channel quality data for a channel in a wireless communication system are provided. The method comprises determining channel quality metrics for frequency intervals within the channel, selecting groups of frequency intervals based on the determined metrics, and transmitting one or more channel quality indicators for the groups. The invention also provides a method of transmitting over a channel based on such channel quality indicators feedback from a receiver, and a corresponding transmitter.10-07-2010
20130215984Overlay Modulation Technique for COFDM Signals Based on Amplitude Offsets - Systems and methods are presented for transmitting additional data over preexisting differential COFDM signals by changing the amplitude of the legacy data symbols. In exemplary embodiments of the present invention, additional data capacity can be achieved for a COFDM signal which is completely backwards compatible with existing legacy satellite broadcast communications systems. In exemplary embodiments of the present invention, additional information can be overlaid on a legacy COFDM signal by applying an amplitude offset to the legacy symbols. In exemplary embodiments of the present invention, special receiver processing can be implemented to extract this additional information, which can include performing channel equalization across frequency bins to isolate the amplitude modulated overlay signal. For example, at each FFT symbol time, average power across neighboring active data bins can be used to determine the localized power at the corresponding FFT bins, and a channel inversion can then, for example, be performed on the data bins to restore, as best as possible, the original transmitted symbol amplitude.08-22-2013
20080279295TDS-OFDMA COMMUNICATION SYSTEM UPLINK TIMING SYNCHRONIZATION - In a TDS-OFDM communications system for uplink wireless communication multiple accesses through sub-channelization, the system comprising: a plurality of users with each user using a portion of available time-frequency radio resources to achieve orthogonal multiple access; a plurality of available bandwidth, wherein the available bandwidth is divided into multiple sub-bands; at least one the sub-carrier in each sub-band. Inside the sub-band for each user, at least one guard sequence, being used as the guard interval between transmitted symbols.11-13-2008
20100226453PILOT PATTERN DESIGN FOR A STTD SCHEME IN AN OFDM SYSTEM - A transmitting device for transmitting data symbols and pilot symbols in an OFDM transmission system; the device comprising symbol generating means for generating said data symbols and said pilot symbols, means for transmitting said data symbols and pilot symbols respectively by using a plurality of subcarriers of said OFDM transmission system, wherein said symbol generating means is designed to selectively generate a first type pilot symbol and a second type pilot symbol being orthogonal to said first type pilot symbol so that a pilot symbol pattern in the frequency dimension comprises at least said first type pilot symbol to be transmitted by using a predefined subcarrier and second type pilot symbol to be transmitted by using other predefined subcarrier, and wherein said pilot symbol pattern has a different pattern from a succeeding pilot symbol pattern in time dimension.09-09-2010
20100226449Method and System for Reducing the Peak-to-Average Power Ratio - This invention provides a method and system for reducing the PAPR. The method involves (i) intentionally inserting error(s) into the time or frequency domain and (ii) employing various bit mapping schemes to provide a significant reduction in the PAPR. An embodiment of the error insertion of the method involves intentionally inserting symbol error(s) into the quadrature amplitude modulation (QAM) symbol stream before applying discrete Fourier transform in OFDM. The method trades off the coding gain of the system for the PAPR reduction of the OFDM signals and does not require transmission of side information. It further has reduced complexity and improved bit error rate (BER) performance when used with a typical non-linear amplifier as compared to alternative existing methods (Gray coding, tone injection, tone reservation, etc.)09-09-2010
20100226450RECEIVER AND WIRELESS COMMUNICATION SYSTEM EQUIPPED WITH THE SAME - A receiver includes: an amplifier that amplifies a received broadband signal up to a predetermined level; a first switch that switches an output signal from the amplifier; a signal generator that generates a signal for controlling a switching operation of the first switch; an integration capacitor that integrates an output signal from the first switch; a comparator that compares an output voltage from the integration capacitor with a predetermined voltage; and a reset circuit that discharges electrical charges accumulated in the integration capacitor based on a comparison result from the comparator.09-09-2010
20100226448CHANNEL EXTRAPOLATION FROM ONE FREQUENCY AND TIME TO ANOTHER - An improved channel estimation technique is provided herein that determines accurate scatterer parameters for the scattering objects in the wireless channel, and extrapolates the scatterer parameters in both time and frequency to characterize the scattering objects for a different time and a different frequency. In one embodiment, a wireless device determines scatterer parameters that characterizes the scattering objects of a reception channel, and extrapolates the scatterer parameters in both time and frequency to predict the scatterer parameters for a future time and frequency, e.g., a future transmission time and frequency.09-09-2010
20100239037System and Method for Wireless Communications with Codebook Quantization - A system and method for wireless communications with codebook quantization are provided. A method for communications device operations includes estimating a channel between a controller and a mobile device, generating channel state information from the channel estimate, quantizing the channel state information by selecting a codeword from a rank n codebook based on a codeword selection mechanism, where n is a non-negative integer value, transmitting an index corresponding to the selected codeword and receiving a transmission from the controller. The transmission is precoded based on the index. The rank n codebook includes 209-23-2010
20100254467METHOD AND DEVICE FOR NOISE PROCESSING AND COMMUNICATION SYSTEM COMPRISING SUCH DEVICE - A method and a device are provided for noise processing. In the method, data is transmitted from at least one transmitter to at least one receiver; and the at least one receiver conveys SNR-data, e.g., link state information and/or link quality information to a precoder and/or to a noise canceller.10-07-2010
20110058618METHOD AND APPARATUS FOR INTERFERENCE MITIGATIONI IN A BASEBAND OFDM RECEIVER - A method of compensating interference of received symbols in a MIMO OFDM receiver employs MMSE equalization and LLR scaling, and a MIMO OFDM receiver includes a linear MMSE equalizer. The method provides a low-complexity, numerically robust method for compensating interference of received symbols and provides a low-cost, robust digital baseband receiver for MIMO-OFDM, achieved by merging linear MMSE equalization and scaling of the corresponding equalized symbols into a single algorithm that, for the 2×M MIMO case, completely avoids computationally extensive matrix inversion and allows for significant simplification of symbol detection as compared to separate equalization and scaling.03-10-2011
20100239035System and Method for Multiple Input, Multiple Output Layer Mapping - A system and method for multiple input, multiple output (MIMO) uplink (UL) layer mapping is provided. A method for mapping modulation symbols to multiple input, multiple output (MIMO) layers includes receiving a first set of modulation symbols corresponding to a first transport block, partitioning the first set of modulation symbols into M09-23-2010
20100239031Multi-Carrier Transmitter Back-Off Estimation - Methods and apparatus taught herein estimate the amount by which to reduce a multi-carrier signal's maximum transmit power based on metrics specific to each carrier of the multi-carrier signal. These carrier-specific metrics may include a maximum-power reduction or cubic metric determined for that carrier as if it would be transmitted alone. In one embodiment, estimation of the required back-off is based on a weighted sum of the carrier-specific metrics, where the weights applied depend on a power ratio. Only a few relatively small look-up tables or simple computations are required in this case: one for obtaining the carrier-specific metrics based on configuration parameters of each carrier, and another for obtaining the weights based on the power ratio. Accordingly, methods and apparatus herein advantageously require less computational complexity and/or memory usage than that needed if estimating the required back-off based on similar metrics obtained for the multi-carrier signal as a whole.09-23-2010
20100254471METHOD OF TRANSMITTING POWER INFORMATION IN WIRELESS COMMUNICATION SYSTEM - A method of transmitting power information in a wireless communication system is provided. The method includes: determining energy per resource element (RE) to which a reference signal or data is mapped for downlink transmission; and transmitting power information of the reference signal and the data, wherein the reference signal comprises a channel state indication-reference signal (CSI-RS) for channel state measurement, power information of the CSI-RS is denoted by a ratio of power for a CSI-RS RE and power for a data RE of an orthogonal frequency division multiplexing (OFDM) symbol on which only data is transmitted or power for a cell-specific RS (CRS) RE used for channel state measurement and data demodulation of different OFDM symbols.10-07-2010
20100254468PILOT DESIGN METHOD, RECORDING MEDIUM, AND TRANSMISSION APPARATUS - In an orthogonal frequency division multiple access (OFDMA) communication system, a transmission apparatus connects a plurality of tiles, which have a 4×3 structure, along a time axis or a frequency axis in an uplink 4-layer PUSC mode, and designs pilots corresponding to one layer at one of a plurality of symbol positions adjacent to a first corner of the plurality of tiles and one of a plurality of symbol positions adjacent to a second corner of the plurality of tiles that face the first corner in a diagonal direction. In this case, null symbols are designed at the rest of the symbol positions adjacent to the first corner or the second corner where the pilots are not designed. Accordingly, a receiving apparatus can obtain n channel values from n tiles. Further, n estimated channel values are applied to a linear interpolation method, so that it is possible to estimate the entire channel value of n tiles.10-07-2010
20100254470APPARATUS AND METHOD FOR SETTING PILOT SUBCARRIER - An apparatus for setting a pilot subcarrier in an antenna selects candidates of power value variables of a pilot subcarrier existing within a predetermined range, and calculates and extracts pilot subcarriers of a predetermined number on the basis of a nonlinear function among the candidates of the selected power value variables. Next, the apparatus removes pilot subcarriers of a predetermined number from the extracted pilot subcarriers of a predetermined number in accordance with a rule and configures the antenna on the basis of position values of final pilot subcarriers except for a virtual subcarrier among the removal result. Further, the apparatus configures the antenna on the basis of the power value by determining the sum total of the power values corresponding to the position values of the final pilot subcarriers to correspond to the number of pilot subcarriers.10-07-2010
20090175363Assignment of sub-channels to channels in a multi transmission-channel system - A method of allocating a set of sub-channels to a plurality of transmission channels in a multi transmission-channel system comprising the steps of; mapping a first, non-zero, set of sub-channels to a first transmission channel, mapping a second, non-zero, set of sub-channels to a second transmission channel, wherein at least one sub-channel of the first set and at least one sub-channel of the second set are allocated to one receiving unit.07-09-2009
20100142637TRANSMITTER COMPENSATION IN DECODING OF INTENSITY MODULATED OPTICAL OFDM WITH DIRECT DETECTION - A method by an optical OFDM receiver includes converting a received optical signal to an electrical signal, deriving a digital signal from the electrical signal, and emulating, with an iterative OFDM demodulator responsive to the digital signal, a transmitter effect in the received signal of lower peak clipping and top peak distortion and applying the transmitter effect to the received signal and a decision-made signal for estimating an error function to be applied to a demodulation of the received optical signal.06-10-2010
20100208831TECHNIQUES FOR QUICK ACCESS CHANNEL INFORMATION LOADING IN WIRELESS NETWORKS - An embodiment of the present invention provides a method of quick access channel information loading in wireless networks, comprising mapping at least one quick access channel to one distributed resource unit of control tiles, said control tiles being spread across consecutive sub-carriers and consecutive OFDMA symbols, wherein each control tile and a predetermined number of sub carriers are used to send a bandwidth indicator and a predetermined number of sub carriers are used to send a bandwidth request message, and wherein there exist unique orthogonal sequences for the bandwidth indicator and each of the sequences are capable of being selected as a preamble sequence.08-19-2010
20100208832FRAME STRUCTURE FOR FAST WIRELESS COMMUNICATION SYSTEM AND APPARATUS FOR FAST WIRELESS COMMUNICATION USING THE FRAME - A method of configuring a frame for fast wireless communication and an apparatus for fast wireless communication are provided. The apparatus for fast wireless communication includes: a frame configuration unit configuring a frame including transmission data; a demultiplexing unit demultiplexing the transmission data included in the frame into N number of parallel streams (N: positive number greater than 2); N number of coding and modulation units connected in parallel to perform error correction coding and orthogonal frequency division multiplexing (OFDM) with respect to each of the N number of parallel streams; and a multiplexing unit multiplexing outputs of the N number of coding and modulation units into serial streams.08-19-2010
20100124294COST-EFFECTIVE PREAMBLE STRUCTURE FOR HIGH-SPEED COMMUNICATION OF PACKETIZED SYSTEMS - The system (05-20-2010
20100142636WIRELESS COMMUNICATIONS SYSTEM THAT SUPPORTS MULTIPLE MODES OF OPERATION - A wireless communications adapts its mode of operation between spatial multiplexing and non-spatial multiplexing in response to transmission-specific variables. An embodiment of a wireless communications system for transmitting information between a base transceiver station and a subscriber unit includes mode determination logic. The mode determination logic is in communication with the base transceiver station and the subscriber unit. The mode determination logic determines, in response to a received signal, if a subscriber datastream should be transmitted between the base transceiver station and the subscriber unit utilizing spatial multiplexing or non-spatial multiplexing. In an embodiment, the mode determination logic has an input for receiving a measure of a transmission characteristic related to the received signal. In an embodiment, the mode determination logic includes logic for comparing the measured transmission characteristic to a transmission characteristic threshold and for selecting one of spatial multiplexing and non-spatial multiplexing in response to the comparison of the measured transmission characteristic to the transmission characteristic threshold. In an embodiment, the transmission characteristic includes at least one of delay spread, post-processing signal-to-noise ratio, cyclical redundancy check (CRC) failure, residual inter-symbol interference, mean square error, coherence time, and path loss. By adapting the mode of operation in response to transmission-specific variables, the use of spatial multiplexing can be discontinued in unfavorable conditions. Additionally, because the wireless communications system can adapt its mode of operation between spatial multiplexing and non-spatial multiplexing, the communications system is compatible with both subscriber units that support spatial multiplexing and subscriber units that do not support spatial multiplexing.06-10-2010
20120140837METHOD OF SEARCHING CODE SEQUENCE IN MOBILE COMMUNICATION SYSTEM - A method for transmitting a signal for cell searching in a mobile communication system having a multi-cell environment includes transmitting the signal to one or more receiving party devices within a cell, wherein the signal is used for a synchronization of the one or more receiving party devices within the cell, the signal is defined by a combination of a first code sequence derived from a first index and a second code sequence derived from a second index, and an identity of the cell is used for defining the combination of the first code sequence and the second code sequence.06-07-2012
20120140834METHOD OF GENERATING ADAPTIVE CODEBOOK AND MULTIPLE INPUT MULTIPLE OUTPUT COMMUNICATION SYSTEM USING THE ADAPTIVE CODEBOOK - Provided is a method of generating an adaptive codebook and a multiple input multiple output (MIMO) communication system using the adaptive codebook. A transmitter and a receiver may generate, from a base codebook based on a matrix associated with statistics of a channel matrix, the adaptive codebook maintaining a unitary characteristic. The transmitter may perform scheduling, transmit filter design, and precoding using adaptive codebook based feedback information.06-07-2012
20100040159METHOD AND APPARATUS FOR GENERATING PILOT TONE IN ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING ACCESS SYSTEM, AND METHOD AND APPARATUS FOR ESTIMATING CHANNEL USING IT - The present invention relates to a pilot tone generating method and apparatus of an orthogonal frequency division multiple access system and method, and a channel estimation method and apparatus using the same. The channel estimation apparatus includes a pilot tone extracting unit for extracting a pilot tone, which is inserted within a frame with data tone, masked with an orthogonal code; a pilot tone unmasking unit for unmasking of the pilot tone extracted from the pilot tone extracting unit by using an orthogonal code information; and a channel estimation operating unit for estimating a channel by calculating an average of the pilot tones which is unmasked in the unmasking unit.02-18-2010
20100040160COMMUNICATION MEETHOD, AND TRANSMITTING APPARATUS AND RECEIVING APPARATUS USING THAT COMMUNICATION METHOD - A method for generating a transmission signal to transmit an orthogonal frequency division multiplexing signal, from one antenna or from a plurality of antennas, to a plurality of terminals. Transmission data for the plurality of terminals is assigned to a plurality of carrier groups, each carrier group including a plurality of carriers. For each of the plurality of carrier groups, one of a first frame configuration is selected, wherein one modulated signal is transmitted, and a second frame configuration is selected wherein a plurality of modulated signals are transmitted by using the plurality of antennas. A transmission signal is generated using the selected frame configuration, for transmitting the transmission data assigned to the plurality of carrier groups during a certain period.02-18-2010
20090257518METHODS FOR SENDING AND RECEIVING A MULTICARRIER SIGNAL COMPRISING A PREAMBLE COMPRISING DATA ELEMENTS, CORRESPONDING DEVICES AND COMPUTER PRODUCTS - A method is provided for receiving a multicarrier signal formed by a temporal succession of symbols including of a set of data elements with real values, including informative data elements and pilots. Due to at least one preamble being inserted into the multicarrier signal and formed by at least two end symbols, encompassing at least one central symbol including of central pilots, such a reception method includes, for at least one central pilot, a step of eliminating or reducing an interference affecting the central pilot, and a step of estimating the transmission channel, taking into account the result of the eliminating or reducing step.10-15-2009
20120033753Communication Method and Radio Transmitter - Radio transmission is performed even to a communication party whose bandwidth that can be used for transmission and reception is limited without having an influence of an offset of a DC component. A radio transmitter applied to an OFDMA communication system in which a plurality of different terminals performs communication using OFDM signals at the same time that includes a mapping part that allocates transmission power to each subcarrier, and also selects a subcarrier to which minimum power of the transmission power to be allocated is allocated and modulates transmission data in units of communication slots to output the modulated data; and a transmission part for transmitting radio signals including the modulated data using each of the subcarriers.02-09-2012
20100266056METHOD AND APPARATUS FOR SCHEDULING MULTIPLE USERS IN A MULTIPLE-INPUT MULTIPLE-OUTPUT SYSTEM - A multi-user scheduling method and apparatus in a Multiple-Input Multiple-Output (MIMO) system are disclosed. The multi-user scheduling method includes calculating a valid channel norm based on statistical characteristics of a channel for every user terminal, selecting a user set that maximizes the sum of valid channel norms and that includes as many user terminals as data are transmittable to simultaneously, and precoding transmission signals for the user terminals included in the user set according to a predetermined scheme. According to the present invention, the volume of computation required for multi-user selection is reduced greatly, thus making real-time implementation possible.10-21-2010
20100266058OFDM TRANSMISSION APPARATUS, OFDM RECEIVING APPARATUS AND INTERLEAVING METHOD - In order to provide a simpler interleaving operation of an OFDM operation than conventional techniques, an OFDM transmission apparatus which transmits transmission data after conducting OFDM (Orthogonal Frequency Division Multiplexing) operation, includes an interleave portion which, in a step before a serial/parallel conversion for a carrier modulation, the transmission data is randomized based on a random number generated by using a predetermined random number generation method.10-21-2010
20090041138EFFICIENT CQICH TRANSPORT FORMAT - An efficient channel quality indicator channel (CQICH) transport method and system are disclosed. The CQICH transport method defines five types of CQI transport formats, to cover known cases of CQI feedback. The CQICH transport method further defines the format of transportation, which enables any of the five types of CQI transport formats to be transmitted.02-12-2009
20110235730METHOD FOR TRANSMITTING AND RECEIVING DOWNLINK REFERENCE SIGNALS IN A WIRELESS COMMUNICATION SYSTEM HAVING MULTIPLE ANTENNAS - A method for transmitting and receiving downlink Reference Signals (RSs) in a wireless communication system using multiple antennas is disclosed. The downlink RS transmission method includes transmitting a first Orthogonal Frequency Division Multiplexing (OFDM) symbol in which RSs for a plurality of antenna port of first group are allocated in a predetermined order along a frequency axis, RSs for a plurality of antenna port of second group are allocated in a predetermined order along the frequency axis, and the RSs for the plurality of antenna port of first group are multiplexed in Code Division Multiplexing (CDM) with the RSs for the plurality of antenna port of second group by pairing each of the plurality of antenna port of first group with one of the plurality of antenna port of second group, and transmitting a second OFDM symbol in which the RSs for the plurality of antenna port of first group and the RSs for the plurality of antenna port of second group are positioned in an RS pattern being a frequency-domain shift of an RS pattern of the first OFDM symbol.09-29-2011
20120033752WIRELESS COMMUNICATION DEVICE AND WIRELESS COMMUNICATION METHOD - To lessen a disparity in stream mapping of transmission data when modulation data are mapped into a plurality of streams and when the plurality of streams are transmitted and received. In a wireless communication device, a stream mapper (02-09-2012
20120033751CHANNEL ESTIMATION FOR A CONTROL CHANNEL IN AN OFDM SYSTEM - A method of channel estimation for a control channel in an OFDM system of the present invention includes the steps of: performing weighted averaging over time of input LS estimates of a plurality of channel condition matrices; performing frequency domain averaging on the input LS estimates; performing channel estimates on multiple subcarriers of pilot OFDM symbols from the frequency domain averaged input LS estimates; and performing channel estimates on multiple subcarriers of OFDM symbols in the control channel from the channel estimates on the subcarriers of pilot OFDM symbols.02-09-2012
20090274228Communication Apparatus - A communication apparatus includes a radio-frequency transmission-reception processing unit configured to perform radio-frequency processing to a transmitted signal and a received signal; a baseband processing unit configured to perform baseband processing; a signal detecting unit configured to detect a signal from which a signal transmitted from another communication system is detected; and an interference-to-another-communication-system avoiding unit configured to suppress an interfering signal to the other communication system in radio-frequency transmission processing by the radio-frequency transmission-reception processing unit if the signal detecting unit detects a signal.11-05-2009
20100195747METHOD AND APPARATUS FOR PERFORMING JOINT DETECTION WITH A COMMON MIDAMBLE - Techniques for performing joint detection with a common midamble for downlink transmission are described. In one design, a user equipment (UE) may obtain samples for a burst transmitted by a Node B on the downlink. The burst may include at least one data field and a common midamble. The UE may derive a channel impulse response estimate for each of multiple orthogonal codes based on (i) a channel impulse response estimate derived based on samples for the common midamble and (ii) a traffic-to-pilot ratio (T2P) estimated for that orthogonal code based on the samples for burst. The UE may perform joint detection, for the multiple orthogonal codes, on samples for the at least one data field based on the multiple channel impulse response estimates.08-05-2010
20090074092OFDM RECEPTION DEVICE AND OFDM RECEIVER USING THE SAME - An OFDM reception device includes: a first channel estimation unit for estimating a channel distortion by using a signal that is supplied from the reception unit and has a first time interval; a second channel estimation unit for estimating a channel distortion by using a signal that is supplied from the reception unit and has a second time interval shorter than the first time interval; a selection unit for selecting and outputting one of a signal from the first channel estimation unit and a signal from the second channel estimation unit, according to a control signal from the control unit; and a correction unit for correcting a reception signal supplied from the reception unit, according to the channel estimation signal from the selection unit. The control unit determines the control signal to be supplied to the selection unit, according a reception state of the reception unit.03-19-2009
20090074089CQI REPORTING TECHNIQUES FOR OFDMA WIRELESS NETWORKS - Various embodiments of the invention may use bitmaps to communicate channel quality index (CQI) information for multiple sub-channels in an orthogonal frequency division multiple access (OFDMA) wireless communications network. A base station may use bitmaps to report on whether the CQI information for each sub-channel has been under-reported or over-reported. A mobile station may use bitmaps to consolidate CQI information for multiple sub-channels into a single CQI set of parameters.03-19-2009
20090074097SYMBOL DE-MAPPING METHODS IN MULTIPLE-INPUT MULTIPLE-OUTPUT SYSTEMS - In a multiple-input multiple-output (MIMO) system, multiple receive antennas produce a received signal vector, Y, which includes an element for each of the receive antennas. In an embodiment of a de-mapping method performed within a MIMO receiver, a quadrature phase shift keying (QPSK) search is performed within a search space that includes the full constellation of symbol points. Based on the results of the QPSK search, the search space is reduced to fewer than all of the quadrants, and the received signal vector data is scaled and transformed to the reduced search space. A lower-level QPSK search is performed, and the process is repeated until the modulation order is reduced to a QPSK constellation. Hard or soft decisions corresponding to the search results may then be passed to a decoder.03-19-2009
20090074096APPARATUS FOR HIGH DATA THROUGHPUT RECEPTION IN A WLAN - An apparatus for high data throughput reception in a WLAN includes a receiving module, first and second determining modules, a generating module, and a producing module. The receiving module receives a symbol vector representing M streams of symbols transmitted via a wireless communication channel. The first determining module determines inner coded bits and extrinsic information of the inner coded bits based on the symbol vector, a channel matrix, and inner extrinsic information feedback. The second determining module determines outer coded bits and extrinsic information of the outer coded bits based on the extrinsic information of the inner coded bits, the inner coded bits, and a soft input soft output decoding process. The generating module generates the inner extrinsic information feedback based on the extrinsic information of the outer coded bits. The producing module produces decoded bits based on the outer coded bits.03-19-2009
20090074088Adaptive Fragmentation for HARQ in Wireless OFDMA Networks - A method performs a hybrid automatic repeat-request (HARQ) operation in a wireless orthogonal frequency division multiple access (OFDMA) network. A quality of a channel between a transmitter and a receiver is estimated as an error metric. A packet for the HARQ operation is fragmented adaptively at the transmitter according to the estimated error metric. The fragmentation is performed at the HARQ layer when the error metric is less than a predetermined threshold, otherwise the fragmentation is performed at the MAC layer.03-19-2009
20090074093APPARATUS FOR TRANSMITTING DATA USING CARRIERS AND METHOD THEREOF - An apparatus for transmitting data using a plurality of carriers and method thereof are disclosed, by which PAPR improving effect is enhanced. A method of generating an OFDM signal, which is transmitted by spreading data symbols using a DFT (Discrete Fourier Transform) matrix, according to the present invention includes the steps of generating an output symbol by data-processing the data symbols in time domain in a manner of giving a specific weight to the data symbols and summing up the weight-given data symbols and generating the OFDM signal by performing OFDM data processing on the output symbol.03-19-2009
20090074087SYSTEM FOR FOLLOW-UP SYNCHRONIZATION TO MAINTAIN SYNCHRONIZATION THROUGHOUT TRANSMISSION - A bidirectional communication system is provided. In one embodiment, a system comprises a host unit to communicate with a plurality of remote units using orthogonal frequency division multiplexing, the plurality of remote units communicatively coupled to the host unit in a multipoint-to-point configuration; the host unit receiving an orthogonal frequency division multiplexing waveform, the orthogonal frequency division multiplexing waveform comprising a plurality of tones transmitted by the plurality of remote units; and wherein the host unit is configured to transmit adjustment information to a first remote unit of the plurality of remote units to maintain the plurality of tones transmitted by the plurality of remote units substantially orthogonal as received at the host unit, the information directing the first remote unit to adjust tones transmitted by the first remote unit.03-19-2009
20090074091INDIVIDUAL INTERLEAVING OF DATA STREAMS FOR MIMO TRANSMISSION - The present invention, generally speaking, provides interleavers and methods of interleaving that satisfy the need for backward compatibility while effectively addressing competing design objectives. In accordance with one aspect of the invention, data is transmitted using a number of transmit antennas greater than an expected number of receive antennas. At least one pair of transmit antennas is formed, and multiple second data streams are formed from a first data stream, successive bits in said first data stream being assigned to different ones of said second data streams. Block interleaving of multiple respective ones of said second data streams is individually performed. During successive transmission intervals, the pair of transmit antennas is used to transmit a pair of data symbols taken from different ones of said second data streams, followed by an equivalent transformed pair of data symbols.03-19-2009
20090074086MIMO-OFDM TRANSMISSION DEVICE AND MIMO-OFDM TRANSMISSION METHOD - A MIMO-OFDM transmission apparatus is provided which allows high accuracy estimation of frequency offset, high accuracy estimation of a transmission path fluctuation and high accuracy synchronization/signal detection.03-19-2009
20090232238METHOD, APPARATUS AND SYSTEM FOR USING GUARD TONES IN OFDM SYSTEMS FOR INCREASING DATA RATES AND IMPROVING ROBUSTNESS - The present disclosure provides a method, apparatus, and system for increasing data rates and improving robustness in a wireless communication system. The method comprises identifying a set of guard tones for wireless Orthogonal Frequency Division Multiplexing (OFDM) signals, encoding data for OFDM transmission, identifying a preferred puncture pattern to puncture the encoded data, puncturing the encoded data with the preferred puncture pattern, and transmitting the punctured encoded data, wherein a portion of the punctured encoded data is transmitted on a portion of the set of guard tones.09-17-2009
20090323843METHOD AND APPARATUS FOR ESTIMATING SYMBOL TIMING OFFSET IN WIRELESS COMMUNICATION SYSTEM - A method and an apparatus for estimating a symbol timing offset in an Orthogonal Frequency Division Multiplexing (OFDM) based communication system are provided. A Carrier to Interference Ratio (CIR) of an Reference Signal (RS) is acquired using received pilot signals. The RS CIR includes power information on channel components of the RS. A CIR of a Secondary Synchronization Channel (S-SCH) is acquired using the received pilot signals. The S-SCH CIR includes power information on channel components of the S-SCH. Unnecessary channel components are suppressed from the RS CIR using the S-SCH CIR. Real channel components of the RS remain. An observation window is set having a predetermined duration for windowing the real channel components of the RS. A first arriving channel component is searched for within the observation window. A start point of data is estimated using the first arriving channel component.12-31-2009
20100266057GROUP RESOURCE ALLOCATION TECHNIQUES FOR IEEE 802.16M - Group resource allocation techniques for IEEE 802.16m are generally presented. In this regard a method is introduced comprising generating a plurality of bitmaps to identify resource allocations and multiple input multiple output (MIMO) modes for a group of broadband wireless mobile stations, wherein each mobile station in the group is assigned a position within a user bitmap to identify whether the mobile station is allocated frame resources and wherein the position within one or more MIMO bitmap(s) to identify a MIMO mode, and transmitting the bitmaps in a group resource allocation (GRA) information element (IE) of a broadband wireless media access protocol (MAP) frame portion. Other embodiments are also disclosed and claimed.10-21-2010
20110176626Pilot Signal Determination Method and Wireless Communication System Using the Same - The present invention disclose a pilot signal determination method for a wireless communication system. The wireless communication system utilizes a plurality of sub-carriers. The pilot signal determination method includes steps of generating at least one vector corresponding to at least one sub-channel; and determining a plurality of pilot signals according to the at least one vector.07-21-2011
20090323840METHOD OF TRANSMITTING CODEBOOK INDEX IN WIRELESS COMMUNICATION SYSTEM - A method of transmitting a codebook index in a wireless communication system includes receiving a feedback index regarding an entity selected from a plurality of entities belonging to a feedback codebook, selecting a precoder from a precoding codebook using the feedback index, the precoding codebook comprising a plurality of precoders and transmitting a precoder index of the selected precoder. Flexibility can be given to codebook designs, and overhead due to the feedback of codebook indices can be reduced.12-31-2009
20090323839EFFICIENT CQI SIGNALING IN MIMO SYSTEMS WITH VARIABLE NUMBERS OF BEAMS - The present invention relates to the signaling of channel quality information in a multi-beam transmission system, wherein a plurality of sets of channel quality information are transmitted for controlling the transmission rate on one of the beams, wherein each set of channel quality information is derived dependent on an assumed parameter of at least one other beam which could be transmitted, comprising selecting a parameter of the transmission of each of the sets of channel quality information dependent on the assumed parameter of the at least one other beam.12-31-2009
20090220015COARSE CARRIER FREQUENCY OFFSET ESTIMATION FOR CMMB MOBILE TV RECEIVER - A method of estimating coarse frequency offset of received symbols based on a received frequency domain sample at a k09-03-2009
20110033002Location of Wideband OFDM Transmitters With Limited Receiver Bandwidth - One illustrative embodiment takes the form of a system for locating wireless transmitters employing an Orthogonal Frequency Division Multiplexing (OFDM) digital modulation scheme. The OFDM scheme comprises transmitting signal components over narrowband frequency channels spanning a wideband channel. The system includes a first receiving system configured to receive a fraction of the signal components transmitted by a first wireless transmitter to be located in a fraction of the narrowband frequency channels, and to process the fraction of the signal components to derive location related measurements. The system further includes at least a second receiving system configured to receive the fraction of the signal components transmitted by the first wireless transmitter, and to process this fraction of the signal components to derive location related measurements. The system also includes a processing system configured to use location related measurements from the first and second receiving systems to compute the location of the wireless transmitter.02-10-2011
20110033001Layer mapping method and data transmission method for MIMO system - A method for indicating a combination between a codeword and a layer in a MIMO communication system, a layer mapping method, and a data transmission method using the same are disclosed. A minimum number of codeword-layer mapping combinations from among all available combinations based on the numbers of all codewords and all layers are pre-defined in consideration of a ratio of a codeword to a layer, a reception performance of a receiver, and reduction of combinations, so that a data transmission method using the predefined combinations is implemented. If a specific one codeword is mapped to at least two layers, a diversity gain can be acquired.02-10-2011
20090202008WIRELESS COMMUNICATION APPARATUS - A wireless communication device including a sending data amount determination unit, a data sending unit, a monitor function unit, a transmission control data producing unit, a transmission control data sending unit, a data reception unit, and an application I/F (interface) unit. The transmission control data sending unit includes a transmission control data separation unit, a transmission control data replication unit, and a data mapping unit.08-13-2009
20080317150FILTER STRUCTURE FOR ITERATIVE SIGNAL PROCESSING - The present invention relates to improved multiple access communications. In one form, the invention relates to an improved signal processing method and apparatus for an iterative method of determining the reception of a signal in a multi user packet based wireless OFDM (Orthogonal Frequency Division Multiplexing) communication system. In other forms the present invention provides recursive filtering for joint iterative decoding in a variety of systems and functions such as linear multiple access channel decoders, iterative equalisation, iterative joint channel estimation and detection/decoding, iterative space-time processing, iterative multi user interference cancellation and iterative demodulation. In one particular form the present invention provides an iterative decoding circuit for a wireless multiuser communications receiver comprising a first signal processing means for receiving at least one received signal, said first signal processing means comprising at least two linear iterative filters such that the first linear iterative filter provides an estimate of a selected received signal to an estimated signal output and a second linear iterative filter provides estimates of at least one other received signal, delayed by one iteration cycle, to an input of said first linear iterative filter, a second signal processing means for receiving the estimated signal output of the first linear iterative filter and providing a further received signal estimate to the input of the first signal processing means in a succeeding iteration cycle of the decoding circuit.12-25-2008
20090316807METHOD AND APPARATUS FOR ACHIEVING TRANSMIT DIVERSITY AND SPATIAL MULTIPLEXING USING ANTENNA SELECTION BASED ON FEEDBACK INFORMATION - A method of achieving transmit diversity in a wireless communication system is disclosed. The method comprises encoding and modulating data stream based on feedback information, demultiplexing symbols to at least one encoder block, encoding the demultiplexed symbols by the at least one encoder block, transforming the encoded symbols by at least one inverse fast Fourier transform (IFFT) block, and selecting antennas for transmitting the symbols based on the feedback information.12-24-2009
20090135927METHOD AND APPARATUS OF TRANSMITTING AND RECEIVING CHANNEL PARAMETER ATTRIBUTES IN WIRELESS COMMUNICATION SYSTEMS - A method and apparatus of transmission and reception of SetManagementSameChannelParameters, the method comprising generating a SetManagementSameChannelParameters attribute comprising an 8 bit Length field, an 8 bit AttributeID field, a 6 bit PilotAdd field, a 6 bit PilotCompare field, a 6 bit PilotDrop field, a 4 bit PilotDropTimer field, a 1 bit DynamicThresholds field, a 0 or 6 bit SoftSlope field, a 0 or 6 bit AddIntercept field, a 0 or 6 DropIntercept field, a 4 bit NeighborMaxAge field and a variable bit Reserved field and transmitting the SetManagementSameChannelParameters attribute over an OFDM communication link.05-28-2009
20090316811DATA COMMUNICATION METHOD, COMMUNICATION SYSTEM AND MOBILE TERMINAL - In a communications system which complies with LTE including a base station 12-24-2009
20090110088System and Method for Providing a Versatile RF and Analog Front-End for Wireless and Wired Networks - Embodiments related to analog front-ends for wireless and wired are described and depicted.04-30-2009
20080304585Method For Suppressing The Inter-Carrier Interference In The Orthogonal Frequency Division Multiplexing Mobile Communication System - The present invention relates to a method for suppressing inter-carrier interference in an orthogonal frequency division multiplexing mobile communication system, comprising: performing down conversion of the signal received in the receiver; removing the cyclic prefix of the signal so as to obtain the original signal; performing cyclic extension of the original signal over again; adding a window to the signal after cyclic extension, wherein the window function satisfies Nyquist criterion. The method according to the invention does not need time delay information of channels, and thereby is simple to realize. The selected roll-off coefficient can be up to 1 so as to suppress ICI to the utmost extent. Additionally, the invention also suggests that the generic window functions without the ICI can be used in OFDM system, which makes the system capability of suppressing ICI stronger by means of finding the best polynomial coefficients on the condition that the roll-off coefficient is 1.12-11-2008
20130128995CHANNEL ESTIMATION IN A COMMUNICATIONS SYSTEM - A method includes generating representative noise variance estimates based on a plurality of received symbols received in an orthogonal frequency division multiplexing (OFDM) signal. The representative noise variance estimates correspond to respective frequency intervals of a plurality of frequency intervals of the OFDM channel. Individual frequency intervals of the plurality of frequency intervals include a plurality of contiguous frequency bins of the OFDM signal.05-23-2013
20130128997Adaptive Two-Dimensional Channel Interpolation - A method and apparatus for improving channel estimation within an OFDM communication system. Channel estimation in OFDM is usually performed with the aid of pilot symbols. The pilot symbols are typically spaced in time and frequency. The set of frequencies and times at which pilot symbols are inserted is referred to as a pilot pattern. In some cases, the pilot pattern is a diagonal-shaped lattice, either regular or irregular. The method first interpolates in the direction of larger coherence (time or frequency). Using these measurements, the density of pilot symbols in the direction of faster change will be increased thereby improving channel estimation without increasing overhead. As such, the results of the first interpolating step can then be used to assist the interpolation in the dimension of smaller coherence (time or frequency).05-23-2013
20130128998TRANSMITTER, RECEIVER, MOBILE COMMUNICATION SYSTEM AND SYNCHRONIZATION CHANNEL - A transmitter includes an amplitude adjustment unit multiplying an amplitude adjustment sequence value for adjusting amplitude with a synchronization channel transmitted from a base station for establishing synchronization with a mobile station.05-23-2013
20100220798PREAMBLE FORMATS SUPPORTING HIGH-THROUGHPUT MIMO WLAN AND AUTO-DETECTION - A method for generating a preamble of an Orthogonal Frequency Division Multiplexed (OFDM) data frame for a multiple input multiple output (MIMO) wireless communication includes determining at least one system condition preamble format parameter. When the system condition preamble format parameter satisfies a first preamble format parameter a preamble having a first preamble format is formed. When the system condition preamble format parameter satisfies a second preamble format parameter, a preamble having a second preamble format is formed. Further, when the system condition preamble format parameter satisfies a third preamble format parameter, a preamble having a third preamble format is formed. The first, second, and third preamble formats differ based upon their lengths, fields, and modulation formats of a high throughput signal field.09-02-2010
20080273610METHOD AND APPARATUS FOR RANDOM ACCESS IN AN ORTHOGONAL MULTIPLE-ACCESS COMMUNICATION SYSTEM - Techniques for accessing a wireless communication system are described. A user equipment (UE) sends a random access preamble for system access. The random access preamble may include a random identifier (ID), a channel quality indicator (CQI), etc. The UE may randomly select the random ID or may be assigned this random ID. The UE receives a random access response from a base station. The random access response may include control channel resources (e.g., CQI and PC resources), uplink resources, and/or control information (e.g., timing advance and PC correction) for the UE. The random access response may be sent in two parts using two messages. A first message may be sent on a control channel and may include identification information and possibly other information. A second message may be sent on a shared data channel and may include remaining information for the random access response.11-06-2008
20090110096COMMUNICATION APPARATUS, COMMUNICATION METHOD AND INTEGRATED CIRCUIT - A communication apparatus carries out multicarrier communication with another communication apparatus through a transmission channel. The communication apparatus includes a first communication unit which carries out communication using a subcarrier at a first frequency band; a second communication unit which carries out communication using a subcarrier at a second frequency band higher than the first frequency band; and a third communication unit which carries out communication by synchronizing the first communication unit with the second communication unit and concurrently using the first and second frequency bands.04-30-2009
20090110103ADAPTIVE PUNCTURING TECHNIQUE FOR MULTICARRIER SYSTEMS - Various embodiments are described for adaptive puncturing techniques.04-30-2009
20090110101COMMUNICATION APPARATUS - A wave detecting section of a receiver has a first wavelet transformer involving a plurality of wavelet filters orthogonal to each other for performing a wavelet transform on received waveform data, a Hilbert transformer for performing a Hilbert transform on the received waveform data, a second wavelet transformer having the same configuration as that of the first wavelet transformer for performing a wavelet transform on outputs from the Hilbert transformer, a code converter for inverting the codes of outputs in odd-numbered places among outputs from the second wavelet transformer, a level converter for correcting fluctuations of outputs from the code converter attributable to a ripple of the Hilbert transformer, and a complex data generator for generating complex data, by defining outputs of the first wavelet transformer as in-phase components of the complex information and outputs from the level converter as orthogonal components of the complex information.04-30-2009
20090110098DATA PROCESSING APPARATUS AND METHOD - A data processing apparatus maps input symbols to be communicated onto a predetermined number of sub-carrier signals of an Orthogonal Frequency Division Multiplexed (OFDM) symbol. The data processor includes an interleaver memory which reads-in the predetermined number of data symbols for mapping onto the OFDM sub-carrier signals. The interleaver memory reads-out the data symbols on to the OFDM sub-carriers to effect the mapping, the read-out being in a different order than the read-in, the order being determined from a set of addresses, with the effect that the data symbols are interleaved on to the sub-carrier signals. The set of addresses are generated from an address generator which comprises a linear feedback shift register and a permutation circuit. The linear feedback shift register has ten register stages with a generator polynomial for the linear feedback shift register of R′04-30-2009
20090110095DATA PROCESSING APPARATUS AND METHOD - A data processor maps input symbols to be communicated onto a predetermined number of sub-carrier signals of an Orthogonal Frequency Division Multiplexed (OFDM) symbol. The data processor includes an interleaver memory which reads-in the predetermined number of data symbols for mapping onto the OFDM sub-carrier signals. The interleaver memory reads-out the data symbols on to the OFDM sub-carriers to effect the mapping, the read-out being in a different order than the read-in, the order being determined from a set of addresses, with the effect that the data symbols are interleaved on to the sub-carrier signals. The set of addresses are generated from an address generator which comprises a linear feedback shift register and a permutation circuit. A generator polynomial for the linear feedback shift register is R′04-30-2009
20090110093DATA PROCESSING APPARATUS AND METHOD - A data processing apparatus maps input symbols to be communicated onto a predetermined number of sub-carrier signals of an Orthogonal Frequency Division Multiplexed (OFDM) symbol. The data processor includes an interleaver memory which reads-in the predetermined number of data symbols for mapping onto the OFDM sub-carrier signals. The interleaver memory reads-out the data symbols on to the OFDM sub-carriers to effect the mapping, the read-out being in a different order than the read-in, the order being determined from a set of addresses, with the effect that the data symbols are interleaved on to the sub-carrier signals. The set of addresses are generated from an address generator which comprises a linear feedback shift register and a permutation circuit. A generator polynomial for the linear feedback shift register of R′04-30-2009
20090110089Cross layer network optimization for OFDMA systems using message passing algorithm - A method determines channel state information of a channel of a wireless network. Each of the wireless devices is configured to operate over the wireless network. An allocation of available transmission resources is performed according to a utility-based cross-layer resource management framework that transforms a utility function into an equivalent bipartite graph to concurrently maximize throughput and fairness in the resource allocation.04-30-2009
20090110099SIGNAL RECEIVING APPARAUTS, SIGNAL RECEIVING METHOD AND PROGRAM - Disclosed herein is a signal receiving apparatus including a profile inference section; a delay-spread computation section; a position determination section; a signal-by-function multiplication section; an interval extraction section; an interval-to-signal addition section; and a signal processing section.04-30-2009
20090110086Method and apparatus for performing bit loading in a multicarrier system - Bit loading is performed in a multicarrier communication system in an efficient and computationally simple manner. In at least one embodiment, bit loading techniques are used that allow bit loading to be performed using fixed point computation. A bit loading cost function may be used that is calculated as the difference between two other functions. In one approach, the two other functions may be implemented as lookup tables. Bits may be allocated to subchannels having a lowest cost.04-30-2009
20100296595COMMUNICATION APPARATUS, COMMUNICATION METHOD, AND MOBILE STATION APPARATUS - A communication apparatus includes a plurality of transmitting units that transmit a signal stream from each different antenna; a scheduling unit being configured such that the number of outputs is set so as to not exceed the number of transmitting units capable of transmitting, and a combination of transmitting units corresponding to the number of outputs, to each of which one of the signal streams is to be input, is defined in the form of a precoding matrix; a codeword generating unit that generates, from data to be transmitted, a predetermined number of codewords to be transmitted out simultaneously; an encoder that generates, from the codewords, signal streams corresponding to the number of outputs; and a modulation unit that supplies each of the signal streams to a corresponding one of the transmitting units in accordance with the precoding matrix.11-25-2010
20100296594APPARATUS AND METHOD FOR INITIAL SYNCHRONIZATION IN WIRELESS COMMUNICATION SYSTEM BASED ON OFDM - An apparatus and a method for acquiring initial synchronization in a wireless communication system based on Orthogonal Frequency Division Multiplexing (OFDM) are provided. The apparatus includes a frame synchronizer for acquiring frame synchronization using a preamble signal, a first offset determiner for determining a first time offset and a first frequency offset based on the frame synchronization, a preamble identifier estimator for estimating a preamble identifier in a receive signal interpolated with the first time offset and the first frequency offset, and a second offset determiner for generating a first preamble signal and a first pilot signal corresponding to the preamble identifier, for derandomizing a preamble signal and a pilot signal, and for determining a second time offset and a second frequency offset. Thus, the initial synchronization acquisition time in a low Signal-to-Noise Ratio (SNR) environment can be reduced.11-25-2010
20110129026METHOD AND APPARATUS FOR TRANSMITTING AND RECEIVING DATA USING FREQUENCY DIVERSITY SCHEME - Provided are a transmitter and a receiver. The transmitter combines N data signals received from an encoded bit stream to generate N symbols; maps the N symbols to subcarriers that are spaced more than a coherent bandwidth apart; and receives and moves the N symbols, which are mapped to the subcarriers that are spaced more than a coherent bandwidth apart, to their own positions. The receiver demodulates N pieces of data using the N symbols received from the transmitter in a manner similar to that used by the transmitter.06-02-2011
20110129025APPARATUS FOR ASSIGNING AND ESTIMATING TRANSMISSION SYMBOLS - An apparatus for assigning transmission symbols to a media data stream of information symbols is described, the media data stream including a first substream for representing a media content in a basic quality and a second substream including additional data for representing the media content, along with the first substream, in an improved quality. The apparatus includes a first means for assigning first transmission symbols to the information symbols of the first substream and a second means for assigning second transmission symbols to the information symbols of the second substream, the first transmission symbols being transmissible, via a transmission channel, with reduced error probability as compared to the second transmission symbols.06-02-2011
20110129023WIRELESS RANGING SYSTEM AND RELATED METHODS - A wireless ranging system for determining a range of a remote wireless device may include a wireless transmitter and a wireless receiver. The wireless ranging system may also include a ranging controller to cooperate with the wireless transmitter and receiver to generate a multi-carrier base waveform, transmit a sounder waveform to the remote wireless device including concatenated copies of the multi-carrier base waveform, and receive a return waveform from the remote wireless device in response to the sounder waveform. The ranging controller may also generate time domain samples from the return waveform, convert the time domain samples into frequency domain data, and process the frequency domain data to determine the range of the remote wireless device.06-02-2011
20110129022Systems and Methods for Providing Geolocation Using Wireless Signals - A system for determining a location of a receiver is disclosed. The system includes at least one transmitter transmitting one or more radio signals, respectively. The system also includes a receiver comprising a clock, a memory, and a processor configured to execute computer-executable instructions stored in the memory. The instructions makes the receiver operable to receive the radio signals, capture the radio signals as one or more received signal waveform, respectively, and store the received signal waveforms in the memory. The instructions also make the receiver operable to calculate one or more virtual transmitted waveforms based upon the received signal waveforms, respectively and determine, based upon the received signal waveforms and the virtual transmitted waveforms, a position of the receiver relative to the transmitters.06-02-2011
20100309999METHOD AND DEVICE FOR CYCLIC DELAY MAPPING FOR THE SIGNAL IN THE MULTI-ANTENNA TRANSMITTER - A method of carrying out cyclic delay mapping, wherein, the CDD-like transmitter generate multiple branches of signals c0orresponding to the multiple transmitting antennas with varying cyclic delay mapping rules, so as to make the cyclic delay parameter, corresponding to at least one of the multiple transmitting antennas, vary as time goes by, in order to prevent the system performance from degrading as time goes by.12-09-2010
20100309997RADIO COMMUNICATION TERMINAL DEVICE, RADIO COMMUNICATION BASE STATION DEVICE, AND CQI FEEDBACK METHOD - It is possible to provide a radio communication terminal device, a radio communication base station device, and a CQI feedback method which can improve the CQI reproducibility while reducing the feedback overhead. A terminal channel judgment unit judges whether a local terminal is a TU terminal or a LOS terminal. A feedback CQI decision unit selects a Best-M report if the local terminal is the TU terminal, and selects a DCT report if the local terminal is the LOS terminal. The feedback CQI decision unit feeds back the CQI by using the selected report method.12-09-2010
20100296596Wireless Communication Apparatus And Method For Wireless Communication - A wireless communication technology which realizes high-speed transmission while making effective use of existing frequency bands. A wireless communication apparatus includes a communication unit to perform a wireless communication with a target communication device by simultaneously using a plurality of carrier frequency bands each of which has a specified bandwidth and is discontinuous between each carrier frequency-band interval.11-25-2010
20100303165PILOT TRANSMISSION AND CHANNEL ESTIMATION FOR AN OFDM SYSTEM WITH EXCESS DELAY SPREAD - Pilot transmission and channel estimation techniques for an OFDM system with excess delay spread are described. To mitigate the deleterious effects of excess delay spread, the number of pilot subbands is greater than the cyclic prefix length. This “oversampling” may be achieved by using more pilot subbands in each symbol period or different sets of pilot subbands in different symbol periods. In one example, a first set of pilot subands may be received in a first symbol period, and a second set of pilot subands may be received in a second symbol period. The first set of pilot subands and the second set of pilot subbands may be staggered in frequency.12-02-2010
20100310000METHOD OF TRANSMITTING PRECODING INFORMATION IN MULTIPLE ANTENNA SYSTEM - A method of transmitting precoding information in a multiple antenna system includes selecting M subbands from a plurality of subbands constituting a whole frequency band in a descending order of a channel quality indicator (CQI), where M is an integer satisfying M>0, and transmitting a first precoding matrix indicator (PMI) for the M subbands and a second PMI for a remaining band, wherein the first PMI is a PMI of a codebook selected from a first codebook set including a plurality of codebooks and the second PMI is a PMI of a codebook selected from a second codebook set including a part of the plurality of codebooks of the first codebook set. Accordingly, precoding information can be effectively transmitted by separately preparing a codebook for a best band and a codebook for a non-selected band.12-09-2010
20100303161RECEIVER APPARATUS - A receiver apparatus (12-02-2010
20110122959OFDM MODULATION/DEMODULATION METHOD, OFDM MODULATION DEVICE, OFDM DEMODULATION DEVICE, AND OFDM MODULATION/DEMODULATION SYSTEM - An OFDM modulation/demodulation method in a transmission system that transmits data from a transmission source to a transmitting destination through OFDM modulation/demodulation is provided, which includes an extension step (step S05-26-2011
20100309998METHOD FOR TRANSMITTING PRECODED SIGNAL IN COLLABORATIVE MULTIPLE-INPUT MULTIPLE-OUTPUT COMMUNICATION SYSTEM - A method for transmitting a precoded signal in a collaborative multiple-input multiple-output (MIMO) communication system is described. A method for receiving a precoded signal in a MIMO communication system includes estimating, by a mobile station, channels for one or more base stations through signals received from the one or more base stations including a serving base station, transmitting precoding matrix indexes of the one or more base stations determined based on the estimated channels to the serving base station, and receiving signals precoded by the one or more base stations based on the precoding matrix index.12-09-2010
20100309996Method of Transmitting Feedback Information for Performing Collaborative Mimo - A method of transmitting information necessary for performing collaborative multi input multi output (MIMO) operation between a mobile station and a base station in order to improve reception performance of the mobile station in a multi-cell environment is provided. The mobile station may receive a feedback channel for the collaborative MIMO which is allocated by a serving base station and transmit a collaborative MIMO indicator including information indicating that the collaborative MIMO is started to the serving base station. In addition, the mobile station may transmit the feedback information of each of the serving base station and a collaborative base station to the serving base station through the feedback channel, and the serving base station may transmit the feedback information to the collaborative base station via a backbone network. The mobile station may receive the collaborative MIMO supported by the serving base station and the collaborative base station.12-09-2010
20100303162MULTI-USERS DETECTING METHOD AND DEVICE OF OFDM TRANSMISSION SIGNAL - Multi-users detecting method and device of OFDM transmission signal include that: a received data sequence is composed of the received signal which is in the position of the time and frequency symbol corresponding to the same data symbol in multi-repeating blocks; the composed repeating channel response sequence array which is corresponding to the received data sequence is determined; the received data sequence is detected to acquire the data symbol information of multi-users by using the composed repeating channel response sequence array. The technical solution can effectively restrain the multi-address interference and the interference between symbols during OFDM transmitting signal and improve the system performance greatly.12-02-2010
20100322330Mode Switching Between SU-MIMO and MU-MIMO - The present invention relates to a method and arrangements in a communication system for Multi User Multiple-Input-Multiple-Output (MU-MIMO) signaling via Multiple-Input-Multiple-Output (MIMO) antennas between a base station and one of a plurality of mobile terminals supporting both Single User and Multi User Multiple-Input-Multiple-Output (SU-MIMO and MU-MIMO) signaling modes. Switching between the modes is supported in the system and the modes have partly shared signaling. SU-MIMO mode signaling which is redundant, i.e. not needed, for MU-MIMO mode signaling is identified. Bits, i.e. data bits, of the identified redundant signaling is re-interpreted or re-defined to comprise signaling information associated with MU-MIMO mode. The signaling information associated with MU-MIMO mode is signaled to the mobile terminal by using the reinterpreted redundant bits.12-23-2010
20100322329METHOD AND APPARATUS FOR TRANSMITTING AND RECEIVING UPLINK BANDWIDTH REQUEST INFORMATION IN WIRELESS COMMUNICATION SYSTEM - Methods and apparatus are provided for requesting uplink Bandwidth (BW) over a BW Request (REQ) channel in an Orthogonal Frequency Division Multiple Access (OFDMA) communication system. A BW REQ indicator is transmitted with a BW REQ message over the BW REQ channel from a Mobile Station (MS) to a Base Station (BS) to request an uplink resource for uplink traffic of a delay sensitive service. A grant of the requested uplink resource is received from the BS in accordance with the transmitted BW REQ indicator and the BW REQ message. The uplink traffic is transmitted from the MS to the BS using the granted uplink resource.12-23-2010
20110110441JOINT LAYER 3 SIGNALLING CODING FOR MULTICARRIER OPERATION - Systems and methodologies are described that facilitate encoding layer 3 control information in a multicarrier wireless communication environment. The layer 3 control information can be jointly encoded for a plurality of component carriers. Further, the jointly encoded layer 3 control information for the plurality of component carriers can be included in a data transmission (e.g., PDSCH, PUSCH, . . . ) sent on a component carrier from the plurality of component carriers. Moreover, an allocation for the data transmission on the component carrier can be indicated by a control transmission (e.g., PDCCH, . . . ). For example, the control transmission and the data transmission, which can be scheduled by the control transmission, can be sent on a common component carrier or different component carriers from the plurality of component carriers (e.g., same carrier signalling or cross-carrier signalling can be implemented, . . . ).05-12-2011
20100322326Efficient tuning and demodulation techniques - Techniques for the reception and processing of wireless signals are disclosed. For instance, an apparatus may include a first hardware module (e.g., a mixed signal module) and a second hardware module (e.g., a digital signal module). The first hardware module may convert an analog signal corresponding to a received wireless signal into a digital signal having a first sampling rate. In turn, channel filtering may be performed on this digital signal. Following this, the filtered digital signal may be resampled from the first sampling rate to a second sampling rate. At this point, the resampled signal may be transferred across an interface from the first hardware module to the second hardware module. Upon receipt, the second hardware module may correct a sampling rate error in the second sampling rate, and demodulate the digital signal into one or more symbols.12-23-2010
20100322327Method of estimating and removing noise in OFDM systems - The present invention relates to impulse noise estimation and removal in orthogonal frequency division multiplexing (OFDM) transmissions, and particularly to transmissions in power line communications and digital subscriber line (DSL) transmissions. The method includes the steps of: modulating data to be transmitted; performing an inverse fast Fourier transform; inserting a cyclic prefix into the data; transmitting the data as a set of OFDM symbols via a channel; receiving the set of OFDM symbols; removing the cyclic prefix; performing a fast Fourier transform; estimating impulse noise; canceling the impulse noise based upon the estimated impulse noise to produce a set of impulse noise-free data; estimating the channel; and demodulating and detecting the data transmitted based upon the estimated channel and the set of impulse noise-free data.12-23-2010
20090268828SYSTEMS AND METHODS FOR DOPPLER SHIFT COMPENSATION IN OFDMA COMMUNICATIONS - Systems and methods for Doppler Shift compensation in OFDMA communications are provided. In one embodiment, a system for orthogonal frequency division multiple access communication comprises: a basestation for communicating with a plurality of subscriber units using orthogonal frequency division multiple access. The basestation performs a ranging process with the plurality of subscriber units at a periodicity based on adaptive carrier frequency ranging periods. The basestation performs measurements of transmissions received from the plurality of subscriber stations, the measurements indicative of Doppler Shift frequency errors. The adaptive carrier frequency ranging periods are adjusted based on the measurements.10-29-2009
20090213944Receiver Parametric Covariance Estimation for Precoded MIMO Transmissions - A model-based technique for estimating signal impairments that can accommodate various transmitted signal configurations, including closed-loop transmit diversity signals and pre-coded MIMO signals, is disclosed. In an exemplary method, an impairment model is constructed for a received composite information signal comprising at least a first data stream transmitted from first and second antennas according to a first antenna weighting vector. The impairment model includes one or more model terms scaled by corresponding scaling parameters, wherein the model terms capture propagation channel effects and are independent of the first antenna weighting vector, and wherein the scaling parameters capture effects of the first antenna weighting vector. A parametric estimate of the impairment covariance is calculated using the impairment model.08-27-2009
20110129027WIRELESS COMMUNICATION BASE STATION DEVICE, WIRELESS COMMUNICATION TERMINAL DEVICE, AND METHOD FOR SETTING CYCLIC DELAY - Provided is a base station enabling an increase of the resource utilization efficiency of a precoded dedicated pilot signal. In a base station (06-02-2011
20110007831FRAME TRANSMISSION METHOD IN A WIRELESS COMMUNICATION SYSTEM - A frame transmission method in a wireless communication system comprises setting a primary frame including a multiplicity of primary sub-frames, setting a secondary frame including a multiplicity of secondary sub-frames, and transmitting the secondary frame, wherein each of the primary sub-frames and each of the secondary sub-frames consists of multiple OFDM symbols, the OFDM symbols included in the primary sub-frame and the OFDM symbols included in the secondary sub-frame have different CP (Cyclic Prefix) lengths from one another, and the primary sub-frames and the secondary sub-frames are all equal in length. It is an advantage of the invention that frames consisting of OFDM symbols with different CP lengths can coexist together. Moreover, when each of the sub-frames within one frame consists of multiple OFDM symbols with different CP lengths, even the sub-frames can coexist together.01-13-2011
20110026618METHOD AND SYSTEM FOR LOW COMPLEXITY CHANNEL ESTIMATION IN OFDM COMMUNICATION NETWORKS USING CIRCULAR CONVOLUTION - A mobile device in an OFDM system receives an OFDM signal comprising a plurality of RS tones and data OFDM symbols. The received RS tones are extracted for channel estimation, which is performed by masking channel responses of the extracted RS tones. Pointers of the extracted RS tones are shifted so that the extracted RS tones are spaced in a subcarrier at regular intervals. Pointers of associated positive counted or indexed subcarriers are shifted one subcarrier lower while no pointer shifting on associated negative counted or indexed subcarriers. IFFT operation is applied to the resulting pointer shifted RS tones to determine the channel impulse responses. Desired channel taps are weighted using non-zero masking values, while undesired channel taps and/or channel tap replicas are weighted using zero. The masked channel impulse responses are back shifted in subcarrier prior to channel equalization.02-03-2011
20090067524GUARD INTERVAL LENGHT SELECTION IN AN OFDM SYSTEMS BASED ON COHERENCE BANDWIDTH OF THE CHANNEL - A system, apparatus and methods are described that identify a maximum cyclic delay and corresponding cyclic prefix for a multi-path communications channel. In one embodiment, the maximum cyclic delay (03-12-2009
20090067523FAST INITIALIZATION USING SEAMLESS RATE ADAPTATION - A method for initializing modems in a multicarrier transmission system to establish a communication link between the transmitter and the receiver. An exemplary embodiment includes the steps of providing a predetermined parameter value that approximates a corresponding actual parameter value of the communication link, establishing a data communication link between a first transceiver and a second transceiver using the predetermined parameter value to allow the transmission of data, determining the actual parameter value, and seamlessly increasing the data rate of the established data communication link by using the determined actual parameter value to provide an steady state communication link with an updated data rate.03-12-2009
20110019754POWER CONTROL IN A WIRELESS COMMUNICATION SYSTEM - A method of power control in a wireless communication system wherein blocks are transmitted from a transmitter to a receiver on multiple wireless transport channels. The method comprises comparing a target signal quality value with a received signal quality value and providing the results of the comparing step to the transmitter to adjust transmit power, and a mechanism for controlling the target signal quality for transport channels that have been inactive for a predefined period. A corresponding receiver is also provided.01-27-2011
20090067518Interpolation Method and a Related Device for Channel Estimation in Communication Systems - A method for interpolating between a first and a second point includes the steps of calculating a first distance between a first and a second independent value and a second distance between a first and a second dependent value, right shifting the first and the second distances by a predetermined number of bits for obtaining respectively a hold step and a variations step and generating a number of interpolated points, having independent values between the first and the second independent values and corresponding dependent values obtained by alternating hold and variations phases, wherein the hold phase consists of generating a number of points corresponding to the hold step having the same dependent value, and wherein the variations phase consists of varying the dependent value by the variations step until the number of interpolated points has been calculated. The method is particularly suitable for channel estimation in communication systems.03-12-2009
20090067519ESTIMATION OF LENGTH OF CHANNEL IMPULSE RESPONSE - In a receiver for processing OFDM encoded signals, wherein the OFDM encoded digital signals are transmitted by means of a symbol in each of subcarrier frequency channels, with at least some of said subcarriers containing user data symbols, an initial estimate of a channel frequency response is formed from magnitudes of user data symbols received in those subcarriers. Then, a correlation function of a channel impulse response is estimated by performing an inverse Fourier transform on the initial estimate of the channel frequency response, and the length of the channel impulse response is estimated by examining peaks in the estimated correlation function of the channel impulse response.03-12-2009
20090067515SYSTEM AND METHOD FOR DETERMINING TRANSMISSION PARAMETERS IN AN ORTHOGONAL FREQUENCY-DIVISION MULTIPLEXED DATA STREAM - A system for identifying transmission parameters of an OFDM signal transmitted according to a transmitter clock includes a first correlator to receive and correlate samples of the signal sampled according to a receiver clock and provide a first metric indicative of whether the signal has a first transmission mode, a plurality of additional correlators, operable in parallel with the first correlator, to receive and correlate the samples of the signal sampled according to the receiver clock and provide a plurality of additional metrics indicative of whether the signal has a second transmission mode and whether the receiver clock is aligned with or displaced by at least one sample over one OFDM symbol relative to the transmitter clock, and a processor. The processor receives the metrics, and determines whether the signal has the first or second transmission mode and whether the receiver clock is aligned or displaced by the at least one sample relative to the transmitter clock.03-12-2009
20090067516RANGING AND ROUND TRIP DELAY TIMING ADJUSTMENT IN A MULTI-POINT TO POINT BIDIRECTIONAL COMMUNICATION SYSTEM - A bidirectional communication system is provided. In one embodiment, a method for an orthogonal frequency division multiplexing multipoint-to-point communications system comprises establishing communication between a first remote unit of a plurality of remote units and a host unit, the plurality of remote units communicatively coupled to the host unit in a multipoint-to-point configuration using orthogonal frequency division multiplexing; and adjusting a round trip path delay associated with the first remote unit.03-12-2009
20090067514METHOD OF NON-UNIFORM DOPPLER COMPENSATION FOR WIDEBAND ORTHOGONAL FREQUENCY DIVISION MULTIPLEXED SIGNALS - Described is a method for compensation of an OFDM signal propagating through Doppler-distorted, time-varying multipath channels. The method is based on low-complexity post-FFT signal processing. Minimum mean square error combining of signals is performed for signals received at spatially-distributed receiver elements using adaptive channel estimation and phase tracking. Doppler shifts are modeled as a consequence of motion-induced time compression and dilation. The Doppler rate is assumed constant over one OFDM block but can vary between OFDM blocks. Thus a non-constant Doppler shift is accommodated by the method. Non-uniform Doppler compensation across subchannels is based on adaptive estimation and prediction of the Doppler rate. A single adaptively estimated parameter is used to track the phases of all the carriers and channel estimates are updated on a block by block basis.03-12-2009
20110110442Systems, Devices, And Methods For Generating Pilot Patterns For Use In Communications - A computer-implemented method for generating a pilot pattern for use in an orthogonal frequency-division multiplexing (OFDM) based communication system. The method includes: generating a basic resource unit to which a plurality of pilot symbols are allocated, each of the pilot symbols corresponding to a subcarrier frequency and an OFDM symbol; deriving one or more variant resource units from the basic resource unit; and combining ones of the basic resource unit and the one or more variant resource units to generate a resource block including the pilot pattern.05-12-2011
20110110446SCATTERED PILOT CORRELATION IN DVB-H SYSTEMS - A method for correlating scattered pilot locations in a sequence of OFDM symbols in a multi-carrier transmission system, and includes mapping pilot locations comprising pilot symbols having predetermined known values, wherein the pilot symbols are positioned among data subcarriers in time and frequency dimensions consisting of received pilot symbols and having a predetermined position pattern in the time and frequency dimensions, wherein the predetermined position pattern comprises a finite number of sub-position patterns each corresponding to positions of the pilot symbols; estimating a Doppler spread in a frequency spectrum between the transmitter and the receiver in the multi-carrier transmission system; estimating a channel length of a set of channel paths received at the receiver; and the receiver automatically selecting one of a plurality of predetermined methods of correlating the scattered pilot locations in the sequence of OFDM symbols based only on the estimating processes.05-12-2011
20110110445System and Method for Estimation and Correction of Carrier Frquency Offset in MIMO-OFDM Based Wireless Communications Systems - This invention relates to a Multi-Input Multi-Output Orthogonal Frequency Divisional Multiplexing (MIMO-OFDM) is a transmission technology for many current and next generation wireless communication systems. Carrier Frequency Offset (CFO) Estimation and Correction is one of the most important requirement of the proper reception of MIMO-OFDM Signals. The invention provides a null subcarrier based scheme to accomplish this task. The CFO is estimated by employing the co-variance matrix of the signals on all receiving antennas with a cost function which minimizes the energy falling on the null subcarrier locations due to frequency offset. The proposed approach results in very low computational complexity as it uses a two step procedure, making it very attractive for real time applications. Also a new null subcarrier allocation scheme based on Fibonacci series is proposed which ensures a frequency offset estimation range equal to the maximum possible range equal to the OFDM bandwidth. 05-12-2011
20110019755DATA TRANSMISSION METHOD AND APPARATUS BASED ON JOINT SPACE DIVISION MULTIPLE ACCESS TECHNOLOGY IN COLLABORATIVE DOWNLINK MIMO SYSTEM - A channel condition information feedback method and apparatus are provided for a collaborative wireless communication network using a multiple input multiple output antenna system. The apparatus includes a downlink channel estimator that estimates channels of adjacent base stations, groups base stations from among the adjacent base stations that are capable of collaborative communication, and obtains a maximum singular vector to base stations belonged to a same group; and a vector selector which selects a weight io vector most accurately representing the maximum singular vector and a complex variable most accurately representing the maximum singular vector in combination with the weight vector.01-27-2011
20110019757COMMUNICATION SYSTEM, RECEPTION DEVICE, AND COMMUNICATION METHOD - A reception device which communicates with a transmission device including multiple transmission antennas, the reception device including: at least one reception antenna which receives multiple transmission signals transmitted by the transmission device from the multiple transmission antennas; a propagation channel response estimation unit which estimates propagation channel responses among the multiple transmission antennas and the reception antenna; a block division unit which divides a reception signal of at least one of the reception antennas into multiple blocks based on a multipath; and a transmission signal detection unit which detects the transmission signals transmitted by the transmission device based on the reception signal divided by the block division unit into the multiple blocks and the propagation channel responses estimated by the propagation channel response estimation unit. The transmission signal detection unit includes: an interference cancellation unit which generates and removes an interference replica; and a signal separation unit which separates a signal into which a transmission signal is multiplexed from an output of the interference cancellation unit.01-27-2011
20110026623Methods and Apparatus for WLAN Transmission - In a method for generating a physical layer (PHY) data unit for transmission via a communication channel, a first set of modulation coding schemes (MCSs) and a second set of MCSs that correspond to a number of spatial streams and a number of encoders are provided. The first set of MCSs correspond to a first channel bandwidth and the second set of MCSs correspond to a second channel bandwidth, and the first set of MCSs is different than the second set of MCSs. An MCS is selected from the first set of MCSs when the PHY data unit is to be transmitted using a channel having the first channel bandwidth, and the MCS is selected from the second set of MCSs when the PHY data unit is to be transmitted using a channel having the second channel bandwidth. Information bits are encoded using the number of encoders and according to the selected MCS, and the encoded information bits are parsed into the number of spatial streams. The encoded information bits are modulated according to the MCS, and a plurality of OFDM symbols are formed based on the modulated encoded information bits.02-03-2011
20110026621OFDM TRANSMISSION METHODS IN THREE PHASE MODES - Systems and methods for power line transmission are disclosed in which transmitters and receivers are connected to one or more phases of the power line. At least one symbol stream to be transmitted on the power line network is generated. The at least one symbol stream is scaled using a weight vector to generate a plurality of scaled symbol streams. The weight vector comprises a plurality of weights, each corresponding to a phase of the power line network. Each of the scaled symbol streams are transmitted on a corresponding phase of the power line network. A zero crossing detector identifies phase information for a receiver. A concentrator adapts signals to be sent to the receiver based upon the phase associated with the receiver.02-03-2011
20110026624METAMATERIAL ANTENNA ARRAY WITH RADIATION PATTERN SHAPING AND BEAM SWITCHING - Apparatus, systems and techniques for using composite left and right handed (CRLH) metamaterial (MTM) structure antenna elements and arrays to provide radiation pattern shaping and beam switching.02-03-2011
20110026625Discontinuous Reception (DRX) Timer Triggered with the Transmission of a Buffer Status Report (BSR) - A method implemented at a user equipment (UE) may include receiving a grant from a base station permitting the user equipment to transmit data to the base station and transmitting data to the base station, where the data includes a buffer status report (BSR) that indicates an amount of data in a buffer of the UE. The method may further include starting or restarting a discontinuous reception (DRX) timer when the data including the BSR is transmitted to the base station. The method may additionally include monitoring (02-03-2011
20110026622HYBRID AUTOMATIC REPEAT REQUEST OPERATION AND DECODING STATUS SIGNALING FOR UPLINK MULTIPLE-INPUT MULTIPLE-OUTPUT - Systems and methodologies are described that facilitate conveying decoding statuses in a wireless communication environment. A UE can transmit a plurality of codewords as part of an uplink multiple-input multiple-output (MIMO) transmission to a base station. The base station can receive and attempt to decode the plurality of codewords. Further, decoding statuses for the plurality of codewords can be determined. Moreover, the decoding statuses for the plurality of codewords can be signaled to the UE. For example, the decoding statuses for the plurality of codewords can be conveyed via a single PHICH. According to another example, multiple PHICHs can convey the decoding statuses. Pursuant to a further example, the decoding statuses can be conveyed at least in part via a PDCCH.02-03-2011
20110038433CODEBOOK SEARCHING APPARATUS AND METHOD THEREOF - Exemplary embodiments of the present disclosure propose multiple codebook searching methods for a receiver in a communication system, wherein the communication system uses a codebook having L pre-coding matrices. First, L matrices are calculated according to the L pre-coding matrices, and the L matrices are inversed mean square error matrices of the L pre-encoding matrices. Then, diagonal cofactors or determinants of at least S matrices of the L matrices are calculated, and a pre-coding matrix used by the receiver is found according to the maximum cofactors of the diagonal of the at least S matrices or ratios between the maximum cofactors of the diagonals and the determinants of the at least S matrices.02-17-2011
20090022234RESOURCE MANAGEMENT IN A WIRELESS COMMUNICATION NETWORK - A method of transmitting more than one signal in a wireless communication system is provided. The method comprises allocating multiple symbols to a first signal constellation and a second signal constellation, wherein the first signal constellation refers to base layer signals and the second signal constellation refers to enhancement layer signals; modulating the multiple symbols of the first signal constellation and the second signal constellation; and transmitting the modulated symbols, wherein configuration information used for modulating the multiple symbols is provided in a control message.01-22-2009
20090034637TRANSMITTING APPARATUS, RECEIVING APPARATUS, AND LINK ADAPTATION METHOD - A link adaptation method and others wherein feedback information amount can be reduced. According to this method, a receiving apparatus (02-05-2009
20090034636Feedback scheduling to reduce feedback rates in MIMO systems - In a closed-loop wireless communication system, a codebook-based feedback control mechanism is provided where feedback from each of a plurality of receivers is scheduled to control the feedback so that the receiving devices do not needlessly feed back precoding information to the transmitting device. The feedback may be controlled by establishing and distributing a schedule to control when each receiver feeds back preceding information, or by establishing and distributing a metric-based feedback threshold that must be satisfied before feedback is permitted.02-05-2009
20090034638RADIO PARAMETER GROUP GENERATING APPARATUS, TRANSMITTER AND RECEIVER - An apparatus for generating sets of radio parameters includes a first deriving unit deriving a set of radio parameters for specifying a symbol including an effective symbol part with the same period as the effective symbol part specified by another set of radio parameters and a guard interval part with a different period from the guard interval part specified by the other set of radio parameters. The apparatus further includes a second deriving unit deriving a set of radio parameters so that an occupancy proportion of the guard interval part in a single symbol specified by another set of radio parameters is equal to an occupancy proportion of the guard interval part in a single symbol specified by the other set of radio parameters.02-05-2009
20090232233MIMO RECEIVER APPARATUS AND MIMO TRANSMITTER APPARATUS - A MIMO receiver apparatus and a MIMO transmitter apparatus capable of reducing the feedback information amount to reduce the system traffics. A wireless communication apparatus (09-17-2009
20100172423PREAMBLE SEQUENCES FOR WIRELESS COMMUNICATION SYSTEMS - A method is provided to generate preamble sequences. The method includes transmitting a periodic set of samples as part of a wireless communications preamble sequence and determining a set of null periods in which zero samples are transmitted. The null periods are interspersed among the periodic set of samples in order to enhance correlation efficiency and mitigate processing complexity.07-08-2010
20110243265WIRELESS COMMUNICATION SYSTEM - A wireless communication system is disclosed including a MIMO wireless communication apparatus that can communicate through multiple antennas and a non-MIMO wireless communication apparatus that can communicate through a single antenna or multiple antennas. The MIMO wireless communication apparatus includes a communication unit configured to transmit and receive control information divided into a second control information containing information related to the demodulation and decoding of traffic channel and a first control information containing information related to the MIMO separation of the second control information.10-06-2011
20110044391METHOD AND APPARATUS FOR CONFIGURING CONTROL CHANNEL IN OFDM SYSTEM - A control channel configuration method and apparatus is provided for supporting Inter-Cell Interference Coordination (ICIC) in an OFDM-based communication system. The control channel configuration method includes determining a Resource Block (RB) to be used for configuring control channels; configuring the control channels by mapping the control channels in a data channel region within the RB; and transmitting the configured control channels, wherein configuring the control channels includes mapping the control channels in units of Resource Element Groups (REGs) formed by binding one or more Resource Elements (REs) in a time domain-preferred allocation manner within the same RB.02-24-2011
20110116564TRANSMITTING SPREAD SIGNAL IN COMMUNICATION SYSTEM - The present invention provides for spreading a first signal using a plurality of spreading codes, multiplexing the first spread signal by code division multiplexing, transmitting the first multiplexed signal via a plurality of neighboring frequency resources of an OFDM symbol of a first antenna set, spreading a second signal using a plurality of spreading codes, multiplexing the second spread signal by code division multiplexing, transmitting the second multiplexed signal via a plurality of neighboring frequency resources of the OFDM symbol of the first antenna set, transmitting the first multiplexed signal via a plurality of neighboring frequency resources of an OFDM symbol of a second antenna set, and transmitting the second multiplexed signal via a plurality of neighboring frequency resources of the OFDM symbol of the second antenna set, wherein the first multiplexed signal is transmitted on frequency resources that neighbor frequency resources that the second multiplexed signal is transmitted on.05-19-2011
20110116561MONITORING AND CORRECTING TIMING ERRORS IN WIRELESS COMMUNICATION - Providing for improved tracking and correction of timing in wireless communications is disclosed herein. By way of example, a first algorithm can be employed to track timing of a wireless signal, based on one dimension of the signal. Additionally, a second algorithm based on a different dimension of the signal can be employed to verify the timing and reduce errors in timing analysis. Various signal dimensions can be employed for the analysis, including cyclic prefix, frequency, channel impulse response, or the like, or a combination thereof. Additionally, different channels of the wireless signal can also be analyzed by the first algorithm and the second algorithm. Furthermore, the second algorithm can be selected to reduce deficiencies identified in the first algorithm, to improve overall timing analysis, reduce undetected timing errors or false errors, and improve timing correction.05-19-2011
20110116560OFDM SPACE-TIME OR SPACE-FREQUENCY BLOCK CODE TRANSMITTER - A transmitter for transmitting OFDM signals includes a space-time or space-frequency encoder to generate coded OFDM symbols by arranging a sequence of OFDM symbols or variants thereof in a predetermined space-time or space-frequency block matrix or a portion thereof. The transmitter also includes a frequency selector to select a particular OFDM carrier frequency out of a number of available OFDM carrier frequencies, and a signal generator to generate OFDM signals by applying the selected OFDM carrier frequency to the coded OFDM symbols.05-19-2011
20110044392Systems And Methods For High-Throughput Wideband Wireless Local Area Network Communications - A frame format provides for wideband wireless local area network communications and informs narrower-band communication units when the channels are occupied by wider-band communication units. In some embodiments, the frame format includes a channelization field identifying channels that are used for communicating subsequent wideband fields of a packet, and a wideband-header field communicated on the identified channels. The wideband-header field may identify sub-fields that may be present in the wideband-header field, and may identify the presence of a wideband-data field. A long-compatibility field may be present that provides protection at the MAC level. The long-compatibility field may transport MAC frames that may include medium-reservation information compatible with narrower-band communication units.02-24-2011
20110044390SYSTEM AND METHOD FOR GENERATING AND DETECTING THE IDENTIFIER SEQUENCE OF THE BANDWIDTH-LIMITED TRANSMITTER - A system and method for generating and detecting identifier sequence of a bandwidth-limited transmitter are disclosed, comprising an identifier sequence generating portion and a detection portion. The identifier sequence generating portion comprises: generating a frequency-domain random sequence; generating a frequency-domain orthogonal sequence; performing frequency-domain truncation; performing frequency-time transformation; and performing cycle extension. The identifier sequence receiving portion comprises: truncating the time-domain for the received signal; performing time-frequency domain transformation to obtain a frequency-domain signal; generating frequency-domain random sequence; generating a frequency-domain orthogonal sequence; correlating the frequency-domain orthogonal sequence with the frequency-domain signal de-scrambled by the frequency-domain random sequence; and detecting an output from a frequency-domain correlator by a threshold detecting device and determining the transmitter identifier sequence. The random sequence bandwidth generated by the system and the method of the present invention can be configured flexibly according to transmission bandwidth requirement, and the sequence may be arbitrarily allocated at the power of each frequency point inside the bandwidth. The present invention may be widely applied to multimedia broadcasting, terrestrial radio broadcasting, cable broadcasting and the like.02-24-2011
20120033754OFDM CHANNEL ESTIMATION METHOD AND APPARATUS - Smaller patterns of regularly-spaced pilot symbols are discerned from a larger pattern of irregularly-spaced pilot symbols transmitted in the time-frequency domain. Accordingly, the irregularly-spaced pilot symbols can be partitioned into at least two different groups of regularly-spaced pilot symbols in the time-frequency domain. Each group of regularly-spaced pilot symbols is individually processed with lower complexity and the results combined to generate an accurate time-frequency channel response estimate. According to an embodiment, a set of irregularly-spaced pilot symbols is transmitted over a time-frequency window. Channel response is estimated based on the pilot symbols by grouping the pilot symbols into subsets of regularly-spaced pilot symbols. An intermediate quantity is generated for each subset of regularly-spaced pilot symbols as a function of the pilot symbols included in the subset. The channel response is estimated over the time-frequency window as a function of the intermediate quantities.02-09-2012
20110116565Method and Apparatus for Preamble Training with Shortened Long Training Field in a Multiple Antenna Communication System - Methods and apparatus are provided for communicating data in a multiple antenna communication system having N transmit antennas. According to one aspect of the invention, a header format includes a legacy preamble having at least one legacy long training field and an extended portion having at least N additional long training fields on each of the N transmit antennas, wherein one or more of the at least N additional long training fields are comprised of only one Orthogonal Frequency Division Multiplexing (OFDM) symbol. The extended portion optionally comprises one or more repeated OFDM symbols for frequency offset estimation. In one implementation, the extended portion comprises a first high throughput long training field comprised of two repeated OFDM symbols and N−1 high throughput long training fields comprised of only one OFDM symbol. In another variation, the extended portion comprises N high throughput long training fields comprised of only one OFDM symbol.05-19-2011
20110080966BASE STATION APPARATUS, SEQUENCE ASSIGNING METHOD AND REFERENCE SIGNAL GENERATING METHOD - Provided is a sequence allocation method capable of reducing inter-cell interference of a reference signal when a ZC sequence is used as the reference signal in a mobile communication system. In the sequence allocation method divides R×M sequences specified by a ZC sequence number r (r=1 to R) and a cyclic shift sequence number m (m=1 to M) into a plurality of sequence groups X (X=1 to R) in accordance with the transmission band width of the reference signal, so that the ZC sequence is allocated to each cell in each sequence group unit. When it is assumed that R=9 and M=6, the number of sequence is 54. Each of the sequence groups is formed by two sequences. Accordingly, the number of sequence groups is 27. The 27 types of sequence groups are allocated to each cell.04-07-2011
20110080967Methods and Arrangements in a Wireless Communication System for Producing Signal Structure with Cyclic Prefix - The present invention relates to methods and arrangements in a wireless communication system supporting cyclic-prefix insertion, using a symbol sequence comprising a number of samples for transmission over a radio channel that enables the handling of very large signal delay spreads. The symbol sequence is built up by a first symbol with CP and a second symbol with CP. The second symbol is a copy of the first symbol with the samples shifted in a way that makes the two adjacent symbols with CP match in regards to the sample order. The symbol sequence may also comprise a third symbol with CP or more, where the third symbol is a copy of the second symbol and with the samples shifted in analogy with the symbol shift described above. The resulting symbol sequence will thus appear as an extended continuous symbol thanks to the precise cyclic shift that matches adjacent symbols. This allows the receiver to place its FFT window anywhere during the extended symbol, e.g. at the end of the symbol sequence thus making it possible to handle a delay spread longer than the CP duration. It also allows to place e.g. two FFT windows and to combine the extracted signal into one SNR improved signal, while still handling a longer delay spread.04-07-2011
20090323837METHOD FOR ESTIMATING FREQUENCY OFFSET IN SYSTEM UTILIZING A PLURALITY OF SUB-CARRIERS - An integer frequency offset estimation scheme in an orthogonal frequency division multiplexing (OFDM)-based system is disclosed. A receiving apparatus for receiving a signal according to an OFDM includes an OFDM symbol acquisition module for acquiring at least two consecutive OFDM symbols, a symbol operation module for operating upon pilot symbols and/or data symbols belonging to frequency bands determined according to a plurality of candidates for integer frequency offsets among a plurality of pilot symbols and a plurality of data symbols included in the acquired OFDM symbols, and an integer frequency offset estimation module for selecting a final integer frequency offset among a plurality of candidates for integer frequency offsets according to magnitudes of operation values obtained by the symbol operation module, wherein the frequency bands determined according to the candidate for integer frequency offsets are obtained by frequency-shifting preset frequency bands at which all pilot symbols are transmitted according to the candidate for integer frequency offsets.12-31-2009
20100142632FREQUENCY SYNCHRONIZATION APPARATUS AND METHOD IN OFDM SYSTEM - A frequency synchronization apparatus includes: a correlating unit that obtains a first correlation value by correlating a known reference guard interval of an OFDM symbol and a reference copy interval corresponding to the reference guard interval, and obtains a second correlation value by correlating the estimate guard interval and an estimate copy interval corresponding to the estimate guard interval; a determining unit that compares the first and second correlation values to determine a first case where the first correlation value is larger by a pre-set magnification than the second correlation value, a second case where the second correlation value is larger by a pre-set magnification than the first correlation value, and a third case which is not the first case nor the second case; and a frequency offset estimating unit that estimates a frequency offset by using a correlation value corresponding to any one of the first to third.06-10-2010
20110085611METHODS AND APPARATUS FOR USE IN A WIRELESS COMMUNICATIONS SYSTEM THAT USES A MULTI-MODE BASE STATION - A multi-mode base station includes a transmit standby mode and an active mode. Transmit standby mode of base station operation is a low power/low interference level of operation as compared to active mode. In transmit standby mode at least some of the synchronization signaling such as pilot tone signaling is reduced in power level and/or rate with respect to the active mode. In transmit standby mode, the base station has no active state registered wireless terminals being serviced but may have some sleep state registered wireless terminals being serviced. Mode transitions from active to transmit standby may be in response to: a detected period of inactivity, scheduling information, base station mode change signals, and/or detected wireless terminal state transition. Mode transitions from transmit standby to active may be in response to: scheduling information, access signals, wake-up signals, hand-off signals, wireless terminal state change signals, and/or base station mode change signals.04-14-2011
20110085612COGNITIVE RADIO SYSTEM, COGNITIVE RADIO APPARATUS, AND RADIO SIGNAL DETECTION METHOD - A radio system includes: a memory which stores a system parameter and a pseudo parameter, the system parameter being used for generation of a feature value specific to a search target radio system, the pseudo parameter being similar to the system parameter; a feature value generator which generates one or a plurality of the feature values based on a signal in a received frequency band by using the system parameter; a non-feature value generator which generates one or a plurality of non-feature values based on the signal in the received frequency band by using the pseudo parameter; and a determination section which determines whether or not a signal of the search target radio system exists by using the one or the plurality of the feature values and the one or the plurality of non-feature values.04-14-2011
20110085610Configurable Spatial Channel Information Feedback in Wireless Communication System - A method for configurable spatial channel information feedback in wireless communication systems is disclosed including receiving, at the wireless communication device, transmission from a plurality of antennas, receiving an indication of a feedback mode for feeding back spatial channel information that is based on correlations among at least some of the plurality of antennas, decomposing a correlation matrix representative of the correlations among at least some of the plurality of antennas into at least two Kronecker components, and feeding back parameters representative of the Kronecker components according to the feedback mode indicated.04-14-2011
20090202012SYSTEM AND METHOD FOR DATA SCRAMBLING TO REDUCE THE CREST FACTOR IN AN OFDM WAVEFORM - A method is provided for minimizing the peak power level in a combination of orthogonal frequency division multiplexed (OFDM) tones. The method is particularly effective when the information to be communicated is digital data consisting of long patterns of “1”s or “0”s. The digital data of the message is combined with a scrambling vector before the data is modulated. The randomization of data patterns, in turn, leads to a more random combination of OFDM tone amplitude being transmitted. The message is recovered at the receiver by removing the scrambling vector. A table of scrambling vectors is maintained at the transmitters and receivers. The table pointer to select the scrambling vector is selected in response to the position of the message in the communication structure. An OFDM communication system using the above-described method is also provided.08-13-2009
20090323841CODEBOOK DESIGN METHOD FOR MULTIPLE INPUT MULTIPLE OUTPUT SYSTEM AND METHOD FOR USING THE CODEBOOK - A multiple input multiple output (MIMO) communication method using a codebook is provided. The MIMO communication method may use one or more codebooks and the codebooks may change according to a transmission rank, a channel state of a user terminal, and/or a number of feedback bits. The one or more codebooks may be adaptively updated according to a time correlation coefficient of a channel.12-31-2009
20090323835METHOD AND APPARATUS FOR DETECTION OF ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING (OFDM) SIGNALS BY COGNITIVE RADIOS - Efficient frequency spectrum sharing between at least one incumbent communication system(s) (12-31-2009
20130156120APPARATUS AND METHOD FOR REFERENCE SYMBOL TRANSMISSION IN AN OFDM SYSTEM - A base station is capable of communicating with a plurality of subscriber stations using a beamforming scheme that varies beams over different time instances. The base station includes a plurality of antenna arrays configured to transmit N spatial beams and carry a reference symbols corresponding to specific spatial beams. The base station also includes N06-20-2013
20120243630METHOD FOR IMPROVING CHANNEL ESTIMATION PERFORMANCE IN DYNAMIC SPECTRUM ACCESS MULTICARRIER SYSTEMS - A method for improving channel estimation performance in dynamic spectrum access multicarrier systems is disclosed. The method includes determining a pattern of pilot symbols to be included in transmitted signals sent from a sender to a receiver through an interference-affected propagation environment by deriving a covariance matrix of interference and white Gaussian noise (R09-27-2012
20120243629Digital Communications Receiver - A method for a digital Communications receiver. The method comprises receiving a signal transmitted from a transmitter. The transmitted signal includes a first modulated carrier representing one or more data bits and a second modulated modulated carrier optionally representing one or more padding bits only. The padding bits are inserted at the transmitter and have predefined values known to both the transmitter and receiver. The method further comprises determining whether the one or more padding bits were inserted at the transmitter; if so, analysing the second modulated carrier in the received signal, using knowledge of the predetermined values of the one or more padding bits; and, using information determined from the analysis, estimating the values of the one or more data bits from the first modulated carrier.09-27-2012
20120243627ADAPTIVE POWER CONTROL DATA TRANSMISSION SYSTEM AND METHODS - Systems and methods of performing power control in combination with AMC are provided. AMC is performed on the basis of an AMC parameter such as CINR. Once the AMC is set to a highest available AMC for transmission to a given receiver, if the CINR indicates that the highest AMC could be transmitted with less transmit power, the power is reduced. For receivers that are not receiving the highest available AMC for that receiver, they may have their transmit power increased.09-27-2012
20120243626SYSTEM ACCESS AND SYNCHRONIZATION METHODS FOR MIMO OFDM COMMUNICATIONS SYSTEMS AND PHYSICAL LAYER PACKET AND PREAMBLE DESIGN - A method and apparatus are provided for performing acquisition, synchronization and cell selection within an MIMO-OFDM communication system. A coarse synchronization is performed to determine a searching window. A fine synchronization is then performed by measuring correlations between subsets of signal samples, whose first signal sample lies within the searching window, and known values. The correlations are performed in the frequency domain of the received signal. In a multiple-output OFDM system, each antenna of the OFDM transmitter has a unique known value. The known value is transmitted as pairs of consecutive pilot symbols, each pair of pilot symbols being transmitted at the same subset of sub-carrier frequencies within the OFDM frame.09-27-2012
20120243625TREATMENT PROCESS OF A MULTICARRIER SIGNAL WITH FILTER BANKS FOR SYNCHRONISATION BY PREAMBLE - The invention relates to a treatment process of a signal received from a multi-carrier transmitter (09-27-2012
20110129024ACCOUNTING FOR INTER-CARRIER INTERFERENCE IN DETERMINING A RESPONSE OF AN OFDM COMMUNICATION CHANNEL - In an embodiment, a channel estimator includes first and second stages. The first stage is operable to generate a respective one-dimensional array of first channel-estimation coefficients for each communication path of a communication channel, and the second stage is operable to generate a multi-dimensional array of second channel-estimation coefficients in response to the first channel-estimation coefficients. For example, such a channel estimator may estimate the response of a channel over which propagates an orthogonal-frequency-division-multiplexed (OFDM) signal that suffers from inter-carrier interference (ICI) due to Doppler spread. Such a channel estimator may estimate the channel response more efficiently, and with a simpler algorithm, than conventional channel estimators. Furthermore, such a channel estimator may be able to dynamically account for changes in the number of communication paths that compose the channel, for changes in the delays of these paths, or the portions of the transmitted symbol energy carried by these paths.06-02-2011
20110080964ADAPTIVE CODEBOOK FOR BEAMFORMING IN LIMITED FEEDBACK MIMO SYSTEMS - A method for beamforming is described. The method includes generating a pseudo-random unitary matrix. A first codebook is rotated with the pseudo-random unitary matrix. The method includes generating a second codebook based upon the rotated codebook and a correlation matrix. A codeword is selected from the second codebook using a channel matrix. The correlation matrix is updated based upon the selected codeword. The method includes transmitting an index of the selected codeword in the codebook. The method includes receiving the codeword index. A codebook is consulted using the codeword index to locate a codeword. Beamforming is performed based upon the located codeword. An apparatus is also described.04-07-2011
20110080965METHOD AND SYSTEM FOR FEEDBACK OF CHANNEL INFORMATION - A base station is provided. The base station includes a transmit path circuitry configured to transmit downlink control information in a downlink control information (DCI) format to a subscriber station, and a receive path circuitry configured to receive multiple-input multiple-output (MIMO) feedback from the subscriber station in response to the downlink control information. The MIMO feedback from the subscriber station is determined by two or more codepoints in the DCI format. One of the two or more codepoints indicates a rank-limited single user multiple-input multiple-output (SU-MIMO) feedback corresponding to a rank up to a maximum rank.04-07-2011
20110142146MULTI CARRIER SYSTEM AND METHOD FOR RECEIVING MULTI CARRIER - Provided are a multi-carrier system and a method for receiving a multi-carrier. The multi-carrier system may include a transformation unit to transform an input signal from a time domain to a frequency domain, a signal accumulation unit to accumulate a magnitude of the input signal in a predetermined accumulation interval unit, and to count a number of overflows based on the accumulated magnitude of the input signal, a signal level determination unit to generate bit shift information for adjusting a level of the transformed input signal based on the counted number of overflows, and a signal level adjustment unit to adjust the level of the transformed input signal based on the generated bit shift information.06-16-2011
20100220797COMMUNICATION APPARATUS - When in-phase data with an amplitude of 1 is located in each subcarrier, the envelope waveform of a time domain signal contains guard band 09-02-2010
20110211646CONTROL STATION DEVICE, TRANSMITTING STATION DEVICE, COMMUNICATION METHOD, AND COMMUNICATION SYSTEM - In a communication system configured by a transmitting station device and a receiving station device for transmitting and receiving a multicarrier signal using a spectrum including a plurality of subcarriers, a superposed rate which is a rate in which a superposed band in which interference is occurring is used in a used frequency band used for transmitting the multicarrier signal is set so as to increase frequency utilization efficiency of the used frequency band, and the multicarrier signal is transmitted using a spectrum allocated in accordance with the set superposed rate.09-01-2011
20120230442Multi-Transceiver System with MIMO and Beam-Forming Capability - A system and method for communicating with a second communication system utilizing a plurality of antennas. Various aspects of the present invention may comprise determining whether communicating with the second communication system utilizing a plurality of antennas in a first configuration, which comprises a beam-forming configuration, is preferable to utilizing a plurality of antennas in a second configuration, which comprises a MIMO or MISO configuration. If it is determined that the first configuration is preferable to the second configuration, the communication system may be configured to communicate with the second communication system by utilizing at least a portion of the plurality of antennas in the first configuration. If it is determined that the second configuration is preferable to the first configuration, then the communication system may be configured to communicate with the second communication system by utilizing at least a portion of the plurality of antennas in the second configuration.09-13-2012
20110090975OFDM inter-carrier interference cancellation method - The OFDM channel estimation and Inter-Carrier Interference (ICI) cancellation method uses a few pilots within Orthogonal Frequency Division Multiplexing (OFDM) systems in general, and mobile OFDM systems in particular. The frequency domain channel is estimated using an eigenvalue based model reduction technique with high accuracy. A Minimum Mean Square Error (MMSE) based Finite Impulse Response (FIR) equalizer is then used to obtain an ICI free estimate of the transmitted signal.04-21-2011
20090323838WIRELESS COMMUNICATION SYSTEMS AND METHODS USING REFERENCE SIGNALS - A method used in a wireless communication apparatus based on reference signals is provided. The method may include obtaining a plurality of pilot rules and obtaining radio channel information of a radio channel between the wireless communication apparatus and another wireless communication apparatus. The wireless communication apparatus may be in an area including at least one cell and using one or more data streams. Further, the method may include selecting applicable pilot rules from the plurality of pilot rules based on the radio channel information, creating at least one pilot structure to be used in the radio channel; and using the created at least one pilot structure to transmit data over the radio channel.12-31-2009
20090323836Radio Base Station and Method of Controlling Radio Base Station - A radio base station 12-31-2009
20090323842MAC MULTIPLEXING FOR UPLINK MIMO - A method and apparatus for logical channel prioritization in a wireless transmit receive unit (WTRU), including the WTRU receiving multiple streams of a multiple input/multiple output (MIMO) signal, a physical layer (PHY) of the WTRU providing an indicator for each of the multiple streams to a medium access control (MAC) layer of the WTRU, and the MAC layer performing logical channel multiplexing based on the indicator for each of the multiple streams.12-31-2009
20100008432METHODS AND SYSTEMS FOR REDUCING PAPR OF AN OFDM SIGNAL - Certain embodiments of the present disclosure provide a method and an apparatus for peak-to-average power ratio (PAPR) reduction of a transmission signal in a single carrier frequency division multiple access (SC-FDMA) system. The method may utilize a permutation of a time domain signal, and/or a permutation of a frequency domain signal or a permutation of a signal transformed by a unitary matrix. The apparatus may include an M-point DFT or some other M×M unitary matrix, N-point IDFT, interpolation and frequency conversion units, and a pair of possibly different permutation matrices of size M×M, where M can be less or equal than N.01-14-2010
20100054351METHOD FOR DEMODULATING SIGNAL AND TERMINAL AND BASE STATION FOR EXECUTING THE METHOD - A method of modulating and/or demodulating a signal in a communication system and a terminal for demodulating a signal received from a base station are provided. A terminal includes a singular value extractor to extract at least one singular value of a channel matrix associated with a channel that is formed between a base station and the terminal, a modulation order determination unit to determine a modulation order based on the at least one singular value, and a received signal demodulator to demodulate a received signal according to the determined modulation order.03-04-2010
20090034640MULTI-ELEMENT ANTENNA BEAMFORMING IN A WIRELESS ACCESS NETWORK - A communication node of a wireless local area network utilizes a multi-element array antenna to estimate an angle-of-arrival for one or more signal sources which may communicate on symbol-modulated orthogonal subcarriers. Channel coefficients may be estimated from the angle-of-arrival for the one or more signal sources to increase channel capacity, improve channel equalization and reduce the effects of multipath fading. Beamforming based on the angle-of-arrival may also be performed for directional reception and/or transmission of communications with the one or more signal sources.02-05-2009
20090034639Apparatus and method for supporting a plurality of MIMO modes in a wireless communication system - An apparatus and method for supporting a plurality of MIMO modes in a wireless communication system are provided, in which a receiver selects one of the plurality of MIMO modes according to at least one of a received signal strength, a speed of the receiver, a correlation between a transmitter and the receiver, a presence or absence of channel quality information, a precoding index, and an antenna information, a rank, and a number of users, generates feedback information in a transmission format corresponding to the selected MIMO mode, and transmits the feedback information to the transmitter using a feedback resources allocated according to the selected MIMO mode.02-05-2009
20090213951Method of suppressing carrier leak in OFDM transmission and radio transmitter using same method - In an OFDM type radio transmitter, an orthogonal modulator performs an orthogonal modulation of an I-component and a Q-component, an orthogonal component output circuit produces the I-component and the Q-component in accordance with set values, and a correction circuit sets the I-component and the Q-component to zero. The correction circuit further corrects offset values of the I-component and the Q-component by way of the orthogonal component output circuit to minimize an output power of the orthogonal modulator. The number of times of changing the set values of the orthogonal component output circuit is limited to predetermined values in correcting the offset values.08-27-2009
20090213950PILOT SIGNAL TRANSMISSION FOR AN ORTHOGONAL FREQUENCY DIVISION WIRELESS COMMUNICATION SYSTEM - Transmission patterns for pilot symbols transmitted from a mobile station or base station are provided. The pattern allows for improved receipt of the pilot symbols transmitted. In addition, schemes for improving the ability to multiplex pilot symbols without interference and/or biasing from different mobile stations over the same frequencies and in the same time slots.08-27-2009
20100054350MODULATION METHOD AND MODULATOR USING PULSE EDGE SHIFT - A variable delay circuit delays a carrier signal having a predetermined frequency, and outputs a modulated signal. A delay setting unit sets a delay period for the variable delay circuit according to a data signal to be modulated. The delay setting unit assigns each symbol in the data signal to any one of positive edges and negative edges in the carrier signal, and sets a delay period for the variable delay circuit at the timing at which a positive edge in the carrier signal passes through the variable delay circuit, according to the symbol value in the data signal assigned to the positive edge. Furthermore, the delay setting unit sets a delay period for the variable delay circuit at the timing at which a negative edge in the carrier signal passes through the variable delay circuit, according to the symbol value in the data signal assigned to the negative edge.03-04-2010
20100054353LAYER MAPPING METHOD AND DATA TRANSMISSION METHOD FOR MIMO SYSTEM - A method for indicating a combination between a codeword and a layer in a MIMO communication, system, a layer mapping method, and a data transmission method using the same are disclosed. A minimum number of codeword-layer mapping combinations from among all available combinations based on the numbers of all codewords and all layers are pre-defined in consideration of a ratio of a codeword to a layer, a reception performance of a receiver, and reduction of combinations, so that a data transmission method using the predefined combinations is implemented. If a specific one codeword is mapped to at least two layers, a diversity gain can be acquired.03-04-2010
20100054352Correlation-based detection in a cognitive radio system - Samples are extracted from a received signal. For each of a plurality of candidate cyclic frequencies, cyclic covariance of the received signal is determined using a Fourier transform FT having a length that is less than the number of extracted samples. The frequency channel within which the signal was received is chosen for opportunistic/cognitive radio transmissions when none of the plurality of candidate cyclic frequencies exhibits a peak that exceeds a threshold, or results are transmitted for collaborative sensing. The extracted samples may be filtered and decimated prior to executing the FT, and the length of the FT depends on the number of samples that remain. Decimating is at a rate that depends on a bandwidth of the filtering. The bandwidth of filtering is determined by the lowest cyclic frequency where the signal to be detected exhibits cyclostationarity. Each of the candidate cyclic frequencies are near zero and determining the covariance employs a windowing function centered on zero cyclic frequency.03-04-2010
20100061468METHOD FOR ESTIMATING CHANNEL STATISTICS IN AN OFDM RECEIVER - A method of estimating channel statistics includes storing a plurality of pilot symbols from a plurality of received signals, establishing a reference for correlation; computing instantaneous correlations for each time lag of each of the plurality of pilot symbols relative to the reference, providing a table comprising non-isotropic scattering correlation values, computing current refined correlations using previous refined correlations and instantaneous correlations, comparing current refined correlations to the table of correlation values, and choosing correlation values from the table based on the step of comparing current refined correlations to the table.03-11-2010
20100061470SLICEABLE ROUTER WITH PACKET OVER OPTICAL OFDM TRANSMISSION - A sliceable router includes a forwarding engine; a routing engine coupled to the forwarding engine; multiple virtual packet interfaces coupled to the forwarding engine, wherein the interfaces shares an optical orthogonal frequency-division multiple accesses (OFDMA)-based programmable transceiver for interface virtualization; and one or more physical packet interfaces coupled to the forwarding engine.03-11-2010
20100061469Graph-Based Method for Dynamic Fractional Frequency Reuse - A method allocates frequency subchannels in an orthogonal frequency-division multiple access (OFDMA) network including a set of base stations and a set of mobile stations for each base station. A graph of nodes and edges is constructed, in which the nodes represent the mobile stations in the network, and the edges connecting the nodes represent subchannel allocation constraints to be satisfied for the mobile stations represented by the nodes. The nodes are colored with colors selected from a set of colors such that subchannel allocation constraints of a pair of nodes connected by one of the edges are satisfied. The subchannels are allocated to the mobile stations according to the colors of the corresponding the nodes.03-11-2010
20100061474FFT SPREADING AMONG SELECTED OFDM SUB-CARRIERS - An improved communications system for frequency-selective fading channels spreads the data-bearing modulation symbols across many OFDM sub-carriers using a discrete Fourier transform (FFT) at the transmitter, and despreads them using an inverse discrete Fourier transform (IFFT) at the receiver. An IFFT is included at the transmitter to form the OFDM symbols in the usual way, and a corresponding FFT is used at the receiver for the frequency-domain processing of the received signal. The difference is, the size of the FFT used for spreading at the transmitter is smaller than that of an IFFT used just after the FFT to create the OFDM symbols for transmission. This results in improved bit-error-rate, similar to single carrier block transmission (SCBT), while retaining the frequency domain benefits of conventional OFDM, e.g., low out of band emissions and the ability to control the power spectral density using active interference cancellation and other frequency-domain techniques. The improved frequency diversity is especially useful in the higher data rate modes of WLAN or WiMedia Physical Layer Standards, and in other cases where low redundancy forward error correction is employed.03-11-2010
20110176624OFDM Networks with Pseudo-Random Phase Precoding - In an orthogonal frequency division multiplexing (OFDM) network, a set of pseudo random sequences (PRS) are stored at a transmitter and a receiver. Each OFDM symbol is mapped to subcarriers for a set of transmit antennas to produce a mapped symbol. The mapped symbol is encoded using a pseudo-random phase precoder (PRPP) and the PRS to produce a precoded symbol. An inverse fast Fourier transform (IFFT) is applied to the precoded symbol, and the encoded symbol is transmitted to the receiver using the set of transmit antennas.07-21-2011
20110176627Multi-user Transmission Method, Multiple Input Multiple Output Transmission System Using the Same, Scheduling Method and Access Point Using the Same - The present invention discloses a multi-user (MU) transmission method for a multiple input multiple output (MIMO) transmission system comprising a first station and a plurality of second stations. The MU transmission method includes the step of the first station performing simultaneous transmission to a first group of stations of the plurality of second stations in a first transmission interval.07-21-2011
20110176623MATRIX POWER AMPLIFIERS FOR HIGH SPEED WIRELESS APPLICATIONS - A wireless communication device includes an RF transceiver configured to up convert a base band signal to a transmitting RF signal, a configurable matrix power amplifier circuit configured to amplify the transmitting RF signal to produce an amplified RF signal, and an antenna configured to transmit a wireless signal in response to the amplified RF signal.07-21-2011
20100239034METHOD FOR TRANSMITTING LOCATION BASED SERVICE -REFERENCE SIGNAL IN WIRELESS COMMUNICATION SYSTEM AND APPARATUS THEREFOR - A method for allowing a mobile station to detect a Location Based Service-Reference Signal (LBS-RS) in a wireless communication system is disclosed. The method includes receiving LBS-RS setup information of at least one target cell participating in location measurement from a serving cell, acquiring a frequency offset value of the target cell using the LBS-RS setup information, and detecting the LBS-RS transmitted from the target cell using the LBS-RS setup information and the frequency offset value. In addition, the method further includes measuring a reception delay time of the detected LBS-RS, and transmitting a reception delay time to the serving cell.09-23-2010
20100239033Joint carrier synchronization and channel equalization method for OFDM systems - A joint carrier synchronization and channel equalization method for OFDM systems, that is suitable for use in a receiver of said orthogonal frequency division multiplexer (OFDM) systems, comprising the following steps: firstly, receiving a reception signal sample of an OFDM symbol, and obtaining simultaneously a phase error and a gain error on each sub-channel in a frequency domain, through outputting a sub-channel signal on each said sub-channel in said frequency domain; next, obtaining an execution carrier frequency offset factor, an execution phase compensation factor, and an execution gain compensation factor based on said phase error and said gain error; and finally, eliminating a phase offset of said reception signal sample of a next symbol in a time domain based on said factors, and compensating a magnitude distortion and a phase distortion on each said sub-channel in said frequency domain for said reception signal of said next symbol.09-23-2010
20100067591EFFICIENTLY IDENTIFYING SYSTEM WAVEFORM IN UPLINK TRANSMISSION - Systems and methodologies are described that facilitate indicating a type of waveform utilized for uplink transmission in a wireless communication environment. An access terminal can select a type of waveform from a set of possible waveform types. Moreover, a reference signal can be generated based upon the selected type of waveform. For instance, a sequence employed to yield the reference signal can be generated and/or chosen as a function of the selected type of waveform. According to another illustration, a tone location and/or a symbol location of the reference signal can be based upon the selected type of waveform. Further, the reference signal can be sent as part of the uplink transmission to the base station from the access terminal. The base station can detect the selected type of waveform utilized by the access terminal for the uplink transmission based upon parameter(s) recognized from the reference signal.03-18-2010
20090213949METHOD FOR TRANSMITTING A MULTICARRIER SIGNAL DESIGNED FOR LIMITING INTERFERENCE, SIGNAL, EMITTING DEVICE, RECEIVING METHOD AND DEVICE AND CORRESPONDING COMPUTER PROGRAMS - A method is provided for transmitting a multi-carrier signal formed of a temporal succession of symbols comprised of a set of data elements. The method includes: calculating an interference affecting a set of at least two data elements which are to be protected and are spaced out two by two from no more than one time carrier and no more than one frequency carrier, the interference taking into account the value of the data elements to be protected and values of the data elements of a contour ring consisting of carriers immediately adjacent to data elements to be protected, and; determining at least one value to be attributed to at least one data element of the contour ring for reducing, upon reception, the calculated interference.08-27-2009
20090213947BLOCK BOUNDARY DETECTION FOR A WIRELESS COMMUNICATION SYSTEM - Method and apparatus for block boundary detection is described. A signal is received. The signal is quantized to provide a quantized signal to at least one correlator, the quantized signal being a sequence of samples. The sequence of samples and a reference template including totaling partial results from the at least one correlator are cross-correlated to provide a result, the result being a symbol timing synchronization responsive to the cross-correlation also known as block boundary detection. The cross-correlation is provided in part by combining by exclusive-ORing a regression vector obtained from the sequence of samples and a coefficient term vector obtained from the reference template.08-27-2009
20090213946PARTIAL RECONFIGURATION FOR A MIMO-OFDM COMMUNICATION SYSTEM - Partial reconfiguration of programmable logic for supporting a Multiple-input, Multiple-Output Orthogonal Frequency Division Multiplexing (“MIMO-OFDM”) communication system is described. A PHY block in a programmable device may be instantiated generally in part in programmable logic of the programmable device. Control information is obtained for a network node when deployed and/or from a wireless transmission of a packet or frame, which is demodulated in the PHY block. Responsive to the control information demodulated, bitstream information is obtained to configure the portion of the PHY block using the programmable logic of the programmable device.08-27-2009
20110103498METHOD AND APPARATUS FOR CONTROL AND DATA MULTIPLEXING IN A MIMO COMMUNICATION SYSTEM - Systems and methodologies are described herein that facilitate control and data multiplexing for uplink (UL) multiple-input-multiple-output (MIMO) communication within a wireless communication system. As described herein, a device conducting uplink MIMO communication in a wireless communication system can multiplex control signaling and data across one or more of a plurality of layers (e.g., corresponding to spatial layers, codewords, etc.) associated with an uplink transmission. Techniques are described herein for selecting layers of a transmission on which to schedule control signaling and selecting offsets to apply to the control signaling scheduled on selected layers. Further, techniques are described herein for leveraging a multi-layer transmission to increase the efficiency of acknowledgement communication. In addition, techniques are described for selecting a modulation and coding scheme (MCS) to apply to control signaling that is combined with data in an uplink multi-layer transmission.05-05-2011
20110103495COMMUNICATIONS LINK REDUNDANCY INCLUDING MULTIPLE INPUT, MULTIPLE OUTPUT ARCHITECTURE - A communications network includes two base stations and a mobile station. The mobile station has at least one transceiver, and at least one splitter/combiner module, where each module is coupled to the at least one transceiver. At least two antennas are included, with each antenna coupled to the at least one splitter/combiner module. A controller selects at least one of the transceivers for communication with the two antennas, where one antenna is configured to communicate with one base station and the other antenna is configured to communicate with the other base station. Each transceiver includes a transmitter, a receiver and a switch. The switch selectively connects the transmitter or the receiver to a respective splitter/combiner module.05-05-2011
20090028260METHOD AND APPARATUS FOR PROVIDINGCHANNEL QUALITY FEEDBACK IN AN ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING COMMUNICATION SYSTEM - In an Orthogonal Frequency Division Multiplexing communication system, wherein frequency bandwidth may be represented by multiple Resource Block Group (RBG) levels, wherein each RBG level comprises a division of the frequency bandwidth into a number of RBGs different from the number of RBGs of the other RBG levels, a user equipment measures a channel quality associated with one or more RBGs of one or more RBG levels of the multiple RBG levels, selects an RBG of from among the measured RBGs based on the measured channel qualities, and reports channel quality information associated with the selected RBG to a radio access network, wherein reporting comprises providing an index to the selected RBG and providing channel quality information for the indexed RBG.01-29-2009
20090028258Methods and systems for transmission of orthogonal frequency division multiplexed symbols - In some embodiments of the present invention there is provided a frame structure for transmitting an integer number of OFDM symbols in which some of the OFDM symbols are to be transmitted in a unicast format and some of the OFDM symbols are to be transmitted in a broadcast format. The frame structure includes partitioning of a frame into at least two portions to accommodate both unicast and broadcast modes in the frame. The frame structure is used for transmitting multiple frames in a serial manner from at least one transmitter. The unicast mode supports transmission of OFDM symbols from a single transmitter to a single receiver. The broadcast mode supports transmission of OFDM symbols from multiple transmitters to all receivers within range of the multiple transmitters. The multicast mode supports transmission of OFDM symbols from multiple transmitters to multiple receivers within range of the multiple transmitters.01-29-2009
20090028259MIMO TRANSMITTING APPARATUS, AND DATA RETRANSMITTING METHOD IN MIMO SYSTEM - MIMO transmitting apparatus wherein data to be retransmitted and data to be transmitted anew are rearranged, thereby using HARQ technique to improve the reliability of the system transmission, while increasing the system throughput and improving the efficiency of the whole data transmission. In this apparatus, a retransmittal data selecting means (01-29-2009
20090028256METHOD AND APPARATUS FOR SENSING SIGNALING PARAMETERS IN A WIRELESS COMMUNICATIONS NETWORK - A new channel is added to FLO networks that carries embedded signaling parameter information. The design is such that regardless of the actual values of the signaling parameters conveyed, a receiver will be able to demodulate this new channel. Moreover, the addition of the new channel does not render a FLO network that has been so configured to not be backwards-compatible with existing devices.01-29-2009
20090028254TIME DOMAIN SYMBOL TIMING SYNCHRONIZATION CIRCUIT AND METHOD THEREOF FOR COMMUNICATION SYSTEMS - A time domain symbol timing synchronization circuit is disclosed, which comprises: an autocorrelation function calculator for calculating cyclic prefix autocorrelation functions and an offset time estimator for searching peak positions of cyclic prefix autocorrelation functions to indicate symbol boundary of received communication symbols. The offset time estimator compares a current peak position and a previous peak position. If (a) the difference of the positions is larger than a threshold and (b) the current peak is smaller than a reference average peak, the current peak is determined as false; the offset time estimator weeds out and replaces the current peak position by the previous peak position; and the current peak is not introduced in the reference average peak calculation.01-29-2009
20090213945Reduced Complexity Parametric Covariance Estimation for Precoded MIMO Transmissions - A model-based technique for estimating impairment covariance associated with a MIMO signal is disclosed. In an exemplary method, an impairment model is constructed for a received composite information signal comprising at least a first data stream transmitted from first and second antennas according to a first antenna weighting vector. The impairment model includes first and second model terms corresponding to the first and second antennas, respectively, but in several embodiments does not include a cross-antenna interference term. In another embodiment, an impairment model for a received MIMO signal is constructed by computing an impairment model term for each antenna and an additional term to account for preceding interference in a single-stream MIMO transmission scenario. The impairment terms are grouped so that only two associated scaling terms are unknown; values for the scaling terms are estimated by fitting the model to measured impairment covariance values.08-27-2009
20110075747Wireless transmission system, wireless communication device and wireless transmission method - Disclosed herein is a wireless transmission system. Transmission antennas are provided on a first communication apparatus while reception antennas individually corresponding to the transmission antennas are provided on a corresponding second communication apparatus. Each reception antenna receives a desired wave from a corresponding transmission antenna as a direct wave and receives an unnecessary wave from a different transmission antenna as a direct wave. The first communication apparatus modulates only the amplitude of a carrier signal for all channels. The second communication apparatus demodulates composite waves of desired waves and unnecessary waves received by the reception antennas by envelope detection or square-law detection and carries out correction operation for the demodulation signals based on transmission characteristics of transmission spaces between the transmission and reception antennas to acquire transmission subject signals.03-31-2011
20110075749WIRELESS COMMUNICATION METHOD, WIRELESS COMMUNICATION SYSTEM AND BASE STATION - One of the objects of the present invention is to more completely avoid impossibility of access between a mobile station and a base station, in wireless communication using an OFDM (Orthogonal Frequency Division Multiplexing) modulation scheme. In one embodiment, a base station removes a guard interval from an OFDM symbol received from a PHS terminal through a timing correction channel at two different timings to obtain two effective symbols, calculates a timing correction amount by including one timing, at which an guard interval is removed for the effective symbol that has caused detection of one correlation peak within a predetermined timing detection range of two correlation peaks detected from the respective effective symbols, into a differential from reference timing of the base station at the time of detection of the one correlation peak, and transmits the timing correction amount to the PHS terminal by means of a timing correction burst.03-31-2011
20110249764RADIO PARAMETER GROUP GENERATING APPARATUS, TRANSMITTER AND RECEIVER - An apparatus for generating sets of radio parameters includes a first deriving unit deriving a set of radio parameters for specifying a symbol including an effective symbol part with the same period as the effective symbol part specified by another set of radio parameters and a guard interval part with a different period from the guard interval part specified by the other set of radio parameters. The apparatus further includes a second deriving unit deriving a set of radio parameters so that an occupancy proportion of the guard interval part in a single symbol specified by another set of radio parameters is equal to an occupancy proportion of the guard interval part in a single symbol specified by the other set of radio parameters.10-13-2011
20110249763DUAL INDICATOR SCHEME FOR CHANNEL STATE INFORMATION FEEDBACK - Codebook based communication of precoding data between two stations involves determining a ‘best fit’ precoding at a receiving station, on the basis of channel state measurements taken therein. The best fit precoding is compared with pre-agreed entries in a codebook, and an indicator is sent back to the terminal emitting the analysed signal. The determination is separated into two elements, one being sufficient for use with SU-MIMO, and another being provided, with a second codebook indicator, if MU-MIMO is to be employed. This second codebook indicator points to a codebook of eigenvector representations for the multi-user space in which the channel is persisting.10-13-2011
20100124297Receiving a Pilot Design and Channel Estimation - Embodiments of the invention provide a receiver in an OFDM based communication system adapted to perform channel estimation using a received reference signal transmitted from at least one antenna, said reference signal being substantially located into two OFDM symbols of a transmission time interval comprising of more than two OFDM symbols. A method of generating pilot structure, the pilot structure provides information to an apparatus for channel estimation in the OFDM system with a transmission time interval of seven OFDM symbols. The pilot structure comprising pilot signals from at least one transmitting antenna located in various OFDM symbols of the transmission time interval.05-20-2010
20090022235CONTROL CHANNEL FORMAT INDICATOR FREQUENCY MAPPING - Systems and methodologies are described that facilitate selecting frequency for transmitting control channel format indicator (CCFI) data such to identify a related cell. In one example, the CCFI data can be transmitted in an initial portion of frequency (such as an orthogonal frequency division multiplexing (OFDM) symbol) in a time transmit interval (TTI). The CCFI data can be spread across the initial portion of frequency and be shifted to identify the transmitting cell. Additionally, the CCFI data can be scrambled to further identify the cell. The CCFI data can also be utilized to determine structure of subsequent control and/or data channels.01-22-2009
20110069770Method of Data Modulation and Demodulation in SoC - A method of modulating data, which is represented by two data types of ‘high’ and ‘low’, and demodulating the modulated data, is disclosed. In a method of data modulation and demodulation for a communication system which has a transmitting end modulating a data and a receiving end demodulating the transmitted data from the transmitting end, the data is represented by two types including ‘high’ and ‘low’, and the receiving end receives at least one data which consists of at least one code-word spread by a unique orthogonal code. The receiving end adds up the received data in the unit of code-word, and subtracts the length of the orthogonal code from a value which is obtained by doubling the sum of the code-word, when the code-word of the orthogonal code is ‘0’. The receiving end then averages the result after the subtraction in the unit of orthogonal code length and extracts the result, and therefore, obtains the data from the transmitting end.03-24-2011
20110075748USE OF FIRST AND SECOND PREAMBLES IN WIRELESS COMMUNICATION SIGNALS - A method and system for a method of transmitting data within a signal frame. The method comprises inserting a first synchronization preamble into a first location within the signal frame and inserting a second synchronization preamble into a second location within the signal frame, wherein the first synchronization preamble conveys information indicative of the second location. The method further comprises issuing the signal frame towards a receiving device in a wireless communication environment.03-31-2011
20110075746Transmission of precoding codebook over an air interface - Embodiments of the present invention include a system for transmitting a precoding codebook over an air interface. The system includes a first station configured to signal a set of indicators via at least one antenna to a second station from which the precoding codebook is derived at the second station based on the signaled set of indicators. The set of indicators includes less information than the precoding codebook.03-31-2011
20110069771OFDM RECEIVER AND DOPPLER FREQUENCY ESTIMATING CIRCUIT - A radiofrequency signal is converted to an intermediate frequency signal by a tuner, which is amplified by a variable gain amplifier. The so-amplified signal is converted into a digital signal by an ADC, which is supplied to an FFT, where it is separated into signals set every carrier, followed by being supplied to equalizers different in characteristic. The digital signal outputted from the ADC is further supplied to a level converting circuit from which a control signal is generated. The control signal is supplied to a DAC and a Doppler frequency detector. The DAC generates a gain control signal and supplies the same to the variable gain amplifier. The Doppler frequency detector outputs a frequency component of the control signal as a Doppler detection signal. The Doppler detection signal is compared with a threshold value by a comparator. A selector selects one of signals outputted from the equalizers, in accordance with a select signal indicative of the result of comparison.03-24-2011
20120201318APPARATUS AND METHOD FOR TRANSMITTING AND RECEIVING REFERENCE SIGNAL (RS) FOR DEMODULATION - An apparatus and method for transmitting and receiving a demodulation reference signal (DM RS) are disclosed. A method for controlling a base station (BS) to transmit a demodulation reference signal (Demodulation RS or DM RS) in a wireless communication system includes transmitting, by the base station (BS), a DM RS for a relay node (RN) to the relay node (RN) through a specific backhaul subframe to which an extended cyclic prefix (CP) is applied. The DM RS is transmitted over two resource elements (REs) of individual subcarriers having subcarrier frequency indexes 2, 5, 8 and 11 in a frequency axis within a second slot of the specific backhaul subframe.08-09-2012
20120201317STACK SIGNALING TO APPLICATION WITH LACK OF REQUESTED BANDWIDTH - A system for signaling an application when a requested data rate and Quality of Service cannot be achieved using OFDM wireless data transmission, and the application proceeds by either renegotiating QoS and data rate, or waiting until they requested rate and QoS are met.08-09-2012
20120201314APPARATUS AND METHOD FOR REDUCING PEAK TO AVERAGE POWER RATIO THROUGH RECOMBINATION OF ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING SYMBOL - There are provided an apparatus and a method for reducing a peak to average power ratio (PAPR) through the recombination of an orthogonal frequency division multiplexing (OFDM) symbol. The apparatus includes an orthogonal frequency division multiplexing (OFDM) symbol transforming unit sequentially transforming an OFDM symbol in a time domain obtained through an inverse fast Fourier transform (IFFT) to generate a plurality of OFDM symbols; a peak power measuring unit measuring peak powers of each of the OFDM symbol and the plurality of OFDM symbols generated therefrom; and an OFDM symbol selecting unit selecting an OFDM symbol having a minimum value among the measured peak powers as a candidate OFDM symbol to be transmitted and transmitting the selected candidate OFDM symbol, wherein the OFDM symbol transforming unit generates the plurality of OFDM symbols by (a) performing a process of rotating the OFDM symbol by a predetermined angle in a complex plane and performing cyclical shifting with respect to the rotated OFDM symbol and (b) repetitively performing process (a) with respect to the cyclically shifted OFDM symbol. Therefore, diversity is secured, whereby the PAPR may be reduced.08-09-2012
20120201316Control Mode PHY for WLAN - In a method for generating a physical layer (PHY) data unit for transmission via a communication channel, information bits to be included in the PHY data unit are encoded using a forward error correction (FEC) encoder. The information bits are mapped to a constellation symbols. Additionally, either the information bits are encoded according to a block coding scheme, or the constellation symbols are encoded according to the block coding scheme. Orthogonal frequency division multiplexing (OFDM) symbols are generated to include the constellation symbols and the PHY data unit is generated to include the OFDM symbols.08-09-2012
20120201315Control Mode PHY for WLAN - A first preamble for a first data unit includes a first long training field and a first signal field modulated according to a first technique. The first data unit is generated according to a first data unit format and includes the first preamble. A second preamble, generated for a second data unit, includes a second signal field and a second long training field. Information in the second signal field is repeated and/or the second long training field is generated so that a duration of the second long training field is longer than a duration of the first long training field. A portion of the second signal field is modulated according to a second technique or a portion of the second long training field is modulated according to the second technique to signal to a receiver that the second data unit is formatted according to a second data unit format.08-09-2012
20110150118ANTENNA ARRANGEMENT FOR INTERFERENCE REDUCTION AND MIMO COMMUNICATION - The present invention relates to an antenna arrangement for use in a wireless communication system, where the arrangement comprises at least two single-polarized antenna functions. Each antenna function is adapted for radiating an antenna radiation lobe pattern having a horizontal extension in an azimuth plane, and a vertical extension in an elevation plane, perpendicular to the azimuth plane. The antenna functions both have a first polarization in a first direction. In a second direction separated from the first direction, the second antenna function has a second polarization and the first antenna function has a third polarization, the second polarization and the third polarization being orthogonal to each other.06-23-2011
20110150117SYSTEM FOR TRANSMITTING AND RECEIVING CHANNEL STATE INFORMATION - A system for transmitting and receiving channel state information (CSI) is provided, in which a terminal receives a pilot signal transmitted from a transmitter; the terminal estimates CSI of part of downlink channels based on the received pilot signal; the terminal superposes the CSI of part of downlink channels onto a uplink sounding signal orthogonally, and transmits them together; the transmitter obtains the CSI of the rest part of downlink channels by estimating the uplink sounding signal; the transmitter performs orthogonal de-multiplexing on the received signal to obtain the CSI of the part of downlink channels; the transmitter, by using the CSI of the two parts of downlink channels, pre-codes downlink data and transmits it to the terminal. With the system of the present invention, it is possible to solve the problem that the transmitter can not obtain complete CSI due to the fact that uplink and downlink antenna configurations are not matched with each other. Accordingly, it is possible to improve system performance and reduce the complexity of the receiver. Meanwhile, system overhead can be suppressed.06-23-2011
20110150113Distortion-Aware multiple input multiple output precoding - Precoding parameters used for precoding of a source are selected to minimize distortion that would otherwise be induced in the source during encoding and transmission of the source over a multiple input multiple output (MIMO) channel.06-23-2011
20110150112Remote transmit IQ imbalance calibration and correction at multicarrier receivers - Transmit IQ imbalance is calibrated and compensated for within a receiver. In at least one embodiment, a Multimedia over Coax Alliance (MoCA) Type II probe signal is transmitted from the transmitter to the receiver for use in performing transmit IQ imbalance calibration.06-23-2011
20110150111Distortion-aware multiple input multiple output communications - Parameters for encoding of a source are selected to minimize distortion between the source and a reconstructed source induced by transmission of the source over a multiple input multiple output (MIMO) channel.06-23-2011
20110211645Radio device, electronic device, and imaging device - A radio device for transmitting or receiving desired information through an MIMO transmission line, and an electronic device and an imaging device which have the radio device and supplied with drive power together with the radio device may realize to implement a desired radio transmission flexibly in the form suitable for the battery residual amount and power consumption, in which plural antenna sections for performing radio communication by a spatial division multiplexing method on an MIMO transmission line, and a controller for increasing or decreasing the number of the antenna portions used for the radio transmission.09-01-2011
20100309995METHOD FOR SENDING AND RECEIVING A SIGNAL IN A MULTIPLE-ANTENNA SYSTEM IMPLEMENTING SPATIAL PRE-ENCODING, CORRESPONDING SENDER, RECEIVER AND COMPUTER PROGRAM PRODUCTS - A method and apparatus are provided for emitting and receiving a signal in a multi-antennae system, using spatial precoding. A method for emitting a signal from an emitter towards a receiver via a transmission channel, in the form of a set of data flows, includes distributing the emission antennae into a plurality of groups containing at least one antenna, at least one group containing two antennae, according to at least one piece of information representing the transmission channel. The method also includes: attributing an efficiency to each emission antenna; allocating an emission power to each data flow; and spatial precoding the signal, using a matrix for diagonal precoding by blocks, containing at least two blocks, each block being associated with one of the groups of antennae.12-09-2010
20100260277COMMUNICATION APPARATUS, MULTICARRIER COMMUNICATION SYSTEM AND COMMUNICATION METHOD - To efficiently perform adaptive modulation and adaptive scheduling in a communication control apparatus, while suppressing the total notified amount of reception quality information, provided is a communication terminal apparatus 10-14-2010
20100260276Zero Correlation Zone Based Preamble for Oversampled OFDM Networks in URWIN - In an oversampled orthogonal frequency-division multiplexing (OFDM) orthogonal network, the preamble used for time synchronization does not have an ideal autocorrelation function due to guard bands, which degrade the accuracy of symbol timing. Therefore, a zero-correlation-zone (ZCZ) based preamble is used for time synchronization. Across correlation function (CCF) used for time synchronization is forced to 0 within a certain region around a main lobe. The length of the ZCZ is guaranteed to be larger than a cyclic prefix length of OFDM data symbols synchronization accuracy.10-14-2010
20100296593DATA PROCESSING APPARATUS AND METHOD - A data processing apparatus maps input symbols to be communicated onto a predetermined number of sub-carrier signals of an Orthogonal Frequency Division Multiplexed (OFDM) symbol. The data processor includes an interleaver memory which reads-in the predetermined number of data symbols for mapping onto the OFDM sub-carrier signals. The interleaver memory reads-out the data symbols on to the OFDM sub-carriers to effect the mapping, the read-out being in a different order than the read-in, the order being determined from a set of addresses, with the effect that the data symbols are interleaved on to the sub-carrier signals. The set of addresses are generated from an address generator which comprises a linear feedback shift register and a permutation circuit. A generator polynomial for the linear feedback shift register of R′11-25-2010
20100118991Method For Allocating Radio Resource In Wireless Communication System And Method For Transmitting Or Receiving Data Using The Same - A method for allocating a radio resource in a wireless communication system comprises defining a plurality of resource regions within a frame, a resource region comprising at least one orthogonal frequency division multiple access (OFDMA) symbol and at least one subchannel, configuring radio resource allocation information indicating which resource region selected from the plurality of resource regions is allocated to a UE, the radio resource allocation information comprising at least one resource region identifier (ID), a resource region ID indicating a resource region selected from the plurality of resource regions, and transmitting the radio resource allocation information to the UE.05-13-2010
20100266054QUANTIZATION OF CHANNEL STATE INFORMATION IN MULTIPLE ANTENNA SYSTEMS - We propose a new vector quantization (VQ) algorithm for reducing bit rate used for channel state information feedback in a variety of multiple antenna systems on flat and frequency selective channels.10-21-2010
20080317144Method for Improving Paging Speed of a Called User in Cdma Trunking System - The present invention discloses a method for improving paging speed of a called user in CDMA trunking system. For a first trunking terminal supporting minus time slot call manner, said method includes: it makes minus time slot paging cycles of the first trunking terminal and a trunking core network keep synchronous; the first trunking terminal selects a minus time slot paging cycle to calculate a paging time slot according to the presence of its own minus time slot paging cycle and the presence of a minus time slot paging cycle contained in an overhead message of a call channel, and monitors the call channel on the calculated paging time slot; the base station system selects a minus time slot paging cycle to calculate a paging time slot of the user according to the presence of its own minus time slot paging cycle and the presence of a minus time slot paging cycle contained in a paging request message, and transmits a paging message on the call channel according to the calculated paging time slot. The method of the present invention effectively shortens the duration of establishment of a trunking call, and simultaneously maintains the compatibility for the existing trunking terminals.12-25-2008
20100098177RADIO TRANSMISSION DEVICE, CONTROL DEVICE, RADIO COMMUNICATION SYSTEM, AND COMMUNICATION METHOD - A radio communication system converts a time domain signal into a plurality of frequency signals to be allocated onto a plurality of subcarriers to be transmitted. The radio communication system changes a method of allocating the plurality of frequency signals onto the plurality of subcarriers based on transmission power information.04-22-2010
20100098181METHOD AND MOBILE COMMUNICATION STATION FOR COMMUNICATING OFDM SYMBOLS USING TWO OR MORE ANTENNAS - A method and mobile communication station for communicating orthogonal frequency division multiplexed (OFDM) symbols uses two or more antennas. The antenna parameters are set for beamforming, a transmit power level is initially set, and subcarrier modulation assignments are selected after the antenna parameters and the transmit power level are set to achieve a quality-of-service level for a particular application and data type of a service flow. The transmit power level may also be set based on a desired cell size.04-22-2010
20100098179METHOD AND APPARATUS FOR TRANSMITTING AND RECEIVING ORTHOGONAL FREQUENCY DIVISION MULTIPLEX-BASED TRANSMISSIONS - A method and apparatus for transmitting and receiving orthogonal frequency division multiplex (OFDM)-based transmissions are disclosed. Control information may be transmitted at least one symbol prior to the corresponding data symbols so that a wireless transmit/receive unit (WTRU) has time to determine which parts of the subcarriers need to be received without having to buffer any corresponding data symbols. Control information related to frequency location of the data may be received in the first subframe and control information not related to the frequency location of the data may be received in the second subframe that includes the corresponding data. The offset between the control information and the data may be a fixed value, may be received from the network, or may be included in the control information preceding the corresponding data.04-22-2010
20100054354WIRELESS COMMUNICATION APPARATUS - Processing data presented in the form of a vector representation involves representing direction of the vector with incremental accuracy by using a set of vector codebooks of decreasing dimensions per accuracy increment.03-04-2010
20110150114LIMITED CHANNEL INFORMATION FEEDBACK ERROR-FREE CHANNEL VECTOR QUANIZATION SCHEME FOR PRECODING MU-MIMO - A multiuser downlink multiple-input multiple-output (MIMO) system with limited channel information feedback includes an error-free channel vector quantization scheme. Each user has multiple antennas, and the base station includes a matching number of antennas. Each MIMO channel is measured at the terminus end of a corresponding user, and used to obtain the channel state information at the receiver (CSIR). A few data bits of CSIR information are feed back to the base station through the limited feedback channels. The base station collects all these CSIR feedback data bits into a CSI at the transmitter (CSIT). The CSIT is used to determine which users are served, and how to configure a corresponding multi-user precoder. The user data channels will later all be transmitted through such precoder. A codebook of channel quantization vectors is pre-defined and distributed amongst the base station and all the users.06-23-2011
20090003477Radio Communication Base Station Apparatus and Report Channel Signal Transmission Band Setting Method - Provided is a base station capable of effectively transmitting BCH data. The base station (01-01-2009
20100002790Higher Order Multiple Input, Multiple Output Extension - A method of multiple input multiple output downlink communications including mapping complex-valued modulation symbols onto one or more transmission layers by mapping complex-valued modulation symbols onto the layers and preceding the complex-valued modulation block of vectors and generating a block of vectors mapped onto at least four antenna ports. A first embodiment employs a maximum of two layers per codeword. A second embodiment employs no more than two codewords.01-07-2010
20100002789INCREASED CAPACITY COMMUNICATIONS SYSTEMS, METHODS AND/OR DEVICES - Communications architectures, systems, devices and/or methods are disclosed that can increase capacity of conventional OFDM/OFDMA systems, devices, methods and/or protocols by as much as 100%. Conventional OFDM/OFDMA transmitter/receiver architectures, methods, systems and/or devices are improved upon via additional signal processing to provide the increased capacity and reduce non-linear distortion effects on higher-order modulation alphabets such as, for example, 256-QAM.01-07-2010
20110150109INTERLACED SYMBOL CONSTELLATION MAPPING FOR WIRELESS COMMUNICATION - Briefly, in accordance with one or more embodiments, a data packet to be transmitted is encoded and one or more subpackets are generated from the encoded data packet. A first bit pattern is applied to a first symbol of the subpackets to provide a constellation, and a different bit pattern is applied to a next adjacent symbol in the constellation for one or more additional symbols. The data packet is then modulated according to the constellation and transmitted one or more times until the data packet is decoded by a receiver or until said transmitting is aborted according to a hybrid automatic repeat request error correction technique.06-23-2011
20110150115PILOT SUBCARRIERS IN WIRELESS TRANSMISSIONS - An integrated circuit includes logic configured to encode pilot signals in a first set of subcarriers of an orthogonal frequency division multiplexing (“OFDM”) symbol and in a second set of subcarriers of a consecutive OFDM symbol. The symbol and the consecutive symbol are in the same smart-utility-network packet.06-23-2011
20110150116Double Search Algorithm of User Group Selection for Multiuser MIMO Downlink Transmission - A method and system for a double search algorithm of user group selection for multiuser MIMO downlink transmission are provided. The use of optimal brute-force user group selection may require high computational expense. A first search operation may be based on a first user having a channel gain greater than that of other users, while a second search operation may be based on a second user having a channel gain greater than that of the remaining users. A maximized system capacity may be determined based on the maximized system capacities determined in the first and second search loop. A receiver pair associated with the maximized system capacity may be selected as the user group. The double search algorithm may reduce the computational complexity while achieving performances that may exceed the TDMA scheme and be similar to that of systems with ideal CSI at the transmitter.06-23-2011
20090316816METHOD FOR MULTIPLE USE SUBCHANNELS - Systems and methods for multiuse subcarriers in multipoint-to-point communication using orthogonal frequency division multiplexing (OFDM) are provided. In one embodiment, a remote unit for communicating with a host unit using OFDM is provided, the host unit communicatively coupled to a plurality of remote units in a multipoint-to-point configuration. The remote unit comprises a modulator for modulating up to a plurality of tones with upstream information using orthogonal frequency division multiplexing, wherein the modulator is configured to adjust a carrier frequency and timing of the plurality of tones such that spectrally overlapping tones transmitted from the remote unit and at least one other remote unit of the plurality of remote units are orthogonal and combine to form an OFDM waveform when received at the host; and wherein a first tone of the plurality of tones carries both control data and payload data.12-24-2009
20090316814METHOD FOR SIGNALING OF RESOURCE ALLOCATION TO ADJUST GRANULARITY IN CELLULAR MULTI-CARRIER SYSTEM - A method for adjusting a granularity of resource allocation in a wireless mobile communication system supporting a compact scheduling is disclosed. A resource indication value (RIV) corresponds to a start index (S) of one set of consecutive virtual resource blocks (VRBs) and a length of the VRBs. The start index (S) is selected from among ‘s’ values (where s=P+mT12-24-2009
20090274232REVERSE LINK POWER CONTROL IN AN ORTHOGONAL SYSTEM - A closed-loop reverse-link power control algorithm for a frequency hopping orthogonal frequency division multiple access (FH-OFDMA) system is described. The power control algorithm adjusts the user's transmit power based on effective carrier-to-interference (C/I) and Received-Power-Over-Thermal (RpOT) measurements. The algorithm is inherently stable and is effective for FH-OFDMA systems with retransmissions.11-05-2009
20090022238MB-OFDM system and method for frame boundary detection - A method of detecting a frame boundary for a multi-band orthogonal frequency division multiplexing mode is comprised of: calculating an autocorrelation value of a reception signal; estimating an error of the autocorrelation value; and detecting a frame boundary with reference to the error, a sign of the autocorrelation value, and a sign of an autocorrelation value of a previous reception signal. The method is able to substantially exactly detect the frame boundary even when the frequency error rate of all band groups of the UWB spectrums defined by the WiMedia PHY specification is conditioned over ±70 ppm.01-22-2009
20090022236METHOD AND APPARATUS FOR ESTIMATING SAMPLING FREQUENCY OFFSET, AND SAMPLING TIMING RECOVERY LOOP INCLUDING THE APPARATUS - An apparatus for estimating a sampling frequency offset includes a waveform characteristic extraction unit, a variation quantity calculation unit, and a SFO (sampling frequency offset) estimator. The waveform characteristic extraction unit extracts a waveform characteristic of a training sequence period in one frame period of a sample data signal and outputs a waveform characteristic value corresponding to the waveform characteristic of the training sequence period. The variation quantity calculation unit calculates a waveform characteristic variation quantity representing a variation quantity in waveform characteristic between an m-th frame and an (m−k)-th frame based on a waveform characteristic value in the m-th frame and a waveform characteristic value in the (m−k)-th frame, where m and k are independently integers of 1 or more. The SFO estimator estimates an SFO of the sample data signal based on the waveform characteristic variation quantity.01-22-2009
20090022232RADIO TRANSMITTER APPARATUS AND RADIO RECEIVER APPARATUS - A radio receiver apparatus and a radio transmitter apparatus wherein the energy loss caused by addition of GI is suppressed, while the reception quality is improved. A signal having been subjected to an IFFT process is repetitively transmitted N times with a length of one OFDM symbol interval. At a receiver apparatus receiving the transmitted signals, a leading data extracting part (01-22-2009
20080247479Pilot Scheme For A Mimo Communication System - The present invention employs a pilot scheme for frequency division multiple access (FDM) communication systems, such as single carrier FDM communication systems. A given transmit time interval will include numerous traffic symbols and two or more short pilot symbols, which are spaced apart from one another by at least one traffic symbol and will have a Fourier transform length that is less than the Fourier transform length of any given traffic symbol. Multiple transmitters will generate pilot information and modulate the pilot information onto sub-carriers of the short pilot symbols in an orthogonal manner. Each transmitter may use different sub-carriers within the time and frequency domain, which is encompassed by the short pilot symbols within the transmit time interval. Alternatively, each transmitter may uniquely encode the pilot information using a unique code division multiplexed code and modulate the encoded pilot information onto common sub-carriers of the short pilot symbols.10-09-2008
20090190681SPACE-TIME/SPACE-FREQUENCY CODING FOR MULTI-SITE AND MULTI-BEAM TRANSMISSION - The present invention relates to space-time or space-frequency coding in cellular systems. The same data is transmitted from different antennas with different coverage areas, corresponding to different cells. The different data streams have different parts of the space-time block codes applied. A mobile terminal can combine the different parts of the space-time block codes in different received signals. This provides better performance than the known techniques for single frequency networks. The invention can also be applied to antennas with different coverage areas from the same site, and different beams formed with antenna arrays.07-30-2009
20090190675SYNCHRONIZATION IN A BROADCAST OFDM SYSTEM USING TIME DIVISION MULTIPLEXED PILOTS - In an OFDM system, a transmitter broadcasts a first TDM pilot on a first set of subbands followed by a second TDM pilot on a second set of subbands in each frame. The subbands in each set are selected from among N total subbands such that (1) an OFDM symbol for the first TDM pilot contains at least S07-30-2009
20090180564DITHERING SCHEME USING MULTIPLE ANTENNAS FOR OFDM SYSTEMS - A ground- or roof-top-based repeater in an OFDM system uses multiple transmission antennas to transmit multiple identical OFDM signals. Dithering is performed by introducing a slight variable-frequency phase offset to all but one of the multiple identical transmitted OFDM signals. The effective overall channel is more dynamic and provides spatial diversity to minimize long periods of fading in fading subchannels of the OFDM signals when the receiver is in a slow moving or stationary situation. To overcome the additional cancellation problem that can occur when two or more of the transmitting antennas are (i) in a line-of-site position with the receiver and (ii) approximately the same distance from the receiver, a delay is deliberately introduced to make the delayed signals appear to be reflected signals. This delay will not negatively impact the OFDM receiver performance as long as the delay is within the guard interval used in the OFDM process.07-16-2009
20090141822METHOD AND SYSTEM FOR SYNCHRONIZING OFDM TRANSMISSION SYMBOLS - A method for synchronizing orthogonal frequency division multiplexing (OFDM) transmission symbols includes: an OFDM transmission module receives a synchronization signal, and adjusts the OFDM symbols sent by all lines to synchronous symbols according to the synchronization signal and send the symbols out. The present invention also provides a system for synchronizing OFDM transmission symbols. In the present invention, the weaknesses of the prior art are overcome; a synchronization signal generator generates a synchronization signal and sends it to the OFDM transmission equipment; and the OFDM transmission equipment adjusts the OFDM symbols sent by all lines to synchronous symbols according to the synchronization signal and send the symbols out, thus accomplishing synchronization between OFDM symbols and optimizing the performance of the dynamic spectrum management (DSM).06-04-2009
20090086838WIRELESS TRANSMITTER - A wireless transmitter includes: a plurality of transmission antennas; and a phase rotating unit which adds phase rotation to signals which are respectively input to the plurality of transmission antennas, wherein the phase rotating units adds first phase rotation for controlling the maximum delay time between the plurality of transmission antennas and second phase rotation for controlling the phases of arbitrary antennas among the plurality of transmission antennas.04-02-2009
20090052560TRANSMISSION METHOD AND TRANSMISSION APPARATUS USED IN MULTIANTENNA WIRELESS COMMUNICATION SYSTEM - A transmission bit and transmission power distributing method that can reduce the arithmetic amount in a multiantenna-input/multiantenna-output (MIMO) wireless communication system. This method comprises steps of calculating a signal-to-interference-noise ratio (SINR) gain after MIMO detection of each of transport substreams (S02-26-2009
20110176625METHOD AND DEVICE FOR OBTAINING AT LEAST ONE CALIBRATION FREQUENCY FOR CALIBRATING A TRANSMISSION CHAIN, CORRESPONDING COMPUTER PROGRAM PRODUCT AND CORRESPONDING STORAGE DEVICE - A method is provided for obtaining a calibration frequency for calibrating a transmission chain that can transmit information signals on a frequency band comprising a plurality of channels. The chain includes an amplifier that can be configured according to at least one gain configuration. The method includes: obtaining an output power value of the amplifier; obtaining a frequency dispersion, based on the power value; detecting whether a constraint linked to said frequency dispersion is satisfied; and if the constraint is not satisfied, then obtaining a current frequency subband and a calibration frequency for said current frequency subband.07-21-2011
20080317145MULTIPLE INPUT MULTIPLE OUTPUT COMMUNICATION SYSTEM AND A METHOD OF ADAPTIVELY GENERATING CODEBOOK - A Multiple-Input Multiple-Output (MIMO) communication system and a method of adaptively generating a codebook are provided. A terminal includes a channel estimator to estimate a channel formed between a base station and the terminal to calculate a channel matrix and a codebook generator to adaptively generate a codebook based on a spatial correlation matrix of the channel matrix.12-25-2008
20080310532Method for Signal Reception - In an OFDM mobile communications system, an algorithm for forming a preliminary estimate of the channel on pilot subcarriers is carried out. Based on this preliminary estimate, a channel property is estimated. This channel property is then used to decide whether to enter a mobile receiver mode or a stationary receiver mode. For example, in the mobile mode channel estimation is performed using only pilot symbols from the current symbol period, while in the static mode channel estimation is performed using pilot symbols from the current symbol period and pilot symbols from other symbol periods.12-18-2008
20080310537PORTABLE TERMINAL, COMMUNICATION SYSTEM, AND COMMUNICATION METHOD - A portable terminal communicates with a plurality of base stations by use of an OFDM signal. The portable terminal includes a communication unit sending and receiving the OFDM signal to and from the base stations, a switching timing detector, and an OFDM signal controller. The switching timing detector detects switching timing at which handover and a normal state are switched therebetween. The OFDM signal controller changes a guard time length of the OFDM signal upon detecting the timing by the switching timing detector.12-18-2008
20080285671ADAPTIVE MAXLOGMAP-TYPE RECEIVER STRUCTURES - A method and apparatus is disclosed herein for adaptive MaclogMAP-type receiver structures. In one embodiment, a device comprises a receiver to receive information-bearing signals from the transmitter wirelessly transmitted using OFDM and bit interleaved coded modulation, and the receiver comprises an inner decoder structure having a multiple-in multiple-out (MIMO) joint demapper to perform most likely transmitted symbol estimation using a modified MaxLogMAP process that is operable to adapt a degree of metric correction based on quality of OFDM tones.11-20-2008
20080267305METHOD AND APPARATUS FOR ACQUIRING FREQUENCY OF MULTI-PATH SIGNAL - A method and an apparatus for acquiring a target frequency of a multi-path signal are disclosed. The multi-path signal includes a first path signal and a second path signal. First, the first path signal is received through a first path and the second path signal is received through a second path. Then, a target region is determined. The target region is a portion of a second cyclic prefix in the second path signal which overlaps with a first cyclic prefix in the first path signal. Afterward, the target frequency is determined based on the target region.10-30-2008
20110255620ALLOCATING AND RECEIVING TONES FOR A FRAME - A communication device for allocating tones is described that includes a processor and instructions in memory in electronic communication with the processor. The communication device determines whether a bandwidth for signal transmission is 20, 40, 80 or 160 megahertz (MHz). The communication device respectively allocates tones for 20, 40, 80 or 160 MHz as follows: for a very high throughput (VHT) signal A10-20-2011
20110255621SYNCHRONIZED MULTIPOINT-TO-POINT COMMUNICATION USING ORTHOGONAL FREQUENCY DIVISION - A multipoint-to-point, orthogonal frequency division multiplexed (OFDM) communication system is provided. The system includes a plurality of remote units and a host unit that includes a demodulator. Each of the remote units transmits an upstream OFDM signal using a multiple access scheme to the host unit demodulator using at least one of a plurality of orthogonal tones within an OFDM waveform. The host unit receives the upstream OFDM signals from a plurality of the remote units. Portions of upstream OFDM signals from at least two of the remote units arrive at the host unit at the same time. The host unit demodulator demodulates the portions and the upstream signals from the plurality of remote units arrive at the host unit synchronized in time and frequency within the OFDM waveform.10-20-2011
20100284478Channel Estimating Apparatus and Method Thereof - A channel estimating technique is applied to an Orthogonal Frequency-Division Multiplexing (OFDM) communication system which receives a plurality of OFDM symbols. In one aspect, a channel estimating method includes performing Inverse Fast Fourier Transform (IFFT) with a second number of sampling points and a phase shift on each of preliminarily estimated frequency-domain channel responses including a first number of response values corresponding to each of the OFDM symbols, so as to obtain a first time-domain channel impulse response corresponding to each of the OFDM symbols, where the first number is lager than the second number. The method also generates a plurality of frequency-domain channel responses corresponding to the OFDM symbols according to the time-domain channel impulse responses.11-11-2010
20100303164BLOCK SPREADING FOR ORTHOGONAL FREQUENCY DIVSION MULTIPLE ACCESS SYSTEMS - A method of block spreading data, the method comprising the steps of: (a) providing a first input data sequence; (b) forming a periodic extension of the input data sequence to form an extended input data sequence; (c) multiplying the extended input data sequence by a complex number spreading sequence to produce a spread signal sequence; and (d) outputting the spread signal sequence.12-02-2010
20110164695METHOD AND SYSTEM FOR SELECTING A USER GROUP USING HYBRID-QUANTIZED CHANNEL DIRECTION INFORMATION FEEDBACKS FROM MIMO CAPABLE MOBILE DEVICES - A mobile device receives beams orthogonal to a single user downlink MIMO channel associated with a selected first user in a user group. The mobile device estimates relative channel direction information with respect to the received beams for an associated single user downlink MIMO channel. The estimated relative channel direction information is hybrid-quantized to generate a semi-orthogonal matrix transmitted to the base station over a finite-rate feedback link. The mobile device receives downlink data transmission according to the hybrid-quantized relative channel direction information. The base station receives multiple semi-orthogonal matrices from remaining mobile devices to generate a semi-orthogonal group for the selected first user. A mobile device having the strongest quantized projected channel capacity is selected from the generated semi-orthogonal group as a second user. Mutual channel capacity information for the selected first and second users is determined to schedule corresponding downlink data transmissions, accordingly.07-07-2011
20100322333HS-SCCH Orders for CQI Mode Selection - A network node (12-23-2010
20100322328METHOD AND APPARATUS FOR IMPLEMENTING UPLINK TRANSMIT DIVERSITY IN A SWITCHED ANTENNA ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING COMMUNICATION SYSTEM - A method and a customer's wireless communication device are provided that perform uplink transmit diversity in a switched antenna OFDM communication system. A switching of antennas used by the customer's wireless communication device to transmit an uplink signal is restricted to switching time periods that comprise one or more of a transition gap immediately preceding a transmission of a channel quality-related uplink signal and a time period subsequent to the occurrence of the transition gap but prior to the transmission of the channel quality-related uplink signal, which channel quality-related uplink signal may be used by a serving radio access network to update a channel response and antenna array weights associated with the customer's wireless communication device. The customer's wireless communication device then switches antennas used for uplink transmissions only during the switching time periods.12-23-2010
20100322331ADAPTIVE CODEBOOK PROCESSING METHOD - An adaptive codebook processing method comprises: step S102, initializing the local codebook set by using the initial codebook set; and step S104, updating the initialized local codebook set by using the feedback codebook set.12-23-2010
20080212703METHOD AND APPARATUS FOR SUBCHANNEL ASSIGNMENT FOR SUPPRESSING INTERANTENNA INTERFERENCE IN OFDMA SYSTEM - Disclosed is a method and an apparatus for subchannel assignment for suppressing inter-antenna interference in an Orthogonal Frequency Division Multiplexing Access (OFDMA) system based distributed wireless communication system equipped with antennas that are randomly distributed in a geographical manner and can simultaneously communicate with multiple Subscriber Stations (SSs). The method includes selecting and obtaining access to distributed antennas which satisfy the data transmission rate that an SS requires and with which the SS can communicate; re-queuing a distributed antenna having the maximum transmitted power within the same cell in high priority; and assigning subchannels to the relevant distributed antennas in an order from the relevant distributed antenna having the high priority.09-04-2008
20110164697METHODS AND DEVICES FOR SPATIAL CODING - Embodiments of the invention relates to a method in a controller node for distributing code text of a joint spatial coding in a communications network. The communications network comprises at least two communication nodes each comprising at least one transmit antenna. The method comprises to joint spatial code (07-07-2011
20080253471SYSTEMS AND METHODS FOR ADAPTIVE BIT LOADING IN A MULTIPLE ANTENNA ORTHOGONAL FREQUENCY DIVISION MULTIPLEXED COMMUNICATION SYSTEM - In an orthogonal frequency division multiplexed (OFDM) system, a transmitter and/or receiver communicate separate data streams on non-orthogonal spatial channels. Each spatial channel may use the same set of OFDM subcarriers and may take advantage of the multipath characteristics of the spatial channel allowing the communication of additional data without an increase in frequency bandwidth. Space-frequency subcarrier modulation assignments may be dynamically assigned on a per subcarrier basis as well as a per spatial channel basis to help maximize the data-carrying capacity of the channel. In some embodiments, each of the spatial channels may be associated with one of a plurality of spatially diverse antennas. In other embodiments, beamforming may be performed to allow the transmission and/or reception of signals within the spatial channels.10-16-2008
20080253469Methods and Systems for Ofdm Using Code Division Multiplexing - In some embodiments of the invention, OFDM symbols are transmitted as a plurality of clusters. A cluster includes a plurality of OFDM sub-carriers in frequency, over a plurality of OFDM symbol durations in time. Each cluster includes data as well as pilot information as a reference signal for channel estimation. In some embodiments, a plurality of clusters collectively occupy the available sub-carrier set in the frequency domain that is used for transmission. In some embodiments of the invention data and/or pilots are spread within each cluster using code division multiplexing (CDM). In some embodiments pilots and data are separated by distributing data on a particular number of the plurality of OFDM symbol durations and pilots on a remainder of the OFDM symbol durations. CDM spreading can be performed in time and/or frequency directions.10-16-2008
20080205534Method and system of channel analysis and carrier selection in OFDM and multi-carrier systems - The invention presents a novel method to channel estimation in OFDM systems. The embodiment of this invention is a block of new logic and modifications performed to other components of the system, added to any existing OFDM receiver, which utilizes information available from other blocks as found in the receiver. This logic would improve the units' error rate because of the improved channel quality estimations it makes available. This improvement is made possible because both channel noise data and channel signal data are used in the estimation process. This data goes through a learning process over time and multiple data blocks for further improvements in the quality of the estimate. This improvement is possible without any direct communications with other remote units, but it could be used in a multi-node environment to improve the performance of the system as the whole.08-28-2008
20110164696MULTIPLE-INPUT MULTIPLE-OUTPUT (MIMO) COMMUNICATION SYSTEM USING A CODEBOOK AND METHOD OF DESIGNING THE CODEBOOK - Provided is a multiple input multiple output (MIMO) communication system using a codebook. A transmitter and a receiver included in the MIMO communication system may generate a codebook having a different size for each eigenvector of a channel matrix or a channel covariance matrix, based on eigenvalues of the channel matrix or the channel covariance matrix.07-07-2011
20090067513Smart antenna system and method thereof for forming uplink eigenbeam of ofdm/tdd - A mobile station transmitting and receiving method and a corresponding mobile station transmitter and receiver of a smart antenna system for forming uplink eigenbeams of the OFDM/TDD (orthogonal frequency division multiplex/time division duplex), wherein OFDM symbols are received from a base station through a downlink via multiple antennas (03-12-2009
20110019753APPARATUS FOR TRANSMITTING AND RECEIVING A SIGNAL AND METHOD OF TRANSMITTING AND RECEIVING A SIGNAL - A method of transmitting and receiving a signal and an apparatus for transmitting and receiving a signal are disclosed. The method includes receiving the signal of a first frequency band, obtaining layer-1 information from a preamble of the first time-frequency slicing (TFS) signal frame of the received signal, said layer-1 information including a radio frequency (RF) channel identifier of a first TFS signal frame including the PLP in a super frame of TFS structure, and an identifier of a starting radio frequency (RF) channel which can receive the PLP in the TFS signal frame, parsing the TFS signal frame using the layer-1 information and obtaining a physical layer pipe (PLP) of the TFS signal frame, and converting the PLP to a service stream.01-27-2011
20100284481COMMUNICATION METHOD, AND TRANSMITTING APPARATUS AND RECEIVING APPARATUS USING THAT COMMUNICATION METHOD - A method for use in a communication apparatus that receives an orthogonal frequency division multiplexing (OFDM) signal transmitted from a base station. The OFDM signal includes a plurality of carrier groups each comprising a plurality of carriers, the plurality of carrier groups being assigned transmission data for a plurality of communication apparatuses. Each of the plurality of carrier groups adopt one of a first frame configuration, where the transmission data is transmitted using one modulation signal, and a second frame configuration, where the transmission data is transmitted using a plurality of modulated signals. The method includes specifying a carrier group to which transmission data for the communication apparatus is assigned, based on control information included in the received OFDM signal and generating reception data associated with the specified carrier group based on one of the one modulated signal used in the first frame configuration and the plurality of modulated signals used in the second frame configuration.11-11-2010
20100284480METHOD AND APPARATUS FOR CHANNEL QUALITY MEASUREMENTS - A method and apparatus are provided for measuring channel quality over which has been transmitted a sequence of symbols produced by encoding and constellation mapping a source data element sequence. The method includes receiving a sequence of received symbols over the channel whose quality is to be measured. The sequence of received symbols is de-mapped based on a first channel quality indicator previously transmitted to a transmitter of the sequence of symbols. The method also includes decoding the de-mapped symbols to produce a decoded output sequence. In some embodiments, the decoding may be based on the first channel quality indicator. The method also includes re-encoding the decoded output sequence to produce a re-encoded output sequence. The method also includes correlating the de-mapped symbols with the re-encoded output sequence to produce a second channel quality indicator. The second channel quality indicator is transmitted to the transmitter to adaptively select a type of mapping based on the second channel quality indicator. In some embodiments, the transmitter may adaptively select a type of encoding based on the second channel quality indicator.11-11-2010
20100284477METHOD FOR TRANSMITTING SIGNAL IN MULTIPLE ANTENNA SYSTEM - A signal transmission method in a multiple antenna system is described. The signal transmission method includes, upon receiving channel state information from a receiving end, estimating a channel according to the channel state information, determining a precoding matrix according to the estimated channel and modifying the signal of the transmitting end using the precoding matrix in a process of mapping a symbol of the signal to a subcarrier, and transmitting the signal to the receiving end. According to the present invention, pre-equalization of a transmission signal can cause a receiving end to perform coherent combination, reduce pilot density by decreasing unnecessary pilots, and reduce interference within a cell or between cells.11-11-2010
20110038436METHOD FOR TRANSMITTING AND RECEIVING DATA IN A COOPERATIVE MULTIPLE-INPUT MULTIPLE-OUTPUT MOBILE COMMUNICATION SYSTEM - A method for transmitting and receiving data in a cooperative Multiple-Input Multiple-Output (MIMO) mobile communication system is disclosed. The method includes selecting a transmission path for transmitting precoding-related feedback control information to one or more cooperative base stations operating in the cooperative MIMO mode, and transmitting the precoding-related feedback control information to the one or more cooperative base stations through the selected transmission path.02-17-2011
20110038435METHOD AND SYSTEM FOR REDUCING OUT OF BAND RADIATION IN ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING SYSTEMS - The various embodiments herein provide a method and system for reducing Out of Band Radiation in Orthogonal Frequency Division Multiplexing (OFDM). The method includes transmitting a plurality of signals with a plurality of modulated symbols on each subcarrier. The method includes introducing a controlled amount of correlation among the consecutive modulated symbols across time. Further the method includes removing the controlled amount of correlation among the plurality of modulated symbols. The method also includes reducing an out of band radiation in OFDM. The system for reducing Out of Band Radiation in Orthogonal Frequency Division Multiplexing (OFDM) includes a transmitter to transmit one or more signals with a plurality of modulated symbols on each subcarrier. The system includes a transmitter with digital filters and a receiver. The receiver includes a Maximum Likelihood Sequence Detector (MLSD) to remove the controlled amount of correlation among the plurality of modulated symbols.02-17-2011
20110038434RADIO PARAMETER GROUP GENERATING APPARATUS, TRANSMITTER AND RECEIVER - An apparatus for generating sets of radio parameters includes a first deriving unit deriving a set of radio parameters for specifying a symbol including an effective symbol part with the same period as the effective symbol part specified by another set of radio parameters and a guard interval part with a different period from the guard interval part specified by the other set of radio parameters. The apparatus further includes a second deriving unit deriving a set of radio parameters so that an occupancy proportion of the guard interval part in a single symbol specified by another set of radio parameters is equal to an occupancy proportion of the guard interval part in a single symbol specified by the other set of radio parameters.02-17-2011
20110038432APPROACH FOR OPTIMIZING ENERGY CONSUMPTION OF MULTIPLE-INPUT MULTIPLE- OUTPUT SYSTEM - The present disclosure generally relates to techniques to reduce energy consumption in a multiple-input multiple-output (MIMO) system. Some example embodiments may include collecting a set of information associated with one or more of an energy consumption, a network traffic condition, an environmental condition, and/or quality of a communication link associated with the first wireless communication device and/or the MIMO system, configuring the first wireless communication device to operate at a first reduced energy consumption level based on the collected set of information, identifying operation information associated with the first wireless communication device based upon at least the configuration of the first wireless communication device, and transmitting the operation information for reception by the second wireless communication device so that the second wireless communication device can be configured to operate at a second reduced energy consumption level based on the operation information.02-17-2011
20100329376METHOD FOR ACCELERATING THE PRECODING AND PRE-DECODING OF SYMBOLS IN OFDM SYSTEMS12-30-2010
20100329374TECHNIQUES FOR ESTIMATING CHANNEL AND INTERFERENCE IN OFDM WIRELESS COMMUNICATION SYSTEM WITH MULTIPLE ANTENNAS - A method and multiple antenna transmitting apparatus for transmitting a midamble in a wireless communication system, and a method and receiving device for receiving a midamble in a wireless communication system are provided. A method for transmitting a midamble by a multiple antenna transmitting device includes determining a pattern for a midamble including null subcarriers and pilot subcarriers, wherein each of the pilot subcarriers corresponds to one of a plurality of pilot signals, and each of the plurality of pilot signals corresponds to a different one of a plurality of transmit antennas, and transmitting the pilot signals in corresponding pilot subcarriers based on the determined pattern, wherein the pilot signals are transmitted in an Orthogonal Frequency Division Multiplexing (OFDM) symbol of a resource block comprising a plurality of subcarriers and a plurality of OFDM symbols.12-30-2010
20100329375WIRELESS COMMUNICATION SYSTEM, WIRELESS COMMUNICATION APPARATUS AND WIRELESS COMMUNICATION METHOD - A channel estimation unit 12-30-2010
20100329373RECEIVER, SIGNAL PROCESSING APPARATUS AND RECEIVING METHOD - A receiver for receiving a signal including a series of symbols, the signal being performed Time Window processing at portions including a boundary of adjacent symbols by a transmitter so as to eliminate a discontinuity between the symbols, the receiver includes: a receiving unit that receives the signal; and a processor extracts the series of symbols and performing an inverse processing of the Time Window processing at the portions performed the Time Window processing by the transmitter.12-30-2010
20100329370Selection of a Subset of Antennas for Transmission - A method and apparatus of a subscriber station selecting a subset of a plurality of antennas for uplink transmission are disclosed. One method includes a base station transmitting a cyclic delay diversity transmission signal. The subscriber station receives the cyclic delay diversity transmission signal through the plurality of antennas. The subscriber station selects a subset of the plurality of antennas based on a received quality signal parameter. The subscriber station transmits uplink signals to the base station through the selected subset of the plurality of antennas.12-30-2010
20100329372Method and Apparatus for Generating a Carrier Frequency Signal - A method and apparatus for generating a carrier frequency signal is disclosed. The method includes generating a first frequency signal; injecting a modulation signal at a first point of the two-point modulation architecture; generating a second frequency signal from the modulation signal; introducing the second frequency signal by mixing the first frequency signal and the second frequency signal to generate a mixed frequency signal and outputting the carrier frequency signal selected from the mixed frequency signal.12-30-2010
20100329371MULTIPLE INPUT MULTIPLE OUTPUT (MIMO) COMMUNICATION SYSTEM FOR FEEDFORWARDING INTERFERENCE VECTOR INDICATOR - Provided are a base station configured to provide an interference vector indicator to a terminal, and the terminal configured to recognize at least one remaining precoding vector using the interference vector indicator. Each of the base station and the terminal may configure a mapping table between at least one bit for the interference vector indicator indicating the at least one remaining precoding vector, and a plurality of vectors included in a codebook, based on a probability that the plurality of vectors may be included in a precoding matrix. In this instance, the base station may generate the interference vector indicator using the mapping table, and the terminal may recognize the at least one remaining precoding vector using the mapping table. The mapping table may be differently configured according to various modes.12-30-2010
20110135023COMMUNICATION SYSTEM AND METHOD USING SPACE DIVISION MULTI-USER MULTIPLE INPUT MULTIPLE OUTPUT (SD-MIMO) COMMUNICATION METHOD - Provided is a communication system using a space division multi-user multiple input multiple output (SD-MIMO) communication method. A transmission apparatus may transmit, to each of terminals included within a coverage, common control information commonly transmitted to the terminals and individual control information individually transmitted to each of the terminals. The transmission apparatus does not precode the common control information and transmits the non-precoded common control information. The transmission apparatus precodes the individual control information and transmits the precoded individual control information.06-09-2011
20110255618METHOD AND SYSTEM FOR MULTI-USER TRANSMIT OPPORTUNITY FOR MULTI-USER MULTIPLE-INPUT-MULTIPLE-OUTPUT WIRELESS NETWORKS - Wireless communication in a wireless system using a multiple user transmission opportunity is provided. Data blocks at a wireless station are transmitted to multiple wireless receivers over a shared wireless communication medium. The data blocks are organized in order of transmission priority based on access categories. Contention for access to the communication medium during a transmission opportunity period is based on a backoff timer of each access category and the transmission priority. Upon successful contention for a transmission opportunity period, during the transmission opportunity period, a data block of a primary access category is wirelessly transmitted from the wireless station to one or more primary destination wireless receivers. Simultaneously, a data block of a secondary access category is wirelessly transmitted from the wireless station to one or more secondary destination wireless receivers.10-20-2011
20110135024PRECODING MATRIX DESIGN METHOD FOR MULTIPLE BASE STATION USING MIMO TECHNIQUE - Provided is a precoding matrix design method for a cooperative communication of multiple base stations in a multiple input multiple output (MIMO) communication system. A method of designing a precoding matrix in a base station of the MIMO communication system may include: determining whether to use a cooperative communication; verifying a cooperative base station when the cooperative communication is determined to be used; selecting a precoding matrix to be applied by a home base station and the cooperative base station; and requesting the home base station and the cooperative base station for the cooperative communication using the selected precoding matrix.06-09-2011
20110135020System and Method for Quantization of Channel State Vectors - A system and method for the quantization of channel state vectors is provided. A method for communications node operation includes measuring a communications channel between the communications node and a controller, generating channel state information based on the measurement, computing a bit representation of the channel state information, transmitting the bit representation to the controller, and receiving a transmission from the controller. The computing makes use of tail-biting trellis decoding, and the transmission makes use of the channel state information transmitted by the communications node.06-09-2011
20100303160MULTIFUNCTIONAL SIGNAL TRANSFORM ENGINE - A technique involves using a fast Fourier transform (FFT) module to transform multiple different types of signals. This may be accomplished using one or more of three techniques: logic within the FFT module can enable different processing depending upon a processing state, the FFT module can be called iteratively to transform a signal that is larger than the FFT implemented in the FFT module, the FFT module can be used for parallel transformation of multiple signals that are smaller than the FFT implemented in the FFT module. Thus, a single FFT module can be used to transform a first type of signal (e.g., WIFI) and a second type of signal (e.g., GPS) if configured according to the technique.12-02-2010
20110255622METHODS AND APPARATUS FOR REDUCTION OF A PEAK TO AVERAGE RATIO FOR AN OFDM TRANSMIT SIGNAL - Methods and apparatus for reduction of a peak to average ratio for an OFDM transmit signal. In an aspect, a method is provided for reducing a peak to average ratio of a transmit waveform. The method includes obtaining a primary scrambler sequence, generating a secondary scrambler sequence having a length characteristic based on data to be scrambled, and combining the primary and secondary scrambler sequences to produce a PAR reduction sequence. In another aspect, an apparatus is provided for reducing a peak to average ratio of a transmit waveform. The apparatus includes a secondary generator configured to generate a secondary scrambler sequence having a length characteristic based on data to be scrambled, and combining logic configured to combine a primary scrambler sequence and the secondary scrambler sequences to produce a PAR reduction sequence.10-20-2011
20080219371Channel estimation and ICI cancellation for OFDM - An iterative channel estimation and inter-carrier interference (ICI) cancellation process is provided for OFDM receivers, and more particularly for mobile OFDM receivers. The iterative process uses decision feedback to estimate both the channel gain and the ICI gains, the latter being the multiplicative gain applied to the adjacent sub-carriers. Thus the receiver performs equalization and ICI cancellation in an iterative fashion and is advantageous for estimating fast fading channels.09-11-2008
20080219369ROBUST RATE, POWER AND PRECODER ADAPTATION FOR SLOW FADING MIMO CHANNELS WITH NOISY LIMITED FEEDBACK - System and methodologies are provided herein for rate, power and precoder adaptation for slow fading MIMO communication channels with noisy limited feedback. To optimize a rate of successful information delivery from a wireless transmitter to a wireless receiver and to provide robustness to channel noise, a joint design and optimization technique is utilized to provide optimal power, rate, and precoding adaptation policies for use by a wireless transmitter and an optimal feedback scheme and index assignment mapping for use by a wireless receiver. Additionally, various optimization and design techniques described herein are performed using a low-complexity online adaptation coupled with an offline optimization design.09-11-2008
20080219367TRANSMITTING DEVICE AND CONTROL METHOD THEREOF - A transmitting device is provided that generates OFDM symbols by identifying a sampling frequency of input data that is input from an external device, determining a number of inverse Fourier transform sample points and a number of sampling points of a redundant data portion in accordance with the identified sampling frequency, and subjecting the input data to OFDM modulation using the determined number of sampling points. The transmitting device then transmits the generated OFDM symbols.09-11-2008
20080219365METHOD OF GROUPING AND MAPPING TRANSMISSION STATIONS IN A WIRELESS NETWORK - A method of mapping transmission stations in a wireless network by grouping the transmission stations such that each transmission station in the same group transmits a sounding signal in the same time symbol. A method of grouping transmission stations in a wireless network includes sorting the transmission stations in descending order according to a number of transmission links of each transmission station that are unmapped, evaluating each transmission station based on how many unmapped transmission links can be mapped if the evaluated transmission station is made to transmit a sounding signal, placing each transmission station into a group, based on the evaluation, until all of the transmission links are mapped or until the maximum number of sounding bands are used, and, if all of the transmission links are not mapped, repeating the sorting, evaluating, and placing for each time symbol until all of the transmission links are mapped.09-11-2008
20080219364DELAY-SENSITIVE CROSS LAYER SCHEDULER FOR MULTI-USER WIRELESS COMMUNICATION SYSTEMS - CSIT error considerate delay-sensitive user access systems are provided in a multi-user OFDMA environment comprises a user delay sensitivity tracking component, a CSIT estimating component, a system queue state tracking component and a cross layer scheduling component. The techniques assume heterogeneous users with respect to delay and assume that CSIT information includes error, and optimally allocates broadcast resources, e.g., power, subcarriers and data rate, based on such assumptions.09-11-2008
20080219361Adaptive Pilot Symbol Allocation Method and Apparatus - According to one embodiment, a wireless communication device estimates channel response based on a reduced-density common pilot signal comprising a plurality of regularly spaced common pilot symbols when the reduced-density common pilot signal is sufficient for estimating the channel response with a desired accuracy. The wireless communication device estimates the channel response based on the reduced-density common pilot signal and one or more additional pilot symbols adaptively allocated to the wireless communication device when the reduced-density common pilot signal is insufficient for estimating the channel response with the desired accuracy.09-11-2008
20080219360SYSTEM AND METHOD FOR PERFORMING CHANNEL ESTIMATION USING INTERPOLATION - A system and method for performing channel estimation. The system includes a receiver for decoding OFDM. Upon receiving an OFDM symbol, a plurality of demodulated subcarrier modulation symbols for the OFDM symbol are generated. The demodulated subcarrier modulation symbols are then decoded to generate decoder output code symbols. At least a portion of the decoder output code symbols are reencoded, interleaved, and mapped to a set of reference symbols, where the set of reference symbols correspond to at least a portion of the plurality of subcarriers. A first set of channel estimates is generated, based on at least a portion of the set of reference symbols and a corresponding portion of the plurality of demodulated symbols. Remaining channel estimates are then interpolated from the first set of estimates by filtering the first set of estimates. The channel estimates are then used in decoding a current OFDM symbol being received by the receiver.09-11-2008
20100124293Method to Reduce Peak to Average Power Ratio in Multi-Carrier Modulation Receivers - Provided is a method for performing channel estimation in an Orthogonal Frequency Division Multiplexed (OFDM) signal. The method includes performing the channel estimation based upon use of reserved tone channel carriers.05-20-2010
20100202545Power distribution method and apparatus for OFDM system - An apparatus is capable of distributing power over a number of subcarriers in an OFDM system. The transmission power control method for an Orthogonal Frequency Division Multiplexing (OFDM) communication system according to the present invention includes measuring, at a receiver, channel coefficients of subcarriers, classifying the subcarriers into a predetermined number of groups according to sizes of channel coefficients, generating group indices, and transmitting the group indices of the subcarriers to a transmitter. A transmitter is capable of receiving the group indices of the subcarriers, determining per-group transmission powers, allocating the per-group transmission powers to the corresponding groups, distributing the per-group transmission power over subcarriers in the same level within respective groups, and transmitting signals over the subcarriers with the distributed power level.08-12-2010
20100202543COMMUNICATION SYSTEM AND METHOD OF OPERATIONS THEREFOR - A method of operation in a communication system is presented in which a first terminal sends to a second terminal a communication including ranging information by which the second terminal is able to calculate a range between the first terminal and the second terminal. The communication is sent in a plurality of frames. In at least one of the frames ranging information is included in a ranging region of the frame. The size and position of the ranging region is known to the first and second terminals without a ranging information indicator being sent in the frame to indicate the size and position of the ranging region.08-12-2010
20110096855POLARIZATION DIVISION MULTIPLEXED OPTICAL ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING TRANSMITTER AND RECEIVER - Provided is a polarization division multiplexed optical OFDM transmitter. The polarization division multiplexed optical OFDM transmitter includes a data demultiplexer, a training symbol generation unit and an optical up-converter and polarization division multiplexing unit. The data demultiplexer divides a transmission signal into a plurality of groups. The training symbol generation unit allocates a plurality of training symbols for each OFDM data which is included in the respective multiplexed groups, and allocates repetitive data in a time domain for the respective training symbols for data of 0 to periodically appear for the respective training symbols in a frequency domain. The optical up-converter and polarization division multiplexing unit performs optical frequency band conversion and polarization division multiplexing on an output of the training symbol generation unit to output a polarization division multiplexed optical OFDM signal corresponding to a plurality of polarization components.04-28-2011
20110096856OFDM TRANSMITTER AND METHOD FOR MULTI-USER MIMO TRANSMISSIONS - An orthogonal-frequency division multiplexed (OFDM) transmitter is configured to transmit a data unit in accordance with a multiple-input multiple-output (MIMO) technique over a wideband channel comprising a 20 MHz channel and another channel using a plurality of spatially diverse antennas. The transmitter is further configured to include in the data unit, a parameter indicating a modulation and coding scheme and a parameter indicating number of spatial streams. Each of the spatial streams is encoded and beamformed for receipt by one or more different receiving stations.04-28-2011
20110096854COMMUNICATIONS SYSTEM UTILIZING ORTHOGONAL LINEAR FREQUENCY MODULATED WAVEFORMS - An orthogonal linear frequency modulation (OLFM) communications system where orthogonal sub-sweeps experience the same channel condition and subsequent SNR allowing for uniform power allocation and data modulation per sub-sweep and an efficient exchange of modulation parameters for more optimized communications.04-28-2011
20110096853Channel estimation in communications - A time averaging filter for channel estimation is described. Different time averaging is used for different taps or tones of a communication system. Two methods are suggested for determining the time-averaging filter for channel estimation for the communication systems without prior knowledge of SNR, channel Doppler and fading statistics. The first method includes a bank of different filters, each tuned for optimality in a certain range of SNR and Doppler. For each tone in the frequency domain (or tap in the time domain), the first method selects a filter among the set of filters that minimizes a certain computed metric. The second method directly computes, at each tone (or tap), the “best” filter in a least-squares sense, using empirically determined second-order statistics.04-28-2011
20100215109Layer Mapping for Up Link Single User Multiple Input Multiple Output Wireless Telephony - This invention is a method and an apparatus to up link transmission of data from a user equipment to a base station for single user multiple input, multiple output. This invention includes receiving at least one codeword, permuting the received codewords, precoding the permuted codewords and transmitting the predecoded codewords on plural antennas. The codewords may be permuted by layer permutation or by codeword permutation.08-26-2010
20100215107METHODS AND APPARATUSES FOR DEALING WITH SPECTRUM INVERSION - An apparatus of processing a time domain synchronous orthogonal frequency-division-multiplexing (TDS-OFDM) signal is provided. The apparatus includes a receiving block and a demodulating block. The receiving block receives the TDS-OFDM signal, and generates a down-converted signal according to the received TDS-OFDM signal. The demodulating block is coupled to the receiving block, and demodulates the down-converted signal to generate a transport stream. The demodulating block has a transmission parameter signaling (TPS) decoder implemented for performing a TPS decoding operation to generate a TPS decoding result and verifying a spectrum direction of the received TDS-OFDM signal according to the TPS decoding result.08-26-2010
20090190677Physical Layer and Data Link Layer Signalling in Digital Video Broadcast Preamble Symbols - Aspects of the invention are directed to physical layer and data link layer signaling in digital video broadcast preamble symbols. Embodiments are directed to distributing physical layer pre-signalling data among preamble symbols. If physical layer data is larger than a predetermined number of preamble symbols, then excess physical layer data is written to data symbols immediately following the preamble symbols in top-down order symbol by symbol or the predetermined number of preamble symbols is increased. If physical layer data is not larger than the predetermined number of preamble symbols such that there is excess preamble symbol space, physical layer pipe 0 data comprising link layer signaling and notification data is carried in the excess preamble symbols or the excess preamble symbols are left empty. Different permutation rules may be used to frequency interleave odd-numbered versus even-numbered orthogonal frequency division multiplexing symbols.07-30-2009
20100166087DOWNLINK SUBCHANNELIZATION SCHEME FOR 802.16M - Two novel subchannelization methods are disclosed, for use in a 802.16m system. A downlink subchannelization method supports both localized and distributed sub-carriers, different modulation modes, and supports a variety of different fractional frequency reuse (FFR) group allocations.07-01-2010
20100166092TPS decoder for DVB-T television system and receiver using the same - A TPS decoder for a DVB-T digital television system includes an input signal estimator, a masking device, a vector index determinator and a lookup table device. The input signal estimator receives a plurality of frequency-domain input signals and a plurality of channel measure signals to thereby produce a plurality of estimated input signals. The masking device performs a masking operation on the estimated input signals to thereby produce a plurality of masking signals. The vector index determinator is based on the masking signals to determine a vector index corresponding to the frequency-domain input signals. The lookup table device is based on the vector index to produce a codeword.07-01-2010
20100166086Blind selected mapping for peak-to-average power ratio reduction in OFDM with PSK input - Orthogonal frequency division multiplexing (OFDM) is a spectrally efficient multicarrier modulation technique for high speed data transmission over multipath fading channels, but has low power efficiency. OFDM signals have large crest factors, or peak-to-average power ratios (PARs) which lead to power inefficiency in the RF portion of the transmitter. Selected mapping (SLM) is a distortionless technique that has good PAR reduction capability. However, the biggest limitation of SLM is the need to transmit side information. Disclosed is a technique or algorithm using constant modulus (i.e., phase shift keying, PSK) inputs that implements SLM without having to transmit any side information and without causing any distortion.07-01-2010
20100166089OFDM TRANSMITTER APPARATUS AND OFDM RECEIVER APPARATUS - An OFDM transmitter apparatus and an OFDM receiver apparatus wherein the calculation amount of cell search can be reduced and a faster cell search and a reduced circuit scale can be accomplished. A base station apparatus (07-01-2010
20100158145MULTIPLE INPUT MULTIPLE OUTPUT RADIO COMMUNICATION SYSTEM WITH PRE-EQUALIZER AND COMMUNICATION METHOD THEREOF - Multiple Input Multiple Output (MIMO) radio communication system and method are provided. A transmitter of the MIMO radio communication system includes an STBC encoding unit, a pre-equalization unit, and a transmit antenna unit. The STBC encoding unit receives a transmit data and performs an STBC encoding to output a plurality of encoded signals. The pre-equalization unit performs a pre-equalization process on the plurality of encoded signals to output a plurality of transmit signals. The transmit antenna unit transmits the plurality of transmit signals at different time. Also, a receiver of the MIMO radio communication system which includes a receive antenna unit, an STBC decoding unit, and a data output unit is provided.06-24-2010
20100158140SYSTEM AND METHOD FOR GENERATING A SIGNAL WITH A RANDOM LOW PEAK TO AVERAGE POWER RATIO WAVEFORM FOR AN ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING SYSTEM - A method for generating a signal with a random low peak to average power ratio waveform for an orthogonal frequency division multiplexing system involves processing a complex vector to generate a processed complex vector and performing an inverse fast Fourier transform on the processed complex vector to generate a signal with a random low peak to average power ratio waveform for an orthogonal frequency division multiplexing system.06-24-2010
20100158144SAMPLING FREQUENCY OFFSET ESTIMATION APPARATUS AND METHOD OF OFDM SYSTEM - A sampling frequency offset estimation apparatus of an orthogonal frequency division multiplexing (OFDM) system according to an aspect of the invention may include: a first differential operation unit performing complex conjugate multiplication of scattered pilots of complex symbols subjected to a fast Fourier transform (FFT) in an OFDM receiver; an interpolation unit repeating an operation of obtaining a median complex symbol between two consecutive symbols among complex symbols having first phase difference information from the first differential operation unit by a predetermined number; a second differential operation unit performing complex conjugate multiplication of two consecutive median complex symbols among median complex symbols from the interpolation unit; and a sampling frequency offset estimation unit estimating sampling frequency offset using complex symbols having second phase difference information from the second differential operation unit.06-24-2010
20100158143SYSTEM AND METHOD FOR SUBCARRIER ALLOCATION AND PERMUTATION - A subcarrier allocation method for use by a transmitter, the transmitter being configured to, when transmitting first and second data streams, allocate pilot symbols for the first and second data streams to subcarriers, such that a first plurality of subcarriers carry the pilot symbols for the first data stream and a second plurality of subcarriers carry the pilot symbols for the second data stream. The method includes allocating, when the transmitter transmits the first data stream but does not transmit the second data stream, the second plurality of subcarriers to carry no formation or information relating to the first data stream.06-24-2010
20100158142Multiple-Input Multiple-Output (MIMO) with Relay Nodes - A method for providing multiple-input multiple-output (MIMO) feedback information and configuration information. The method includes transporting the MIMO feedback information, configuration information, or both over an uplink relay link using higher layer signaling. Also included is a method for providing uplink data transmission over an access link. The method includes transporting the uplink data over an uplink access link using orthogonal frequency-division multiplexing access (OFDMA). Also included is a relay node comprising a processor configured to promote transmitting MIMO feedback information, configuration information, or both over an uplink relay link using higher layer signaling. Also included is a user agent (UA) comprising a processor configured to promote transmitting uplink data over an uplink access link using OFDMA.06-24-2010
20100067589METHOD AND APPARATUS FOR OPTIMIZING DOWNLINK TRANSMISSION IN A WIRELESS COMMUNICATION NETWORK - A method and apparatus for optimizing downlink transmission in a wireless communication network (03-18-2010
20100067590ADAPTIVE PILOT INSERTION FOR A MIMO-OFDM SYSTEM - A transmitting entity transmits a “base” pilot in each protocol data unit (PDU). A receiving entity is able to derive a sufficiently accurate channel response estimate of a MIMO channel with the base pilot under nominal (or most) channel conditions. The transmitting entity selectively transmits an additional pilot if and as needed, e.g., based on channel conditions and/or other factors. The additional pilot may be adaptively inserted in almost any symbol period in the PDU. The receiving entity is able to derive an improved channel response estimate with the additional pilot. The transmitting entity sends signaling to indicate that additional pilot is being sent. This signaling may be embedded within pilot symbols sent on a set of pilot subbands used for a carrier pilot that is transmitted across most of the PDU. The signaling indicates whether additional pilot is being sent and possibly other pertinent information.03-18-2010
20100067594Codebook generation system and associated methods - A codebook generation system and associated methods are generally described herein.03-18-2010
20100067593Method and Apparatus for Transmitting and Receiving Control Information in a Wireless Communication System - A base station transmits control information to a mobile station. A first control channel is transmitted to the mobile station. The first control channel contains an indication of the number of control channel occurrences in a frame. A second control channel is transmitted to the mobile station in a control subframe. The second control channel contains information for communicating a packet between the base station and the mobile station. The control subframe is determined from the number of control channel occurrences in the frame. The packet can then be communicated between the base station and the mobile station in a subframe based on the control channels transmitted.03-18-2010
20100067588Wireless Communication Apparatus, Antenna Calibration Method, and Computer Program - Reversibility in the directivity in the event of transmission/reception through a multi-antenna system is well suitably compensated for by executing self-calibration. A branch is set to a reference branch, and a forward loopback transfer function and a backward loopback transfer function are acquired, whereby per-branch calibration factors are calculated. Subsequently, an other branch is set to a reference branch, and calibration factors are calculated in a similar manner. Then, the calibration factor for the reference branch is corrected in accordance with the secondly obtained calibration factor so that a calibration condition is satisfied.03-18-2010
20110051829Method and Arrangement in a Cellular Communications System - The present invention relates to the area of wireless communication, and especially to a method and an arrangement for transmission output power control in a cellular telecommunications network. An improved transmission output power control is achieved by adapting a pre-defined power mask to a signal transmission characteristic of the signal transmission and applying the adapted power mask to a sub-frame or an OFDM symbol. The present invention could be implemented in a network node such as an eNodeB or in a user equipment.03-03-2011
20110051828METHOD AND SYSTEM FOR AN EFFICIENT CHANNEL QUANTIZATION METHOD FOR MIMO PRE-CODING SYSTEMS - A method and system for processing communication signals is provided and may comprise, quantizing a channel estimate at a MIMO receiver onto a codebook based on a cost function, wherein the codebook comprises a plurality of unitary matrices. A codebook index may be fed back from the MIMO receiver to a MIMO transmitter, wherein the codebook index is associated with one of the plurality of unitary matrices that minimizes the cost function. The cost function may be minimized by choosing a smallest scalar cost from a plurality of scalar costs, wherein each one of the scalar costs is generated from one or more sums and one or more products of elements of a product matrix, and wherein the product matrix is generated from one of the plurality of unitary matrices, a matrix comprising the channel estimate, and their respective Hermitian Transposes.03-03-2011
20110051827METHOD AND APPARATUS FOR TRANSMITTING PILOT IN WIRELESS COMMUNICATION SYSTEM - A method and apparatus for transmitting a pilot in a wireless communication system is provided. A pilot generating unit generates the pilot. A transmission circuitry transmits the pilot and a radio signal. A a processor assigns a first index and a second index to each of a plurality of pilot patterns, determines a selection pilot pattern having a first selection index and a second selection index calculated based on a cell ID, which are respectively identical with the first index and the second index, from among the plurality of pilot patterns, and maps the generated pilot to a resource element based on the selection pilot pattern.03-03-2011
20110051826Method for efficiently performing MULTI-BS MIMO operation in a broadband wireless access system - A method for determining temporary Base Station (BS) Identifiers (IDs) to efficiently set a multi-BS Multiple Input Multiple Output (MIMO) transmission mode and an apparatus for implementing the same in a broadband wireless access system are disclosed. To perform a multi-BS MIMO operation, a Mobile Station (MS) receives a first broadcast message including system information about a plurality of neighbor BSs from a serving BS, receives a second broadcast message including BS set information from the serving BS, the BS set information specifying indexes of one or more neighbor BSs which can be involved in the multi-BS MIMO operation among the plurality of neighbor BSs, and determines a temporary BS ID of each BS included in the BS set information using the specified indexes.03-03-2011
20110051825A MULTI-CARRIER DIGITAL MOBILE MULTIMEDIA BROADCAST SYSTEM AND THE DIGITAL INFORMATION TRANSMISSION METHOD THEREOF - The present invention discloses a multi-carrier digital multimedia broadcast system and the digital information transmission method thereof. After RS encoding and byte interleaving, LDPC encoding, bit interleaving and constellation mapping to an upper layer of data streams in turn, the obtained data symbol is multiplexed with scattered pilots and continual pilots which include the system information to form an OFDM frequency domain symbol and scrambled; an OFDM time domain symbol is generated by IFFT transforming, and after inserted with the frame head to build a time slot, it is connected to form a signal frame of the physical layer; the signal frame of the physical layer is transmitted after being low-pass filtered and orthogonal upconverted. The system and method thereof provide wireless broadcast with high quality such as audio, video and multimedia data and the like for mobile, fixed and portable receivers, and can use the satellite transmission and terrestrial transmission method for transmitting. The method utilizes the LDPC OFDM scheme, and the system applies the microwave and large scale integrated circuit technologies while fulfills the needs for low cast and high performance.03-03-2011
20110182376WIRELESS COMMUNICATION SYSTEM, BASE STATION DEVICE, MOBILE STATION DEVICE, AND COMMUNICATION METHOD - A reference signal specific to each base station device and a reference signal specific to each mobile station device are not mixed within one OFDM symbol of a resource block, and OFDM symbols including the reference signal specific to each mobile station device are arranged at regular intervals on a time axis. By using such a signal arrangement pattern, it is possible to overcome the problems in Non-Patent Document 1 mentioned above caused by mixing a reference signal specific to each base station device and a reference signal specific to each mobile station device in one OFDM symbol. Thus, it becomes possible to prevent the reference signal specific to each base station device and the reference signal specific to each mobile station device from being mixed within one OFDM symbol of a resource block.07-28-2011
20110188594METHOD AND APPARATUS FOR TRANSMITTING SIGNALS - Disclosed herein is a method for transmitting signals in a wireless communication system, including joint coding one or more signals, separating the joint coded signal by a number of a plurality of channel aggregation used for transmission, respectively allocating the separated signals to the plurality of the channel aggregation, and transmitting the signals, such that a receiver smoothly performs decoding.08-04-2011
20110188593MOBILE STATION APPARATUS, MOBILE COMMUNICATION SYSTEM AND TRANSMISSION METHOD - To transmit all the data at a time, while controlling the PAPR to within low levels in a simplified configuration when a response to downlink data, downlink CQI and request for uplink data transmission are made at the same time, a mobile station apparatus 08-04-2011
20110188592BASE STATION AND METHOD FOR TRANSMITTING DOWNLINK REFERENCE SIGNALS FOR MIMO CHANNEL ESTIMATION - In a wireless network, a base station is configured to transmit downlink reference signals to allow a mobile device to derive a MIMO channel estimate.08-04-2011
20110188591Method and Apparatus for Impairment Correlation Estimation in MIMO Systems - The teachings herein disclose methods and apparatus that simplify impairment correlation estimation for received signal processing, based on determining, for any given processing interval, which impairment contributors should be considered in the estimation of overall received signal impairment correlations. These simplifications reduce computational processing requirements, allowing reduced circuit complexity and/or reduced operating power, and improve receiver performance. A corresponding transmitter and transmission method include transmitting multiple information streams to targeted receivers according to ongoing scheduling, and controlling the ongoing scheduling to reduce the number of impairment contributors considered in impairment correlation estimation at the targeted receivers. In one embodiment, a receiver identifies which impairment contributors to consider based on receiving control information. In another embodiment, the receiver identifies the impairment contributors to consider based on background processing, e.g., background determination of parametric model fitting parameters for a plurality of impairment contributors, and observing those model fitting parameters over time.08-04-2011
20110188590Method and System for Providing Broadband Access to a Data Network Via Gas Pipes - A method and system for providing broadband access to a data network via gas pipes is disclosed. Embodiments of the present invention utilize Orthogonal Frequency-Division Multiplexing (OFDM) or Frequency-Division Multiplexing (FDM) as a modulation technique in order to protect against the effects of dispersion in the gas pipes. An OFDM transceiver modulates a digital data stream into an OFDM signal, RF up-converts the OFDM signal, and transmits the RF up-converted OFDM modulated signal through a gas pipe.08-04-2011
20110188589MULTIPLEXING DEVICE AND METHOD FOR ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING SYSTEM - A multiplexing device for orthogonal frequency division multiplexing (OFDM) system comprises a first unit for combining N-path differential-modulation symbol sequences and mapping to sub-carriers of inverse fast Fourier transformation, N is an integer which is greater than 1, and a second unit for executing the IFFT of sub-carriers to realize frequency division multiplexing of multi-path differential-modulation symbol sequences. The multiplexing transmitting device can not only realize multiplexing transmission of multi-path signals in differential OFDM system, but also the device can be very simply realized, the multiplexing method for OFDM system is also disclosed.08-04-2011
20110188587MIMO RELATED SIGNALING IN WIRELESS COMMUNICATION - Certain aspects of the present disclosure relate to techniques for multiple-input multiple-output (MIMO) related signaling in a wireless communication system. In an aspect, a method for wireless communication is provided which includes receiving a signal associated with a downlink control channel, the signal including information specific to a user equipment (UE); and selecting, based on the information, a UE-specific reference signal (RS) pattern from a plurality of UE-specific RS patterns.08-04-2011
20090175370PILOT SIGNAL TRANSMITTING METHOD, RADIO COMMUNICATION SYSTEM, AND APPARATUS AND PROGRAM USED FOR THE SAME - A larger cell uses a pilot pattern with a higher pilot density in a frequency axis direction to improve a channel estimation accuracy when a frequency selective fading variation is large. Meanwhile, a smaller cell uses a pilot pattern with a lower pilot density in the frequency axis direction. A pilot pattern that each base station uses is transmitted to a mobile station in a cell as a report signal.07-09-2009
20090175365Modulation and demodulation apparatuses and methods for wired/wireless communication system - Wired/wireless optical signal modulation and demodulation apparatuses and methods using an intensity modulation/direct detection method and an orthogonal frequency division multiplexing (OFDM) method are provided. A unipolar OFDM symbol frame is generated by determining the polarity of each of a plurality of sub-frames of a bipolar OFDM symbol frame which comprises both a plurality of positive pulses and a plurality of negative pulses, inverting the polarity of the sub-frames which are determined to be negative, delaying one of the positive sub-frame and a positive sub-frame obtained through the inversion by the duration of the sub-frames, and multiplexing the result of the delaying and whichever of the positive sub-frame and the positive sub-frame obtained through the inversion is not the result of the delaying. The unipolar OFDM symbol frame can guarantee high power amplification efficiency and high transmission power efficiency, and is robust against a multi-path channel environment. Therefore, the unipolar OFDM symbol frame can be used in various optical signal modulation/demodulation methods for wireless indoor broadband optical transmission devices, wired broadband optical transmission devices using multi-mode optical fibers, and radio-over-fiber devices which transmit baseband analog signals as optical signals.07-09-2009
20090175373SYMBOL MAPPING METHOD FOR REPETITION CHANNEL CODING - A symbol mapping method for repetition coding is disclosed. The symbol mapping method comprises performing repetition coding on codeword to output repeated codeword symbols, and mapping the repeated codeword symbols with subcarriers located in different localized resource blocks. According to the embodiments of the present invention, it is possible to obtain maximum reliability in a receiving side by mapping codeword bits with subcarriers to reduce the number of bits having low reliability when a transmitting side uses repetition coding. Also, it is possible to improve decoding throughput and obtain channel diversity.07-09-2009
20090175372METHOD OF TRANSMITTING DATA IN WIRELESS COMMUNICATION SYSTEM - A method of transmitting data in a wireless communication system, includes: transmitting first data via a first frame for a first wireless communication system; transmitting second data via a second frame for a second wireless communication system supporting backward compatibility with respect to the first wireless communication system; and transmitting control information with respect to the first and second frames, wherein the control information includes a frame control header (FCH) which indicates information about the second frame by using a reserved bit region of the first frame.07-09-2009
20090175371Methods and apparatus for downlink PDSCH power setting - Methods and apparatus for transmitting power setting information in a downlink Physical Downlink Shared Channel (PDSCH) in a communication system. In this communication system, a plurality of methods for calculating traffic-to-pilot ratios (T2P) are established. In addition, a mapping scheme between a plurality of overhead signals and a plurality of reference signal (RS) overhead ratios, η07-09-2009
20090175368Multiple Resolution Mode Orthogonal Frequency Division Multiplexing System and Method - The disclosed embodiments relate to a system and method for processing communication signals. An exemplary method of processing a received orthogonal frequency division multiplexing (OFDM) broadcast signal having a frequency spectrum comprises demodulating the OFDM broadcast signal over a subset of the frequency spectrum to create a first demodulated signal component corresponding to a first signal component the first signal component being representative of a lower resolution version of a second signal component and providing data corresponding to the first demodulated signal component.07-09-2009
20090175367WIRELESS COMMUNICATION DEVICE - A wireless communication device (07-09-2009
20090175362APPARATUS, AND ASSOCIATED METHOD, FOR DETECTING PACKETS - In a robust system and method for detecting packets in SISO and MIMO broadband multicarrier transmission, a packet detector computes continuously the sum of the moduli of the power-normalized auto-correlations of a sequence of received signals (07-09-2009
20090175364METHODS AND APPARATUS FOR MAXIMUM RATIO COMBINING FOR DUPLICATED SIGNALS IN OFDMA SYSTEMS - In accordance with a method for processing a received orthogonal frequency division multiple access (OFDMA) signal that comprises a duplicated signal, sub-carriers within the OFDMA signal may be arranged into a duplicated format. The OFDMA signal may be equalized and combined after the sub-carriers have been arranged into the duplicated format. The equalizing and combining may be performed in accordance with a maximum ratio combining (MRC) scheme. The OFDMA signal may be demapped after the equalizing and combining is performed.07-09-2009
20090175366METHOD AND SCHEME FOR SPACE-TIME CODED COCHANNEL INTERFERENCE CANCELLATION - An apparatus, system, and method for space-time cochannel interference cancellation are described. The apparatus may include a time stacking module to stack consecutive subcarrier signals for a period of time equal to several symbols and a space-time subcarrier beamformer module to perform space-time subcarrier beamforming by applying space-time beamformer weights to stacked symbols on one or more subcarriers. The space-time beamformer weights may be calculated based on spatial and time correlation properties of one or more interference signals. Other embodiments are described and claimed.07-09-2009
20110188588APPARATUS FOR TRANSMITTING AND RECEIVING A SIGNAL AND METHOD OF TRANSMITTING AND RECEIVING A SIGNAL - The present invention relates to method of transmitting and receiving signaling and a corresponding apparatus. One aspect of the present invention relates to a method of receiving a signal, which includes a preamble, where a bandwidth of the preamble is identical with a bandwidth of a tuner of a receiver.08-04-2011
20100027700Communication System, Base Station, Terminal and Communication Method of OFDM System - Provided are a communication system, a base station, a terminal and a communication method of an OFDM system, using an adaptive array, which are capable of alleviating signal quality deterioration by reducing the probability of instant peak power raises. The communication system includes a data producing means 11 for acquiring communication network side data and a user assignment band in a predetermined format, encoding the data, and performing mapping for the user assignment band, null symbol inserting means 02-04-2010
20100027699COMMUNICATION SYSTEM, TRANSMISSION APPARATUS, AND RECEIVING APPARATUS - A transmission apparatus for performing an orthogonal frequency division multiplexing (OFDM) transmission generates an OFDM symbol in which a modulation parameter used at a time of transmitting data is arranged in a subcarrier of a direct current component and transmits a transmission frame including the generated OFDM symbol. A receiving apparatus calculates an average value in an effective symbol period within the OFDM symbol included in the transmission frame received, extracts the modulation parameter arranged in the subcarrier of the direct current component based on the calculated average value, and performs OFDM demodulation processing using the extracted modulation parameter.02-04-2010
20100027698APPARATUS AND METHOD FOR ESTIMATING CHANNEL IN OFDM/OFDMA BASED WIRELESS COMMUNICATION SYSTEM - A channel estimation apparatus of the present invention includes a preamble channel operation unit for carrying out an operation on pilot channel estimation values of pilots, which are transmitted from a transmitting antenna that transmits a preamble, as an improved pilot channel estimation value by employing a preamble channel estimation value based on a preamble included in received signals respectively received by a plurality of receiving antennas, a first channel estimation unit for estimating a channel for each of the receiving antennas through interpolation of a symbol axis and a frequency axis employing the improved pilot channel estimation value, and a second channel estimation unit for estimating a channel for each of the receiving antennas through interpolation of a symbol axis and a frequency axis employing pilot channel estimation values of pilots transmitted from the same transmitting antenna, of pilots transmitted from a transmitting antenna that does not transmit the preamble, of a plurality of transmitting antennas.02-04-2010
20100027697MIMO TRANSMISSION WITH LAYER PERMUTATION IN A WIRELESS COMMUNICATION SYSTEM - Techniques for supporting MIMO transmission with layer permutation are described. In one aspect, multiple codewords may be generated for transmission from multiple antennas (e.g., virtual antennas), with the number of codewords being less than the number of antennas. Each codeword may be mapped across the multiple antennas. Two codewords may be generated. For rank 3, the first codeword may be mapped to one layer (or one antenna on each subcarrier), and the second codeword may be mapped to two layers (or two antennas on each subcarrier). For rank 4, each codeword may be mapped to two layers. In another aspect, a base CQI indicative of an average signal quality may be determined. A delta CQI indicative of improvement over the average signal quality may also be determined. In yet another aspect, selection may be performed with different penalty factors for different ranks or number of codewords.02-04-2010
20100027696METHOD OF DATA TRANSMISSION IN A WIRELESS COMMUNICATION SYSTEM - A method for transmitting data in a wireless communication system is provided. The method includes encoding one or more input data according to a specific coding rate and modulating the input data according to a specific modulation scheme, applying virtual antenna signaling to the one or more encoded and modulated input data based on a specific spatial multiplexing rate, and performing spatial processing on the input data, to which the virtual antenna signaling has been applied, and then transmitting the input data to a receiving end.02-04-2010
20100027695METHOD FOR TRANSMITTING CONTROL INFORMATION TO INSTRUCT RECEIVER - A method for transmitting control information to indicate a receiver, comprising following steps: the control information is formed at transmitting side and is encoded based on the working status of the transmitting side of the system; after the encoded control information is mapped, it is multiplexed with other pilot symbol and service load, then an OFDM symbol is generated; the OFDM symbol is transformed from frequency domain to time domain, then a time domain sampling signal is obtained and transmitted to the receiving side of the system; at the receiving side, the time domain sampling signal transmitted by the transmitting side is received and transformed from time domain to frequency domain to form OFDM symbol; the control information is obtained from the valid sub carrier of the OFDM symbol, and the control information is decoded; each work information is extracted form the decoded control information, and the receiving terminal is indicated to execute respective receive process based on the extracted work information. The method can ensure the receiving terminal to receive data based on its own expectation, then reduces the work power consumption of the receiving terminal, and saves the run cost of the digital broadcast system.02-04-2010
20100027692METHOD AND SYSTEM FOR A REFERENCE SYMBOL (RS) FREQUENCY CONTROL LOOP FOR TXCO SYNCHRONIZATION AND TRACKING - Aspects of a method and system for an RS frequency control loop for TXCO synchronization and tracking may include tracking a carrier frequency in an Orthogonal Frequency Division Multiplexing (OFDM) signal based on at least a reference symbol set. A receiver frequency may be adjusted based on at least the tracked carrier frequency. The carrier frequency may be tracked by generating an output signal as a function of a frequency offset Δf in a frequency discrimination feedback loop. The reference symbol (RS) set may be generated in an RS extraction module or circuit, from at least a fast Fourier transform of the received OFDM signal. The receiver frequency may be coarsely adjusted and then finely adjusted. The coarse receiver frequency adjustment may be based on processing at least a primary synchronization signal and a secondary synchronization signal.02-04-2010
20100020892APPARATUS AND METHOD FOR GENERATING SYMBOL FOR MULTIPLE ANTENNAS - The present invention relates a symbol generation apparatus for multiple antennas having low receiving complexity and having flexibility with respect to an increase in the number of antennas. The symbol generation apparatus includes a plurality of space-time channel encoders respectively corresponding to a plurality of channels, and an inverse fast Fourier transformer group. The respective space-time channel encoders receive a digital-modulated symbol group from the corresponding channel, perform a space-time encoding operation with respect to a plurality of space areas and at least one time area, shift phases by using a plurality of phase values, and generate a plurality of phase-shifted space-time codewords. The inverse fast Fourier transformer group performs an inverse fast Fourier transform operation by using the plurality of phase-shifted space-time codewords in a plurality of subcarriers respectively corresponding to the plurality of channels, and generates a plurality of inverse fast Fourier transformed signals.01-28-2010
20100020891WIRELESS COMMUNICATION SYSTEM, WIRELESS COMMUNICATION APPARATUS AND WIRELESS COMMUNICATION METHOD, ENCODING APPARATUS AND ENCODING METHOD, AND COMPUTER PROGRAM - A wireless communication apparatus includes: plural antennas; a channel matrix acquiring unit acquiring a channel matrix for each sub-carrier; a channel matrix encoding unit encoding the acquired channel matrix of each sub-carrier, by decomposition from signals in fixed-point representation into data and amplitude parts with a predetermined bit width; and a channel matrix information delivery unit delivering the encoded channel matrix information to a communication party. The encoding unit retrieves a first maximum value as the maximum of channel matrix elements in all sub-carriers, in plural levels, and determines an amplitude part and a normalization coefficient for normalizing channel matrix elements to a data part having the predetermined bit width, based on a ratio between a second maximum value as the maximum of channel matrix elements with respect to each sub-carrier and the first maximum value, and multiples channel matrix elements by the normalization coefficient to obtain a data part.01-28-2010
20100020890WIRELESS COMMUNICATION SYSTEM WITH MULTIPLE TRANSMISSION ANTENNAS USING PILOT SUBCARRIER ALLOCATION - A method of allocating pilot subcarriers in a resource block for a wideband wireless mobile communication system with multiple transmission antennas using orthogonal frequency division multiplexing (OFDM) modulation is disclosed. In this method, pilot subcarriers are allocated to the resource block comprised of five (5) or seven (7) OFDM symbols so that only four (4) OFDM symbols of the resource block are allocated for pilot subcarriers.01-28-2010
20110216842TRANSMISSION OF UE-SPECIFIC REFERENCE SIGNAL FOR WIRELESS COMMUNICATION - Techniques for transmitting UE-specific reference signals (UE-RSs) in a wireless network are described. In an aspect, a UE-RS may be transmitted in different manners depending on the number of layers used for data transmission. In one design, a cell may determine subcarriers for a UE-RS based on a frequency shift if data is transmitted on one layer and based on a predetermined set of subcarriers (with no frequency shift) if data is transmitted on multiple layers. In another aspect, a UE-RS may be transmitted on subcarriers determined based on a frequency shift for data transmission on multiple layers. In yet another aspect, a UE-RS may be transmitted from a plurality of cells to a UE for coordinated multi-point (CoMP). In yet another aspect, a UE-RS may be transmitted in a data section of a subframe including only the data section.09-08-2011
20110216844BASE STATION, MOBILE STATION AND METHOD - A base station performs communication of an orthogonal frequency division multiplexing (OFDM) scheme with a mobile station by using any one of equal to or greater than two frequency bands. The base station includes means that transmits a synchronization channel and a control channel using a band that includes a center frequency f09-08-2011
20110216843TECHNIQUES TO REDUCE FALSE DETECTION OF CONTROL CHANNEL MESSAGES IN A WIRELESS NETWORK - A method and system of reducing false detection of control channel messages in a wireless communication system. This facilitates blind detection of control channel messages in the wireless communication network. In one embodiment of the invention, the control messages in the wireless communication system are randomized or scrambled to minimize or lower the probability of false detection of the control channel messages. The control channel message includes, but is not limited to, an Assignment Advanced Media Access Protocol (A-A-MAP) Information Element (IE) and the like. In one embodiment of the invention, the contents of the A-A-MAP IE are randomized or scrambled before encoding into A-A-MAP symbols.09-08-2011
20110216841BLOCK AGGREGATION OF OBJECTS IN A COMMUNICATION SYSTEM - A method of mapping m individual objects to source symbols for delivering data from a transmitter to a receiver in a communication system, the m individual objects ordered from object 09-08-2011
20100189188AUTOMATIC GAIN CONTROL (AGC) FOR OFDM-BASED TRANSMISSION IN A WIRELESS COMMUNICATION NETWORK - Techniques for performing automatic gain control (AGC) at a receiver are described. The receiver may receive an OFDM-based symbol composed of a cyclic prefix and a useful portion. The receiver may scale the OFDM-based symbol with an initial receiver gain, adjust the initial receiver gain based on the cyclic prefix, apply the adjusted receiver gain prior to the useful portion, and process the useful portion to recover at least one signal sent by at least one transmitter. The receiver may select the initial receiver gain, e.g., based on a predicted received power level for the at least one transmitter, a pattern of different receiver gains, etc. The receiver may apply the initial receiver gain at the start of the OFDM-based symbol. The receiver may measure the power of a set of samples in the cyclic prefix and may adjust the receiver gain based on the measured power and a target power.07-29-2010
201201479814K MODE INTERLEAVER WITH ODD INTERLEAVING ONLY AND PER OFDM SYMBOL PERMUTATION CODE CHANGE IN A DIGITAL VIDEO BROADCASTING (DVB) STANDARD - A data processing apparatus maps input symbols to be communicated onto a predetermined number of sub-carrier signals of an Orthogonal Frequency Division Multiplexed (OFDM) symbol. The data processor includes an interleaver memory which reads-in the predetermined number of data symbols for mapping onto the OFDM sub-carrier signals. The interleaver memory reads-out the data symbols on to the OFDM sub-carriers to effect the mapping, the read-out being in a different order than the read-in, the order being determined from a set of addresses, with the effect that the data symbols are interleaved on to the sub-carrier signals. The set of addresses are generated from an address generator which comprises a linear feedback shift register and a permutation circuit. The linear feedback shift register has eleven register stages with a generator polynomial for the linear feedback shift register of R06-14-2012
20090003470OFDM OOB emission suppression at specific frequencies - In general, in one aspect, the disclosure describes an apparatus that includes a radio to provide wireless communications using Orthogonal Frequency Division Multiplexing (OFDM) signaling. A controller is used to determine location of un-modulated carriers in order to suppress out of band (OOB) emissions at a particular frequency.01-01-2009
20110044393APPARATUS FOR TRANSMITTING AND RECEIVING A SIGNAL AND METHOD OF TRANSMITTING AND RECEIVING A SIGNAL - The present invention relates to method of transmitting and receiving signals and a corresponding apparatus. One aspect of the present invention relates to a method of receiving a signal, which includes an L1 signaling region where the L1 signaling has an adaptive L1 block structure for increased spectrum efficiency in a channel bonding environment.02-24-2011
20090067522WIRELESS COMMUNICATION SYSTEM USING PILOT SUBCARRIER ALLOCATION - A wireless communication system using pilot subcarrier allocation and a method of allocating the pilot subcarriers for use in downlink and uplink communication in a multiple-input multiple-output (MIMO) antenna system using orthogonal frequency division multiplexing (OFDM) modulation are disclosed. The method includes providing a frame structure comprising OFDM symbols in time domain and subcarriers in frequency domain and alternately allocating first pilot subcarriers for a first antenna and second pilot subcarriers for a second antenna in the time and frequency domains, wherein each of the alternating first pilot subcarriers and the second pilot subcarriers is separated by multiple of 9 subcarriers in the frequency domain and further allocated in two contiguous OFDM symbols.03-12-2009
20080285669MIMO WLAN SYSTEM - A multiple-access MIMO WLAN system that employs MIMO, OFDM, and TDD. The system (1) uses a channel structure with a number of configurable transport channels, (2) supports multiple rates and transmission modes, which are configurable based on channel conditions and user terminal capabilities, (3) employs a pilot structure with several types of pilot (e.g., beacon, MIMO, steered reference, and carrier pilots) for different functions, (4) implements rate, timing, and power control loops for proper system operation, and (5) employs random access for system access by the user terminals, fast acknowledgment, and quick resource assignments. Calibration may be performed to account for differences in the frequency responses of transmit/receive chains at the access point and user terminals. The spatial processing may then be simplified by taking advantage of the reciprocal nature of the downlink and uplink and the calibration.11-20-2008
20090147873ROBUST INTEGER CARRIER FREQUENCY OFFSET ESTIMATOR - A robust integer carrier frequency offset estimation method for OFDM systems is disclosed. Compared with conventional methods which use either two consecutive OFDM symbols or only one training symbol, the method is insensitive to the timing offset as long as the channel spread is shorter than the OFDM cyclic prefix length. Most importantly, it does not require any information on the scrambling code used in systems such as STiMi. The method improves the accuracy of integer carrier frequency offset, especially in channels with long and strong echoes. It offers the receiver more freedom in setting the FFT window since it is insensitive to the timing offset.06-11-2009
20100034305Method and Apparatus of Establishing a Synchronisation Signal in a Communication System - A method of establishing a synchronization signal in a communication system is disclosed. A set of discrete Fourier frequency coefficients is defined and transformed into a discrete time representation, the discrete time representation being particularly useful as a synchronization signal. According to example embodiments of the invention, signal symmetry is exploited. Preferably, the center frequency, also referred to as DC subcarrier, is not used for transmission. The invention also concerns a transmitter and receiver of a communication system.02-11-2010
20090116568Method and Apparatus for Interference Rejection Combining and Detection - A multi-branch OFDM receiver combines diversity signals received over different receiver branches using interference rejection combining. The receiver generates first channel estimates associated with a serving base station, second channel estimates associated with at least one non-serving base station, and a time offset between the serving base station and non-serving base station. The receiver computes a noise covariance matrix based on the second channel estimates and the time offset, and then combines the diversity signals received over different branches using the first channel estimates and the noise covariance matrix.05-07-2009
20100177832CALCULATING PEAK-TO-AVERAGE POWER RATIO REDUCTION FOR MULTI-CARRIER MODULATED SIGNALS USING A GRADIENT-DESCENT APPROACH - In one embodiment, the present invention is a method for reducing the peak-to-average power ratio (PAPR) of a multi-carrier modulated symbol, such as an orthogonal frequency division multiplexed (OFDM) symbol. The method first transforms a set of data symbols into a multi-carrier modulated symbol. The method then uses the multi-carrier modulated symbol and a gradient-descent algorithm to generate a set of symbols for PAPR-reduction tones. The data symbols and the PAPR-reduction symbols are then transformed to generate an updated multi-carrier modulated symbol. The PAPR-reduction symbols are iteratively updated until a terminating condition occurs (e.g., an acceptable PAPR is achieved for the multi-carrier modulated symbol). In another embodiment, the method uses the multi-carrier modulated symbol generated in the first step and a gradient-descent algorithm to generate an updated multi-carrier modulated symbol directly, where the need for transforming the data symbols and the PAPR-reduction symbols is eliminated for subsequent iterations. 07-15-2010
20100246699Communication system, data transmitter, and data receiver capable of detecting incorrect receipt of data - A transmitter cyclic pattern having a pattern length of N bits is generated and converted into an M-bit transmitter parallel data stream, where N≠M. A bit-sequence altered transmitter parallel data stream is generated by performing a transmitter altering process, converted into a serial data and transmitted together with a clock signal. The serial data is received and converted into an M-bit receiver parallel data stream, and a bit-sequence restored parallel data stream is generated by performing a process opposite to the transmitter altering process. A receiver cyclic pattern is generated by using bits in the bit-sequence restored parallel dada stream and converted into an M-bit reference parallel data stream, and a bit-sequence altered reference parallel data stream is generated by performing a process same as the transmitter altering process and compared with the received parallel data to test if the data is correctly received.09-30-2010
20120307925Peak-To-Average Power Ratio Reduction For Wireless Communication Systems - Disclosed is a wireless communication signal peak-to-average power ratio reduction, method. The method comprises calculating a peak envelope from an envelope of an input signal using a clipping threshold; smoothing the peak envelope using a window function; mapping the smoothed peak envelope to an attenuation function using the clipping threshold; and applying the attenuation function to the input signal.12-06-2012
20120307923Inverse Signal Transformation - This application presents inverse signal transformation (IST) reversing transmission channel transfer function, in order to achieve a direct recovery of original data and synchronizing clock from received signals affected by all deterministic and random distortions introduced by the channel. The direct data recovery can eliminate an intermediate recovery of signal transmitted originally from received signal, required in conventional solutions before actual data recovery can be made. Therefore IST can prevent signal processing errors added by such intermediate recovery and reduce power consumption and computing resources required in conventional receivers.12-06-2012
20120307924MULTIPLE INPUT MULTIPLE OUTPUT (MIMO) TRANSMITTED SIGNAL VECTOR ESTIMATION EMPLOYING MONTE CARLO SAMPLING TECHNIQUES - A method of determining a transmitted vector (x) in a MIMO receiver includes the steps of receiving a received vector (y) representative of the transmitted vector (x), generating a first random number and forming, in a first iteration, a first symbol of a first candidate vector, the candidate vector representing a potential solution vector. The step of forming is based on a first approach if the first random number is greater than a first predetermined value (q), but is based on a second approach if the random number is less than or equal to the first predetermined value (q). The first approach randomly selects the first symbol from a uniform distribution of symbols in the transmission alphabet. The second approach selects the first symbol based on Gibbs sampling. The method represents a randomized Markov Chain Monte Carlo (RMCMC) sampling technique.12-06-2012
20120307922UE SIGNAL QUALITY MEASUREMENTS ON A SUBSET OF RADIO RESOURCE ELEMENTS - A user equipment (UE) receives a radio signal which includes a time-frequency grid of radio resource elements. A UE detector measures a signal quality parameter associated with a subset of the radio resource elements in the time-frequency grid. The subset of the radio resource elements is less than a total number of the radio resource elements in the time-frequency grid and corresponds to an individual radio channel. Radio circuitry in the UE reports to a network node the signal quality parameter measured for the subset of the radio resource elements in the time-frequency grid to enable an operation related, for example, to the individual radio channel.12-06-2012
20110103496IQ Impairment Estimation in an OFDM Signal - System and method for evaluating a transmitter by estimating IQ impairments in an orthogonal frequency division multiplexed (OFDM) signal generated by the transmitter. The OFDM signal may be received. The OFDM signal may represent a stream of symbols, each comprising a plurality of subcarriers. At least a subset of the subcarriers may be pilot subcarriers. The pilot subcarriers may be grouped into one or more groups of pilot subcarriers based on one or more conditions: a pilot subcarrier which satisfies a condition in its relation to a mirror subcarrier may be grouped with other pilot subcarriers which also satisfy the condition in relation to mirror subcarriers. An estimate of one or more of gain imbalance or quadrature skew of the OFDM signal may be calculated based on the one or more groups of pilot subcarriers and the one or more conditions. The estimate may be used to evaluate the transmitter.05-05-2011
20100239036METHOD AND APPARATUS FOR TRANSMITTING PRECODING MATRIX INDEX IN A WIRELESS COMMUNICATION SYSTEM USING CoMP SCHEME - A method and apparatus for transmitting a Precoding Matrix Index (PMI) in a Coordinated Multi-Point (COMP) communication system are disclosed. The method includes receiving signals in a same frequency band from Base Stations (BSs) included in a CoMP set, which operate in joint processing mode, selecting a first precoding matrix for each of the BSs using the received signals, generating a second precoding matrix by combining the first precoding matrices, and transmitting an index of the second precoding matrix to a serving BS among the BSs.09-23-2010
20110116563MIMO DESIGN WITH CODEBOOK RESTRICTIONS - A method of wireless communication includes utilizing a first outer loop for single-stream transmissions when a requested PCI by a UE is within a first set. The utilizing the first outer loop includes utilizing a first outer loop margin to adjust a size of a transport block by a first backoff margin when the UE requests a PCI within the first set. The method further includes utilizing a second outer loop for single-stream transmissions when the requested PCI by the UE is within a second set different from the first set. The utilizing the second outer loop includes utilizing a second outer loop margin to adjust the size of the transport block by a second backoff margin when the UE requests a PCI within the second set.05-19-2011
20110116562Digital Communications Receiver and Method of Estimating Residual Carrier Frequency Offset In A Received Signal - A residual carrier frequency offset of a signal received by a receiver, which has a local frequency oscillator that generates a carrier frequency different from a carrier frequency generated by a local frequency oscillator at a transmitter that transmitted the received signal is estimated using first and second channel impulse responses derived from first and second portions of the received signal, an estimated phase difference between the first and second channel impulse responses, and an estimate of the residual carrier frequency offset computed using the estimated phase differences. The residual carrier frequency offset is estimated after most of the carrier frequency offset has been removed from the received signal using conventional means.05-19-2011
20090135932POWER-LINE CARRIER COMMUNICATION APPARATUS - The invention provides a power-line carrier communication apparatus including a transmission unit with a signal point mapping device for mapping a plurality of bit streams produced from transmission data, a wavelet inverse transforming device for modulating the respective sub-carriers by wavelet waveforms which are orthogonal to each other for producing temporal waveform series data, and a D/A converter for converting the temporal waveform series data into an analog temporal waveform series signal; and a reception unit with an A/D converter for obtaining sampling-series waveform data from a power-line communication signal, a wavelet transforming device for wavelet-transforming the sampling-series waveform data into signal point data of the respective sub-carriers, and a symbol judging device for judging bit streams mapped by the signal point mapping device by inverse-mapping a plurality of these signal point data, and for synthesizing the judged bit streams with each other as a reception data series.05-28-2009
20110150110Tone Count Selection - A tone selection module selects tones suitable for use in an orthogonal frequency division multiplexing (OFDM) data transmission device based on several constraints. These constraints include number of available tones, modulation type, and code rate. The OFDM device may use either wired or wireless transmission.06-23-2011
20110135022METHOD OF ESTIMATING TRANSMISSION CHANNEL RESPONSE AND DIFFERENCE OF SYNCHRONIZATION OFFSETS INTRODUCED IN A RECEIVED STREAM OF PACKETS OF OFDM DATA AND RELATIVE RECEIVER - An OFDM receiver includes a sampling circuit configured to sample an incoming signal received through a transmission channel and an estimation circuit configured to receive samples of the incoming signal and to estimate transmission channel response and eventual differences of synchronization offsets introduced at a receiver side. An equalizer may be coupled to the estimation circuit and configured to compensate an effect of the transmission channel response and of the differences of synchronization offsets on the received samples and to generate equalized samples. An OFDM detector may be configured to generate a stream of demodulated digital symbols based upon the equalized samples.06-09-2011
20090245397SYSTEM AND METHOD FOR COMMUNICATING DATA USING EFFICIENT FAST FOURIER TRANSFORM (FFT) FOR ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING (OFDM) DEMODULATION - A communications device includes a signal input that receives an orthogonal frequency division multiplexed (OFDM) communications signal. A demodulator is connected to the signal input for receiving the OFDM communications signal and demodulating the OFDM communication signal. It includes at least one memory element for storing the at least one sine/cosine basis waveform approximation as complex exponential functions. A logic circuit performs logical shifts in additions and multiples of ±210-01-2009
20100027694WIRELESS TELECOMMUNICATONS NETWORK - A femtocell including a transceiver and a processor coupled to the transceiver for implementing transmission and reception in a wireless communication network utilizing OFDM/OFDMA, and the processor including modules for collecting information about neighboring base stations and femtocells and utilizing the collected information to select the femtocell's own radio parameters, and a method for radio resource allocation in a wireless communication network implementing OFDM/OFDMA, the method including performing preamble synchronization by a sniffing femtocell on a neighboring femtocell, and determining radio resource parameters of the neighboring femtocell based on the synchronized preamble.02-04-2010
20110305289METHOD FOR GENERATING DOWNLINK SIGNAL IN DOWNLINK MIMO SYSTEM - A method for generating a downlink signal in a downlink MIMO (Multiple Input Multiple Output) comprises the steps of: mapping at least one transport block to at least one codeword; mapping at least one layer to each codeword; classifying at least one layer mapped to each codeword into a certain number of layer groups and performing layer permutation by the layer groups; and generating an OFDM (Orthogonal Frequency-Division Multiplexing) symbol using a signal which is permutated by the layer groups. A CRC (Cyclic Redundancy Check) is attached by the layer groups.12-15-2011
20110305288Method and Apparatus for Determining Channel Bandwidth - In a method implemented in a communication device an available bandwidth for transmitting one or more data frames is determined, wherein the available bandwidth corresponds to a first composite communication channel comprising a plurality of communication channels. A control frame to indicate a request to transmit via the first composite communication channel is generated, wherein the control frame includes a header, and wherein a portion of the header includes information indicating the bandwidth of the first composite channel. The control frame is transmitted via the first composite communication channel, wherein at least the portion of the header is duplicated in a plurality of bandwidth portions of the first composite communication channel.12-15-2011
20110305287Method of Transmitting Signal in a Wireless System - A method of transmitting a signal of a mobile station that performs communication with a plurality of cells in a wireless communication system comprises transmitting a control signal or a data signal through an asynchronous channel to a neighboring cell which is not synchronized with the mobile station, the asynchronous channel including cyclic prefix and guard time.12-15-2011
20110305286TRANSMISSION APPARATUS, TRANSMISSION METHOD, COMMUNICATION SYSTEM, AND COMMUNICATION METHOD - In a transmission apparatus which multicarrier-modulates and transmits symbols, which are basic units of digital signals, a subcarrier in which a symbol is arranged in a first multicarrier symbol having a first guard interval and a subcarrier in which a symbol is arranged in a second multicarrier symbol having a second guard interval longer than the first guard interval are scattered among a plurality of subcarriers constituting a multicarrier at the same time. Therefore, it is possible to improve the resistance to inter-symbol interference without substantially degrading transmission efficiency.12-15-2011
20110305285Process and Apparatus for Performing Initial Carrier Frequency Offset in an OFDM Communication System - A process for estimating the carrier frequency offset (CFO) for a Orthogonal Frequency Division Multiplex (OFDM) communication system, said process being performed in a receiver receiving a pilot sequence x=(x12-15-2011
20110305284Method for Transmitting a Data Signal in a MIMO System - A method for transmitting a data signal by a transmission unit of a wireless multiple-input/multiple-output (MIMO) communication system. The communication system includes the transmission unit and a reception unit, the transmission unit having a plurality of transmission antennas and the reception unit having a plurality of reception antennas. The method includes performing a first transmission of a data signal, the first transmission including transmitting the data signal by each one of the plurality of transmission antennas, and performing a second transmission of the data signal at a time later than the first transmission, the second transmission including transmitting at least one spectrally modified signal variant of the data signal by at least one antenna of the plurality of transmission antennas.12-15-2011
20110142151AN ADAPTIVE SCHEME TO DETERMINE THE SUB-CARRIER SPACING FOR MULTI-CARRIER SYSTEMS - Orthogonal Frequency Division Multiplexing (OFDM) is a typical multi-carrier technique that has been applied by many advanced wireless communication systems, e.g., 3GPP Long Term Evolution (LTE) and WiMAX. In order to support high mobility transmission, the sub-carrier spacing of multi-carrier systems is made large enough to overcome the Doppler frequency offset. However, this large sub-carrier spacing results in lower transmission efficiency since the CP (Cyclic Prefix) consumes a considerable of radio resources. The present invention provides an adaptive scheme to determine the sub-carrier spacing in which the default sub-carrier spacing is set to support lower mobility, while the adaptively adjusted sub-carrier spacing based on User Equipment (UE) mobile velocities is set to support higher mobility.06-16-2011
20090285317METHODS AND SYSTEMS FOR EFFECTIVE CHANNEL ESTIMATION IN OFDM SYSTEMS - A method and apparatus for channel estimation in wireless communications are provided. After an initial channel estimation and an estimation of the effective channel length (ECL) are performed, a weighting based on the ECL may be applied in an effort to remove noise from the initial channel estimate and provide an estimated channel with increased accuracy. Different weightings may apply for different channel lengths. A threshold may be used during the ECL estimation, and the threshold may be predetermined or calculated in an effort to adapt to different channel environments.11-19-2009
20090074095SYSTEM FOR MULTI-FRAME ALIGNMENT - A bidirectional communication system is provided. In one embodiment, a system comprises a host and a plurality of remote units, wherein a plurality of tones is shared among the plurality of remote units in order to communicate with the host using orthogonal frequency division multiplexing, wherein the plurality of tones is shared in a manner that permits at least two of the remote units to transmit to the host at any one time using the plurality of tones. The host causes at least one remote unit to adjust a timing of symbols transmitted on at least one of the plurality of orthogonal tones in order to improve an alignment of multiframes received at the host.03-19-2009
20080292012MULTIPLE-INPUT MULTIPLE-OUTPUT COMMUNICATION METHOD AND MULTIPLE-INPUT MULTIPLE-OUTPUT COMMUNICATION SYSTEM OF ENABLING THE METHOD - A Multiple-Input Multiple-Output (MIMO) communication system and method. The MIMO communication system includes: an antenna number determination unit to determine a number of active antennas among a plurality of transmitting antennas based on a power of a transmission signal wherein the number of active antennas is at least one and the at least one active antenna transmits the transmission signal; and a beam generator to generate the transmission signal corresponding to the number of active antennas by using channel information wherein the channel information is fed back from each of a plurality of user terminals.11-27-2008
20080298486MULTI-CELL INTERFERENCE MITIGATION VIA COORDINATED SCHEDULING AND POWER ALLOCATION IN DOWNLINK ODMA NETWORKS - A multi-cell Orthogonal Frequency-Division Multiple Access (OFDMA) based wireless system and method with full spectral reuse co-channel interference mitigation via base station coordination in a downlink channel includes a plurality of base stations configured to handle communications with mobile units. A central controller is configured to mitigate interference between base stations via jointly optimizing coordinated scheduling and power allocation in accordance with a sub-optimal iterative solution. Five methods provide the solution, which include: 1) Improved Iterative Water-Filling (I-IWF); 2) Iterative Spectrum Balancing (ISB); 3) Successive Convex Approximation for Low-complexity (SCALE); 4) Opportunistic Base Station Selection (OBSS) and 5) Per-tone binary power control (PT-BPC).12-04-2008
20090028257METHOD AND APPARATUS FOR INITIAL ACQUISITION OF SIGNALING PARAMETERS FOR A WIRELESS COMMUNICATIONS NETWORK - A method of acquiring a forward link only (FLO) network in a radio frequency (RF) in a wireless communication environment, includes selecting a RF from a first list; selecting a signal parameter (SP) from a second list; determining if a first parameter is found using the selected RF and SP; and, upon determination that the first parameter is found, enabling the use of the selected RF and SP to communicate in the FLO network. An apparatus for implementing the method is also disclosed.01-29-2009
20080232481METHOD AND APPARATUS FOR CHANNEL INTERPOLATION IN A TDS-OFDM SYSTEM OR DVB T/H SYSTEM - In an OFDM system, a method for interpolating comprising the steps of: subdividing at least one frame among a plurality of frames into segments; and using at least two known quantities to interpolate a corresponding estimate.09-25-2008
20100166088METHOD AND SYSTEM FOR OFDM SYMBOL TIMING RECOVERY - A method and system for OFDM symbol timing recovery is described. A symbol timing recovery module of an OFDM receiver is configured to determine an optimum trigger point for performing a discrete Fourier transform in a manner that minimizes inter-symbol interference.07-01-2010
20110110444METHOD OF RESOURCE BLOCK (RB) BUNDLING - A method of sizing bundled resource blocks (RBs) having at least one user equipment (UE)-specific demodulation reference signal in an orthogonal frequency division multiplexing (OFDM) system is disclosed. According to one embodiment, the method includes: receiving configuration information related to at least one UE-specific demodulation reference signal; receiving a plurality of resource blocks (RBs) from a network, wherein the plurality of resource blocks comprises the at least one UE-specific demodulation reference signal, at least one cell-specific demodulation reference signal or data, wherein a number of the plurality of RBs is dependent on a size of a system bandwidth, the size of the system bandwidth corresponding to one of four size ranges; and processing at least one of the received plurality of RBs by bundling the plurality of RBs into RB bundles, wherein the size of each RB bundle is based on the one of the four size ranges.05-12-2011
20110110448Method and Computer Program Product for Precoding - A method and a computer program product for precoding are provided. The precoding method includes selecting, by a processor, a codeword for precoding data from a codebook, wherein the codebook includes05-12-2011
20110110447Scattered Pilot Correlation in DVB-H Systems - A method for correlating scattered pilot locations in a sequence of OFDM symbols in a multi-carrier transmission system, and includes mapping pilot locations comprising pilot symbols having predetermined known values, wherein the pilot symbols are positioned among data subcarriers in time and frequency dimensions consisting of received pilot symbols and having a predetermined position pattern in the time and frequency dimensions, wherein the predetermined position pattern comprises a finite number of sub-position patterns each corresponding to positions of the pilot symbols; estimating a Doppler spread in a frequency spectrum between the transmitter and the receiver in the multi-carrier transmission system; estimating a channel length of a set of channel paths received at the receiver; and the receiver automatically selecting one of a plurality of predetermined methods of correlating the scattered pilot locations in the sequence of OFDM symbols based only on the estimating processes.05-12-2011
20110110443DATA RECEIVING APPARATUS FOR RECEIVING DATA FRAME USING CONSTELLATION MAPPING SCHEME AND DATA TRANSMISSION APPARATUS FOR TRANSMITTING THE DATA FRAME - Disclosed are a data receiving apparatus that may discriminate a type of a received data frame, and a data transmission apparatus that may apply a constellation mapping scheme to a data frame so that a data receiving apparatus may discriminate the data frame in accordance with the constellation mapping scheme applied to the data frame.05-12-2011
20110075745REDUCING TRANSMITTER-TO-RECEIVER NON-LINEAR DISTORTION AT A TRANSMITTER PRIOR TO ESTIMATING AND CANCELLING KNOWN NON-LINEAR DISTORTION AT A RECEIVER - A communication system is provided that includes a transmitter device and a receiver device. The transmitter device transmits input data as a transmitted signal having the known non-linear distortion (NLD) characteristic. The receiver receives a received signal that represents a channel affected version of the transmitted signal and that has the known NLD characteristic. The received signal includes power amplifier distortion (PAD) induced by the transmitter device's power amplifier. The receiver is designed to iteratively estimate, based on the known NLD characteristic, remaining PAD caused by the power amplifier, and to iteratively cancel estimated PAD to reduce PAD in the received signal.03-31-2011
20080273616BASE STATION TRANSMITTER FOR USE WITH AN OFDM COMMUNICATIONS SYSTEM, A METHOD OF DYNAMICALLY ALLOCATING OFDM SYMBOLS FOR PDCCH IN THE SYSTEM AND A USER EQUIPMENT RECEIVER FOR USE WITH THE SYSTEM - A base station transmitter for use with an orthogonal frequency division multiplexing (OFDM) communications system, a method of dynamically allocating OFDM symbols needed for a physical downlink control channel (PDCCH) in a downlink sub-frame from a base station and a user equipment (UE) receiver for use with the OFDM communications system. In one embodiment, the UE receiver includes: (1) a receive unit configured to receive a downlink signal, the signal having groups of control information and (2) a processing unit configured to extract from the groups of control information a number of OFDM symbols needed for PDCCH in a sub-frame of the downlink signal.11-06-2008
20100124292Method and System for Receiver Synchronization - Provided is a method for synchronizing a multiple carrier receiver to receive a transmitted signal. The method includes determining a location of one or more scattered pilot carriers in a received symbol sequence and modulating the scattered pilot carriers in accordance with a single pseudorandom binary sequence. The method also includes performing phase error correction via the modulated scattered pilot carriers.05-20-2010
20100158148Double Search User Group Selection Scheme with Range Reduction for FDD Multiuser MIMO Downlink Transmission with Finite-Rate Channel State Information Feedback - Aspects of a double search user group selection scheme with range reduction for FDD multiuser MIMO downlink transmission with finite-rate channel state information feedback are provided. The method may comprise maximizing system capacity using feedback information for a plurality of signals in a frequency division duplex system to reduce a search range within which a group of signals having maximum channel gain are located. The feedback information may comprise quantized gain for the signals. Quantized channel direction for the signals within the reduced search range may be requested and received by the transmitter. One or two signals from the reduced search range that maximizes system capacity may be selected. The receivers associated with these signals may then be selected as the user group.06-24-2010
20120039406CHANNEL DESCRIPTION FEEDBACK IN A COMMUNICATION SYSTEM - In a method for estimating a channel between a transmitter and a receiver in a communication network, a plurality of training signal fields are received at the receiver. Each training signal field includes a plurality of orthogonal frequency division multiplexing (OFDM) tones, and the OFDM tones include at least a plurality of training data tones and one or more pilot tones. Channel estimate data corresponding to the plurality of training data tones and the one or more pilot tones is determined. Channel estimate data corresponding to only a subset of the OFDM tones or data generated using the channel estimate data corresponding to the subset of OFDM tones is transmitted to the transmitter, wherein the subset excludes pilot tones.02-16-2012
20090290652Pilot Signal Set Management in a Multi-Carrier Communication System - In a wireless communication system where different frequency bands are deployed to generate various communication zones, pilot signal set management for a plurality of pilot signals generated from an additional coverage zone is based on identifying a preselected signal set from the plurality of pilot signals and determining whether a predetermined criterion is met.11-26-2009
20090185632FLEXIBLE OFDM/OFDMA FRAME STRUCTURE FOR COMMUNICATION SYSTEMS - A flexible OFDM/OFDMA frame structure technology for communication systems is disclosed. The OFDM frame structure technology comprises a configurable-length frame which contains a variable length subframe structure to effectively utilize OFDM bandwidth. Furthermore, the frame structure facilitates spectrum sharing between multiple communication systems.07-23-2009
20090285314ADAPTIVE FREQUENCY DOMAIN EQUALIZATION IN OFDM BASED COMMUNICATION SYSTEM - An apparatus, system, and method of performing adaptive frequency domain equalization in an Orthogonal Frequency Domain Multiplexing (OFDM) based communication system transmitting data information, wherein the method comprises receiving OFDM symbols comprising scattered pilots; obtaining channel estimates on every third bin of the scattered pilots in a frequency domain, wherein the channel estimates are obtained by performing an interpolation in a time domain across the received OFDM symbols; estimating an original channel based on the channel estimates, wherein the original channel in the time domain is estimated by applying a finite impulse response (FIR) low-pass filter in a frequency domain, wherein the FIR low-pass filter is adaptive according to a delay span of an original channel impulse response and is sufficiently wide to cover the delay span of the original channel impulse response; and dividing the received OFDM symbols by the channel estimate to obtain transmitted data information.11-19-2009
20110158337OFDM TRANSMITTER AND METHODS FOR REDUCING THE EFFECTS OF SEVERE INTERFERENCE WITH SYMBOL LOADING - Embodiments of an OFDM transmitter and method of reducing the effects of interference on subcarriers in an OFDM system by symbol loading are disclosed herein. A linear transformation is performed on a group of two or more input data symbols that are mapped to different signal dimensions to generate a corresponding two or more output data symbols. Each of the output data symbols has an increased number of constellation points. Each output data symbol is configured for transmission within one of the different signal dimensions. The linear transformation is configured so that each of the two or more output data symbols carry the information of each of the input data symbols of the group. This coding together of input data symbols that are mapped to different signal dimensions may provide improved reliability against fading and severe interference. The different signal dimensions may comprise a frequency, a time and/or a space dimension.06-30-2011
20110158336PEAK-TO-AVERAGE POWER RATIO (PAR) REDUCTION BASED ON ACTIVE-SET TONE RESERVATION - In an embodiment, a transmitter includes first and second processing blocks, which may each include hardware, software, or a combination of hardware and software. The first processing block is operable to generate a first peak-reducing vector. And the a second first processing block is operable to receive a first data vector, the data vector comprising a plurality of samples, the first data vector having a first peak with a first index and a first magnitude, a second peak with a second index and a second magnitude that is less than the first magnitude, and a first peak-to-average power ratio, and to generate a second data vector having a second peak-to-average power ratio that is lower than the first peak-to-average power ratio by using the first peak-reducing vector.06-30-2011
20110090979MIDAMBLE ALLOCATIONS FOR MIMO TRANSMISSIONS - Allocation of multiple training sequences transmitted in a MIMO timeslot from multiple transmit antenna elements is provided. For example, a method of generating signals in a MIMO timeslot, the method comprising: selecting a first training sequence; preparing a first data payload; generating a first signal including the prepared first data payload and the first training sequence; transmitting the first signal in a MIMO timeslot from a first antenna of a network element; selecting a second training sequence, wherein the second training sequence is different from first training sequence; preparing a second data payload; generating a second signal including the prepared second data payload and the second training sequence; and transmitting the second signal in the MIMO timeslot from a second antenna of the network element.04-21-2011
20110090978METHOD, APPARATUS, AND SYSTEM FOR CHANNEL ESTIMATION - In the field of communications technologies, a method, an apparatus, and a system for channel estimation are provided. The method for channel estimation includes the following steps. An error signal returned by a terminal is received, where the error signal is an error signal of at least two tones in a downlink frequency band. Channels of the at least two tones are obtained according to the error signal. The channels of the at least two tones are interpolated, and channels of remaining tones in the downlink frequency band are obtained. In the method, the apparatus, and the system for channel estimation, a convergence speed of the channel estimation is improved by reducing data of error signals returned by the terminal.04-21-2011
20110090976METHOD FOR TRANSMITTING BEAM FORMING INFORMATION AND A METHOD FOR TRACKING POSITION OF A MOBILE STATION IN MULTI INPUT MULTI OUTPUT SYSTEM USING CODEBOOK-BASED BEAM FORMING SCHEME - A method for transmitting feedback information in a codebook-based multiple-input multiple-output (MIMO) system is disclosed. For example, a method for transmitting beamforming information in a MIMO system using a codebook-based beamforming scheme includes receiving a signal and estimating a reception channel, and transmitting beamforming information selected through the estimated channel information from a codebook which is updated using phase shift matrices having a phase value as a parameter and using previous beamforming information.04-21-2011
20110090974Scheduling Collaborative Uplink Transmissions in OFDMA Systems Using Multipath Direction of Arrival Analysis - Techniques are provided for receiving uplink transmissions at a plurality of antennas at a base station from a plurality of client stations. Uplink spatial transmissions are analyzed to produce a plurality of direction of arrival (DOA) components associated with the plurality of client stations. The DOA components associated with the plurality of client stations are compared and two or more client stations are selected to participate in an uplink collaborative spatial multiplexing transmission session based on dissimilarities of their DOA components.04-21-2011
20110090973SYSTEM AND METHOD FOR SYMBOL BOUNDARY DETECTION IN ORTHOGONAL FREQUENCY DIVISON MULTIPLEXING BASED DATA COMMUNICATION - A method for determining a symbol boundary of a data packet of a received signal, where the data packet includes a first training field, a guard interval, and a second training field. The received signal is sampled to obtain multiple samples. A first symbol boundary estimate is determined using one or more block auto-correlation values. Thereafter, a second symbol boundary estimate is determined based on the first symbol boundary estimate and using one or more cross-correlation values. The second symbol boundary estimate then is shifted using moving average auto-correlation values for the samples in the vicinity of the second symbol boundary estimate to obtain an accurate symbol boundary estimate.04-21-2011
20110090972BLIND SLM AND PTS METHOD WITH LOW DECODING COMPLEXITY OF OFDM SIGNALS - Disclosed is a BSLM method of generating U independent alternative symbol sequences by changing a phase of symbol sequences by phase sequences and transmitting the alternative symbol sequences with a PAPR to lower the PARR of a transmission signal of a transmitter in an OFDM system. The transmitter uses m-sequences as the phase sequence and a receiver uses an ML decoder to distinguish the phase sequence. The BSLM method includes rotating phases in blocks according to the m-sequences used in the respective symbol sequences, selecting a signal sequence with a minimum PAPR among U alternative signal sequences generated by the m-sequences in the transmitter, and partitioning U alternative symbol sequences into U/2 blocks in the transmitter. Block partitioning and predetermined phase rotation are used to embed side information in an alternative signal sequence, and the BSLM scheme may be extended to a BPTS. Since low decoding complexity is given while detecting side information, the same BER performance is obtained as that of the conventional BSLM scheme in the AWGN channel.04-21-2011
20110317780METHOD AND APPARATUS FOR TRANSMITTING SYNCHRONIZATION SIGNAL IN MULTI-NODE SYSTEM - A method of transmitting a synchronization signal in a multi-node system having a plurality of nodes and a base station for controlling the plurality of node is provided. The method includes: generating a synchronization signal sequence; and mapping the generated synchronization signal sequence to a resource element, and thereafter transmitting the mapped synchronization signal sequence to a user equipment via at least one node among the plurality of nodes, wherein the synchronization signal sequence is generated based on an identifier (ID) of a transmission node for transmitting the synchronization signal sequence.12-29-2011
20110317779SCRAMBLING SEQUENCES FOR WIRELESS NETWORKS - An integrated circuit includes logic configured to generate scrambling sequences, each based on a different scrambling seed, for a smart-utility-network data packet communication. A Hamming distance between any two scrambling sequences is half the length of a PSDU of the data packet or greater.12-29-2011
20110317778MULTI-BIT HARQ-ACK AND RANK INDICATOR TRANSMISSION ON PHYSICAL UPLINK SHARED CHANNEL WITH SINGLE USER MULTIPLE INPUT-MULTIPLE OUTPUT OPERATION - In accordance with an exemplary embodiment of the invention, there is at least a method, computer program instructions, and an apparatus to perform operations including replicating and time-aligning, at a wireless communication device, more than two hybrid automatic repeat request acknowledgment or rank indicator bits across layers and codewords of an uplink transmission signal, and providing an ability to define per codeword either an effective modulation order or a coding rate when a different modulation order is configured to the codewords so that time-alignment across all the layers and the codewords of the uplink transmission signal is maintained. Further, in accordance with the embodiments there is receiving an uplink transmission signal comprising more than two hybrid automatic repeat request acknowledgment or rank indicator bits across layers and codewords of the uplink transmission signal, and demodulating the uplink transmission signal, where either an effective modulation order or a coding rate per codeword is modified so that time-alignment across all the layers and the codewords of the uplink transmission signal is maintained.12-29-2011
20090016454TIME DE-INTERLEAVER IMPLEMENTATION USING AN EMBEDDED DRAM IN A TDS-OFDM REC - A receiver having a de-interleaver with a processor for processing interleaved data; and a built-in eDRAM coupled to the processor for processing the interleaved data is provided.01-15-2009
20120045005COMMUNICATION METHOD OF A TERMINAL AND AN ACCESS POINT FOR MULTI-USER TRANSMISSION OPPORTUNITY (TXOP) POWER SAVING - Provided is a terminal and an access point in an active mode for multi-user transmission opportunity (TXOP) power saving that may decrease power consumption by changing an operation state of the terminal from an awake state to a sleep state if there is no stream of data to be transmitted during a TXOP duration.02-23-2012
20120045004CORRELATOR AND DEMODULATION DEVICE INCLUDING THE CORRELATOR - The Present invention provides a correlator including, a read-out processing circuit that reads out an OFDM signal in RAM as 2n−1 number of delay OFDM signals that are increased and delayed sequentially with their adjusted read-out timings. Complex conjugate circuits that outputs complex conjugates of the inputted n02-23-2012
20120045003COMMUNICATION STATION AND METHOD FOR EFFICIENTLY PROVIDING CHANNEL FEEDBACK FOR MIMO COMMUNICATIONS - Embodiments of a communication station and methods for efficiently providing channel feedback for MIMO communications over an OFDM channel are generally described herein. In some embodiments, receiving stations may perform a recursive differential quantization of channel information across time and/or frequency to generate quantized differential channel feedback. The quantized differential channel feedback from each receiving station may be used by a transmitting station to precode MIMO transmissions to one or more of the receiving stations. The quantized differential channel feedback may be either a quantized differential channel matrix or a quantized differential beamforming matrix.02-23-2012
20120002739DATA PROCESSING APPARATUS AND METHOD - A data processing apparatus maps input symbols to be communicated onto a predetermined number of carrier signals of an Orthogonal Frequency Division Multiplexed (OFDM) symbol. The data processor includes an interleaver memory which reads-in the predetermined number of data symbols for mapping onto the OFDM carrier signals. The interleaver memory reads-out the data symbols on to the OFDM carriers to effect the mapping, the read-out being in a different order than the read-in, and the order being determined from a set of addresses. The set of addresses are generated from an address generator. The address generator includes a linear feedback shift register and a permutation circuit.01-05-2012
20120002741METHOD FOR PERFORMING CONTENT SYNCHRONIZATION FOR DOWNLINK SERVICE DATA IN COLLABORATIVE MIMO AND APPARATUS THEREOF - A method for controlling, in collaborative MIMO of a wireless communication network, downlink service data in collaborative MIMO to perform content synchronization is provided in the present invention. The method comprises: performing, by a serving base station in the collaborative MIMO, data link layer processing on service data to be transmitted to a mobile station, so as to achieve a first data packet, and transmitting the first data packet to other collaborative base station(s) in the collaborative MIMO; thereafter, transmitting, by each base station (which may or may not include the serving base station) participating in transmitting data packets in the collaborative MIMO, the first data packet to the mobile station on the same time-frequency resource. With the technical solution of the present invention, it can be realized effectively that each base station in the collaborative MIMO transmits the same data to the mobile station on the same time-frequency resource. Namely, content synchronization of downlink service data in the collaborative MIMO can be realized.01-05-2012
20120002740METHOD AND APPARATUS FOR TRANSMITTING A REFERENCE SIGNAL IN A WIRELESS COMMUNICATION SYSTEM - A method and an apparatus for transmitting a reference signal in a wireless communication system are provided. A first base station maps a first reference signal to a resource region and transmits the first reference signal to a user equipment. A second base station maps a second reference signal to said resource region and transmits the second reference signal to said user equipment. The resource elements, to which the first reference signal and the second reference signal are mapped in the resource region, are determined in accordance with the index on a Latin square matrix occupied by two different elements, respectively, from among N elements constituting the Latin square matrix with a size of N×N.01-05-2012
20120002738METHOD AND APPARATUS TO SUPPORT SCALABILITY IN A MULTICARRIER NETWORK - A multicarrier communication device using orthogonal frequency division multiplexing (OFDM) symbols can vary the number of subcarriers being used on multicarrier communication within a network, based on a predetermined criterion and capability information. The capability information can include a data file, which indicates portions of an electromagnetic spectrum for which regulatory body licenses are currently obtained for a network cell. Alternatively, the capability information can include capability information about the wireless devices in communication with the multicarrier communication device, where the capability information for each wireless device includes device power limitations, device bandwidth width limitations, or which subcarriers a wireless device is capable of using.01-05-2012
20100111209DTF Spread OFTM - The invention applies DFT-spread-OFDM which is proposed for the 3GPP LTE uplink. The core of the invention is that we use a cyclic frequency shift operation over part of the bandwidth spanned by the IFFT. Furthermore, the cyclic frequency shift enables efficient inter-cell interference coordination in case neighbouring cells hop with the same pattern and different initial offsets. Equivalent operation may be performed in the time domain.05-06-2010
20120207232MULTI-CLOCK PHY PREAMBLE DESIGN AND DETECTION - In a method for detecting a clock rate of a data unit, the data unit is received via a communication channel. The data unit includes i) a first preamble portion and ii) an orthogonal frequency division multiplexing (OFDM) portion following the first preamble portion. The OFDM portion includes a second preamble portion including one or more long training fields. Based on the first preamble portion, whether a clock rate of the OFDM portion is a first clock rate or a second clock rate lower than the first clock rate is determined based on the first preamble portion.08-16-2012
20120207231MULTI-CLOCK PHY PREAMBLE DESIGN AND DETECTION - In a method for generating a data unit for transmission via a communication channel, a first preamble portion of the data unit is generated based on whether a physical layer (PHY) mode is a first PHY mode or a second PHY mode. An OFDM portion of the data unit is generated. The OFDM portion follows the first preamble portion, includes a second preamble portion including one or more long training fields, is clocked at a first clock rate when the PHY mode is the first PHY mode, and is clocked at a second clock rate lower than the first clock rate when the PHY mode is the second PHY mode.08-16-2012
20110096857QUALITY CONTROL SCHEME FOR MULTIPLE-INPUT MULTIPLE-OUTPUT (MIMO) ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING (OFDM) SYSTEMS - A method and apparatus for optimizing the system capacity of an Orthogonal Frequency Division Multiplexing (OFDM) system that uses with Multiple-Input Multiple-Output (MIMO) antennas. In a receiver, a target quality of service (QoS) metric and reference data rate are set. The target QoS metric may be set to a predetermined value and/or may be adjusted dynamically with respect to packet error rate (PER) by a slow outer-loop control processor. The QoS of received signals are compared to the target QoS. Depending on the comparison, the receiver generates a channel quality indicator (CQI) which is sent to the transmitter. The CQI is a one or two bit indicator which indicates to the transmitter to disable, adjust or maintain data transmission rates of particular sub-carriers, groups of sub-carriers per transmit antenna, or groups of sub-carriers across all transmit antennas. At the transmitter, the transmitted data rate is disabled, adjusted or maintained.04-28-2011
20120008702METHOD FOR PRECODING AND DECODING DISTRIBUTING MIMO CHANNELS IN RELAY-BASED DF COOPERATIVE WIRELESS NETWORKS - It is well known that relay-based DF cooperative wireless networks outperform AF cooperative networks. However, this performance enhancement is achievable through considerable signal processing (precoding/decoding) at relay nodes. To reduce the precoding/decoding complexity, a method for precoding and decoding a distributive MIMO channel in the relay-based DF cooperative wireless network using EVD based on properties of Jacket transformations is provided.01-12-2012
20090010346TDS-OFDMA Communication System - In a TDS-OFDM communications system, a frame structure comprising: a frame such that within a frame time, a transmitted signal comprising a preamble, a downlink sub-frame, and an uplink sub-frame is provided.01-08-2009
20110090977METHODS FOR MAPPING AND DE-MAPPING DATA, TRANSMITTING DEVICE AND RECEIVING DEVICE - An apparatus and a method for mapping data and de-mapping data are provided. In the method, each modulated datum is mapped into two centrosymmetric Orthogonal Frequency Division Multiplexing (OFDM) subcarriers at the transmitting end, a certain functional transformation is performed on data in one of the two OFDM subcarriers, and original data may be restored at the receiving end according to data of the two centrosymmetric OFDM subcarriers. Exemplary embodiments of the invention also provide a transmitting device and a receiving device. By adopting embodiments of the invention, self-cancellation of interference among subcarriers may be implemented effectively, and the interference among subcarriers may be reduced.04-21-2011
20080304589WIRELESS RECEIVER, METHOD FOR CONTROLLING THE WIRELESS RECEIVER, PROGRAM FOR CONTROLLING THE WIRELESS RECEIVER, AND SEMICONDUCTOR INTEGRATED CIRCUIT - According to an embodiment of the invention, a wireless receiving apparatus includes: an antenna that receives an OFDM signal having an OFDM symbol and a guard interval; a front end section that performs frequency conversion and synchronization on the received OFDM signal; an ISI canceller that extracts a delay profile and removes leakage of the guard interval into the OFDM symbol by the use of the delay profile; a converter that performs orthogonal conversion on the ISI removed OFDM signal; an equalization section that performs equalization processing on the converted OFDM signal; an outer decoder that decodes the equalized OFDM signal; and an inner decoder that corrects an error in an inner code of the decoded OFDM signal, wherein the equalization section performs re-equalization processing on the converted OFDM signal by using a signal output from the inner decoder as the reference signal.12-11-2008
20090074098System and method for embedding OFDM in CDMA systems - Systems and methods of combining OFDM and CDMA signals are provided. An OFDM packet data channel is overlaid over CDMA transmissions. The channel is scheduled slotwise between multiple users. In some embodiments, there is a CDMA packet data channel which is scheduled together with the OFDM packet data channel.03-19-2009
20120014468METHOD AND APPARATUS FOR CONTROLLING CO-CHANNEL INTERFERENCE IN A WIRELESS COMMUNICATION SYSTEM - The present invention provides a method and an apparatus of controlling co-channel interference in a base station of a wireless communication system based on collaborative MIMO and the corresponding method and apparatus of assisting a serving base station to control co-channel interference in a mobile station of a wireless communication system based on collaborative MIMO. Since the feedback mechanism based on the codebook is employed in the collaborative MIMO system in the present invention to enable the BS to obtain the precoding information, the present invention can be used to the both TDD mode and FDD mode. Moreover, since the precoding vectors selected by the different mobile stations for a same BS are always orthogonal, multi-user co-channel interference can be reduced.01-19-2012
20120014463METHODS AND APPARATUS FOR SELECTING AND USING COMMUNICATIONS RESOURCES IN A COMMUNICATION SYSTEM - Methods and apparatus for determining, e.g., selecting, communications resources, e.g., tones, to use in a communications system are described. The methods are well suited for use in Orthogonal Frequency Division Multiplexing (OFDM) systems. Devices seeking to transmit information select tones in pairs for use in transmitting the information. Each tone pair includes a tone and the corresponding image tone. By restricting a communications device to select communications frequencies in pairs, the problem of interference and reduced dynamic range at a receiver due to IQ imbalance is reduced, as compared to the case where devices may use a tone independent of the corresponding image tone for transmission purposes, since the path loss from the transmitter to the receiver is likely to be the same for both tones and the transmission power level is controlled by an individual device using both of the tones.01-19-2012
20080317149WIRELESS COMMUNICATION DEVICE AND METHOD FOR REDUCING CARRIER FREQUENCY OFFSETS OVER A SIMULTANEOUS MULTI-USER UPLINK IN A MULTICARRIER COMMUNICATION NETWORK - Each of a plurality of multicarrier wireless communication devices generate a carrier frequency offset (CFO) estimate from a downlink polling frame (12-25-2008
20100172425METHOD AND APPARATUS FOR CLOSED LOOP BEAMFORMING FOR MIMO OFDM WIRELESS COMMUNICATION SYSTEMS - Varying embodiments of the present invention describe a closed loop system for processing the beamforming information, qualifying the expected performance, activating and deactivating the beamforming system. A first embodiment is a method for closed loop beamforming in a wireless communication system, the system comprising a transmitter and a receiver, the method comprising initiating beamforming on a communication channel between the transmitter and the receiver, monitoring the communication channel, periodically determining a condition of the communication channel and controlling beamforming based on the condition of the communication channel.07-08-2010
20090086833Radio Signal Generator - A signal generator includes a memory for storing content information in the form of vectors including in-phase and quadrature elements of an orthogonal frequency division multiplexing waveform, a processor for converting the vectors to a radio frequency signal, and a logic device for controlling the operation of the memory and the processor. The in-phase and quadrature elements represent baseband content of the orthogonal frequency-division multiplexing waveform.04-02-2009
20080279296METHOD FOR TRANSMITTING CONTROL INFORMATION, AND METHOD FOR GENERATING CODEWORD FOR THE SAME - A method for transmitting downlink control information and a method for generating a codeword for the same are disclosed. In generating a long code having a low code rate, a basic code of which minimum distance between codes is maximized is repeated by a prescribed number of times and bits of the repeated code are adjusted. Therefore, a minimum distance condition between codes of a long code is satisfied and simultaneously the code can be simply generated. Furthermore, control information can be transmitted with a low error rate by using the generated code.11-13-2008
20080310533Mega-frame Initialization Packet Generation and Synchronous Re-generation with Bit Rate Adaptation for Single Frequency Networks with Multiple Modulation Schemes - A system and processes create a Mega-frame Initialization Packet such that remote MIP inserters can regenerate Transport Stream bit rate and MIPs for Single Frequency Networks with modulation schemes different from an incoming stream in a totally deterministic way. This process guarantees that all MIP re-generators having the same signal at the input and having the same modulation scheme generate exactly the same stream (bit exact) even in multiple locations.12-18-2008
20120250778MODULATION SCHEME FOR ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING SYSTEMS OR THE LIKE - Briefly, in accordance with one embodiment of the invention, bit and power loading may be utilized to select a modulation rate and subcarrier power scaling based on channel state information. As a result, a higher data rate may be utilized for a given signal-to-noise ratio while maintaining a constant bit error rate.10-04-2012
20110064155 DISTORTION COMPENSATION CIRCUIT AND A DISTORTION COMPENSATION METHOD - A distortion compensation circuit and a distortion compensation method in which signal level of a signal after distortion compensation is limited, and which can improve the distortion compensation effect are provided. A distortion compensation circuit of the present invention includes an input level limitation means which limits signal level of an input signal from outside to no more than the first limit value, and outputs a signal before distortion compensation; a distortion compensation means which, based on a distortion compensation coefficient, performs distortion compensation processing to the signal before distortion compensation and outputs a signal after distortion compensation; a distortion compensation coefficient calculation means which, based on a difference between part of output signals of an amplifier which amplified the signal after distortion compensation and the signal before distortion compensation, calculate a coefficient for compensating distortion of the output signal of the amplifier as the distortion compensation coefficient; a storage means which stores the distortion compensation coefficient by correlating it to signal level of the signal before distortion compensation, and a limit value calculation means which calculates signal level of the signal before distortion compensation when signal level, when distortion compensation processing is performed based on the distortion compensation coefficient stored in the storage means, is no more than the second limit value which is a limit value of signal level of the input signal to the amplifier, as the first limit value.03-17-2011
20110064154Methods and Systems For Performing Channel Estimation In A Wireless Communication System - The invention provides methods and systems for channel estimation. A method comprises receiving a plurality of signal frames, comprising at least a first zone and a second zone, from a plurality of base stations in the wireless communication system. Two or more first delay profiles corresponding to two or more base stations are determined using the first zone. The method further comprising detecting at least one aliased tap in a time domain channel response of the second zone using the two or more first delay profiles. Another method comprises receiving a signal frame, comprising at least a preamble symbol and a data part, from a base station. A first delay profile corresponding to the preamble symbol is determined and a second delay profile corresponding to the data part is obtained. The first delay profile is analyzed in conjunction with the second delay profile to detect one or more aliased taps in a time domain channel response of the data part. The detected one or more aliased taps are nulled/rectified.03-17-2011
20110064153APPARATUS AND METHOD FOR ADAPTIVE CHANNEL QUALITY FEEDBACK IN A MULTICARRIER WIRELESS NETWORK - A subscriber station for use in a wireless network capable of communicating according to a multicarrier protocol. The subscriber station determines a total average signal level across N subbands, where each of subband comprises a plurality of subcarriers. The subscriber station also determines a first average signal level within a first subband. The subscriber station then transmits a channel quality indicator (CQI) feedback message to the wireless network. The CQI feedback message comprises a first data field indicating the total average signal level and a second data field indicating the first average signal level. The first data field may indicate the total average signal level as an absolute value and the second data field may indicate the first average signal level relative to the total average signal level.03-17-2011
20110064151Dispersion control in underwater electromagnetic communications systems - A data communication system comprising a transmitter for transmitting an electromagnetic and/or magneto-electric signal, a receiver for receiving an electromagnetic and/or magneto-electric signal, and means for compensating for reducing or substantially eliminating signal dispersion, wherein at least one of the transmitter and receiver is underwater.03-17-2011
20110064152CHANNEL INFORMATION PREDICTION SYSTEM AND CHANNEL INFORMATION PREDICTION METHOD - Provided is a channel information prediction system (03-17-2011
20120114054Systems and Methods for Low-Complexity Max-Log MIMO Detection - Embodiments provide novel systems and methods for multiple-input multiple-output (MIMO) Max-Log detection. These systems and methods enable near-optimal performance with low complexity for a two-input two-output channel. Some embodiments comprise using a Max-Log detector to compute a set of log-likelihood ratio (LLR) values for a channel input by minimizing cost function while computing only one instance of the cost function for each value of each bit in a symbol. Other embodiments comprise using a Max-Log detector to compute a set of log-likelihood ratio (LLR) values for a channel input by computing all instances of a cost function for each value of each bit in a symbol and selecting the minimum cost from all computed instances of the cost function for each value of each bit.05-10-2012
20120114053DETERMINING A RESPONSE OF A RAPIDLY VARYING OFDM COMMUNICATION CHANNEL USING AN OBSERVATION SCALAR - In an embodiment, a channel estimator includes first and second stages. The first stage is configurable to generate an observation scalar for a communication path of a communication channel, and the second stage is configurable to generate channel-estimation coefficients in response to the first observation scalar. For example, such a channel estimator may use a recursive algorithm, such as a VSSO Kalman algorithm, to estimate the response of a channel over which propagates an OFDM signal that suffers from ICI due to Doppler spread. Such a channel estimator may estimate the channel response more accurately, more efficiently, with a less-complex algorithm, and with less-complex software or circuitry, than conventional channel estimators. Furthermore, such a channel estimator may be able to dynamically account for changes in the number of communication paths that compose the channel, changes in the delays of these paths, and changes in the signal-energy levels of these paths.05-10-2012
20100111211Apparatus and method for transmitting/receiving data in a mobile communication system using multiple antennas - An apparatus and method for transmitting/receiving data in a mobile communication system using multiple antennas are provided. A receiver estimates a fading channel of received data, selects a weight set relative to a maximum data transmission rate from at least one weight set with elements of a plurality of orthogonal weight vectors, and transmits feedback information including the selected weight set and channel-by-channel state information to a transmitter. The transmitter demultiplexes data to be transmitted on a basis of the feedback information into at least one sub-data stream, multiplies each sub-data stream by an associated weight, and transmits the data.05-06-2010
20110080963IDENTIFICATION OF PACKET TRAFFIC TRANSMITTED BY VARIOUS DEVICES OPERATED IN MULTIPLE OVERLAPPED FREQUENCY BANDS IN PACKET-BASED OFDM SYSTEMS - Techniques for header encoding include encoding a plurality of bits using a forward error correction code, generating an FEC codeword comprising a plurality of encoded bits, and concatenating a first copy of the FEC codeword with a second copy of the FEC codeword, wherein the concatenating comprises cyclically shifting by two bits the second concatenated copy of the FEC codeword relative to the first concatenated copy of the FEC codeword, wherein the encoded bits of the first and second copies of the FEC codewords are modulated on at least one OFDM symbol. techniques for header decoding include receiving a plurality of encoded bits comprising at least two concatenated copies of an FEC codeword, decoding a first copy of the FEC codeword to generate a first plurality of decoded bits, and decoding a second copy of the FEC codeword to generate a second plurality of decoded bits.04-07-2011
20090147869COMMUNICATION TERMINAL APPARATUS, BASE STATION APPARATUS AND RECEPTION QUALITY REPORTING METHOD - A communication terminal apparatus that can eliminate the waste of reception quality report, suppress the interference of an upstream network, perform an optimum assignment using a scheduling, prevent the loss of resources, and ensure the fairness of transmission assignment using the scheduling. In this apparatus, a reception quality determining part (06-11-2009
20120027109PROCESS AND RECEIVER FOR INTERFERENCE CANCELLATION OF INTERFERING BASE STATIONS IN A SYNCHRONIZED OFDM SYSTEM - A process and receiver for canceling interference generated by a set interference base stations in a synchronized OFDM communication system and receiver in a User Equipment comprising a set of Nrx antennas. The process and receiver that cancels interference generated by a set of base stations performs OFDM demodulation on a receiver signal for each antenna of a user equipment (UE). The process and receiver also monitors each UE antenna for pilot signals generated by nearby base stations. Then the process or receiver extracts the pilot signals and establishes a list of existing base station antennas. The channel power of any interfering antennas is measured and then the Nrx-N most powerful antenna is selected. The process or receiver then performs a joint detection of the N useful Data Symbols (UDS), together with the (Nrx-N) Interfering Data Symbols (IDS) that are demodulated by demodulation blocks. Thus, after being detected, the Nrx-N most powerful IDSs can be encoded and re-injected into a cancellation loop.02-02-2012
20120027110METHOD AND APPARATUS FOR TRANSMITTING POSITIONING REFERENCE SIGNAL IN WIRELESS COMMUNICATION SYSTEM - Provided are a method and an apparatus for transmitting a positioning reference signal (PRS) in a wireless communication system. A terminal obtains positioning subframe configuration information to determine at least one positioning subframe among a plurality of downlink subframes in a wireless frame, obtains downlink subframe configuration information to determine the type of each downlink subframe in the wireless frame, receives PRSs in at least one positioning subframe from a plurality of cells, and reports measured time differences between the PRSs received from the plurality of the cells. The type of each downlink subframe of the wireless frame is classified into a 102-02-2012
20120027108METHOD AND APPARATUS FOR COORDINATED MULTI-POINT COMMUNICATION FOR EACH SUB-BAND BASED ON LONG-TERM CHANNEL STATE INFORMATION - Provided is a coordinated communication method and apparatus that may perform coordinated communication based on long-term channel information, for each sub-band. Base stations may exchange scheduling information of each sub-band with each other to determine a priority among the base stations, and may perform rescheduling for each sub-band based on the determined priority. The base stations may obtain the long-term channel information, and thus may reduce overhead occurring with exchanging of information between a base station and a terminal or between base stations, and may decrease damage due to a delay of channel information associated with a terminal.02-02-2012
20120106665TRANSMITTING AND RECEIVING METHOD, AND RADIO APPARATUS UTILIZING THE SAME - A processing unit transmits, from at least one of a plurality of antennas, data corresponding respectively to the plurality of antennas. A control unit generates request signals with which to let a second radio apparatus supply information on rates at the second radio apparatus. When transmitting the request signal, the processing unit also transmits, from a plurality of antennas which includes antennas other than the antennas that transmit the data, known signals corresponding respectively to the plurality of antennas.05-03-2012
20120063527Receiver, Channel State Information Compressing Method, and Computer Program - A receiver receives a signal from a transmitter via communication channels, informs the transmitter of channel state information, and includes a channel correlation value computation unit that computes a correlation value assigned to each channel state information combination; a conversion input data generation unit that determines a channel state information combination having a relatively large correlation based on the correlation value, to be conversion input data; a time-to-frequency region conversion unit that converts the region of the conversion input data from a time region to a frequency region; an information compressing unit that compresses information of a frequency component included in the conversion input data obtained by the time-to-frequency region conversion unit; and a transmitting unit that sends the transmitter, information-compressed data obtained by the information compressing unit and information used for isolating the channel state information items included in the conversion input data.03-15-2012
20120170672MULTICARRIER TRANSCEIVER AND METHOD FOR PRECODING SPATIALLY MULTIPLEXED OFDM SIGNALS IN A WIRELESS ACCESS NETWORK - A multicarrier transceiver for communicating spatially multiplexed orthogonal frequency division multiplexed (OFDM) signals over two or more spatial channels in a wireless access network in accordance with an orthogonal frequency division multiple access technique with a plurality of antennas is generally disclosed herein. In some embodiments, the multicarrier transceiver comprises a matrix generator to generate a matrix for precoding transmission symbols based an indicator received from a receiving station, the indicator being based at least in part on channel characteristics. The multicarrier transceiver also includes a precoder to multiply the transmission symbols by the matrix for transmission on groups of subcarriers that comprise the OFDM signals using the antennas for transmission through two or more spatial channels, each of the two or more spatial channels to concurrently convey separate spatially multiplexed data streams over a same set of subcarriers.07-05-2012
20090135923Mobile channel estimation for DVB-T COFDM demodulator - A channel estimator for use in a DVB-T system is capable of high Doppler performance without incurring restrictive delay spread limitations, in a hardware efficient manner. A first channel impulse response is generated that has ambiguity due to under-sampling in the frequency domain. A filter is then used to filter scattered pilots to generate a mask that is capable of resolving the ambiguities. In at least one approach, a finite impulse response filter is used during the mask generation process to generate a snapshot of the channel frequency response in non-real time. In another approach, an infinite impulse response filter is used during the mask generation process to generate a channel frequency response in real time.05-28-2009
20090135931RECEPTION APPARATUS, RECEPTION METHOD AND PROGRAM - Disclosed herein is a reception apparatus, including, an orthogonal frequency division multiplexing signal reception section, a first filter section, a subtraction section, a second filter section, a coefficient production section, and a Fast Fourier Transformation mathematic operation section.05-28-2009
20090135930METHOD FOR GENERATING A DELAY IN THE TRANSMISSION OF A MULTICARRIER SIGNAL, AND CORRESPONDING COMPUTER PROGRAM, STORAGE MEANS AND DEVICE - A method is provided for generating a delay in the transmission of a multicarrier signal formed by a time-dependent series of symbols, in which the symbols include a set of complex time-dependent samples, in which each symbol includes a useful part and a guard time. The method includes the following steps: writing the samples forming the multicarrier signal in a memory; reading the memory with a variable latency corresponding to the delay; and modifying the variable latency by duplicating or suppressing at least one sample contained in a guard time.05-28-2009
20090135929Receiving Apparatus, Communication System, Receiving Method and Program - A receiving apparatus according to the present invention has a plurality of synchronizing circuits which is provided corresponding to different preamble signals of a reception signal and operate simultaneously at the time of receiving the preamble signals so as to output synchronous signals, a correlation value comparing section which compares correlation values of the synchronous signals output from the plurality of synchronizing circuits, and a synchronizing section which determines whether the received signal is for the subject apparatus based on a comparison result from the correlation value comparing section.05-28-2009
20090135928DEVICE, APPARATUS, AND METHOD FOR LOW-POWER FAST FOURIER TRANSFORM - A device, apparatus and method for performing a Fast Fourier Transform (FFT). The Fast Fourier Transform (FFT) processing device includes a coefficient generator, a memory, and an accumulator. The coefficient generator is configured to generate a first set of coefficient values from one or more twiddle factor coefficients. The memory stores the first set of coefficient values. The accumulator receives and accumulates one or more coefficient values from the first set of coefficient values, the accumulator generating one or more output values based on the accumulated one or more coefficient values.05-28-2009
20090135926JOINT CONSTELLATION MULTIPLE ACCESS - A method for communication includes defining N respective symbol constellations in a signal space for N transmitters (05-28-2009
20090135924RADIO COMMUNICATION BASE STATION APPARATUS AND RADIO COMMUNICATION METHOD IN MULTI-CARRIER COMMUNICATIONS - Provided is a radio communication base station device capable of acquiring both a multi-user diversity effect and a frequency diversity effect simultaneously in multi-carrier communications. In this devices modulation units (05-28-2009
20090135922POWER SAVINGS IN OFDM-BASED WIRELESS COMMUNICATION - In a wireless communications system using Orthogonal Frequency Division Multiplex technology, changing the nature of the signals being transmitted/received may be used to reduce power consumption. In one embodiment, reducing the number of carriers that are being employed may be used to decrease power consumption by permitting a reduced clock rate for driving some of the circuitry. Similarly, increasing the duration of the symbols used to encode the data may be used to reduce the clock rate. Other power savings may be found by using single-rail processing, allowing some of the signal processing circuitry to simply be shut down.05-28-2009
20090274225MULTI-RESOLUTION PRECODING CODEBOOK - Systems and methods are for generating a codebook by: generating a multi-resolution codebook by selecting a common precoder index from a low resolution codebook for a group of adjacent resource blocks (RB)s and for each RB within the group, selecting a high-resolution codebook to fine-tune each RB precoder; and generating feedback for the multi-resolution codebook by quantizing channel state variations.11-05-2009
20120207233SIGNALING TO APPLICATION LACK OF REQUESTED BANDWIDTH - A system for signaling an application when a requested data rate and Quality of Service cannot be achieved using OFDM wireless data transmission, and the application proceeds by either renegotiating QoS and data rate, or waiting until they requested rate and QoS are met.08-16-2012
20120300866SIMULTANEOUS TRANSMISSION OF SIGNALS, SUCH AS ORTHOGONAL-FREQUENCY-DIVISION-MULTIPLEXED (OFDM) SIGNALS, THAT INCLUDE A SAME FREQUENCY - An embodiment of a transmitter includes detection, generating, and transmission stages. The detection stage is configured to detect a first signal having a first component that includes a frequency, and the generating stage is configured to generate a data component that includes approximately the frequency in response to the detection of the first signal. The transmission stage is configured to transmit a second signal having the data component while the detection stage is detecting the first signal. For example, two or more such transmitters (e.g., two or more smart phones) may simultaneously transmit OFDM signals on the same subcarrier frequencies and over the same channel space. By allowing the simultaneous transmission of multiple signals on the same frequencies and over the same channel space, such a transmitter may increase the effective bandwidth of the channel space, and thus may allow more devices to simultaneously share the same channel space.11-29-2012
20120300865CHANNEL ESTIMATE INTERPOLATION CIRCUIT AND METHOD - To more accurately generate a virtual waveform of channel estimate values outside a bandwidth upon their interpolation in OFDM system while preventing the circuit size from increasing, a converter (11-29-2012
20120300864CHANNEL ESTIMATION BASED ON COMBINED CALIBRATION COEFFICIENTS - Calibration coefficients are combined to provide more robust calibration. In some implementations, calibration coefficients are generated by acquiring two or more sets of calibration coefficients that are associated with different periods of time, different receive devices, or some other condition. These different sets of calibration coefficients are then combined using maximal ratio combining or some other suitable technique. The resulting combined calibration coefficients are used to calibrate implicit channel estimates.11-29-2012
20100232527INTERPOLATION IN CHANNEL STATE FEEDBACK - Feedback bandwidth may be reduced in a closed loop MIMO system by Householder transformations, vector quantization using codebooks, and down-sampling in the frequency domain. A column of a beamforming matrix is quantized using a codebook, a Householder reflection is performed on the beamforming matrix to reduce the dimensionality of the beamforming matrix, and the quantizing and performing of Householder reflection on the previously dimensionality reduced beamforming matrix is recursively repeated to obtain a further reduction of dimensionality of the beamforming matrix. These actions are performed for a subset of orthogonal frequency divisional multiplexing (OFDM) carriers, and quantized column vectors for the subset of OFDM carriers are transmitted.09-16-2010
20120155560LOW COMPLEXITY ITERATIVE MIMO RECEIVER BASED ON SUCCESSIVE SOFT INTERFERENCE CANCELLATION AND MMSE SPATIAL FILTERING - A multiple-input multiple-output (MIMO) system for demapping uses a single stream system of iterative passes in a preferred order using the latest soft-information for better interference cancellation and the minimum mean square error (MMSE) criterion.06-21-2012
20120155561METHOD OF RELAY NODE USING REFERENCE SIGNAL AND RELAY NODE USING THE METHOD - The present invention relates to a method of a Relay Node (RN) using a reference signal. The method includes receiving information about a Dedicated Reference Signal (DRS) which is used to demodulate a control channel via high-layer signaling from an evolved-NodeB (eNB), receiving control information through the control channel from the eNB, receiving data through a data channel from the eNB, and demodulating the control information and the data. The control information is demodulated using a DRS indicated by the information about the DRS, and the data are demodulated using a DRS indicated by the control information.06-21-2012
20110085609DEVICE, SYSTEM AND METHOD OF COMMUNICATING DATA OVER WIRELESS COMMUNICATION SYMBOLS WITH CHECK CODE - Some demonstrative embodiments include devices, systems and/or methods of communicating data over wireless communication symbols with check-code. For example, a wireless communication unit may transmit a sequence of wireless communication symbols representing transmitted data bits, wherein a symbol of the symbols includes at least one data block, which includes a set of data bits and a set of repetition bits, the set of data bits including a first number of the transmitted data bits, and the set of repetition bits including a second number of bits, which are identical to at least a subset of the set of data bits, wherein the symbol includes at least one plurality of check-code bits corresponding to the at least one data block, respectively, and wherein the first and second numbers are based on a number of the transmitted data bits, a symbol bit-size of the symbol, at least one value related to at least one of a data-block bit-size of the data block and a number of the plurality of check-code bits. Other embodiments are described and claimed.04-14-2011
20090103639Peak to Average Power Ratio Reduction Apparatus and Method for a Wireless OFDM transmitter - An OFDM symbol comprises information subcarriers which carry the information to be transmitted, accompanied by edge subcarriers, which are selected to minimize the PAPR of the transmitted signal. The selection of edge subcarriers which minimizes PAPR enables either higher power transmission for the same information content, or lower power consumption for the same transmitted symbol power.04-23-2009
20110075750BASE STATION APPARATUS, USER APPARATUS, AND METHOD USED IN MOBILE COMMUNICATION SYSTEM - A base station apparatus is used in a region in which a first system and a second system co-exist. In the first system, mobile communication is conducted using a variable system bandwidth not more than a basic bandwidth. In the second system, mobile communication is conducted using a variable system bandwidth which is not more than a bandwidth of an advanced system band which is at least as wide as multiple of the basic bandwidths. The base station apparatus generates a control signal for the first system and a control signal for the second system, orthogonally multiplexes them, and includes the same in a downlink signal to transmit the downlink signal. The advanced system band is divided such that it includes multiple of areas (P, Q, R, S) of the basic bandwidth. The control signal for the first system is included in one of the areas (Q). The control signal for the second system is included in at least one of the areas (P, Q, R, S).03-31-2011
20110019756METHOD OF TRANSMITTING RLC DATA - A method of transmitting data is performed by detecting a triggering of a first event, further detecting a triggering of a second event until a third event occurs, and performing a first action if the triggering of the second event is not detected, wherein the first action is based on the detected first event. The first event may be the expiry of a poll retransmit timer, the second event may be a detecting whether a ACK or NACK is not received, the third event may be a next transmission opportunity, and the first action may be setting a polling bit of a data PDU to be transmitted.01-27-2011
20100172424EFFICIENT MIMO TRANSMISSION SCHEMES - A method for communication includes, in a transmitter having a first number of transmit antenna ports, setting an upper limit on a second number of spatial layers to be used by the transmitter to be less than the first number. An actual number of the spatial layers, which does not exceed the upper limit, is allocated for transmission to a given receiver. One or more streams of modulated symbols are mapped onto the allocated actual number of the spatial layers. The actual number of the spatial layers are transmitted from the transmitter to the given receiver.07-08-2010
20100172426DEVICE AND METHOD FOR SELECTING TRANSMISSION PATH IN WIRELESS NETWORK - A device for selecting a transmission path in a wireless network includes a radio frequency (RF) module, a base band (BB) module, and a control module. The RF module is coupled to a plurality of antennas, for processing a packet of a wireless signal respectively received by the antennas. The BB module generates signal strengths (SSs) corresponding respectively to the antennas according to the packet received by each antenna. The control module is coupled to the BB module, for receiving the SSs and respectively controlling the antennas so that they may be enabled or disabled according to a difference between the SSs.07-08-2010
20100172421MIMO RECEIVER AND MIMO COMMUNICATION SYSTEM - An MIMO receiver and MIMO communication system which can have a small hardware scale even if the number of antennas used for MIMO communication. In a radio communication device (07-08-2010
20100172422Transmitter-receiver and Operation Control Method of the Same - A transmitter-receiver of this embodiment includes a plurality of antennas (07-08-2010
20110103501INDEXING METHODS AND SYSTEMS - Methods and systems for indexing signal option selections are disclosed. The signal options can be any of a variety of options that permit the establishment of a communication link, including modulation format, coding rate, precoding index and assigned subbands. The selected options can be represented as a vector and the index can be determined by employing a worth function for a particular selected vector element that is dependent on a selection occurrence count of the element and on an element position count of the element. In particular, the index can be the summation of worth function values for each selected element.05-05-2011
20110103500Methods and apparatus for estimating a sparse channel - Embodiments include a method for sending a selected number of pilots (05-05-2011
20110103499METHOD FOR RANGE EXTENSION IN WIRELESS COMMUNICATION SYSTEMS - The present invention provides a method for range extension is wireless communication systems. One embodiment of the method includes determining whether a mobile unit is within a first range corresponding to a range of timing advances supported by a timing advance command. This embodiment also includes transmitting a plurality of timing advance commands to the mobile unit when the mobile unit is outside the first range so that the mobile unit can synchronize with the base station by combining information in the plurality of timing advance commands.05-05-2011
20110103497CHANNEL ESTIMATION IN OFDM RECEIVER EQUIPMENT - A receiver is operated so as to receive data conveyed on an Orthogonal Frequency Division Multiplexed (OFDM) signal transmitted on a plurality of sub-carriers. Such operation includes ascertaining which of the plurality of sub-carriers have a channel quality that satisfies one or more criteria. Then, sub-carriers are selected based at least in part on whether they have the channel quality that satisfies one or more criteria. The receiver then fully processes data streams only from the selected sub-carriers, wherein fully processing data streams comprises sub-carrier channel estimation or sub-carrier equalization or both sub-carrier channel estimation and sub-carrier equalization.05-05-2011
20110103494FRAME STRUCTURE FOR SUPPORT OF LARGE DELAY SPREAD DEPLOYMENT SCENARIOS - A frame structure for support of large delay spread deployment scenarios (e.g., cellular system operation in large cell sizes or low frequency bands) is generally presented. In this regard a method is introduced comprising partitioning a radio frame into a plurality of equal-sized (or non-equal-sized) sub-frames to simplify system implementation. Other embodiments are also disclosed and claimed.05-05-2011
20120314786MULTI-LEVEL MODULATION SYSTEM AND METHOD - A transmitter communicating data using Orthogonal Frequency Division Multiplexed (OFDM) symbols including plural sub-carrier symbols in the frequency domain for modulating with data to be carried. The transmitter includes a modulator to receive data symbols from a first data pipe according to a first communications channel, to receive data symbols from a local service insertion data pipe according to a local communications channel, and to modulate the sub-carrier signals of the OFDM symbols with either the data symbols from the first data pipe or from both the first data pipe and the local service insertion pipe; modulation from the first data pipe maps the data symbols is according to a first modulation scheme, and modulation from the first data pipe and the local service insertion pipe maps the data symbols is according to a second modulation scheme.12-13-2012
20120314785Method for Data Transmission and Data Transmission System - In a method for data transmission by orthogonal frequency multiplexing (OFDM) between a transmitter and a receiver using a data signal, the data signal having a telegram, which is made up of OFDM symbols, the OFDM symbols are transmitted by the transmitter in symbol-wise fashion at a rate of repetition n-fold in succession within the telegram, and in the process of receiving in the receiver, the respectively n-fold successively transmitted OFDM symbols are added symbol-wise in phase.12-13-2012
20120121029NEAR END CROSS TALK REDUCTION FOR A MIMO SYSTEM - A method and a device perform data processing in a network element of a MIMO system, wherein near end cross talk is reduced at a collaborative network element of the MIMO system. A frequency band is at least partially used for upstream and downstream traffic. Furthermore, an interference canceller and a communication system are suggested.05-17-2012
20100290550 METHOD, A TRANSMITTING STATION, A RECEIVING STATION AND A PREAMBLE STRUCTURE FOR COMMUNICATING A SIGNAL USING ANALOG BEAM STEERING - The present invention relates to a method for communicating a signal to a first station from a second station, the stations having antenna array. For communication in bands like 60 GHz, it is advisable to carry out analog beam steering. But it is needed to compute all the beam forming weights in a single message. Then, the invention-proposes that for each signal, in the preamble, a plurality of training symbols are included, wherein during each training symbol repetition, the receiving station adjusts at least one antenna parameter of the plurality of antennas and measuring the combined signal for computing a set of antenna weights to be applied for an analog beam forming on the antenna array for receiving and/or transmitting the data field.11-18-2010
20100290549Method, System and Apparatus for Improving Throughput Performance of Space Division Multiple Access System - A method, a system, and an apparatus for improving throughput performance of an SDMA system are disclosed herein. The method includes BTS receiving feedback information sent by a UE, where the feedback information comprises an ID of a preferred beam of the UE in a pre-coding codebook, information related to a channel vector modulus value, and information about phase difference between a channel vector and the preferred beam of the UE, and the BTS using a set estimation algorithm to estimate sum throughputs supported by a current SDMA system in each sending mode according to the received feedback information and information about space correlation between multiple antennas of the BTS, selecting a maximum sum throughput among the estimated sum throughputs, and using the sending mode corresponding to this sum throughput to send data. The method, system, and apparatus provided herein improve transmitting performance of the SDMA system.11-18-2010
20100290548WIRELESS COMMUNICATION APPARATUS, WIRELESS COMMUNICATION SYSTEM AND WIRELESS COMMUNICATION METHOD - When power scaling is applied to multi-user MIMO, a reduction in transmission rate is suppressed and transmission efficiency is improved. When signals are transmitted through spatial multiplexing from a wireless base station 11-18-2010
20100290546SYSTEMS AND METHODS FOR DESIGNING A REFERENCE SIGNAL TO BE TRANSMITTED IN A MULTIPLEXED CELLULAR SYSTEM - A method of the present invention for designing a reference signal is a method for designing a reference signal, including: setting a first set of matrices by combining a plurality of first matrices each including a plurality of sequences; dividing the first set of matrices into a plurality of subsets each including at least one first matrix, and selecting at least one sequence from each of the plurality of subsets; and combining the selected sequences so as to generate a second matrix.11-18-2010
20100290545OFDM TRANSMISSION/RECEPTION DEVICE FOR TRANSMITTING AND RECEIVING OFDM SYMBOLS HAVING A VARIABLE DATA TRANSMISSION RATE AND METHOD THEREOF - An orthogonal frequency division multiplexing (OFDM) transmission device transmits OFDM symbols to at least one reception device and includes an OFDM transmission processing unit which generates a plurality of OFDM symbols; a pilot insertion unit which inserts pilot tones into each of the plurality of OFDM symbols; and a control unit which controls the pilot insertion unit to insert the pilot tones according to a pilot insertion pattern which is selected to correspond to a communication environment from among a plurality of pilot insertion patterns.11-18-2010
20100290544BASE STATION, MOBILE STATION AND METHOD - A single carrier scheme is used in an uplink in the mobile communication system. A base station used in the mobile communication system includes: means configured to perform communication with a mobile station that uses the whole or a part of a system frequency band; storage means configured to store correspondence relationship between radio parameters including a bandwidth, a modulation scheme and a channel coding rate of the uplink and filter parameters including at least a roll-off factor of a band limitation filter; and determination means configured to determine radio parameters and filter parameters for each mobile station based on the correspondence relationship according to channel state of the uplink. The radio parameters and the filter parameters determined in the determination means are reported to the mobile station.11-18-2010
20100246696PILOT METHOD FOR 802.16M - A novel pilot method employs a cluster having a particular arrangement of pilot sub-carriers to optimize transmissions under 802.16m, or WiMAX-II. The optimally configured cluster features equal pilot density per OFDM symbol, two or more pilot sub-carriers per cluster, and interlaced pilot sub-carriers, which enables the base stations to successfully boost the pilot sub-carriers, for optimum performance.09-30-2010
20100246697Apparatus, Method and Computer Program Product Providing Feedback for Closed-Loop Wideband MIMO-OFDM System - In one exemplary aspect thereof the embodiments of this invention provide an apparatus that includes a wireless receiver configurable to receive resource units; a wireless transmitter configurable to transmit feedback information to a source of the received resource units; and a channel estimator and feedback generator coupled to the wireless receiver and to the wireless transmitter. The channel estimator and feedback generator is configurable to determine a weight for each of a first resource unit and a second resource unit that are received by the receiver spaced apart at least in frequency, to determine a weight for at least some of a plurality of resource units that are intermediate at least in frequency to the first and the second resource units, and to send feedback via the transmitter. The feedback includes an indication of the determined weight for the first and the second resource units using X bits for representing each of the indications of the determined weights, and further includes an indication of weights for each of the plurality of resource units using Y bits, where Y09-30-2010
20100246702RADIO TRANSMITTING APPARATUS, RADIO RECEIVING APPARATUS AND METHOD THEREFOR - By assigning a plurality of subcarriers 09-30-2010
20100246700CONVERTER - A bit-converting unit inputs from an FFT unit a multicarrier signal converted into the frequency domain and shown as a floating-point number. The bit-converting unit specifies the position of the highest-order bit for each of a plurality of subcarriers that form the multicarrier signal and determines the position of a bit width to be commonly used for each of the plurality of subcarriers based on the specified position of the highest-order bit. The bit-converting unit converts the multicarrier signal from a floating-point number to a fixed-point number while using the determined position of the bit width. The bit-converting unit outputs the converted multicarrier signal to a reception processor that performs fixed-point arithmetic.09-30-2010
20100246701Fast Random Access for an Enhanced Uplink Dedicated Channel - The present invention relates to fast random access methods and arrangements for the enhanced uplink dedicated channel of E-UTRAN (Evolved Universal terrestrial radio access network). A user equipment (UE) being in a low activity state sends a random access request comprising a preamble on a physical random access channel (PRACH) to a NodeB. The NodeB receives the request and sends in response to the received random access request a response comprising information associated with detection of the preamble on an acquisition indicator channel (AICH). The response comprises further in an extension of the AICH an indication of an action to be taken by the UE. In an embodiment of the present invention the action is to access the E-DCH and the response comprises configuration parameters to the E-DCH.09-30-2010
20100246698SYNCHRONIZATION METHOD AND APPARATUS FOR ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING SYSTEM - A synchronization method used in a receiving terminal of an orthogonal frequency division multiplexing (OFDM) system is illustrated. The synchronization method includes following steps: (a) receiving an OFDM training symbol at the receiving terminal, wherein the OFDM training symbol includes many sample points; (b) calculating first function values according to the sample points by using a first function; (c) selecting D timing points from many timing points corresponding to the first function values, wherein D first function values of the D timing points are larger than a first threshold value; (d) calculating D second function values of the D timing points by using a second function; and (e) selecting a first timing point from the D timing points, and setting the first timing point as a timing synchronization point, wherein the second function value of the first timing point is a first one greater than a second threshold value.09-30-2010
20120314788QUANTIZATION METHOD FOR OFDM - A quantization method for OFDM is described. In an embodiment, the method uses an objective function which is defined as a function of the quantization error of the OFDM signal in frequency summed over data subcarriers. A search algorithm is used to optimize the objective function and the solution found is quantized by rounding. The quantized value of the solution may then be fed back into the objective function to compute a value of that function and if the value is less than the value computed in a previous iteration of the method, the method is repeated using the quantized value of the solution as the new starting point for the search algorithm. If the value of the function is, however, not less than the value computed in a previous iteration, the new solution is discarded and the quantized value of the solution from the previous iteration is output.12-13-2012
20120128085SIGNAL PROCESSING METHOD AND RECEIVER - A receiver selects, regarding each of signals corresponding to component elements of a transmission column vector, a number of transmission signal candidates equal to a number according to a predetermined parameter based on inter-signal point distances between a plurality of transmission signal candidates regarding the transmission column vector and the signal from among the plural transmission signal candidates. Then, the receiver reproduces the transmission signal by determining a unique set of transmission signal candidates regarding each component element of the transmission column vector based on the sum total of the inter-signal point distances between the selected transmission signal candidates and the signals.05-24-2012
20120128087TRANSMISSION APPARATUS AND TRANSMISSION METHOD - A wireless receiving apparatus capable of efficiently removing interference signals in a multicarrier communication. In a mobile station incorporating this wireless receiving apparatus, a selecting part selects a plurality of the same symbols in accordance with a mapping pattern established at the time of generating OFDM symbols in a base station. A correlation value calculating part determines correlation values between the subcarriers of the same symbols to generate an R-matrix, and further determines an inverse matrix of the R-matrix. An MMSE processing part performs an MMSE processing to determine a weight from both a P-vector received from a channel estimating part and the inverse matrix of the R-matrix received from the correlation value calculating part. Multipliers multiply each of the symbols selected by the selecting part by the weight determined by the MMSE processing part. A combining part combines the symbols as multiplied by the weight.05-24-2012
20120128088ADAPTIVE MULTIPLE ANTENNA TRANSMISSION METHOD AND APPARATUS IN ACCORDANCE WITH ANTENNA TRANSMISSION POWER IN A WIRELESS COMMUNICATION SYSTEM - The present invention relates to a wireless communication system, and an adaptive multiple antenna transmission method and apparatus in accordance with antenna transmission power are disclosed. A method of performing multiple antenna transmission from a terminal to a base station according to one embodiment of the present invention may include the steps of: determining a reference value for a transmission power of each of a plurality of transmit antennas of the terminal; grouping the plurality of transmit antennas into a first group of transmit antennas and a second group of transmit antennas in accordance with the determined reference value; and transmitting a signal to the base station through at least one of the first group of the transmit antennas and the second group of transmit antennas.05-24-2012
20100158146COMMUNICATION SCHEME DETERMINING APPARATUS, TRANSMISSION APPARATUS, RECEPTION APPARATUS, OFDM ADAPTIVE MODULATION SYSTEM AND COMMUNICATION SCHEME DETERMINING METHOD - Modulation information is efficiently notified to a communicating destination. Provided are a first modulation information determining section 06-24-2010
20120128086IDENTIFICATION METHOD OF AN OFDM SIGNAL - An OFDM signal identification method in a received signal, wherein the received signal is sampled and cut off into blocks of P samples, each block being subjected to an inverse Fourier transform to obtain a plurality of symbols at a plurality of frequencies. For each frequency of the plurality, the kurtosis of the set of symbols thus obtained at this frequency is calculated, and then it is determined whether the kurtosis has a periodicity in frequency domain from kurtosis values calculated for the frequencies of the plurality, and the presence of an OFDM signal in the received signal is identified if the kurtosis has such a periodicity.05-24-2012
20120163485WIRELESS COMMUNICATION DEVICE AND WIRELESS COMMUNICATION METHOD - A wireless communication device with MIMO function conforming to a predetermined wireless standard and communication terminals that communicate with a base station incorporating MIMO function includes a master communication terminal which is any one of the plurality of communication terminals and a slave communication terminal which is connected to the master communication terminal via a predetermined connection element and is one or more communication terminals other than the master communication terminal among the plurality of communication terminals. A configuration in which a part of or all signal processing functions that relate to transmission and reception of one or more antennas incorporated in one or more slave communication terminals can be controlled from the master communication terminal is used. A configuration in which the number of antennas can be arbitrarily increased is implemented and a protocol for call connection is performed only between the base station and the master communication terminal.06-28-2012
20110182375METHOD AND APPARATUS FOR SCHEDULING IN MULTIPLE-INPUT MULTIPLE-OUTPUT COMMUNICATION SYSTEM - In a Multiple-Input Multiple-Output (MIMO) communication system, a serving evolved Node B (eNB) receives a channel covariance matrix of the serving eNB and a channel covariance matrix for a first neighbor eNB with the highest interference among neighbor eNBs, from a User Equipment (UE). Received signal power information is generated for each subband-beam pair. Interference signal power information is generated for each subband-beam pair for the first neighbor eNB. The generated interference signal power information is exchanged with the first neighbor eNB for each subband-beam pair. Beam coordination information indicating a use status of each beam in each subband is generated for the UE, using the interference signal power information of the first neighbor eNB. The generated beam coordination information is exchanged with the neighbor eNB. Scheduling is performed on the UE using the generated beam coordination information and the beam coordination information of the first neighbor eNB.07-28-2011
20110182374OFDM CHANNEL ESTIMATION SYSTEM AND METHOD COMPONENTS - Channel estimation for high mobility OFDM channels is achieved by identifying a set of channel path delays from an OFDM symbol stream including carrier data, inter-channel interference noise and channel noise; determining the average channel impulse response for the identified set of channel path delays in each symbol; generating a path delay curvature for each channel path delay in each symbol based on stored average channel impulse responses for the identified channel path delays; estimating the carrier data in the symbols in the OFDM symbol stream in the presence of inter-channel interference noise and channel noise from the OFDM symbol steam and the average impulse responses for the identified channel path delays; reconstructing the inter-channel interference noise in response to the path delay curvature, the identified set of channel path delays and estimated carrier data to produce a symbol stream of carrier data and channel noise with suppressed inter-channel interference noise.07-28-2011
20120213301WIRELESS COMMUNICATION APPARATUS AND WIRELESS COMMUNICATION METHOD - A wireless communication apparatus is capable of improving communication efficiency by reducing the amount of control information transmitted. A channel quality information extraction section extracts CQI's from a received signal. An allocation control section allocates subcarriers for every communication terminal apparatus and selects a modulation scheme in such a manner that required transmission rate is satisfied for each communication terminal apparatus based on required transmission rate information, etc. and CQI's for communication terminal apparatus of each user. A required subcarrier number determining section decides the number of subcarriers allocated to every communication terminal apparatus so as to satisfy the required transmission rate for each communication terminal apparatus. A required subcarrier number information generating section generates information for the number of subcarriers allocated to every communication terminal apparatus. A subcarrier allocation section allocates packet data to selected subcarriers. Modulating sections adaptively modulate packet data allocated to each subcarrier.08-23-2012
201201344318K MODE INTERLEAVER WITH ODD INTERLEAVING ONLY AND PER OFDM SYMBOL PERMUTATION CODE CHANGE IN A DIGITAL VIDEO BROADCASTING (DVB) STANDARD - A data processing apparatus maps input symbols to be communicated onto a predetermined number of sub-carrier signals of an Orthogonal Frequency Division Multiplexed (OFDM) symbol. The data processor includes an interleaver memory which reads-in the predetermined number of data symbols for mapping onto the OFDM sub-carrier signals. The interleaver memory reads-out the data symbols on to the OFDM sub-carriers to effect the mapping, the read-out being in a different order than the read-in, the order being determined from a set of addresses, with the effect that the data symbols are interleaved on to the sub-carrier signals. The set of addresses are generated from an address generator which comprises a linear feedback shift register and a permutation circuit.05-31-2012
20120134432Method for Improving Synchronization and Information Transmission in a Communication System - A method is provided for improving synchronization and information transmission in a communication system, including: generating a signal with a centrally symmetric part s(k) exploitable for synchronization; and sending the signal over a communication channel. The signal is based on a uniquely identifiable sequence c(l) from a set of sequences exploitable for information transmission. The centrally symmetric part s(k) is centrally symmetric in the shape of absolute value thereof. The centrally symmetric part s(k) is of arbitrary length N.05-31-2012
20120134430Method of Handling Tone Map Interpolation and Related Communication Device - A method of determining a tone-specific information with a tone index for a transmitter or a receiver in a communication system is disclosed. The method comprises selecting at least one base tone index from a plurality of base tone indices according to at least one relation between the tone index and the at least one base tone index, and generating the tone allocation according to at least one base tone allocation with the at least one base tone index of a plurality of base tone allocations, and the at least one relation between the tone index and the at least one base tone index; wherein a base tone map comprises the plurality of base tone indices and the plurality of base tone allocations.05-31-2012
20120163484METHOD AND PROCESSING ARRANGEMENT FOR JOINT PROCESSING OF UPLINK DATA - The invention relates to a method for joint processing of uplink data (g(n), s(n)) transmitted from at least one user equipment (UE06-28-2012
20120163483MU-MIMO ACCESS POINT AND USER STATION INCLUDING METHODS FOR MULTI-USER GROUP MANAGEMENT - Embodiments of a MU-MIMO access point, user station and method for multi-user group management are generally described herein. In some embodiments, a MU-MIMO access point may assign a MU group identifier (GID) and a group member index (GMI) to each of a plurality of associated user stations. The MU-MIMO access point may transmit a MU-MIMO transmission that includes a plurality of spatial streams. The MU-MIMO transmission may be destined for the user stations of a single MU group indicated by a GID that is included within the MU-MIMO transmission. A subset of the spatial streams may be intended for each user station of the indicated MU group that is identified by the GID transmitted within the MU-MIMO transmission. A user station may use its assigned GMI along with an N06-28-2012
20120213300WIRELESS COMMUNICATION SYSTEM, WIRELESS COMUNICATION APPARATUS AND WIRELESS COMMUNICATION METHOD - A wireless communication system which performs data transmission using spatially multiplexed streams from a first terminal including N antennas to a second terminal including M antennas (N is an integer of 2 or more and M is an integer of 1 or more) is disclosed. The system includes notifying means, training means, channel matrix estimation means, beamforming information feedback means, transmission weight matrix setting means, and beamforming means.08-23-2012
20090060069SIGNAL TRANSMITTING APPARATUS, METHOD THEREOF, AND INVERSE FAST FOURIER TRANSFORM APPARATUS FOR SIGNAL TRANSMITTING APPARATUS - The present invention relates to a signal transmitting apparatus, a method thereof, and an inverse fast Fourier transform (IFFT) apparatus for a signal transmitting apparatus. A signal transmitting apparatus according to an embodiment of the present invention receives data, and performs inverse fast Fourier transform (IFFT) on the data on the basis of a twiddle factor for shifting output data by the size of a cyclic prefix. In addition, the signal transmitting apparatus sequentially stores data corresponding to the size of the cyclic prefix starting with initial data among the transformed data, and generates an OFDM symbol on the basis of the stored data and the transformed data. According to the embodiment of the present invention, it is possible to efficiently reduce a time delay and a memory use amount when a cyclic prefix is added at a transmitting end, without changing the size of hardware and power consumption.03-05-2009
20090060073METHOD FOR SUPPRESSING PEAK POWER OF ORTHOGONALLY MULTIPLEXED SIGNAL, PEAK POWER SUPPRESSING CIRCUIT, AND TRANSMITTER - To suppress the peak of the orthogonal multiplex transmission signal which is small in deterioration of the quality of the reception signal by generating the cancellation waveform in synchronization with the timing of the symbol of the transmission signal. There is provided a peak suppressing method that suppresses peaks of an orthogonally multiplexed signal whose orthogonality is ensured in given time units, the method comprising: a first step of detecting the peaks of the orthogonally multiplexed signal; a second step of generating a peak cancellation waveform based on the detected peaks of the orthogonally multiplexed signal; and a third step of removing the peak of the orthogonally multiplexed signal from the orthogonally multiplexed signal using the generated peak cancellation waveform. The second step comprises generating the peak cancellation waveform in said time units of the orthogonally multiplexed signal.03-05-2009
20090060076SYSTEM ACCESS AND SYNCHRONIZATION METHODS FOR MIMO OFDM COMMUNICATIONS SYSTEMS AND PHYSICAL LAYER PACKET AND PREAMBLE - A method and apparatus are provided for performing acquisition, synchronization and cell selection within an MIMO-OFDM communication system. A coarse synchronization is performed to determine a searching window. A fine synchronization is then performed by measuring correlations between subsets of signal samples, whose first signal sample lies within the searching window, and known values. The correlations are performed in the frequency domain of the received signal. In a multiple-output OFDM system, each antenna of the OFDM transmitter has a unique known value. The known value is transmitted as pairs of consecutive pilot symbols, each pair of pilot symbols being transmitted at the same subset of sub-carrier frequencies within the OFDM frame.03-05-2009
20090060072DECODING METHOD FOR RECEIVING OFDM SIGNALS, AND DECODING APPARATUS AND RECEIVING APPARATUS USING THE SAME - A phase derivation unit derives a phase difference between two symbols for each subcarrier, based on phase components of symbols. A weighting factor derivation unit derives a weighting factor for each subcarrier, based on amplitude components of the symbols. A multiplier weights the phase difference with the weighting factor for each subcarrier. A likelihood accumulation unit accumulates the weighted phase differences for a plurality of subcarriers. A decision units determines a result of accumulation. A substitution unit identifies a portion where known data are to be assigned, among the determined data frames, and substitutes the data in the identified portion with known data. A syndrome computation unit performs a syndrome computation on the data frames. An error detector detects an error in the data frames, based on a result of the syndrome computation.03-05-2009
20090060070Apparatus and Method for Peak Suppression in Wireless Communication Systems - A method for suppressing the peak-to-average power ratio (PAPR) while limiting deterioration in signal characteristics in wireless communication devices utilizing wireless communication methods (OFDM method, MIMO method) for multiplexing and sending multiple signals. A weight calculator unit sets a large weight for transmit signals whose channel quality is poor, relative to the weight of each base component based on the acquired channel quality. A peak detector unit detects the peak from the signal string after unitary conversion, and extracts a distortion component to apply for suppressing the peak. A peak suppression signal generation unit calculates the peak signal from the distortion component and weight of each base component, to add to each base component, and adds the peak suppression signal to each base component prior to unitary transformation.03-05-2009
20090060068Method and apparatus for bit interleaving and deinterleaving in wireless communication systems - Disclosed herein is a method and system for interleaving and deinterleaving of data bits in wireless data communications. Interleaving is performed as a single stage parallel operation using a single standard memory block. The disclosed method and system is capable of implementing different interleaving techniques, individually, or as a combination thereof. The disclosed system comprises a plurality of multiplexers, a standard memory block, read and write buses, control block, and a lookup table. The contents of the lookup table are generated based on an interleaving function. The data bits from the input bus and bits from the read bus of the memory are inputted to the plurality of multiplexers. Based on the lookup table's contents the multiplexers are switched to parallelly permute the input data bits and read bits from the read bus. The permuted data bits are in an interleaved sequence.03-05-2009
20090060065Communication system and method for receiving high priority and low priority signals - A communication system and method of communicating signals to a plurality of different types of receivers is provided. At least one transmitter transmits hierarchically modulated high priority and low priority signals as a single frequency network. At least one satellite re-transmits the high priority signal in a first circularly polarized direction and the low priority signal in a second circularly polarized direction. At least one of a first receiver having a single antenna is configured to receive the high priority signal in the first circularly polarized direction and switched to receive the low priority signal in the second circularly polarized direction, and a second receiver having a first antenna is configured to receive the high priority signal in the first circularly polarized direction, and a second antenna is configured to receive the low priority signal in the second circularly polarized direction substantially simultaneously.03-05-2009
20090060064OFDM Communication System, Method for Generating Feedback Information Thereof, and Communication Apparatus - An OFDM communication system which performs appropriate feedback flexibly adapted to channel states, while suppressing an amount of feedback information. The OFDM communication system has first and second communication apparatuses. In a second receiver of the second communication apparatus, a channel quality measurement part measures channel quality for each of sub-carriers. A time variation measurement part and a frequency measurement part respectively measure variation of channel quality in a time domain and a frequency domain, respectively, and output the variation of channel quality as time variation information and frequency variation information, also respectively. Based on the measured time variation information and frequency variation information, a two-dimensional control part performs two-dimensional blocking for forming two-dimensional blocks each from plural adjacent sub-carriers which are adjacent to each other in the time domain and the frequency domain. The two-dimensional control part measures and outputs channel quality of each two-dimensional block, as feedback information.03-05-2009
20090060063Method and Apparatus for Robust Control Signaling Distribution in OFDM Systems - Orthogonal Frequency Division Multiplex (OFDM) systems distribute some number of pilot subcarriers within the larger set of subcarriers comprising an OFDM signal. In that context, according to teachings presented herein, control signaling is sent on subcarriers selected for their proximity to pilot subcarriers. Correspondingly, an OFDM receiver is configured to receive an OFDM signal having a control signaling subcarrier positioned proximate in a frequency-time plane to a pilot subcarrier, and generate a scalar-valued channel estimate for demodulating symbols from the control signaling subcarrier based on observations limited to the proximate pilot subcarrier. Channel estimation with respect to the control signaling subcarriers thus is robust, yet simplified. The method may be applied to all control signaling, or selectively applied to higher-priority control signaling, such as paging.03-05-2009
20090060071DEMODULATION METHOD FOR RECEIVING OFDM SIGNALS, AND DEMODULATION APPARATUS AND RECEIVING APPARATUS USING THE SAME - A phase derivation unit derives a phase difference between two symbols for each subcarrier, based on phase components of symbols. A weighting factor derivation unit derives a weighting factor for each subcarrier, based on amplitude components of the symbols. A multiplier weights the phase difference with the weighting factor for each subcarrier. A likelihood accumulation unit accumulates the weighted phase differences for a plurality of subcarriers. A decision units determines a result of accumulation. A substitution unit identifies a portion where known data are to be assigned, among the determined data frames, and substitutes the data in the identified portion with known data. A syndrome computation unit performs a syndrome computation on the data frames. An error detector detects an error in the data frames, based on a result of the syndrome computation.03-05-2009
20090060067Determining channel matrices by correlated transmissions to different channels - A method involves performing a plurality of acts. The acts include transmitting a first signal stream to a first channel of a multi-channel communications medium while transmitting a second signal stream to a different second channel of the medium. The second signal stream is substantially temporally correlated to the first signal stream. The method includes receiving an SINR measured at a receiver configured to receive signals from the first channel. The SINR is measured while the receiver received the first signal stream. The method includes determining a channel matrix element between the first and second channels or a ratio of said channel matrix element to a diagonal element of the channel matrix. The act of determining is based on the received SINR.03-05-2009
20120250777DATA PROCESSING APPARATUS AND METHOD - A data processing apparatus maps input symbols to be communicated onto a predetermined number of sub-carrier signals of an Orthogonal Frequency Division Multiplexed (OFDM) symbol. The data processor includes an interleaver memory which reads-in the predetermined number of data symbols for mapping onto the OFDM sub-carrier signals. The interleaver memory reads-out the data symbols on to the OFDM sub-carriers to effect the mapping, the read-out being in a different order than the read-in, the order being determined from a set of addresses, with the effect that the data symbols are interleaved on to the sub-carrier signals. The set of addresses are generated from an address generator which comprises a linear feedback shift register and a permutation circuit.10-04-2012
20120076223Method and System for an Alternating Delta Quantizer for Limited Feedback MIMO Pre-Coders - Aspects of a method and system for an alternating delta quantizer for limited feedback MIMO pre-coders may comprise quantizing a change in channel state information in a MIMO pre-coding system onto at least a first and a second codebook, each of which comprises one or more unitary matrices, using a cost function; feeding back, in an alternating manner, an index to an element of at least the first codebook or the second codebook, associated with the quantizing, from a receiver to a transmitter in said MIMO pre-coding system, and generating the at least first and second codebook based on at least the channel state information. The channel state information may be a matrix V and the cost function may be defined by the following relationship:03-29-2012
20120076222METHOD AND APPARATUS FOR USING CONTROL CHANNEL FORMAT INDICATOR (CCFI) CODEWORDS IN A WIRELESS COMMUNICATION SYSTEM - A method of transmitting a control channel format indicator (CCFI), also known as PCFICH (Physical Control Format Indicator Channel), in case where the length of a coded CCFI is not an integer multiple of three, including mapping a plurality of two-bit CCFI into a codebook with each component codeword having three bits; generating a sequence of codewords selected from the codebook by repeating the selected component codeword for predetermined times; generating a codeword by concatenating the sequence of the selected component codewords with the original CCFI bits; and transmitting the codeword carrying information of CCFI. The method further includes a step of generating a permutation of each of the four codewords by assigning K repetitions of the three-bit component codeword to the number of K resource units respectively and mapping remaining K bits of each of the four codewords separately to the number of K resource units.03-29-2012
20120076221COMMUNICATION METHODS FOR CCFI/PCFICH IN A WIRELESS COMMUNICATION SYSTEM - A method of transmitting a control channel format indicator (CCFI), also known as PCFICH (Physical Control Format Indicator Channel), in case where the length of a coded CCFI is not an integer multiple of three, including mapping a plurality of two-bit CCFI into a codebook with each component codeword having three bits; generating a sequence of codewords selected from the codebook by repeating the selected component codeword for predetermined times; generating a codeword by concatenating the sequence of the selected component codewords with the original CCFI bits; and transmitting the codeword carrying information of CCFI. The method further includes a step of generating a permutation of each of the four codewords by assigning K repetitions of the three-bit component codeword to the number of K resource units respectively and mapping remaining K bits of each of the four codewords separately to the number of K resource units.03-29-2012
20120076220TRANSMISSION APPARATUS AND A RECEPTION APPARATUS IN A MULTICARRIER TRANSMISSION SYSTEM AND A TRANSMISSION METHOD AND A RECEPTION METHOD USING THE MULTICARRIER TRANSMISSION SYSTEM - Inter-carrier interference caused by frequency fluctuations, amplitude fluctuations, phase fluctuations, or the like is reduced without reducing a transmission efficiency. A receiving end has a canceling filter section that alleviates the inter-carrier interference caused by the frequency fluctuations, the amplitude fluctuations, the phase fluctuations, or the like through filtering processing. A transmitting end has a precoding section that facilitates determination of demodulation data in a vector demodulation section on the receiving end through precoding processing. Or, the receiving end has a trellis decoding section that decodes the demodulation data through trellis decoding processing.03-29-2012
20120076218COMMUNICATION DEVICE - A first communication device includes: a control unit functioning as: a first selection unit which, for a first case where first type data is to be transmitted from the first communication device to a second communication device, selects one or more band guarantee values from a plurality of band guarantee values determined on a basis of transmission capability with which the first communication device transmits the first type data; a request unit which provides a first request command indicating the one or more band guarantee values to the second communication device; a communication unit that acquires a first response command indicating one band guarantee value selected from the one or more band guarantee values by the second communication device; and a first transmission execution unit which transmits the first type data to the second communication device in accordance with the one band guarantee value indicated by the first response command.03-29-2012
20120076217Using OFDM to correct distortions in Ultra-Wide-Band radios operating over flat millimeter-wave channels - A Point-to-Point communication system includes (i) a millimeter-wave channel having a substantially flat channel transfer function between a first frequency of millimeter-waves and a second frequency of millimeter-waves, the two frequencies are separated by at least 500 MHz, (ii) a transmission system configured to transmit an Orthogonal Frequency Division Multiplexing (OFDM) signal having a bandwidth of at least 100 MHz over the millimeter-wave channel as a millimeter-wave signal located between the first frequency and the second frequency, and (iii) a reception system comprising a radio receiver having a substantially non-flat reception transfer function over the bandwidth of the OFDM signal, configured to receive the millimeter-wave signal via the millimeter-wave channel and down-convert the millimeter-wave signal into a reconstruction of the OFDM signal having a bandwidth of at least 100 MHz, and an OFDM de-modulator configured to compensate for the substantially non-flat reception transfer function, by de-modulating the reconstruction of the OFDM signal.03-29-2012
20120314789SYSTEM AND METHOD FOR FREQUENCY OFFSETTING OF INFORMATION COMMUNICATED IN MIMO-BASED WIRELESS NETWORKS - A communications system includes a multiple-input/multiple-output (MIMO) architecture for high capacity switched mesh networks. The MIMO architecture has a plurality of radio frequency chains. One of the plurality of radio frequency chains is configured to apply a first frequency offset to a base frequency of an output signal to generate a first transmitting frequency; and another of the plurality of radio frequency chains being configured to apply a second frequency offset to the base frequency to generate a second transmitting frequency. The system uses the carrier frequency offset to lock the clock of the master subsystem to the clock of the slave subsystem, thereby enabling bandwidth expansion to be employed on the MIMO data streams.12-13-2012
20100272202DATA TRANSMISSION DEVICE, DATA RECEPTION DEVICE, AND WIRELESS COMMUNICATIONS SYSTEM - When an error correction decoding unit 10-28-2010
20100272201WIRELESS COMMUNICATION BASE STATION DEVICE, WIRELESS COMMUNICATION MOBILE STATION DEVICE, AND PROPAGATION PATH ESTIMATION METHOD - A wireless communication base station device, whereby precision of propagation path estimation is improved by making possible determination of the contiguity of precoding strings contiguous in frequency regions. In this device, a pre-coding string contiguity determining portion (10-28-2010
20100272200METHOD OF SOFT DECISION DECODING AND APPARATUS FOR SOFT DECISION DECODING - A soft decision decoding method in a multiple-input multiple-output system which respectively receives two simultaneously transmitted data streams, a first transmitting symbol and a second transmitting symbol, in a first receiving signal and a second receiving signal is provided. The soft decision decoding method includes calculating common metrics corresponding to distances between first candidate symbols, which correspond to combinations of all bits that the first transmitting symbol can have, and the first receiving signal using a channel matrix corresponding to a communication channel through which the first and second transmitting symbols are transmitted and determining intermediate nodes between the second receiving signal and the first candidate symbols and nodes between the second receiving signal and second candidate symbols corresponding to combinations of all bits that the second transmitting symbol can have; selecting first nearest candidate symbols that are at a shortest distance from the intermediate nodes on a signal constellation from among the second candidate symbols and determining a soft decision metric for each bit value of the first transmitting symbol based on the first nearest candidate symbols and the common metrics; and determining second nearest candidate symbols based on a logic value of a predetermined bit of each of the second candidate symbols and the positions of the intermediate nodes on the signal constellation and determining a soft decision metric for each bit value of the second transmitting symbol using the second nearest candidate symbols and the common metrics.10-28-2010
20100272199TRANSMISSION DEVICE, RECEPTION DEVICE, AND OFDM TRANSMISSION METHOD - SP signals to be transmitted from a first transmitting antenna 10-28-2010
20100272197OFDM SYSTEM AND DATA TRANSMISSION METHOD THEREFOR - An OFDM system includes a frequency-time transformer configured to receive and transform input data to be transmitted to a time-domain sequence; a serial/parallel transformer configured to divide the time-domain sequence into plural sequences; a phase rotating module configured to perform phase rotation in respects to each of the divided time-domain sequences; and a minimum PAPR signal selector configured to select a sequence having a minimum peak-to-average power ratio (PAPR) among the sequences outputted from the phase rotating module.10-28-2010
20100272196USING CHANNEL ESTIMATES ASSOCIATED WITH OFDM PILOT SYMBOLS TO ESTIMATE ADDITIONAL PARAMETER - Channel estimates respectively associated with OFDM pilot symbols are used to estimate additional parameters such as change in channel phase over time, change in channel phase over frequency, and frequency selectivity.10-28-2010
20100272195PEAK-TO-AVERAGE POWER RATIO REDUCTION WITH BOUNDED ERROR VECTOR MAGNITUDE - Method and apparatus for signal processing to minimize the peak to average power ratio of an Orthogonal Frequency Division Multiplexing (“OFDM”) or Orthogonal Frequency Division Multiple Access (“OFDMA”) signal with bounded error vector magnitude for an integrated circuit are described. An Active Constellation Extension (“ACE”) iteration, using a constellation points adjustment module, is performed. Symbols outside of a bounded region after the ACE iteration are identified. The bounded region is determined responsive to an error vector magnitude target. The symbols identified are translated to the bounded region.10-28-2010
20120177138MULTIDIMENSIONAL CONSTELLATIONS FOR CODED TRANSMISSION - Techniques for rotating and transmitting multidimensional constellations are disclosed. A method for rotating a multidimensional constellation may include constructing a first rotation matrix, constructing a second rotation matrix, applying orthogonality constraints to the first and second rotation matrices; selecting an optimizing rotation matrix from the first and second rotation matrices; and rotating the multidimensional constellation using the optimizing rotation matrix. Constructing the first rotation matrix and second rotation matrices may include constructing a first column that includes first matrix dements based on the number of axes in the multidimensional constellation, and additional columns that include permutations of the first matrix elements.07-12-2012
20120177137SYSTEM AND METHOD OF MODULATION AND CODING SCHEME ADJUSTMENT FOR A LTE SHARED DATA CHANNEL - A system, method and node for modulation and coding scheme adjustment for a Long Term Evolution (LTE) shared Data Channel. The method determines an actual number of orthogonal frequency division multiplexing (OFDM) symbols, N07-12-2012
20120177135INTERACTIVE CONTROL OF MULTIPLE INPUT MULTIPLE OUTPUT CONTROL STRUCTURES - Exemplary embodiments allow users to interactively formulate and solve multivariable feedback control problems. For example, users can solve problems where a plurality of control elements are distributed over one or more feedback loops and need to be jointly tuned to optimize overall performance and robustness of a control system. Embodiments allow users to specify design requirements and objectives in formats familiar to the user. Embodiments can operate on tunable parameters to solve the control problem in a manner that satisfies the design requirements and/or objectives provided by the user.07-12-2012
20100008437Method and System for Pre-Equalization in a Single Weight (SW) Single Channel (SC) Multiple-Input Multiple-Output (MIMO) System - In wireless systems, a method and system for pre-equalization in a single weight (SW) single channel (SC) multiple-input multiple-output (MIMO) system are provided. A first receive antenna and at least one additional receive antenna may receive a plurality of SC communication signals transmitted from at least two transmit antennas. Estimates of the propagation channels between transmit and receive antennas may be performed concurrently and may be determined from baseband combined channel estimates. Channel weights may be determined to modify the signals received by the additional receive antennas. Pre-equalization weight parameters may be determined to modify subsequent signals transmitted from the transmit antennas. The pre-equalization weight parameters may be based on the propagation channel estimates and may be determined by LMS, RLS, DMI, or by minimizing a cost function. Closed loop transmit diversity may also be supported.01-14-2010
20100008436Physical Layer Frame Format Design for Wideband Wireless Communications Systems - Systems and methods are provided for processing a payload portion of a received signal in a single carrier mode or a multiple carrier mode based on a portion of the received signal. A single carrier signaling portion is received at a first rate, and whether the payload portion of the signal is a single carrier signal or a multiple carrier signal is detected from the received single carrier signaling portion. The payload portion of the received signal is received at the first rate and demodulated in a single carrier mode if the detecting determines that the payload portion of the received signal is a single carrier signal, and the payload portion of the received signal is demodulated in a multiple carrier mode if the detecting determines that the payload portion of the received signal is a multiple carrier signal.01-14-2010
20100008435METHOD FOR TRANSMITTING ACK/NACK SIGNAL AND METHOD FOR ESTABLISHING THE SIGNAL TRANSMISSION - A method for transmitting an ACK/NACK signal and a method for establishing the signal transmission are disclosed. A system for the method determines whether the ACK/NACK signal is repeatedly transmitted or not according to channel environments of a user, and transmits the ACK/NACK signal according to the determined result within a single TTI. Areas unused for transmitting the ACK/NACK signal are allocated for data, resulting in an increased reception reliability of the ACK/NACK signal.01-14-2010
20100008434CELLULAR NETWORK SYSTEM - A method for providing a personalized bidirectional channel in broadcasting systems. In cellular broadcasting system the method contains the steps of: allocating a first group of subcarriers to broadcast transmission and a second group of subcarriers to personalized channels; reducing interference in the broadcast transmission by using equalizer; and reducing interference in the personalized channels by using controlled allocation of subcarriers in the second group to each subscriber. In OFDM broadcasting system the method contains the steps of: transmitting OFDM transmission from the base-station to the subscriber units; transmitting from the subscriber units to the base-station signals that are orthogonal to signals transmitted from the base-station; and receiving the orthogonal signals at the base-station.01-14-2010
20090067517Preamble sequence detection and integral carrier frequency offset estimation method for OFDM/OFDMA wireless communication system - In multi-cell OFDM/OFDMA wireless communication systems, any subscriber station (SS) or mobile station (MS) that intends to enter the system needs to establish time and frequency synchronization with the base station (BS) and obtain the identification code of the BS, where in frequency synchronization one usually needs to estimate the fractional carrier frequency offset (CFO) and the integral CFO. (“Fractional” and “integral” refer to, respectively, the fractional and the integral parts of the ratio of the CFO to subcarrier spacing.) The present invention assumes that the SS or MS first does timing and fractional CFO synchronization and then conducts integral CFO estimation and BS identity detection. The present invention considers integral CFO estimation and BS identity detection jointly, i.e., it proposes solutions that address these topics jointly. The present invention formulates the problem as a signal detection problem in multi-channel interference and obtains the theoretically optimal solution first, and then derives simplified, approximately optimal solutions, in which the present invention employs frequency-domain filtering to calculate the required correlation values which can drastically reduce the high computational complexity of the original theoretically optimal solution but results in little impact on precision. In addition, the present invention proposes several further simplified algorithms, some of which can even eliminate the use of multipliers. The above proposition of frequency-domain filtering has high extensibility in application to related signal sequence detection problems.03-12-2009
20100284479Radio Transmission Apparatus, Radio Reception Apparatus, Radio Transmission-Reception System, And Method Thereof - A radio transmission apparatus for transmitting a first radio signal and a second radio signal with different communication system, the apparatus includes: a first transmission unit which generates the first radio signal on the basis of a first communication system and transmits the first radio signal; a diffusion processing unit which performs diffusion processing of data allocated to DC subcarrier on the basis of the first communication system, and generate a diffusion signal; an addition unit which adds the diffusion signal and a signal obtained by orthogonal frequency division multiplex processing; and a second transmission unit which transmits the added signal as the second radio signal.11-11-2010
20090110100Allocating Data Between Tones - A new protocol is proposed for transmission of data through lines such as telephone lines. The tones of a signal are associated into groups 04-30-2009
20120314787CHANNEL INFORMATION TRANSMISSION METHOD AND FEEDBACK METHOD, AN APPARATUS THEREOF, A BASE STATION AND A TRANSMISSION METHOD OF THE BASE STATION - A wireless communication system uses a multiple-input multiple-output (MIMO) antenna in the transceiver mode. The system includes the technical features of a stage in which m bits of a first set of information is transmitted for a first pre-coding matrix (where m is an integer greater than 1), and a stage in which n bits of a second set of information is transmitted for a second pre-coding matrix (where n is an integer greater than 1 but less than n).12-13-2012
20120314784INTEGRATED CIRCUIT, WIRELESS COMMUNICATION UNIT AND METHOD FOR QUADRATURE POWER DETECTION - An integrated circuit for a wireless communication unit has a transmit power control system employing a quadrature (I/Q) based power detector having at least one reference path and at least one detector path. The integrated circuit includes: a first quadrature error determination module for determining a quadrature error of a transmit signal and a second quadrature error determination module for determining a quadrature error of a detector signal input to the at least one detector path; a first quadrature balancing module arranged to correct for quadrature error of the transmit signal and output a reference signal to the at least one reference path; a second quadrature balancing module arranged to correct for quadrature error of the reference signal input to the at least one reference path, and a third quadrature balancing module arranged to correct for quadrature error of the detector signal input from the at least one detector path.12-13-2012
20120224649MULTI-RESOLUTION PRECODING CODEBOOK - Systems and methods are for generating a codebook by: generating a multi-resolution codebook by selecting a common precoder index from a low resolution codebook for a group of adjacent resource blocks (RB)s and for each RB within the group, selecting a high-resolution codebook to fine-tune each RB precoder; and generating feedback for the multi-resolution codebook by quantizing channel state variations.09-06-2012
20120189072COMBINED DATA AND PROBE (CDP) FRAME - A system or method in an OFDM communication environment includes transmitting, by a transmitter, and/or receiving, by a receiver, a frame that includes one or more preamble symbols, one or more header symbols, a plurality of data symbols, and a plurality of probe symbols. The probe symbols are predefined symbols that do not carry user data and are generated by modulating a predefined pseudo-random bit sequence (PRBS). A frame header, communicated in the one or more header symbols, includes one or more bit fields that indicate that the frame includes N probe symbols, wherein N is an integer greater than 1, and wherein the plurality of probe symbols are transmitted or received after the one or more header symbols and before the plurality of data symbols.07-26-2012
20120189070PEAK-TO-AVERAGE POWER RATIO REDUCTION FOR HYBRID FM HD RADIO TRANSMISSION - A method includes: (a) modulating a set of subcarriers with a set of data to produce a modulated OFDM symbol vector; (b) modulating a FM carrier signal with the set of data to produce a modulated FM symbol; (c) combining the modulated OFDM symbol and the modulated FM symbol to produce a modulated hybrid symbol; (d) limiting the magnitude of the modulated hybrid symbol to produce a first limited modulated hybrid symbol; (e) demodulating the first limited modulated hybrid symbol to recover distorted QPSK constellations; (f) constraining the distorted QPSK constellations to values greater than or equal to a minimum threshold value to produce constrained QPSK constellations; (g) demodulating the modulated hybrid symbol to produce a demodulated hybrid symbol vector; (h) subtracting the demodulated FM symbol vector from the Hybrid symbol vector to produce modified OFDM symbol vector; (i) applying a mask to inactive subcarriers in the plurali