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Diversity

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375 - Pulse or digital communications

375259000 - SYSTEMS USING ALTERNATING OR PULSATING CURRENT

375260000 - Plural channels for transmission of a single pulse train

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DocumentTitleDate
20130028342UPLINK CHANNEL ESTIMATION - In one embodiment, a receiver is provided for use in a multiple-input system that includes a receiving antenna receiving a time-domain signal corresponding to a plurality of signals transmitted from a plurality of transmitting antennas. The receiver includes: (a) a transform unit adapted to transform the time-domain signal into a frequency-domain signal; (b) a channel estimation unit adapted to estimate, based on the frequency-domain signal and a frequency-domain pilot signal, a combined transfer function corresponding to a plurality of transfer functions of respective channels between the plurality of transmitting antennas and the receiving antenna; and (c) a channel separation unit including a plurality of frequency-domain convolution units that separate the combined transfer function into a plurality of estimated channel transfer functions.01-31-2013
20090080558SPACE-TIME MIMO WIRELESS SYSTEM BASED ON FEEDBACK OPTIMUM WEIGHT DESIGN - A FOW-based 2-by-2 space-time MIMO wireless system based on Alamouti's Space-Time block code with a feedback optimum weight (FOW) technique is provided, including a MIMO transmitter, a 2-by-2 MIMO channel, two FOW-based MIMO receivers, an optimum weight vector module, a Bayes decision algorithm module, a coherent combining unit, and a maximum likelihood detector (MLD). The FOW-based 2-by-2 space-time MIMO wireless system of the present invention uses the Bayes decision algorithm to determine the optimum weights at the receiver which multiplies the transmitted output signals at spatial antennas via up-link Fast Channel Feedback (i.e. closed-loop MIMO) and also the corresponding receiving signals. In addition, the present invention includes a Scheduler design to arrange these weight elements in accordance with space-time constellation signals, which allows linear processing using Alamouti's 2-branch maximum likelihood detection without increasing the hardware complexity.03-26-2009
20130028345METHOD AND DEVICE FOR EFFICIENT FEEDBACK IN WIRELESS COMMUNICATION SYSTEM SUPPORTING MULTIPLE ANTENNAS - The present description relates to a wireless communication system, and more particularly, discloses a method and a device for efficient feedback in a wireless communication system supporting multiple antennas. According to one embodiment of the present invention, the method for transmitting channel status information on a downlink transmission through an uplink, in the wireless communication system, comprises the following steps: transmitting a rank indicator (RI) in a first subframe; transmitting a first precoding matrix index (PMI) in a second subframe; and transmitting a second PMI and channel quality information (CQI) in a third subframe, wherein the precoding matrix to be applied to the transmission of the downlink can be determined by a combination of the first and second PMIS.01-31-2013
20130028343Method and Arrangement for Adapting a Multi-Antenna Transmission - A method in a first node for adapting a multi-antenna transmission to a second node over a wireless channel is provided. The wireless channel has at least three inputs and at least one output. The first node and the second node are comprised in a wireless communication system. The method includes obtaining at least one symbol stream, determining a precoding matrix having a product structure created by a block diagonal matrix being multiplied from the left with a block diagonalizing unitary matrix, precoding the at least one symbol stream with the determined precoding matrix, and transmitting the precoded at least one symbol stream over a wireless channel to the second node.01-31-2013
20130028344METHOD AND APPARATUS FOR INFORMATION FEEDBACK AND PRECODING - Methods and apparatuses for information feedback and precoding have been provided. A method for processing communication data at a user equipment in a wireless communication system may comprise: deriving a spatial correlation matrix R of multiple transmit antennas of a base station based on an obtained downlink channel transmission matrix H; transforming a precoding codebook F according to the spatial correlation matrix R; selecting a precoding matrix F01-31-2013
20130028341COMBINING BASEBAND PROCESSING AND RADIO FREQUENCY BEAM STEERING IN WIRELESS COMMUNICATION SYSTEMS - A method and apparatus enable combined baseband (BB) and radio frequency (RF) processing of signals. The method includes receiving, by a receiver, channel estimation information for a channel between a transmitter and the receiver. The method includes identifying a plurality of paths in the channel based on the channel estimation information. The method includes calculating an RF precoding matrix for precoding one or more signals to be transmitted on each of the identified paths. The RF precoding matrix includes a phase shift for each of the identified paths. Additionally, the method includes calculating a BB precoding matrix for precoding the one or more signals by a BB precoding unit associated with the transmitter.01-31-2013
20090196372Channel Sounding and Estimation Strategies for Antenna Selection in MIMO Systems - Techniques and devices for antenna selection in a multiple-input-multiple-output (MIMO) system, in which communication is between a transmitter having a first plurality of radio-frequency (RF) chains coupled to a first plurality of antennas and a receiver having a second plurality of RF chains coupled to a second plurality of antennas, are provided. Techniques include receiving consecutive sounding packets each have a training symbol and that collectively sound a full-size channel for the MIMO system. A sub-channel estimate for each sounding packet can then be determined based on various factors, such as a known power level rule and gain factor. Scaling factors may be applied to each of these sub-channel estimates to produce a scaled sub-channel estimates.08-06-2009
20090196371MIMO ANTENNA APPARATUS CHANGING ANTENNA ELEMENTS BASED ON TRANSMISSION CAPACITY - A controller of a MIMO antenna apparatus calculates a current transmission capacity based on signal levels detected by a signal level detector circuit. The controller calculates an estimated transmission capacity assuming that at least one of antenna elements currently connected to a MIMO modulator and demodulator circuit is changed to a further antenna element not connected to the MIMO modulator and demodulator circuit, based on the detected signal levels and degrees of electromagnetic coupling stored in a degree-of-coupling memory. The controller controls a switch circuit to connect the further antenna element to the MIMO modulator and demodulator circuit when the current transmission capacity becomes lower than the estimated transmission capacity.08-06-2009
20090323847OPEN-LOOP BEAMFORMING MIMO COMMUNICATIONS IN FREQUENCY DIVISION DUPLEX SYSTEMS - Techniques are provided for wireless communication between a first wireless communication device and a second wireless communication device. At a plurality of antennas of the first wireless communication device, one or more signals transmitted by a second wireless communication device in a first frequency band are received. Beamforming weights are computed from information derived from the signals received at the plurality of antennas using one or more of a plurality of methods without feedback information from the second wireless communication device about a wireless link from the first wireless communication device to the second wireless communication device. The beamforming weights are applied to at least one transmit signal to beamform the at least one transmit signal for transmission to the second wireless communication device in a second frequency band.12-31-2009
20090147877Network Entry and Recovery - The subject matter disclosed herein provides a network entry and recovery mechanism using a map. In one aspect, there is provided a method. The method may insert a plurality of packets into a plurality of data regions. A map may be inserted into one of the data regions. The map may include information to enable decoding of the plurality of data regions, a location of other maps within the plurality of data regions, and a size of the map. The plurality of data regions may be provided to enable the plurality of data regions to be transmitted to one or more client stations. Related systems, apparatus, methods, and/or articles are also described.06-11-2009
20110194640METHOD AND APPARATUS TO SELECT CODING MODE - An apparatus and method that may select a coding mode of an OFDM sub-carrier symbol stream between a diversity mode or a multiplexing mode according to information received in a wireless network.08-11-2011
20110194639BASE STATION, TERMINAL, BAND ALLOCATION METHOD, AND DOWNLINK DATA COMMUNICATION METHOD - Provided are a base station, a terminal, a band allocation method, and a downlink data communication method in which a mapping method for synchronization signals and report signals is implemented with high resource usage efficiency when a first system in which an independent single communication is allocated to a unit band co-exists with a second system in which a plurality of unit bands can be allocated to a single communication. In a base station (08-11-2011
20110194638CODEBOOK ADAPTATION IN MIMO COMMUNICATION SYSTEMS USING MULTILEVEL CODEBOOKS - A method includes holding in a receiver a definition of a codebook including precoding matrices, and a definition of multiple sub-codebooks including different respective subsets of the precoding matrices in the codebook. A sub-codebook is selected in coordination with a transmitter, for use in a given time interval or frequency range. A Multiple-Input Multiple-Output (MIMO) signal that is transmitted from the transmitter is received. Feedback is generated in the receiver based on the received MIMO signal. The feedback is indicative of one or more preferred precoding matrices, which are chosen from the selected sub-codebook and which are to be used in precoding subsequent MIMO signals in respective partitions of the given time interval or frequency range. The feedback is transmitted from the receiver to the transmitter.08-11-2011
20110194637APPARATUS AND METHOD FOR ENABLING UPLINK BEAMFORMING TRANSIT DIVERSITY - A method and apparatus for enabling uplink beamforming transmit diversity is provided. The method may include receiving, by a wireless communications device (WCD), a beamforming weight vector in response to transmission by the WCD of two or more pilot channels, applying the received beamforming weight vector to at least one of a first of the two or more pilot channels, one or more data channels, or one or more control channels, and transmitting, using two or more antennas, at least one of the one or more data channels or at least one of the one or more control channels, wherein the number of pilot channels is greater than or equal to the number of antennas.08-11-2011
20090122902CHANNEL ESTIMATION FOR WIRELESS SYSTEMS WITH MULTIPLE TRANSIT ANTENNAS - 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.05-14-2009
20090122901METHOD FOR CONFIGURATING BASIC SIGNAL ALLOCATION UNIT AND METHOD FOR TRANSMITTING SIGNALS USING THE SAME - A method for configurating a basic signal allocation unit and a method of transmitting signals using the configurated basic signal allocation unit are disclosed. In particular, a basic frequency domain signal allocation unit is configurated by considering at least one selected from the group consisting of a signaling overhead, a size of a coherent bandwidth and a number of divisors among specific numbers and an OFDM symbol number corresponding to a multiple of a subframe unit, each of the specific numbers multiplied to a predetermined subcarrier spacing to enable a result value of the multiplication to have a difference smaller than a prescribed threshold from a divisor of a system bandwidth. And, a time domain unit is configurated by 1-subframe unit. Accordingly, signaling overhead can be efficiently reduced.05-14-2009
20090122900Noise Power Interpolation in a Multi-Carrier System - A signal is received in a telecommunication network in the form of P signals received on P corresponding antennas, where P is greater than or equal to 1. The received signals correspond to a multi-carrier signal transmitted in the form of frames comprising symbols occupying corresponding positions distributed along a time axis and along a frequency axis; a frame comprising M blocks each having at least N reference symbols. The reference symbols in each of the blocks satisfy a first maximum spacing between each other along the time axis and a second maximum spacing between each other along the frequency axis, less than a first value and a second value respectively, M being an integer number equal to at least two. M estimated noise power values are determined at frame level, each related to one of the M emitted reference symbol blocks. Values of the estimated noise power for the other symbols in the frame are then obtained from the determined estimated noise power values.05-14-2009
20090122898Multiple Sub-Carrier Selection Diversity Architecture and Method for Wireles Ofdm - Sub-carrier selection methods and receiver architectures for receiving an Orthogonal Frequency Division Multiplexing band sensed by a plurality of antennas (05-14-2009
20100074361SPHERE DECODING METHOD APPLIED TO MULTI-INPUT MULTI-OUTPUT (MIMO) CHANNEL - A sphere decoding method applied to a MIMO channel is provided. T signals transmitted via the MIMO channel are received. A first triangular matrix corresponding to a channel matrix is generated and mapped from the complex domain into the real domain to obtain a second triangular matrix. A first zero-forcing soft-output solution corresponding to a first estimation layer is found, and multiple preferred points P(1) are obtained. Multiple n-th zero-forcing soft-output solutions corresponding to an n-th estimation layer are obtained according to multiple preferred points P(n−1), and multiple preferred points P(n) are obtained according to PEDs of multiple n-th constellation points. Multiple 2T-th zero-forcing soft-output solutions are obtained according to the preferred points P(2T−1) and multiple preferred points P(2T) are obtained correspondingly. The preferred point P(2T) corresponding to the least PED is mapped from the real domain into the complex domain to generate an optimal solution of the T signals.03-25-2010
20100074360SIGNAL GENERATION USING PHASE-SHIFT BASED PRE-CODING - A phase-shift based pre-coding scheme used in a transmitting side and a receiving side that has less complexity than those of a space-time coding scheme, that can support various spatial multiplexing rates while maintaining the advantages of the phase-shift diversity scheme, that has less channel sensitivity than that of the pre-coding scheme, and that only requires a low capacity codebook is provided.03-25-2010
20100074359Base Station and Communication Method - Improvement in utilization efficiency of traffic channels and voice quality in an OFDMA scheme is accomplished. A base station communicating which mobile stations by an OFDMA scheme using subchannels includes: a channel assigning unit 03-25-2010
20100074358Sparse Channel Estimation for MIMO OFDM Systems - A method for sparse channel estimation in MIMO OFDM systems with a plurality of subchannels having the same sparsity structure is presented. The inventive method comprises initializing a plurality of residual vectors and observation generating matrices modeling the channel, sending a pilot signal for each subcarrier, converting the pilot signals to tap positions, detecting an optimal tap position, updating the residual vectors by removing the one residual vector having the optimal tap position, updating the generating matrices in accordance with the optimal residual vector, calculating weighted residuals based on the updated residual vectors, and repeating the steps, except initializing, until a stopping condition is met, wherein the updated observation matrices estimate the sparse channel. In one embodiment, the observation generating matrices are omitted. In one embodiment, multiple vectors are removed during one iteration. Pilot placement and pilot allocation techniques are presented to optimize the method.03-25-2010
20100074357METHOD AND APPARATUS FOR TRANSMITTING DATA WITH TIME DIVERSITY AND/OR TIME-FREQUENCY DIVERSITY, AND PATTERN-GENERATING METHOD TO BE USED IN THE SAME - A method and apparatus for transmitting data having time diversity and data having time-frequency diversity, and a pattern generating method for the same are disclosed. The apparatus enables Tx data to have time diversity or time frequency diversity using a predetermined pattern multiplied by Tx data of a time domain or Tx data of time and frequency domains. The apparatus makes a cyclic delay diversity (CDD) scheme to have the diversity of time and frequency domains, and may acquire an additional diversity gain by a combination of the above-mentioned methods.03-25-2010
20100074356Methods for precoding signals for transmission in wireless MIMO system - Methods discussed herein provide more efficient precoding matrices for precoding signals prior to transmission. The methods discussed herein improve throughput in wireless MIMO systems. Methods discussed herein are applicable to frequency division duplexing (FDD) systems, time division duplexing (TDD) systems as well as other wireless communication systems.03-25-2010
20100074355TRANSMIT DIVERSITY SCHEME - The present invention relates to methods for implementing transmit diversity in a telecommunication network. In particular there is provided an algorithm for performing transmit diversity encoding in a transmitter (03-25-2010
20100074362APPARATUS AND METHOD FOR TRANSMITTING AND RECEIVING SIGNAL IN MULTIPLE INPUT MULTIPLE OUTPUT SYSTEM - A method and apparatus for transmitting and/or receiving a signal in a multiple input multiple output (MIMO) system are provided. An apparatus for transmitting a signal in a multiple input multiple output (MIMO) system includes an input unit to receive N03-25-2010
20100111214METHODS AND SYSTEMS FOR INTER-RAT HANDOVER IN MULTI-MODE MOBILE STATION - Methods provided may generally include sending a BS of a first RAT a request message indicating a set of MIMO resources to reallocate; during a scan duration, communicating with the BS of the first RAT using non-reallocated MIMO resources and communicating with a BS of a second RAT using reallocated MIMO resources; and during a normal duration, communicating with the BS of the first RAT using the reallocated and non-reallocated MIMO resources. Apparatus provided may generally include logic for receiving a request message indicating a set of MIMO resources of the MS to reallocate; logic for, during a scan duration, communicating with the MS in a first transmission mode assuming the use of only non-reallocated MIMO resources by the MS; and logic for, during a normal duration, communicating with the MS in a second transmission mode assuming the use of the reallocated and non-reallocated MIMO resources by the MS.05-06-2010
20130077703RETRANSMISSION METHOD FOR HARQ IN MIMO SYSTEMS - In a closed-loop wireless communication system (03-28-2013
20130077704JOINT CODING METHOD BASED ON BINARY TREE AND CODER - The present invention provides a method and a coder for jointly coding Pre-coding Matrix Index #03-28-2013
20130039437Method of Precoding with a Codebook for a Wireless System - A quantized multi-rank beamforming scheme for multiple-antenna systems such as a multiple-input-multiple-output (MIMO) wireless downlink. User equipment (UE) estimates downlink channel and transmit power and determines rank and power allocations. A quantized beamforming matrix is then determined by the UE using successive beamforming. The UE also determines channel quality indices (CQI) which it feeds-back to the wireless downlink base station along with the index of the quantized beamforming matrix. The base station uses the CQI information to select a UE for scheduling of downlink transmission and the quantized beamforming matrix index received from the selected UE to beamform the downlink transmission to the UE. Base station overhead and is minimized while providing near-optimal performance given the constraints of a limited feed-back channel and computational complexity of the UE.02-14-2013
20100046658MULTI-ANTENNA TRANSMISSION DEVICE, MULTI-ANTENNA RECEPTION DEVICE, MULTI-ANTENNA TRANSMISSION METHOD, MULTI-ANTENNA RECEPTION METHOD, TERMINAL DEVICE, AND BASE STATION DEVICE - Provided is a multi-antenna transmission device (02-25-2010
20100046656PREAMBLE EXTENSIONS - Systems and/or methods for communication that generate a plurality of spatial streams are disclosed. Each of the spatial streams comprises a plurality of symbols. At least a portion of a training sequence is distributed across a first symbol in a first one of the spatial streams and a second symbol in a second one of the spatial streams.02-25-2010
20100046657Method and Arrangement for Symbol Mapping in Communication Systems Utilizing OFDM-Techniques - The present invention relates to a method and arrangement for symbol mapping in wireless communication systems utilizing OFDM transmission technology in combination with advanced coding schemes. In the method according to the present invention, adapted for use in a wireless communication system utilising OFDM transmission technology, an OFDM grid is defined by at least a first dimension and a second dimensions from the dimensions time, frequency or space. The advanced coding scheme, for example Alamouti coding, outputs symbols that are related via the coding. At least some of the symbols, defining a code related symbol group should experience identical, or at least very similar, radio channels. According to one embodiment of the present invention, symbols from the same code related symbol group is placed as close together in the OFDM grid as possible.02-25-2010
20130034182METHOD AND APPARATUS FOR CORRECTING ERRORS IN A MULTIPLE SUBCARRIERS COMMUNICATION SYSTEM USING MULTIPLE ANTENNAS - A method for correcting errors in a multiple antenna system based on a plurality of sub-carriers and a transmitting/receiving apparatus supporting the same are disclosed. The method includes determining a phase shift based precoding matrix phase shifted at a predetermined phase angle, initially transmitting each sub-carrier symbol to a receiver in a packet unit by using the phase shift based precoding matrix, reconstructing the phase shift based precoding matrix to reduce a spatial multiplexing rate it a negative reception acknowledgement (NACK) is received from the receiver, and retransmitting the initially transmitted sub-carrier symbol by using the reconstructed phase shift based precoding matrix or by changing the phase shift based precoding matrix using offset information fed back from the receiver or random offset information.02-07-2013
20130034178Method and Apparatus for Channel Estimation and Detection in MIMO System - The prevent invention provides a method for performing channel estimation and detection in a Multiple-Input-Multiple-Output (MIMO) system, including: generating a demodulation reference signal, DM-RS, pattern for an extended cyclic prefix (CP); and estimating and detecting channel performance based on the generated DM-RS signal pattern. The DM-RS pattern supports from rank 1 to rank 8 patterns for 8 layer transmission. A transmitter, a receiver and a system thereof are also provided. The solution of the present invention improves channel estimation accuracy, saves channel estimation implementation and implementation complexity at terminals.02-07-2013
20130034181ANTENNA SELECTION SCHEME BASED ON INFORMATION BITS - A method, transmitter node, and receiver node for communicating a transport block of information bits from the transmitter node to the receiver node are provided. The transmitter node encodes the information bits and divides the coded bits into antenna selection bits and modulation bits. The antenna selection bits are used to select a transmit antenna from a plurality of transmit antennas. The modulation bits are used by a modulator to select modulation symbols for transmission utilizing the selected antenna. The receiver node receives the radio signal with a front-end receiver and computes a plurality of combined signals, each corresponding to one hypothesized transmit antenna at the transmitter node. The receiver forwards the plurality of combined signals to a soft value computer, which computes soft values for the antenna selection and modulation bits. The soft values are combined and decoded to produce decision bits for recovering the transport block.02-07-2013
20130034180Method and Device for Decoding of Precoded Signals - The present invention relates to a method and a device for decoding precoded signals in a wireless communication system and network node or terminal associated therewith. The wireless communication system comprises a sender and a receiver that share a codebook containing a plurality of precoding matrices. The sender precodes at least a data signal to be transmitted with one of the plurality of precoding matrices. Said method comprising receiving signals from the sender, estimating a channel between the sender and the receiver based on a part of received signals that is known a priori, evaluating relevancies of precoding matrices in said codebook to a precoded signal in the received signals based on at least the estimated channel and the codebook according to a predetermined criterion, and selecting a precoding matrix with maximum relevancy by comparing the evaluated relevancies, and applying the selected precoding matrix for decoding the received precoded signal.02-07-2013
20130034177METHOD AND APPARATUS FOR ESTIMATING CHANNEL USING DEDICATED PILOT SIGNAL IN OFDM-BASED WIRELESS COMMUNICATION SYSTEM - The invention relates to a method for channel estimation using a dedicated pilot signal in an OFDM-based communication system with multi-antenna transmission techniques. The receiver estimates the statistical characteristics of a virtual channel generated by beamforming by exploiting the statistical characteristics of common pilot channel, determines the optimum dedicated pilot pattern, and estimates the channel from dedicated pilot signal transmitted in an optimum pattern by means of AMMSE interpolation. The invention minimizes the channel estimation error by exploiting the statistical characteristics of the virtual channel, and optimally determines the dedicated pilot pattern according to the operation environment to maximize the transmission performance in terms of the pilot signaling overhead and the channel estimation error. In particular, the invention is very effective in low signal-to-interference plus noise power ratio (SINR) operation environments.02-07-2013
20120207235SIGNAL PROCESSING CIRCUIT AND METHOD THEREOF - A signal processing circuit is disclosed, comprising a first node for coupling with a first antenna, a second node for coupling with a second antenna, a third node for receiving a first signal from a transmitting circuit, a fourth node for coupling with a receiving circuit, a signal dividing circuit, a phase shifting circuit, and a signal combining circuit. The signal dividing circuit divides the first signal into a second signal and a third signal, and transmits the second signal to the first antenna. The phase shifting circuit shifts the phase of the third signal to generate a fourth signal for canceling at least part of a coupled signal between the third node and the fourth node. The signal combining circuit combines the fourth signal and a fifth signal received from the second antenna, and transmits the combined signal to the receiving circuit.08-16-2012
20130034179Multi-Antenna System and Method for Transmitting and Receiving Information in Multi-Antenna System - Embodiments of the present invention provide a method for transmitting information in a multi-antenna system. The method may include: a transmitting end receives information transmitted by a receiving end, wherein the information includes information of index of a precoder; the transmitting end selects a precoder from a two-layered codebook based on the information of the index of the precoder; the transmitting end precodes to-be-transmitted data by using the precoder; the transmitting end transmits the precoded data to the receiving end. The technical scheme of the present invention obtains codebooks most matching with channel distribution characteristics of dual-polarized antennas and minimizes performance loss brought by codebook quantization to remarkably improve the performances of precoding systems.02-07-2013
20090052570OPERATING ENVIRONMENT ANALYSIS TECHNIQUES FOR WIRELESS COMMUNICATION SYSTEMS - Methods and systems of analyzing an operating environment of wireless communication equipment in a wireless communication system are provided. A stimulus in the operating environment at a location of the wireless communication equipment is sensed and linearly expanded in Slepian sequences using a multitaper spectral estimation procedure. A singular value decomposition is performed on the linearly expanded stimulus, and a singular value of the linearly expanded stimulus provides an estimate of interference at the location of the wireless communication equipment.02-26-2009
20130136202SYSTEMS AND METHODS FOR TRANSPORTING DIGITAL RF SIGNALS - A telecommunications system is provided that can re-sample a digitized signal at a resample rate that is based on one or more factors to better utilize bandwidth. The factors can include the bandwidth of the signal that the digitized signal represents, the amount of bandwidth owned or used by the carrier, the full bandwidth of the designated RF band, the bandwidth of the serial link, the frame length of the serial link, the segmentation of the frames on the serial link, and the capability of the equipment at the receiving end of a serial link. The re-sampled signal can be transmitted to another unit that is remote to the unit transmitting the signal. The other unit can include a re-sampling device that restores the re-sampled signal to a digital signal that can be converted to an analog signal for wireless transmission.05-30-2013
20100104038MULTIDIMENSIONAL CHANNEL ESTIMATION WITHOUT SOUNDING SIGNALS - Techniques are provided herein to estimate parameters of a wireless communication channel. At each of a first plurality of antennas of a first wireless communication device, a transmission is received that is associated with each of one or more spatial streams transmitted via a second plurality of antennas of a second wireless communication device. The transmission comprises at least first and second training fields which are configured for channel estimation. Multidimensional channel information between the first plurality of antennas and the second plurality of antennas is computed from receive values in the first and second training fields for one more dimension above a number of the spatial streams transmitted by the second wireless communication device and up to a lesser of a number of the first plurality of antennas and a number of the second plurality of antennas.04-29-2010
20100104039METHOD 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.04-29-2010
20100104040WIRELESS COMMUNICATION SYSTEM AND WIRELESS COMMUNICATION METHOD - On the transmitting side, a decision is made as to whether to add pilot symbols which are separate from basic pilot symbols, to frames, based on the propagation path state, and when symbols are added, control symbols comprising information relating to the additional pilot symbols are generated, and frames comprising basic pilot symbols, control symbols, additional pilot symbols, and data symbols are assembled and transmitted. On the receiving side, control symbols included in the received frames are demodulated, and a judgment is made as to whether additional pilot symbols are included in the received frames based on the control symbol information, and if additional pilot symbols are included, the additional pilot symbols are used to estimate the propagation path, and the propagation path estimation value is used to demodulate data symbols.04-29-2010
20090154587MIMO ANTENNA RECEIVING APPARATUS AND RECEIVING METHOD - Provided is a reception apparatus and method of a Multiple Input Multiple Output (MIMO) system that receives a plurality of different data streams in a multiple cell environment. The reception apparatus for receiving a plurality of different data streams in a multiple input multiple output (MIMO) antenna system includes a data stream detector for detecting each data stream by removing interference between the different data streams while maintaining channel information; and a cochannel interference (CCI) remover for removing cochannel interference from each data stream detected in the data stream detector. The present invention can remove cochannel interference and increase channel capacity to thereby acquire both diversity gain and multiplexing gain.06-18-2009
20090154585Channel estimation method and training signal creating method for channel estimation in mimo- ofdm system - Provided are a training signal generation method using impulse trains encoded with orthogonal codes and a channel estimation method using an orthogonal code decoding in a Multiple-Input Multiple-Output-Orthogonal Frequency Division Multiplex (MIMO-OFDM) system. The channel estimation method using the orthogonal code decoding in the MIMO-OFDM system includes the steps of creating a plurality of orthogonal codes depending on the number of receive antennas, decoding a signal received through each receive antenna by using the orthogonal codes, and estimating a channel response by averaging the received signals decoded with the orthogonal codes every OFDM symbol.06-18-2009
20100040167OFDM SIGNAL TRANSMISSION METHOD AND APPARATUS - An orthogonal frequency division multiplexing (OFDM) signal transmission apparatus which transmits OFDM signals by using a plurality of transmission antennas includes a subcarrier setting device which sets signals for subcarriers so as to use some of the subcarriers of the OFDM signals as pilot subcarriers to transmit pilot signals and use the remaining subcarriers as data subcarriers to transmit data signals, the subcarrier setting device changing polarities of signals for the pilot subcarriers for each transmission antenna.02-18-2010
20100040166SYSTEMS AND METHODS FOR TRAINING SEQUENCE SELECTION, TRANSMISSION AND RECEPTION - Methods of training sequence selection are provided that involve optimization in terms of SNR degradation. Various sets of training sequences produced using the methods, and transmitters and receivers encoded with such sequences are provided.02-18-2010
20100040164METHOD OF RATIO DATA EMISSION, EMITTER AND RECEIVER USING THE METHOD - Coding and decoding schemes useful in the context of MIMO (Multiple Input Multiple Output) or MISO (Multiple Input Single Output) communications especially used in conjunction of OFDM-like transmission schemes. A space frequency block code (SFBC) is based on the simultaneous use of two variants of Alamouti codes in the frequency domain, each kind of Alamouti code being applied to well-chosen pair of frequencies. The proposed SFBC keeps the constant envelope property for each antenna while leading to performance equal or very close to the pure Alamouti STBC performance.02-18-2010
20090135941Method for Digital Wireless Message Transmission Over a Broadband Mobile Radio Channel - In an OFDM multi carrier modulation method, M sub-carriers are used in a frequency band of a broadband mobile radio channel and several symbols are used in a time band. With application of a MIMO multi-antenna method with T transmitting antennae and R receiving antennae, for all sub-carriers and all symbols, a single, pre-determined, channel-matched transmission strategy is used, which is described by a maximum of T*R complex values on the signal side, independent of the species of the MIMO multi-antenna method and independent of the size of the frequency/time bands.05-28-2009
20120183090WIRELESS COMMUNICATION SYSTEM AND WIRELESS COMMUNICATION METHOD - A base station includes: a MIMO preceding section (07-19-2012
20120183089MODIFYING A SIGNAL BY CONTROLLING TRANSMIT DIVERSITY PARAMETERS - A method for modifying a signal transmitted from a mobile communication device comprising by perturbing a transmit diversity parameter from its nominal value by modulating the parameter with respect to the nominal value in a first direction for a first feedback interval and then in a second direction for a second feedback interval, receiving a feedback signal including feedback information relating to the perturbed signal as received at a feedback device, and based at least on the feedback information, adjusting the nominal value of the transmit diversity parameter by increasing, decreasing, or preserving the nominal value.07-19-2012
20120183088LATTICE REDUCTION ARCHITECTURE AND METHOD AND DETECTION SYSTEM THEREOF - A lattice reduction architecture, a lattice reduction method and a detection system thereof are proposed. The proposed architecture performs lattice reduction on channel matrices corresponding to sub-carriers and includes G processing group blocks, which receives channel matrices corresponding to the sub-carriers, and each of the first to the G-1th processing group blocks includes k processing modules respectively processing k sub-carriers, and the Gth processing group block includes j processing modules, where j<=k. In each one of the processing group blocks, at least one processing module receives an initial matrix, where the processing module includes a lattice reduction processing unit provides a reduction matrix to at least one neighboring processing module when a lattice reduction algorithm is processed on a channel matrix corresponding to its respective sub-carrier for at least iteration loops according to the channel matrix and the received initial matrix.07-19-2012
20130208819Method and System for Channel State Information Feedback - The present invention discloses a method for feeding back channel information, which includes: configuring a same codebook space at a data transmitting end and a data receiving end (08-15-2013
20130083865WIRELESS COMMUNICATION SYSTEM AND BEAMFORMING TRAINING METHOD FOR WIRELESS COMMUNICATION SYSTEM - The invention provides a wireless communication system and a beamforming training method for a wireless communication system. A wireless communication system comprising: a plurality of transmitting stations each including a transmit antenna array, the plurality of transmitting stations transmitting training sequences via the respective transmit antenna arrays in the same period of time; and a plurality of receiving stations corresponding to the plurality of transmitting stations respectively and each including a receive antenna array, each of the plurality of receiving stations receiving the respective training sequences transmitted by the plurality of transmitting stations via the respective receive antenna array and acquiring channel information regarding channel conditions of the respective links between the receiving station and the respective ones of the plurality of transmitting stations, the channel information being used to determine at least one of optimized transmit antenna weight vectors of the transmit antenna arrays of the plurality of transmitting stations and optimized receive antenna weight vectors of the receive antenna arrays of the plurality of receiving stations.04-04-2013
20130083863APPARATUS AND METHOD FOR LOW COMPLEXITY FEEDBACK IN A MIMO WIRELESS NETWORK - A receiver in a multiple input, multiple output (MIMO) system is configured to perform a method for generating channel quality feedback information. The method includes receiving, from a MIMO transmitter, pilot signals in each MIMO layer. The method also includes selecting an optimal precoder matrix for each MIMO layer using a first detection metric. The method further includes determining a signal-to-noise ratio (SNR) for each MIMO layer using a second detection metric and the optimal precoder.04-04-2013
20130083864METHOD FOR OPERATING A SECONDARY STATION - The invention relates to a method for operating a secondary station in a communication network including a primary station, the method comprising generating a pre-coding matrix obtained from the Hadamard product of an alphabet modifying matrix and an original pre-coding matrix, wherein the original precoding matrix consist of complex coefficients of equal magnitude, transmitting a precoding report representative of the precoding matrix to the primary station.04-04-2013
20100067604NETWORK MULTIPLE ANTENNA TRANSMISSION EMPLOYING AN X2 INTERFACE - A coordinated multipoint transmitter is for use with a multiple antenna super-cell and includes primary and secondary base stations jointly connected via an X2 interface link, wherein the primary base station provides a transmission directive corresponding to an X2 interface protocol over the X2 interface link to the secondary base station for a joint transmission from the primary and secondary base stations.03-18-2010
20100067600MMSE MIMO DECODER USING QR DECOMPOSITION - Aspects of the disclosure provide unbiased channel equalization applied in a MIMO OFDM system with spatial multiplexing. According to certain embodiments, a MMSE receiver can be implemented with the QR decomposition (QRMMSE detection) instead of direct inversion of channel matrix by exploiting an augmented channel matrix. A simple and efficient bias removal technique is presented herein, whereby unbiased QRMMSE equalization may provide identical detection accuracy as a conventional unbiased MMSE approach. For certain embodiments, multiple access interference may be further reduced if the VBLAST version of the unbiased QRMMSE detection is applied.03-18-2010
20090067528LINK-ADAPTATION SYSTEM IN MIMO-OFDM SYSTEM, AND METHOD THEREFOR - A system for link adaptation in a MIMO-OFDM system. In this system, the V-BLAST processor (03-12-2009
20130089159PRECODING TECHNIQUES FOR DOWNLINK COORDINATED MULTIPOINT TRANSMISSION IN RADIO COMMUNICATIONS SYSTEM - A precoding vector of coordinated multipoint transmission (CoMP) for at least one user equipment is decided by receiving the channel state information for CoMP from the user equipment, wherein the channel state information includes inter-cell correlation property between a serving cell serving the user equipment and a cooperating cell for CoMP; and deciding the precoding vector of CoMP based on the channel state information.04-11-2013
20130089158METHOD AND DEVICE FOR OBTAINING PRECODING MATRIX - The present invention provides a method and device for obtaining precoding matrix. A network apparatus comprises a plurality of groups of cross-polarized linear array antennas. The method comprises: obtaining first channel indicating information indicating a first code word; obtaining second channel indicating information indicating a second code word; determining the precoding matrix, according to the first channel indicating information and the second channel indicating information, the first code word and/or the second code word comprises phase shifts and/or amplitude differences among the plurality of groups of cross-polarized linear array antennas. Since the first code word and the second code word for determining the precoding matrix by the network apparatus comprise phase shifts and amplitude differences among cross-polarized linear array antennas, the phase shifts and amplitude differences among cross-polarized linear array antennas are considered when the network apparatus sends downlink data according to the precoding matrix, so as to be able to improve the receiving quality of the sent data, thereby improving the system performance effectively.04-11-2013
20100002798MAXIMUM RATIO TRANSMISSION - An arrangement where a transmitter has a plurality of transmitting antennas that concurrently transmit the same symbol, and where the signal delivered to each transmitting antenna is weighted by a factor that is related to the channel transmission coefficients found between the transmitting antenna and receiving antennas. In the case of a plurality of transmit antennas and one receive antenna, where the channel coefficient between the receive antenna and a transmit antenna i is h01-07-2010
20080219374MIMO DETECTION WITH ON-TIME SYMBOL LEVEL INTERFERENCE CANCELLATION - Techniques for receiving a MIMO transmission are described. A receiver processes received data for the MIMO transmission based on a front-end filter to obtain filtered data. The receiver further processes the filtered data based on at least one first combiner matrix to obtain detected data for a first frame. The receiver demodulates and decodes this detected data to obtain decoded data for the first frame. The receiver then processes the filtered data based on at least one second combiner matrix and the decoded data for the first frame to cancel interference due to the first frame and obtain detected data for a second frame. The receiver processes this detected data to obtain decoded data for the second frame. The front-end filter processes non on-time signal components in the received data. Each combiner matrix combines on-time signal components in the filtered data to obtain detected data for a channelization code.09-11-2008
20090316821APPARATUS AND METHOD FOR POWER CONTROL IN MOBILE COMMUNICATION SYSTEM - An apparatus and method for power control are provided. In a receiver in a mobile communication system, a Receive (Rx) signal received through a plurality of antennas is estimated. A power ratio between a traffic channel of the Rx signal and a pilot channel of the Rx signal is determined. A Log Likelihood Ratio (LLR) value is determined using the power ratio between the traffic channel and the pilot channel, a symbol of the traffic channel, and an Rx signal estimation value to which precoding is applied.12-24-2009
20090304107WIRELESS TRANSMITTING AND RECEIVING DEVICE AND METHOD - A wireless device, method, and signal for use in communication of a wireless packet between transmitting device and a wireless receiving device via a plurality of antennas, wherein a signal generator generates wireless packet including a short-preamble sequence used for a first automatic gain control (AGC), a first long-preamble sequence, a signal field used for conveying a length of the wireless packet, an AGC preamble sequence used for a second AGC to be performed after the first AGC, a second long-preamble sequence, and a data field conveying data. The AGC preamble sequence is transmitted in parallel by the plurality of antennas.12-10-2009
20090304106METHOD AND APPARATUS TO SELECT CODING MODE - An apparatus and method that may adaptively select a coding mode of an OFDM sub-carrier symbol of a data stream according to a feedback data packet having the coding information of the OFDM sub-carrier.12-10-2009
20090304105METHOD AND APPARATUS TO SELECT CODING MODE - Briefly, an apparatus and method to transmit data stream by using a multiple-input-multiple-output (MIMO) transmitters receivers system. The MIMO transmitters receivers system may include a coding mode selector to select a coding mode of each orthogonal frequency division multiplexing (OFDM) sub-carrier symbol of a first and second sub-carriers of a data stream according to a feedback data packet having coding information of the OFDM subcarrier symbol. The coding mode may be selected from a diversity coding mode and a multiplexing coding mode.12-10-2009
20090304104TRANSMISSION/RECEPTION METHODS AND MODULES FOR A MULTIPLE-CARRIER MULTIPLE-ANTENNA SYSTEM USING TRAINING SEQUENCES - The present invention relates to a transmission method and device suitable for a system using Nt transmit antennas TX12-10-2009
20090304103Power Allocation Method for MIMO Transmit Beamforming - A transmit power allocation method for computing a transmit beamforming W matrix for a N streams of data, the method has a first step of measuring a receive channel characteristic H matrix, a second step of decomposing the H matrix into a U matrix which is formed from the left eigenvectors of the H matrix, an Σ matrix which is a diagonal matrix formed from the square roots of the eigenvalues of said H matrix and re-ordered by strength, and a V12-10-2009
20090103648WIRELESS COMMUNICATION BASE STATION APPARATUS AND WIRELESS COMMUNICATION METHOD IN MULTICARRIER COMMUNICATION - A base station apparatus wherein the interference suppression symbol combination can be performed in a case of using the repetition technique in a multicarrier communication. In a base station (04-23-2009
20100272204SPACE-TIME-STATE BLOCK CODED MIMO COMMUNICATION SYSTEM USING RECONFIGURABLE ANTENNAS - Space-Time-State Block Coded MIMO communication system using reconfigurable antennas. One or more antennas are operates in accordance with a Space-Time-State Block Code (STS-BC) to effectuate channel coding of a signal being transmitted wirelessly between communication devices. In accordance with such an STS-BC, one or more antennas (being reconfigurable in nature) of a communication device are reconfigured in different radiation states. From some perspectives, this may be viewed as performing three-dimensional channel coding, in that, in addition to achieving at least time diversity of signals being transmitted (and also potentially including spatial diversity), state diversity may be achieved by adapting one or more characteristics of one or more antennas within the communication device. Such an STS-BC may operate in an open loop configuration without requiring any feedback from another communication device to which signals are transmitted. If desired, feedback may be employed for adaptively modifying an STS-BC (or selecting another STS-BC).10-28-2010
20120219084WIRELESS COMMUNICATION SYSTEM FOR A HIGH-SPEED OBJECT THAT MOVES ON A FIXED PATH - The present invention relates to a method for sending a data signal from a transmitter to a receiver in a multiple antenna wireless communication system. In particular, the method comprises: sending information about the number of transmission antennas of the transmitter to the receiver; receiving from the receiver information about the number of effective communication links of the transmitter and the receiver; determining a precoding matrix based on the information about the number of effective communication links; and receiving from the receiver the data signal using the precoding matrix, wherein transmission antennas of the transmitter and receiving antennas of the receiver respectively form effective communication links independent of each other.08-30-2012
20120219083WIRELESS FEEDBACK SYSTEM AND METHOD - A codebook C is provided in a MIMO transmitter as well as a MIMO receiver. The codebook C will include M codewords c08-30-2012
20120219082MIMO Wireless Communication Systems - A wireless communication system is described which includes a transmitter operable to transmit a transmitted signal, the transmitter having one or more transmitting antennae, a receiver operable to receive a received signal, the receiver having one or more receiving antennae, wherein lattice reduction is used in obtaining, at the receiver, an estimate of the transmitted signal based on the received signal, characterized in that the lattice reduction utilises a lattice reduction matrix, a decomposed representation of which is transmitted between the transmitter and the receiver.08-30-2012
20120219081DETERMINISTIC PROCESSING FOR MIMO SYSTEMS - A system and method for a single spatial stream based multiple-input multiple-output (MIMO) communication system in wireless MIMO channels with a non-zero mean or a fixed component is provided which utilizes deterministic beamforming in the transmitter and deterministic combining at the receiver. For transmission and reception of a data over MIMO channels, the method and system avoids the requirement of knowledge of the instantaneous channel values at the transmitter and the receiver. By assuming perfect knowledge of the mean value of the channel matrix at the transmitter, a beamforming vector is obtained for the transmitter. The receiver utilizes deterministic receive weights which are chosen using the channel statistics.08-30-2012
20090041153MIMO RECEIVERS HAVING ONE OR MORE ADDITIONAL RECEIVE PATHS - In a multiple-input, multiple-output (MIMO) system, a receiver is implemented with at least one additional receive path beyond the number of transmit antennas used to transmit the signals (e.g., wireless OFDM signals) received at the receiver. In one embodiment, the additional receive path is used to reduced co-channel interference (CCI) in the recovered OFDM signals. In particular, each receive path applies recursive filtering to generate separate subcarrier signals. A processor converts the separate subcarrier signals from the different receive paths into a first set of subcarrier signals corresponding to each transmitted OFDM signal, where each first set of subcarrier signals has desired signal and possibly CCI. The processor also generates a second set of subcarrier signals corresponding to the CCI. The processor subtracts portions of the second set of subcarrier signals from each first set of subcarrier signals to generate recovered OFDM signals having reduced CCI.02-12-2009
20090041152APPARATUS AND METHOD FOR GENERATING PER STREAM EFFECTIVE SIGNAL TO NOISE RATIO IN A MULTIPLE-INPUT MULTIPLE-OUTPUT WIRELESS COMMUNICATION SYSTEM - In the present invention, an apparatus and a method for generating feedback information for a Maximum Likelihood (ML) detection scheme in a Multiple-Input Multiple-Output (MIMO) wireless communication system are provided. An apparatus of the invention includes a generator for generating constellation difference points by converting a constellation domain representing values of symbols into a constellation difference domain representing values of distance between symbols, a calculator for calculating per stream Symbol Error Rates (SERs) using the constellation difference points, and a determiner for determining per stream Effective Signal to Noise Ratios (ESNRs) using the per stream SER.02-12-2009
20090041150Method and apparatus of codebook-based single-user closed-loop transmit beamforming (SU-CLTB) for OFDM wireless systems - A method includes broadcasting, at a transmitter, messages comprising antenna configuration, antenna spacing and a number of antenna of the transmitter and reference signals; generating, at a receiver, a codebook comprising a plurality of antenna beams based on the broadcasted messages; receiving, at the receiver, the broadcasted reference signals; selecting, at the receiver, an antenna beam among the plurality of antenna beams within the codebook in dependence upon a predetermined performance criteria of a data communication system and in dependence upon the broadcasted reference signals; feedbacking to the transmitter, at the receiver, information comprising the antenna beam selected by the receiver; optimizing, at the transmitter, a beamforming process by utilizing the feedback information from the receiver; transmitting, at the transmitter, data signals by utilizing the optimized beamforming process; and receiving and processing, at the receiver, the data signals in dependence upon the selected antenna beams within the codebook.02-12-2009
20130058426CLOSED FORM SINGULAR VALUE DECOMPOSITION - The subject matter disclosed herein provides methods and apparatus for determining a singular value decomposition, providing feedback from a client station to a base station, and closed loop operation of a wireless system implementing multiple-input multiple-output (MIMO). The method may include determining one or more singular vectors using a closed form singular value decomposition. The one or more determined singular vectors may be provided to a precoder at the base station as feedback. The method may include aligning a phase of one or more singular vectors. The method may also include determining, at a client station, a plurality of singular vectors for channels used in a MIMO transmission from a base station to a client station. The client station may provide an indication to the base station regarding whether to use a singular value decomposition or a uniform channel decomposition. Related systems, apparatus, methods, and/or articles are also described.03-07-2013
20090092200DELAY PROFILE GENERATOR - A delay profile generator that includes a delay profile generating component, a delay profile extracting component, an integrating component, a comparing component and a correcting component, is provided. The integrating component, in the delay profile extracted by the delay profile extracting component, integrates a signal component of a delay profile of a first time period, and integrates a signal component of a delay profile of a second time period that does not overlap the first time period. The comparing component compares integration values of the two time periods obtained by the integrating component. The correcting component corrects a time position of the delay profile window on the basis of results of comparison of the comparing component.04-09-2009
20090092198Communication apparatus and radio communication system - A communication apparatus includes a grouping controlling unit hierarchically groups frequency channels so that the number of channels included in a group of a layer becomes smaller than the number of channels included in a group of a layer immediately above; and a propagation path information estimating unit that estimates propagation path information of the channels. The apparatus also includes an average value calculating unit that calculates an average value of the propagation path information for each group in a highest layer with the estimate values, and calculates the estimate values used in each layer based on an average value of a layer immediately above to calculate an average value of the propagation path information for each group in other layers with the estimate values of the each layer; and a feedback unit that feeds back an average value acquired in each group as feedback information.04-09-2009
20130070867COMMUNICATION DEVICE - Improving the accuracy of estimation of channel responses in receiving signals from a plurality of antennas is disclosed. A transmitting device of a base station includes a preamble A generating unit 03-21-2013
20110058619SIGNAL PROCESSING USING MODIFIED BLOCKWISE ANALYTIC MATRIX INVERSION - In one embodiment, a method for signal processing is provided that uses an improved inversion to mitigate the imprecision introduced by fast approximate methods for division. An input signal is received and processed to generate a matrix M. The matrix M is inverted to generate an inverted matrix M03-10-2011
20130058424Codebook Design and Structure for Multi-Granular Feedback - A first precoding matrix W03-07-2013
20130058425PRECODING PROCESSING METHOD AND USER EQUIPMENT - A precoding processing method and user equipment are disclosed. The precoding processing method includes: selecting a codebook vector for performing precoding processing for data among a codebook set of N03-07-2013
20110013713DATA PROCESSING METHOD AND BASE STATION FOR DOWNLINK TRANSMIT DIVERSITY - A data processing method and a base station for downlink transmit diversity are disclosed. One embodiment of the method comprises: obtaining data symbol groups formed by arranging a first type data symbol and a second type data symbol in an interval, wherein the first type data symbol is more important; determining a first antenna port paring mode corresponding to a current slot; performing, for OFDM symbols including reference signals in the current slot, an antenna port and subcarrier mapping on symbols in a transmit diversity matrix corresponding to the data symbol group according to the first antenna port paring mode, wherein a subcarrier in which a symbol related to the first type data symbol is located is nearer to a subcarrier in which a reference signal at the same antenna port is located; and performing an inverse fast fourier transform and a cyclic prefix insertion processing on symbols mapped to subcarriers and then mapping the symbols to a physical antenna for transmission. According to embodiments of the invention, comparatively important symbols may obtain better protection.01-20-2011
20110013712SYSTEM FOR MIMO SPATIAL ADAPTIVITY IN DYNAMIC ENVIRONMENTS - An adaptive wireless multiple-input multiple-output (MIMO) system switches among two or more modes of operation including Uninformed Transmitter (UT) and Informed Transmitter (IT) modes based on channel conditions as reflected in a set of metrics including a temporal selectivity metric (TSM) indicative of the temporal dynamics of the MIMO channel. In an exemplary embodiment, the adaptive MIMO system uses a dominant eigenmode IT mode of operation if a signal-to-noise ratio is below a threshold, otherwise, the system uses an IT mode or a UT mode based on the TSM. If the TSM indicates a channel that is changing too rapidly for feedback to be effective, the UT mode is used, otherwise the IT mode is used. Overall system capacity in time varying MIMO channels is thereby improved.01-20-2011
20110013711Beamforming Weight Estimation Using Wideband Multipath Direction of Arrival Analysis - Techniques are provided for computing downlink beamforming weights based on the received data at a base station from a mobile station in a MIMO communication system. An uplink transmission is received at a plurality of antennas at a first communication device from a second communication device, where the uplink transmission comprises a plurality of uplink subbands. The uplink spatial signature is estimated for each of the plurality of uplink subbands. The uplink spatial signature is decomposed into a plurality of direction of arrival (DOA) components for each uplink subband using a transform. Data representing multiple propagation paths between the first communication device and the second communication device is computed for each DOA component. A plurality of direction of departure (DOD) components for each of a plurality of downlink subbands is computed based on the data representing the multiple propagation paths. A downlink spatial signature for each downlink subband from the plurality of DOD components is computed using an inverse of the transform. Downlink beamforming weights are computed for each of the plurality of downlink subbands based on the downlink spatial signature, where the downlink beamforming weights are for use by the first communication device when beamforming a downlink transmission via the plurality of antennas of the first communication device to the second communication device.01-20-2011
20090274237BEAMFORMING TECHNIQUES FOR MIMO COMMUNICATION SYSTEMS - Improved beamforming techniques are provided for use in MIMO (multiple-input, multiple-output) communication systems, including MIMO-OFDM systems. The techniques include: (1) determining beamforming (BF) weights using a smoothed singular value decomposition (SVD) of the channel matrix; (2) determining BF weights using a power-optimized minimum mean-square error (MMSE) technique when the number of available transmit antennas exceeds the number of signal streams; and (3) determining BF weights using a hybrid SVD-MMSE technique. Additional techniques for reducing the impulse response length of the BF weights and/or normalizing the power per transmit antenna or per data stream may be used in conjunction with these or other beamforming techniques.11-05-2009
20090086841Platform noise mitigation - In one embodiment of the invention, a Fourier transform unit convert a unsynchronized received through multiple antennas to a frequency domain. Also, a spectrum estimation unit determines a power spectrum for the unsynchronized data. A notch filter removes data within a frequency band from additional unsynchronized data based on the power spectrum. A synchronization unit synchronizes the notch filtered data and a noise estimation unit determines a noise covariance matrix between the synchronized data received from multiple antennas. In addition, an equalization unit performs channel equalization on the synchronized data based on the noise covariance matrix.04-02-2009
20090268841POWER CONTROL SYSTEM AND METHOD FOR COMMUNICATION SYSTEM USING SPACE-TIME TRANSMIT DIVERSITY SCHEME - A power control system and method for communication system using space-time transmit diversity scheme. In the power control method, transmission power information of a plurality of antennas or a plurality of subcarriers is monitored. A new space-time code is generated by concatenating the monitored transmission power information and symbols to be transmitted. Symbols encoded using the generated space-time code are generated and the encoded symbols are transmitted. Accordingly, after determining the transmission power of each antenna, the transmission power information is monitored so that the transmission power information that does not experience the channel gain can be used at a next slot. Therefore, the performance degradation due to the round trip time can be reduced, thereby improving the system capacity and performance.10-29-2009
20090268840MULTIPLE ANTENNA COMMUNICATION SYSTEM INCLUDING ADAPTIVE UPDATING AND CHANGING OF CODEBOOKS - Communication between a base station with multiple transmission antennas and a mobile station is provided. The base station and the mobile station may recognize or estimate, respectively, a channel between the base station and the mobile station, and update a previous codebook with a new codebook based on a variation of the channel. In this instance, the mobile station may provide feedback information to the base station using the new codebook, and the base station may generate a transmission signal for the mobile station using the new codebook and the feedback information.10-29-2009
20090268839FULL DIVERSITY HIGH-RATE CODED TRANSMIT BEAMFORMING TECHNIQUES USING PARTIAL-ALGEBRAIC PRECODING, AND ASSOCIATED NEAR-OPTIMAL LOW-COMPLEXITY RECEIVERS - The present invention concerns a system for transmitting data from a transmitter comprising at least two transmitting antennas, an encoder following an error correcting code structure and a transmit beamforming technique to a receiver comprising at least two receiving antennas and a decoder defined according to the error correcting code structure over a transmit beamformed MIMO channel. This invention aims to achieve high data rate and guaranty a target diversity and high performance while keeping the receiver complexity low. Indeed, the diversity reduction may be overcome by including an algebraic linear precoder which linearly combines modulation symbols at the transmitter side.10-29-2009
20090268838TRANSMISSION APPARATUS AND COMMUNICATION METHOD - A transmission apparatus which multiplexes control channels for multiple reception apparatuses into an OFDM symbol at the same timing in OFDM downlink radio access includes a pattern generating unit configured to generate a frequency mapping pattern which is specific to the transmission apparatus; and a frequency allocating unit configured to allocate subcarriers to the control channels for the multiple reception apparatuses according to the frequency mapping pattern.10-29-2009
20090268837MULTICARRIER MODULATION SCHEME AS WELL AS TRANSMISSION APPARATUS AND RECEPTION APPARATUS USING THE SCHEME - An object is to generate a pilot signal for estimating transmission characteristic of a transmission channel which is suitable for the OFDM/OQAM multicarrier modulation. A phase reference pilot symbol of which a modulation amplitude is suppressed to zero, and an amplitude reference pilot signal obtained through modulation performed by using an amplitude known to a reception end are transmitted from a transmission end, and the transmission characteristic of the transmission channel is estimated and compensated by using the phase reference pilot signal and the amplitude reference pilot signal at the reception end. Thus, it is possible to simplify frame generation process performed at the transmission end, and reduce transmission power for the phase reference pilot signal.10-29-2009
20090268835WIRELESS COMMUNICATION METHOD, WIRELESS COMMUNICATION SYSTEM, AND WIRELESS COMMUNICATION DEVICE - A wireless communication method realizing a large channel capacity even in an environment of high spatial correlation and improving the reception characteristic, a wireless communication system, and a wireless communication device. Signals (X10-29-2009
20100091901METHOD, APPARATUS AND SYSTEM FOR MULTIPLE-DESCRIPTION CODING AND DECODING - A method, apparatus and system for multiple-description coding (MDC) and multiple-description decoding (MDD) are provided in the present invention. The MDC method comprises the following steps: receiving signals, processing the signal according to the first multiple-description method to generate at least two first description signals, processing at least one of the first description signals through the second multiple-description method to generate at least two second description signals, and coding the second description signal to generate the multiple-description bit stream. The MDD method comprises the following steps: receiving the multiple-description bit stream, decoding the multiple-description bit stream to generate the second description signal, processing the second description signal through the second multiple-description inverse transformation method to generate the first description signal, processing the first description signal through the first multiple-description inverse transformation method to generate the reconstruction signal. This invention simplifies the MDC and MDD, and distributes the voice quality deteriorations to different parts, thus improving user experience.04-15-2010
20100091900APPARATUS AND METHOD FOR OFDM MODULATED SIGNAL TRANSMISSION WITH REDUCED PEAK-TO-AVERAGE POWER RATIO - An apparatus and method for reducing peak-to-average power ratio (PAPR) in orthogonal frequency division multiplex (OFDM) comprising forming a plurality of OFDM frequency domain subcarriers; mapping the plurality of OFDM frequency domain subcarriers into a plurality of subset subcarriers; converting the plurality of subset subcarriers into a plurality of time domain subwaveforms; recombining the plurality of time domain subwaveforms into two or more time domain combined signals with low Peak-to-Average Power Ratio (PAPR); and frequency upconverting the two or more time domain combined signals to obtain a transmit signal.04-15-2010
20120224650System and Method for Uplink Inter Cell Interference Coordination in a Wireless Access System - A system and method for uplink inter cell interference coordination and multi-user multiple input, multiple output in a wireless access system are provided. A method for providing uplink inter cell interference coordination in a wireless access system includes categorizing users the wireless access system, selecting a resource allocation plan based on the categorized users, allocating resources to the users in the wireless access system based on the selected resource allocation plan, and receiving transmissions from the users.09-06-2012
20130064317METHOD AND DEVICE FOR FEEDING BACK PRE-CODING MATRIX INDEX OF DUAL-POLARIZED ANTENNA - There is provided a method and device for feeding back a pre-coding matrix index of a dual-polarized antenna which has a first antenna array and a second antenna array and is arranged at a base station to which the index of a first pre-coding matrix for the first antenna array, the index of a second pre-coding matrix for the second antenna array and the phase offset between the first pre-coding matrix and the second pre-coding matrix are fed back from a terminal, comprising: computing a distance between the first pre-coding matrix and the second pre-coding matrix; judging whether the distance is larger than a predetermined threshold or not; and assigning less bits to indicate the phase offset if the distance is larger than the predetermined threshold. The method and device according to the present disclosure can effectively advance the feedback accuracy of a system thus improving the bit error rate and throughput of the system.03-14-2013
20130064318METHOD AND DEVICE FOR ACQUIRING PRECODING MATRIX - A method and device for acquiring a precoding matrix are provided by the present invention. The method for acquiring a precoding matrix includes: for each receiving end, selecting the interference vectors as the interference space basis vectors from whole interference vectors, representing the remaining interference vectors as the linear combination of the interference space basis vectors, wherein the remaining interference vectors are the interference vectors in the whole interference vectors of the receiving end except the interference vectors which act as the interference space basis vectors (03-14-2013
20090252249DETECTING METHOD OF MULTIPLE-INPUT MULTIPLE-OUTPUT SYSTEM - A detecting method of a multiple-input multiple-output system includes the steps of: a) canceling interference between transmit signals by assigning weight values to signals received through a plurality of antennas, and determining K optimal antenna signals through channel gain estimation; b) calculating L transmit signal estimation values by quantizing the optimal antenna signals according to a predefined constellation size of L; c) calculating L residual antenna signals, in which interference of the transmit signal estimation values is removed from the received signals using the L Tx signal estimation values; d) calculating L residual transmit signal estimation values by quantizing the L residual antenna signals according to the predefined constellation size; and e) creating K×L estimated transmit signal candidate groups by repeating the calculation of the L residual transmit signal estimation values for each of the K optimal antenna signals, and detecting transmit signals from the estimated transmit signal candidate groups.10-08-2009
20090245408CQI Table for Wireless MIMO Networks - A Channel Quality Indicator table for wireless multiple input multiple output (MIMO) networks is disclosed. In one embodiment, a method of generating a table for channel quality indicator (CQI) for an open loop MIMO transmission includes calculating performance of a link between a transmitter and a user end unit for each MIMO transmission mode over a range of average signal-to-noise ratio, and selecting the MIMO transmission mode that maximizes performance for each subset of the range of average signal-to-noise ratio. The method further includes storing the selected MIMO transmission mode and the corresponding subset of the range of average signal-to-noise ratio in a CQI table, the CQI table being stored in an user end unit and a base transceiver station of the open loop MIMO network.10-01-2009
20090238299Detecting the Number of Transmit Antennas in Wireless Communication Systems - To detect the number of transmit antennas, a fast Fourier transform operation is performed on the received samples of the transmitted long training symbols of a preamble. Next, each of the Fourier transformed results is multiplied with the reference frequency-domain representation of the long training symbol so as to remove the effect of the symbols and to maintain the channel information. Next, inverse Fourier transform or least squares operations is performed on the multiplied values to compute channel impulse response. The number of shifted impulse response in the channel impulse response represents the detected number of transmit antennas. Packets containing preambles of the present invention may be received by extended devices as well as by legacy receivers that are not configured to receive and interpret these preambles. The training symbols may be cyclically-shifted and transmitted on different transmit antennas.09-24-2009
20090238298Method for transmitting and receiving precoded signal in MIMO communication system - A method for transmitting and receiving a precoded signal in a Multi-Input Multi-Output (MIMO) communication system is provided. In the method, a preceding matrix is selected from a codebook including one or more preceding matrices of each rank, each of the preceding matrices including a unitary matrix modified by an antenna selection element. A signal for transmission is then precoded by applying the selected preceding matrix to the signal for transmission and the precoded signal is transmitted through a selected antenna.09-24-2009
20090238297Method For Selecting Subchannel Mode And MIMO Communication System Using The Same - The invention relates to Method for Selecting Subchannel Mode and MIMO Communication System Using the Same. A method for self-adaptively selecting a code modulation sub-channel mode is suitably used in a MIMO communication system that comprises a base station and mobile terminals, wherein the method comprises the steps of: the mobile terminal estimating channel state information thereof, and determining a sub-channel structure most suitable for data transmission thereto, based on the channel state information; the mobile terminal feeding back information on the determined sub-channel structure most suitable for data transmission thereto to the base station; and the base station determining a sub-channel structure used for a down link, based on the information on the sub-channel structure fed back by the mobile terminal. According to the present invention, the subchannel structure in the communication system can be self-adaptively changed according to the actual communication environment, so as to improve the entire communication quality and efficiency.09-24-2009
20090232247INTERCELL INTERFERENCE MITGATION APPARATUS AND METHOD - There is provided an intercell interference mitigation apparatus for use in a terminal having a single reception antenna in a multi-cell downlink of an OFDMA system. The apparatus includes one or more parallel interference cancellers for canceling intercell interference by respreading soft decision values of cells other than a self cell; one or more LLR creation blocks for creating channel LLRs required for the soft decision for each of subcarriers, and producing channel soft outputs; one or more soft deciders for performing a soft decision of a self user symbol of the self cell in which interferences from other users are mitigated, and producing the soft decision values; and one or more channel estimation blocks for performing iterative channel estimation by respreading symbols of the soft decision values produced from the soft deciders.09-17-2009
20090232246WIRELESS COMMUNICATION DEVICE - A multiband OFDM_UWB transmitting and receiving apparatus is provided in Low-IF configuration to solve problems attributed to a direct-conversion transmitting and receiving apparatus. A Low-IF receiver performs sorting by rotating a sub-carrier after FFT to eliminate the need for frequency conversion using a second local signal and uses the same AD conversion clock as that for a direct conversion receiver. An FFT-free preamble can be detected by using a sequence resulting from previously multiplying an original preamble pattern and an IF frequency together.09-17-2009
20090232245MULTI-RESOLUTION BEAMFORMING BASED ON CODEBOOKS 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
20090232244WIRELESS COMMUNICATION SYSTEM, WIRELESS COMMUNICATION METHOD, TRANSMISSION APPARATUS, AND RECEPTION APPARATUS - The transmission apparatus performs orthogonalization processing to each of the signal sequence obtained by dividing each of the more than one transmission streams into more than one signal sequence based on the orthogonality of wireless resources. The signal sequence is then sent from multiple antennas. The reception apparatus performs the orthogonal separation processing based on the above orthogonality to the received signals to separate multiple reception signal sequence having the orthogonal characteristic, and applies a predetermined signal separation scheme based on the propagation path estimation matrix between the reception apparatus and the transmission apparatus to any one of the pairs of the separated reception signal sequence, thereby separating a signal sequence before subjected to the above orthogonalization processing.09-17-2009
20090232243WIRELESS TRANSMITTING APPARATUS, WIRELESS RECEIVING APPARATUS, WIRELESS COMMUNICATION SYSTEM, WIRELESS TRANSMITTING METHOD AND WIRELESS RECEIVING METHOD - To enable shared control information to be demodulated without requiring advance information on a MIMO block or non-MIMO block prior to demodulation of the shared control information of the block, and further enable the shared control information to be demodulated early. A wireless transmitting apparatus which performs wireless transmission in MIMO or non-MIMO for each radio frame comprised of a block or a plurality of blocks, and has mapping sections (09-17-2009
20090046801METHOD AND APPARATUS FOR CREATING A MULTI-USER MIMO CODEBOOK USING A SINGLE USER MIMO CODEBOOK - A wireless communication method and apparatus for creating a codebook in a multiple input/multiple output (MIMO) wireless communication system are disclosed. The method includes adapting a single user codebook, wherein the single user codebook comprises a plurality single user beamforming vectors, into a multi-user codebook, wherein the multi-user codebook comprises a plurality of multi-user beamforming vectors. The method further includes grouping the codebook into a plurality of unitary matrices, selecting a plurality of beamforming vectors from the plurality of unitary matrices, forming a rank specific code-book from the beamforming vectors and the unitary matrices, and selecting a subset of a total number of pairs to form the plurality of unitary matrices.02-19-2009
20090046800FEEDBACK AND RATE ADAPTATION FOR MIMO TRANSMISSION IN A TIME DIVISION DUPLEXED (TDD) COMMUNICATION SYSTEM - Techniques for sending a MIMO transmission in a wireless communication system are described. In one design, a transmitter sends a first reference signal to a receiver. The receiver selects a precoding matrix based on the first reference signal and in accordance with a selection criterion. The receiver estimates noise and interference at the receiver and determines channel quality indicator (CQI) or modulation and coding scheme (MCS) information based on the precoding matrix and the estimated noise and interference. The receiver sends the CQI or MCS information and a second reference signal to the transmitter. The transmitter selects the precoding matrix based on the second reference signal and in accordance with the same selection criterion used by the receiver. The transmitter then sends a MIMO transmission to the receiver based on the CQI or MCS information obtained from the receiver and the precoding matrix selected by the transmitter.02-19-2009
20090046799DECODER AND DECODING METHOD SUPPORTING OFDM/OFDMA - Provided are an apparatus and method for efficiently decoding signals input through a plurality of antennas in a system supporting an Orthogonal Frequency Division Multiplexing (OFDM)/Orthogonal Frequency Division Multiple Access (OFDMA) scheme. A method for decoding signals received via at least two paths through a plurality of antennas in a system supporting an 0FDM/0FDMA scheme, the method comprising the steps of: measuring power of a signal received via each path; generating correlation metrics by calculating inner products of basis vector sets or multiplying the basis vector sets in units of tiles or bins of the signal; generating decoding metrics based on the measured power of each path and the correlation metrics; and determining a payload on the basis of the decoding metrics. An apparatus for decoding signals received via at least two paths through a plurality of antennas in a system supporting an OFDM/OFDMA scheme, the apparatus comprising: a signal power measuring means for measuring power of a signal received via each path; a demodulation/decoding means for generating correlation metrics corresponding to likelihood of potential payload values of a signal received via each path; and a maximum ratio combining (MRC)/determination means for determining a payload based on the measured power of each path and the correlation metrics.02-19-2009
20090046798SYSTEM AND METHOD FOR ACQUIRING A TRAINING MATRIX FOR A BREAMFORMING ACQUISITION PROTOCOL USING A BUTSON MATRIX - A method and system for obtaining and transfer matrix and or acquiring beamforming vectors using a Butson matrix is disclosed. In one embodiment, the method includes i) determining the number (N) of transmitter antennas, ii) obtaining a unitary matrix having M rows and M columns, wherein M is an greater than or equal to N, and wherein the elements of the matrix are selected from the group consisting of: +1, −1, +j, and −j, iii) selecting N rows of the unitary matrix and iv) generating a training matrix having N rows and M columns based on the selected N rows. The method may further include obtaining a source beamforming vector using the training matrix.02-19-2009
20090010356Array Antenna Arrangement - The present invention relates to a wireless communication system, comprising at least one base station in a communication cell. The base station is equipped with at least one array antenna comprising at least two antenna ports which are coupled to respective at least two corresponding antenna Q elements, where at leas two of the at least two antenna elements have essentially the same polarization. The array antenna is arranged for communication via at least two antenna radiation lobes, each antenna radiation lobe communicating an information stream to at least one UE (user equipment) in the cell. According to a certain aspect of the present invention, in a first mode 0 operation, the array antenna is arranged for communication via one antenna radiation lobe. The present invention also relates to a method for performing said communication.01-08-2009
20090010355RADIO COMMUNICATION APPARATUS AND RADIO COMMUNICATION METHOD - There is provided with a radio communication apparatus for communicating with a receiver. A transmission rate control unit in the radio communication apparatus specifies a signal having small variation of a metric, which is an index for evaluating a channel of the signal, out of first to nth signals to be transmitted to the receiver. The transmission rate control unit controls a transmission rate of a specified signal based on a channel responses and a transmission weight of the specified signal and controls a transmission rate of each of other signals different from the specified signal out of the first to nth signals based on a relationship between a variation characteristic of a metric of the specified signal and a variation characteristic of a metric of each of the other signals.01-08-2009
20090010353Multi-Antenna Communication Method and Multi-Antenna Communicaton Apparatus - A multi-antenna communication method capable of improving the retransmission performance in a multi-antenna transmission. In this method, firstly, the reception quality of a substream to be retransmitted is acquired (Step 01-08-2009
20120114059METHOD, APPARATUS AND SYSTEM FOR PROVIDING FEEDBACK TO A TRANSMIT DIVERSITY DEVICE - A method and system for improving closed loop feedback in transmit diversity communication. In one embodiment of the invention, a predetermined variation of one or more transmit diversity parameters is performed at the transmit transmitter. The receiver compares the transmit diversity parameter values of the received signals to the predetermined variation and transmits to the transmitter a value of a transmit diversity correction parameter. The transmitter may use this correction value to modify the transmit diversity parameter in a subsequent transmission.05-10-2012
20120114058MULTIPLE-INPUT MULTIPLE-OUTPUT SIGNAL DETECTORS BASED ON RELAXED LATTICE REDUCTION - System and methodologies for reduced-complexity signal detection and decoding in a wireless communication system are provided herein. Systems and methodologies presented herein can utilize a relaxed form of the Lenstra-Lenstra-Lovasz (LLL) lattice reduction algorithm to reduce the complexity of lattice reduction operations in the context of MIMO detection. Additional systems and methodologies presented herein can apply lattice reduction in the context of a maximum likelihood (ML) detector for spherical or elliptical lattice space-time (LAST) codes.05-10-2012
20100086072COMMUNICATION SYSTEM AND METHOD OF OPERATION THEREFOR - A Multiple In Multiple Out (MIMO) communication system comprises an air interface scheduler for allocating air interface resource to a plurality of user equipments transmitting to a MIMO receiver. A vector processor of the scheduler determines a receive equalizer vector for the MIMO receiver for each of a plurality of user equipments in response to a channel matrix for the user equipment. The vector processor may specifically apply singular value decomposition to the channel matrix to determine the receive equalizer vector. An orthogonality processor then determines orthogonality measures between receive equalizer vectors for different sets of user equipments. A selection processor selects a set of user equipments to be allocated a shared MIMO air interface resource in response to the orthogonality measures. By scheduling in response to orthogonality of receiver operations, a reduced interference and/or reduced receiver complexity can be achieved.04-08-2010
20100086074APPARATUS AND METHOD FOR SENSING A MULTI-CARRIER SIGNAL USING CYCLOSTATIONARITY - A Wireless Regional Area Network (WRAN) endpoint comprises a transceiver for communicating with a wireless network over one of a number of channels, and a DVB-T (Digital Video Broadcast-Terrestrial) signal detector for use in forming a supported channel list comprising those ones of the number of channels upon which a DVB-T signal was not detected. The WRAN endpoint processes a received signal to provide two data segments and determines an average of the autocorrelation of the two data segments at each one of eight transmission modes for the DVB-T signal. The WRAN endpoint then determines if a DVB-T signal is present as a function of the largest average autocorrelation value.04-08-2010
20110019758 ALAMOUTI ENCODING AND DECODING - The present invention relates to the fields of transmit diversity, receive diversity and space-time block codes. The present invention especially relates to a method of transmitting data from a transmitter to a receiver connected by a communication channel, a transmitter, a receiver and a communication system comprising at least one transmitter and/or at least one receiver. The receiver according to the present invention is a receiver for receiving one or more first signals during a first transmission period and for receiving one or more second signals during a second transmission period, the one or more first signals being based on a first symbol transmitted on a first transmit path during said first transmission period and a second symbol transmitted on a second transmit path during said first transmission period, the one or more second signals being based on a third symbol transmitted on said first transmit path during said second transmission period and a fourth symbol transmitted on said second transmit path during said second transmission period, whereby said first symbol and said fourth symbol carry the same information, said second symbol and said third symbol carry the same information, the information carried by each of said first and forth symbols corresponds to a first input symbol and the information carried by each of said second and third symbols corresponds to a second input symbol, the receiver comprising a decoder adapted to decode the two input symbols based on said one or more first signals and/or is adapted to decode said two input symbols based on said one or more second signals.01-27-2011
20080317155Power Control and Link Adaptation Scheme Based on Multi-User Detection - This invention provides a method for dynamically adjusting the transmitter power (P12-25-2008
20120236956TRANSMISSION METHODS FOR DOWNLINK ACK/NACK CHANNELS - A method from transmitting data via multiple antennas. In this method, four information bits to be transmitted are multiplexed by using either one of a code division multiplexing scheme or a second code division multiplexing scheme combined with a real and imaginary multiplexing scheme, to generate a code division multiplexed symbol including four vectors. Then, the code division multiplexed symbol is repeatedly transmitted by alternatively applying two transmit diversity schemes via four transmission antennas.09-20-2012
20120236955WIRELESS COMMUNICATION SYSTEM AND WIRELESS COMMUNICATION METHOD - A wireless communication system 09-20-2012
20120236954WIRELESS COMMUNICATION SYSTEM AND METHOD WITH ELLIPTICALLY POLARIZED RADIO FREQUENCY SIGNALS - In one embodiment, a UWB transmission system includes a pair of crossed linearly polarized antennas, one of which is fed with a UWB signal current, while the second is fed with a temporally orthogonal UWB signal such as the time-derivative of the UWB signal current. The resultant elliptically polarized radiated fields are simultaneously orthogonal in space and orthogonal in time. In another transmission system, a loop and a co-located dipole are fed with the same current to generate signal exhibiting elliptical polarization. When the energies of the transmissions from each antenna are equal, the polarization is circular. Thus a UWB transmitting and receiving system is shown that utilizes signals that are simultaneously spatially orthogonal and temporally orthogonal, and the several combinations of those signal and polarization states encode data for transmission.09-20-2012
20130163687Method and Device for Processing Codebook Subset Restriction - The present invention discloses a method and device for processing codebook subset restriction, which includes: the codebooks for every rank of N antenna ports are grouped, wherein N is a natural number; after grouping, the status of each group is identified as restricted or unrestricted by using one bit. The present invention can reduce the signaling overhead needed for codebook subset restriction.06-27-2013
20120269283SIGNALING OF DEDICATED REFERENCE SIGNAL (DRS) PRECODING GRANULARITY - A method for communication includes receiving in a receiver signals, which include one or more dedicated reference signals and are transmitted from a transmitter over a communication channel in multiple blocks. The signals in each block, including the dedicated reference signals, are transmitted on a respective group of subcarriers over a respective time interval and are precoded using a respective precoding scheme that maps the signals onto multiple antenna ports of the transmitter. One or more parameters of the communication channel are estimated over the dedicated reference signals included in two or more of the blocks whose respective precoding schemes do not differ from one another. The signals are decoded based on the estimated parameters.10-25-2012
20120269282ENCODING AND DECODING METHODS AND APPARATUS FOR USE IN A WIRELESS COMMUNICATION SYSTEM - The claimed subject matter relates to encoding and decoding information in a wireless communication system using soft-demodulation and interleaving of concatenated code received in a strip channel. A set of symbols is received containing a plurality of information bits, dividing the received set of symbols into a plurality of subsets of symbols, each subset corresponding to the input of an inner code demodulation selecting a set of initial a priori values of the inner code demodulation for each subset of symbols, and demodulating each subset of symbols, using the initial a priori values of the subset of symbols and an inner code generator matrix, to generate a plurality of first soft information values as the output of the inner code demodulation.10-25-2012
20090022239RADIO TRANSMITTER, RADIO RECEIVER AND SYMBOL ARRANGING METHOD - A symbol arranging method by which a processing load due to channel estimation for MIMO channels can be reduced. In the methods a symbol is arranged for a transmission frame format having a pilot area and a data area. The pilot symbol is arranged in the pilot area. An ICE data symbol used for iterative channel estimation (ICE) is arranged in an ICE data area in the data area. The MIMO data symbol not used for ICE is arranged in the MIMO data area in the data area.01-22-2009
20100208833Techniques for Transmitting Data in a Wireless Communication System Using Quasi-Orthogonal Space-Time Code - A technique for communicating in a wireless communication system includes creating, using two distinct Alamouti codes, a power-scaled quasi-orthogonal space-time block code. The technique further includes transmitting, using a transmitter, the power-scaled quasi-orthogonal space-time block code over multiple antennas (e.g., three or four transmit antennas).08-19-2010
20110026632MULTIPLE INPUT, MULTIPLE OUTPUT COMMUNICATIONS SYSTEMS - Embodiments of the present invention include systems and methods for optimizing the transmitter and receiver weights of a MIMO system. In one embodiment, the weights are optimized to create and steer beam nulls, such that each transmitted signal is substantially decoupled from all other signals between a MIMO transmitter a MIMO receiver. In another embodiment, the weights are selected such that, the signal strength of each weighted signal transmitted through a communications channel along a respective signal path is substantially equivalent, but for which the weighting vectors are not necessarily orthogonal. In a further embodiment, each transmitted signal is coupled only between its own transmitter and receiver antennas with a gain, or eigenvalue, that is a consequence of the weights, and which is bounded to within a desired range of values while at the same time the weighing vectors are orthogonal. Embodiments employing various decomposition techniques are also provided.02-03-2011
20090028263MIMO COMMUNICATION APPARATUS AND DATA RETRANSMISSION METHOD - A MIMO communication apparatus wherein HARQ technique is utilized, in a MIMO system, to simplify feedback information and hence reduce the amount of information to be transmitted, thereby saving the transmission resources of the system, while improving the efficiency of data transmission. Additionally, this MIMO communication apparatus has a simple structure, while being capable of performing a reliable data retransmission. This MIMO communication apparatus comprises means (buffer 01-29-2009
20120269279Method of Precoding with a Codebook for a Wireless System - A quantized multi-rank beamforming scheme for multiple-antenna systems such as a multiple-input-multiple-output (MIMO) wireless downlink. User equipment (UE) estimates downlink channel and transmit power and determines rank and power allocations. A quantized beamforming matrix is then determined by the UE using successive beamforming. The UE also determines channel quality indices (CQI) which it feeds-back to the wireless downlink base station along with the index of the quantized beamforming matrix. The base station uses the CQI information to select a UE for scheduling of downlink transmission and the quantized beamforming matrix index received from the selected UE to beamform the downlink transmission to the UE. Base station overhead and is minimized while providing near-optimal performance given the constraints of a limited feed-back channel and computational complexity of the UE.10-25-2012
20110019759ESTIMATING SPATIAL EXPANSION MATRIX IN A MIMO WIRELESS COMMUNICATION SYSTEM - Techniques are provided to derive the spatial expansion matrix used when one wireless communication device sends a transmission with a number of spatial streams less than the number of its transmit antennas to another wireless communication device. These techniques involve, at the receiving wireless communication device, generating channel estimate information for received transmissions sent with different numbers of spatial streams and to determine when sufficient information is available to estimate a spatial expansion matrix for different spatial expansion scenarios.01-27-2011
20090296846MIMO COMMUNICATION SYSTEM HAVING DETERMINISTIC CHANNELS AND METHOD - A MIMO communication system having deterministic channels wherein MIMO is applied to line-of-sight channels having a fixed geometrical positional relationship so as to increase the channel capacity. A line-of-sight MIMO communication system having a plurality of channels includes a channel matrix calculation processing section on a transmission or reception side or both of the transmission and reception sides. The channel matrix calculation processing section updates an orthogonal channel formation matrix in accordance with a fluctuation of a transmission antenna position or reception antenna position or a fluctuation of the channels.12-03-2009
20110002411System and method for link adaptation in DIDO multicarrier systems - A system and machine-implemented method are described for communicating with a plurality of distributed-input-distributed-output (DIDO) clients. For example, a method according to one embodiment comprises: determining channel state information (CSI) defining a channel state between each of a first plurality of DIDO antennas and each of the DIDO clients; using the CSI to determine distributed-input-distributed-output (DIDO) precoding weights for each of the channels between each of the first plurality of DIDO antennas and the antennas of each of the DIDO clients; using the CSI and DIDO precoding weights to determine link quality metrics defining link quality between each of the first plurality of DIDO antennas and the antennas of each of the DIDO clients; using the link-quality metrics, to determine modulation coding schemes (MCSs) for different DIDO clients; and transmitting precoded data streams from each of the first plurality of DIDO antennas to each of the individual DIDO clients using the determined MCSs for those clients.01-06-2011
20110280331PREAMBLE FORMATS FOR MIMO WIRELESS COMMUNICATIONS - A method for generating a preamble of a frame for a multiple input multiple output (MIMO) wireless communication begins by, for each transmit antenna, generating a carrier detect field. The method continues by, for a first grouping of the transmit antennas, generating a first guard interval following the carrier detect field; and generating at least one channel sounding field. Continuing, the method applies cyclical shift prior to transmission via the first grouping of the transmit antennas. When the MIMO wireless communication includes more than the first grouping of the transmit antennas, for another grouping of the transmit antennas. For the another grouping of the transmit antennas, generating at least one other channel sounding field. The method proceeds by generating the first guard interval prior to the at least one other channel sounding field, and applying another cyclical shift prior to transmission via the another grouping of the transmit antennas.11-17-2011
20110280330RADIO COMMUNICATION SYSTEM, RADIO TERMINAL, RADIO BASE STATION, CONTROL DEVICE AND RADIO COMMUNICATION METHOD - A radio communication system comprises a control device that controls a radio base station, which uses a plurality of first transmission antennas to transmit a first radio signal, for which a channel A is used, to a radio terminal and a radio base station, which uses a plurality of second transmission antennas to transmit a second radio signal, for which the channel A is used, to a radio terminal. The radio terminal, if having received the second radio signal, transmits, to the radio base station, interference information based on the arrival direction from which the second radio signal comes to the radio terminal. Based on the interference information received by the radio base station, the control device transmits, to the radio base station, control information to be used for directing, in the arrival direction, the null point of a directional beam formed by the second transmission antennas.11-17-2011
20100111215Beamforming protocol for wireless communications - Beamforming protocol for wireless communications. Various communications are made between an originating communication device and a remote communication device to effectuate steered communications there between. The beamforming approach presented herein is applicable and adaptable to communication devices having any combination of omni-directional and directional transmit and receive functionality (e.g., the transmit functionality and the receive functionality both being omni-directional; the transmit functionality being directional and the receive functionality being omni-directional; or the transmit functionality and the receive functionality both being are directional). The beamforming protocol presented herein allows for all combinations of communication device types and also provides collision rules as may be performed in accordance with the beamforming configuration.05-06-2010
20090147881CLOSED LOOP FEEDBACK IN MIMO SYSTEMS - Feedback bandwidth may be reduced in a closed loop MIMO system by factoring non essential information out of a beamforming matrix.06-11-2009
20090028264Transmit methods with delay diversity and space-frequency diversity - In this invention, several open-loop solutions that encompass the small delay CDD codeword cycling, codeword cycling between different re-transmissions of both small and large delay CDD are proposed. In addition, an open-loop codeword cycling method for SFBC+FSTD scheme, as well as its extension to SFBC+FSTD based HARQ, are proposed. In one method, a plurality of information bits are encoded, scrambled and modulated to generate a plurality of modulation symbols. The plurality of modulation symbols are mapped onto the subcarriers in at least one transmission layer of a transmission resource. The modulation symbols are then precoded by using a matrix for cyclic delay diversity and a set of codewords from a certain codebook to generate a plurality of precoded symbols. The codewords are cycled for every a certain number of subcarriers. Finally, the precoded symbols are transmitted via a plurality of transmission antennas.01-29-2009
20110299617X-mimo systems with multi-transmitters and multi-receivers - A method and apparatus for transmitting and receiving a wireless transmission of a plurality of data streams in a wireless communication system having a plurality of nodes is disclosed. Each node has multiple antennas. The method involves receiving first and second data streams from respective first and second nodes at a receiver node, causing the receiver node to generate a receive filter for decoding each of the received data streams, and causing the receiver node to transmit receive filter information for each of the first and second data streams, the receive filter information facilitating precoding of the first and second data streams for simultaneous transmission within a common frequency band to the receiver node.12-08-2011
20090310699COMMUNICATION APPARATUS, COMMUNICATION METHOD, AND INTEGRATED CIRCUIT - A communication apparatus for transmitting transmission data containing a preamble and a postamble is provided. The communication apparatus includes: a phase vector assigning unit which assigns a first phase vector to a plurality of subcarriers relating to the preamble and assigns a second phase vector to a plurality of subcarriers relating to the postamble, the first phase vector being different from the second phase vector.12-17-2009
20090310701METHOD FOR TRANSMITTING/ RECEIVING SIGNAL IN MIMO SYSTEM - Disclosed is a method for transmitting a signal in a mobile communications system using a plurality of transmit/receive antennas. A method for transmitting a signal in accordance with an embodiment of the present invention comprises the steps of: a receiving end's calculating a signal to interference noise ratio (SINR) with respect to every antenna pairs configuring STTD pairs to be transmittable from a transmitting end; feedbacking information indicating an antenna pair having the greatest SINR to the transmitting end; and the transmitting end's performing a D-STTD transmission through the antenna pair determined by the feedbacked information. A method for transmitting a signal in accordance with another embodiment of the present invention comprises the steps of: a receiving end's feedbacking information of an antenna pair and/or an eigenvector (weight vector) of a channel matrix with respect to transmit antennas included in the space-time multiplexing (STTD) pair to a transmitting end; and the transmitting end's forming beam by multiplying a symbol with respect to each STTD pair by the eigenvector, and thereafter transmitting the beam through each transmit antenna (in case of using two antennas) or a transmit antenna pair (in case of using more than four antennas) determined by the information of the antenna pair.12-17-2009
20090310700Exploiting multiuser diversity through phase modulation multiplexing - A method and apparatus for combining signals of multiple users onto a common channel is disclosed. In one embodiment, the method comprises identifying one or more traffic channels that are of one or more predetermined quality levels to a plurality of subscriber units based on channel profiles of the plurality of subscriber units and transmitting phase modulation multiplexed signals to the plurality of subscriber units through a common set of one or more channels having higher quality than the one or more predetermined quality levels.12-17-2009
20090207930METHODS AND SYSTEMS FOR SPACE-TIME CODING FOR DISTRIBUTED COOPERATIVE COMMUNICATON - Methods and systems for space-time coding for distributed cooperative communication.08-20-2009
20110299618MULTIPLE-BRANCH WIRELESS RECEIVER - A wireless receiver detects signals received at two or more antennas, with each antenna coupled to an input receive chain. A switch is employed to couple selected input receive chains to one or more corresponding output receive chains during listening, coarse-detection, and fine-adjustment modes. At least one channel selection filter (CSF) is employed in each output receive chain, and the receiver employs sub-ranging. During idle mode, one antenna's input receive chain is connected to two or more CSFs to detect the packet. When the packet is detected, during a coarse-adjustment mode, the CSFs are reconfigured to couple each antenna's input receive chain to a corresponding output receive chain using low-gain signals. During fine-adjustment mode, the various gains are adjusted to be either high- or low-gain to maintain signals within the dynamic range of the corresponding CSFs.12-08-2011
20120288025TERMINAL AND COMMUNICATION METHOD THEREOF - A terminal and a communication method thereof whereby, even in a case of employing the asymmetric carrier aggregation system and further employing the MIMO transmission method for upstream channels, the error characteristic of control information can be prevented from being degraded. In the terminal (11-15-2012
20120288024ASYMMETRICAL MIMO WIRELESS COMMUNICATIONS - A method for asymmetrical MIMO wireless communication begins by determining a number of transmission antennas for the asymmetrical MIMO wireless communication. The method continues by determining a number of reception antennas for the asymmetrical MIMO wireless communication. The method continues by, when the number of transmission antennas exceeds the number of reception antennas, using spatial time block coding for the asymmetrical MIMO wireless communication. The method continues by, when the number of transmission antennas does not exceed the number of reception antennas, using spatial multiplexing for the asymmetrical MIMO wireless communication.11-15-2012
20120288023INCREASED CAPACITY COMMUNICATIONS FOR OFDM-BASED WIRELESS COMMUNICATIONS SYSTEMS/METHODS/DEVICES - Numerous embodiments are provided that may be used to provide enhanced capacity and/or Quality-of-Service for OFDM-based systems such as LTE and/or WiMAX. Various service/device modes and/or applications are also provided. According to embodiments of the invention, a transformation may be performed on a data vector by a transmitter, prior to the transmitter transmitting the data vector, to distribute elements of the data vector over an available frequency space, thus providing robustness to channel anomalies such as fading and/or interference. Embodiments relating to architectures, systems, methods, devices, software, firmware and/or computer program products are provided.11-15-2012
20120288022CHANNEL ESTIMATION FOR A VERY LARGE-SCALE MULTIPLE-INPUT MULTIPLE-OUTPUT (MIMO) SYSTEM - A transmitter, receiver, and method for channel estimation for a Multiple-Input Multiple-Output (MIMO) communication system in which the transmitter includes a multiplicity of transmit antennas spaced such that spacing between adjacent antennas provides a spatial correlation coefficient greater than a threshold level. The transmitter selects a subset of the multiplicity of transmit antennas for transmitting the pilot reference signals. The pilot reference signals are transmitted only from the selected subset of transmit antennas to the receiver. The receiver includes a channel estimator configured to derive a channel estimation for all of the multiplicity of transmit antennas using the received pilot reference signals and known or estimated spatial correlation among the multiplicity of transmit antennas.11-15-2012
20120099668TRANSMISSION METHOD, TRANSMITTER, AND RECEIVER FOR MULTI ANTENNA WIRELESS COMMUNICATION SYSTEM - A transmitter includes first generator to generate pilot source signal by modulating pilot sequence, second generator to generate data source signal with time length longer than that of pilot source signal by modulating data sequence, first cyclic shifter to perform cyclic shift of first shift amount to pilot source signal to generate first pilot signal, second cyclic shifter to performs cyclic shift of second shift amount to data source signal to generate first data signal, third cyclic shifter to perform cyclic shift of third shift amount to pilot source signal to generate second pilot signal, fourth cyclic shifter to perform cyclic shift of fourth shift amount to data source signal to generate second data signal, first transmit antenna to transmit first pilot signal and first data signal, and second transmit antenna to transmit second pilot signal and second data signal.04-26-2012
20110299619Methods and Apparatus for Overlapping MIMO Antenna Physical Sectors - A system for communicating with wireless devices. The systems includes radio groups whose MIMO physical sectors overlap. The MIMO physical sectors communicate using different channels. The MIMO physical sectors overlap to form an area of overlap. Each radio group includes directional antennas and radios. Radios are selectively coupled to the antennas. The antennas that are oriented so that the physical sectors of the antennas overlap to operate as MIMO antennas and form the MIMO physical sector for the radio group. The antennas operate as a MIMO antenna.12-08-2011
20110299616SYSTEM AND METHOD OF TRANSMIT DIVERSITY FOR WIRELESS COMMUNICATIONS - A system and method of transmit diversity for wireless communication. The system includes a transmitting terminal having a plurality of transmission antennas and a receiving terminal having a plurality of receiving antennas. The method includes analyzing channel state information obtained by the transmitting terminal; selecting an antenna to be one in use from the receiving antennas; matching the selected antenna in use with the wireless signals that are to be transmitted; transmitting wireless signals that are matched to the receiving terminal for being calculated and determining the pre-selected antenna in use, thereby significantly reducing complexities of the receiving terminal.12-08-2011
20090110105SYSTEM AND METHOD FOR SCRAMBLING THE PHASE OF THE CARRIERS IN A MULTICARRIER COMMUNICATIONS SYSTEM - A system and method that scrambles the phase characteristic of a carrier signal are described. The scrambling of the phase characteristic of each carrier signal includes associating a value with each carrier signal and computing a phase shift for each carrier signal based on the value associated with that carrier signal. The value is determined independently of any input bit value carried by that carrier signal. The phase shift computed for each carrier signal is combined with the phase characteristic of that carrier signal so as to substantially scramble the phase characteristic of the carrier signals. Bits of an input signal are modulated onto the carrier signals having the substantially scrambled phase characteristic to produce a transmission signal with a reduced PAR.04-30-2009
20100284484OPEN LOOP PRECODER CYCLING IN MIMO COMMUNICATIONS - Data is transmitted over multiple input multiple output (MIMO) channels. Plural bit streams are modulated into multiple data symbol vectors. Each vector has a transmission rank with one vector for each MIMO channel. Transmission rank is the number of elements in a data symbol vector corresponding to the number of data streams being transmitted in parallel over each MIMO channel. The multiple data symbol vectors are preceded into multiple precoded symbol vectors using a plurality of precoder cycling sets, one set for each transmission rank including multiple different precoders. The precoders in each precoder cycling set are well-separated with respect to a plurality of distance measures. The precoding includes precoding each data symbol vector of a transmission rank with a precoder belonging to the precoder cycling set of that transmission rank. The precoded symbol vectors are then transmitted over the MIMO channels.11-11-2010
20090097585Apparatus and method for generating per stream channel quality information in multiple-input multiple-output (MIMO) wireless communication system - The generation of per stream Channel Quality Information (CQI) in a Multiple-Input Multiple-Output (MIMO) wireless communication system is provided. An apparatus includes a receiver for receiving signals from a transmitting end via a plurality of antennas; an estimator for estimating channels per antenna in relation with the transmitting end using the received signals and constituting a channel matrix; and a generator for deriving per stream effective noise when a lattice reduction scheme is adopted and generating per stream CQI using the per stream effective noise. Thus, feedback information for a Closed Loop (CL) MIMO system can be produced by generating the per stream CQI using the effective noise obtained through the lattice reduction.04-16-2009
20090041151Pilot boosting and traffic to pilot ratio estimation in a wireless communication system - Methods and circuits for assigning pilot boosting factors and calculating traffic to pilot ratios in a wireless communication system. The data to be transmitted is first modulated to generate a plurality of data modulation symbols. The plurality of data modulation symbols and a plurality of reference signal symbols are mapped into transmission resources of each of a plurality of antennas in accordance with a transmit diversity scheme. The transmission resources of each of the antennas are divided into a plurality of subcarriers in a frequency domain and a plurality of time units in a time domain. Then, a power scaling factor are assigned for data modulation symbols on each of the antennas in dependence upon power levels of the reference signal symbols to maintain a fixed power level across the plurality of antennas in each time unit. Finally, the data modulation symbols and the reference signal symbols are transmitted via the plurality of antennas in accordance with the mapping scheme and the assigned scaling factors.02-12-2009
20090161784TRANSMIT POWER ALLOCATION FOR ADAPTIVE MULTI-CARRIER MULTIPLEXING MIMO SYSTEMS - The present invention relates to transmit power allocation in multi-carrier, multiplexing MIMO communication systems. The present invention especially relates to a MIMO communication device, a method of assigning transmit power to two or more communication channels and a software program product. A multiple-input-multiple-output, MIMO, communication device according to the present invention comprises06-25-2009
20100215112Method and apparatus for multiple input multiple output (MIMO) transmit beamforming - A wireless communications network is provided. The wireless communications network comprises a plurality of base stations. Each one of said base stations is capable of wireless communications with a plurality of subscriber stations. At least one of said plurality of base stations comprises a processor configured to select a codeword from a codebook and precode data with the selected codeword, and a transmitter configured to transmit the precoded data. Rank 1 of the codebook is selected from the following algorithm:08-26-2010
20100290553Probability Based MIMO Mode Selection and Switching System and Method for Wireless Systems - In an embodiment, a method for determining a MIMO mode for a wireless communication system includes providing input parameters, an electronic device determining a probability of each MIMO mode being a dominant MIMO mode; and selecting the MIMO mode based on the determining.11-18-2010
20080304592METHOD AND SYSTEM FOR DIVERSITY RECEIVER BASED ON TDS-OFDM TECHNOLOGY - A method and apparatus for a receiver comprises: a plurality of paths with each path associated with an independent antenna. Each path comprises: a channel estimation device associated with a particular channel; and a set of parameters denoting channel characteristic associated with each path. The receiver further comprises a time de-interleaver or FEC decoder shared by the plurality of paths. Whereby at least one device that use significant amount of memory is shared by the plurality of paths.12-11-2008
20110007832MULTIPLE-OUTPUT MULTIPLE-INPUT (MIMO) COMMUNICATION SYSTEM, MIMO RECEIVER AND MIMO RECEIVING METHOD - A receiver that receives a signal from a transmitter, including: a plurality of antennas; a channel estimation unit; a channel accumulation unit; a transmission weight generator; a feedback information transmission unit; and a reception weight generator. The plurality of antennas receive a second signal from the transmitter, the second signal being transmitted by using first feedback information. The channel estimation unit estimates a communication channel state on the basis of the second signal, and then outputs second channel estimation information. The reception weight generator generates reception weight information to be multiplied by the second signal, on the basis of first channel estimation information accumulated in the channel accumulation unit and a first transmission weight.01-13-2011
20090190685MIMO COMMUNICATION SYSTEM AND TRANSMISSION STATION - An imbalanced amplitude is produced to a pair of weighing factors (U07-30-2009
20080310542Self-Adpting Transmission Scheme of the Channel Environment in the Multiantenna Wireless Transmission System - An adaptive transmission scheme of the channel environment in the multi-antenna wireless transmission system can raise the spectrum use rate and power efficiency of the communication system in fast. Comparing with the traditional single antenna input and single antenna output, the channel environment in MIMO wireless communication system is more complex. When the terminal is moving, the different types of channels between terminal and base station can be gone through and then its capacity can be changed more largely. It is characterized in: at first, obtaining the statistical channel information at the receiving end using the result of channel estimation; then, quantizing and encoding the obtained statistical channel information to get feedback bit information and send the feedback bit information to the transmitting end through a feedback channel; thereby using statistical information, the sending end calculates link self-adapting control parameters, which are used for controlling coding modulation and sending the pre-code; the sending end obtains the digital base band transmission signal using a characteristic mode transmission method and a random virtual space selection transmission method, and the receiving end carries out self-adapting receiving by the same parameters.12-18-2008
20100034311WIRELESS COMMUNICATION APPARATUS AND WIRELESS COMMUNICATION CONTROLLING METHOD - To reduce the influence of Doppler shift, with the sub-carrier interval being widened in a high-frequency band, transmission timings of frames for every frequency band are matched each other. By matching the frame transmission timings, at the receiving side, once the modulation timing in one frequency band is detected, the modulation timing at another frequency band can be obtained. Therefore, demodulation can be simplified. To match the frame transmission timings, the CP length is adjusted, for example.02-11-2010
20100040165GENERATION AND USE OF LDCS IN WIRELESS COMMUNICATION SYSTEMS - A method for generating a Linear Dispersion Code (LDC) for use in a Multiple-Input Multiple-Output (MIMO) communication system in which M transmit antennas are used to transmit a codeword over T time slots, each codeword encoding Q constellation symbols, is provided. The method includes determining M, T and Q, wherein M, T and Q are real numbers, generating a first matrix having 2Q columns and a predefined number m of rows, each column including a plurality of elements, each element being a real number within a respective predefined range for the respective row, deriving a second matrix having 2Q columns and m rows from the first matrix such that the elements of one row of the second matrix are dependent upon the corresponding elements of a corresponding row of the first matrix, and upon M and T, and deriving a set of 2Q LDC dispersion matrices, each including dimensions T×M, from the second matrix.02-18-2010
20100034312Reference Signal Resource Allocation for Single User MIMO - Transmission with multiple antennas in a wireless network is performed by transmitting a plurality of reference sequences (RS) from a UE. A first RS s1[k] is produced using a first cyclic shift and a base sequence s0[k], wherein k={1, 2 . . . K} is an element index. A second RS s2[k] is produced using a second cyclic shift and s0[k]. A first symbol sequence x1[k] is produced using at least s1[k] and s2[k], for at least one k. A second symbol sequence x2[k] is produced using at least s1[k] and s2[k], for at least one k. x1[k] is transmitted using a first transmit antenna and x2[k] is transmitted using a second transmit antenna.02-11-2010
20090268836MULTI-PILOT GENERATION METHOD AND DETECTION METHOD IN MULTI-ANTENNA COMMUNICATION SYSTEM - Provided are a multi-pilot generation method and a detection method in a multi-antenna communication system. In the method, a transmission side superimposes a first preamble sequence and a third preamble sequence to generate a second preamble sequence, which is subjected to serial/parallel conversion before the first preamble sequence and the second preamble sequence are successively transmitted from a plurality of antennas by time division. A reception side receives the first preamble sequence and the second preamble sequence by a plurality of antennas, separates the third preamble sequence from the second preamble sequence by a spatial division process, and performs a pilot correlation process by using the first preamble sequence and the separated third preamble sequence.10-29-2009
20090285321Radio transmission with variable length of guard interval - Information, in particular OFDM-symbols, is transmitted via radio from an emitting unit to a receiving unit. At least one first symbol has a first total length, which includes a first time section during which first user data is transmitted and a second time section during which cyclic repetitions of the first user data are transmitted. Also, at least one second symbol has the first total length which includes a third time section, having a length different than the first time section, during which second user data is transmitted, and a fourth time section, having a length different than the second time section, during which cyclic repetitions of the second user data is transmitted.11-19-2009
20080310540Signaling of implicit ACK/NACK resources - A method includes, in response to receiving implicit signaling of the radio resource, and in response to a plurality of wireless communication system cell-specific static and semi-static input parameters, determining a plurality of output parameters and allocating radio resources using the determined output parameters. Also disclosed are computer readable storage mediums for storing programs that operate in accordance with the methods, as well as various devices that operate in accordance with the methods and that include the computer readable storage mediums.12-18-2008
20090154586MIMO RECEIVER, QR DECOMPOSITION AND MULTI-DIMENSIONAL DETECTION USED IN THE MIMO RECEIVER - Provided are a receiver of a Multiple Input Multiple Output (MIMO) system, QR decomposition and multi-dimensional detection used in the receiver. The receiver includes: a QR decomposing unit for performing a QR decomposing operation in cycles 1 to n06-18-2009
20090147880METHOD FOR REDUCING FEEDBACK INFORMATION OVERHEAD IN PRECODED MIMO-OFDM SYSTEMS - An improved method for reducing an amount of precoding feedback information in a multi-carrier Multiple-Input Multiple-Output (MIMO) communication system using precoding is disclosed. At the receiving end, the method jointly selects, while considering transmission quality for each relevant combination of sub-bands and matrices, a limited number of P codebook indices and a limited number of K′ sub-bands to be included in a subset ω (m06-11-2009
20090147878TRANSMITTING 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.06-11-2009
20100034308Methods and apparatus to generate multiple antennas transmit precoding codebook - A device and method for generating a codebook. The device includes a generator. The codebook generator is configured to generate a precoding codebook using an 8-PSK alphabet-based 4 bits 4 TX and 8 TX antennas for use in a closed-loop SU-MIMO scheme. According to aspects of the present disclosure, it is possible to generate a precoding codebook for use in 8 Transmission Antenna systems.02-11-2010
20090310696METHOD AND APPARATUS FOR MAPPING SIGNALS TO SUBCARRIERS IN MIMO WIRELESS NETWORK - The present invention aims to provide a method for mapping signals to subcarriers in a sending means of a MIMO-based wireless telecommunication network and an apparatus for the same. It is characterized in that, controlling the mapping of the signals in an input signal sequence to the subcarriers, so that the signals sent by different antennas at the same time correspond to nonadjacent signals in the input signal sequence. With the aid of the present invention, burst error due to deep fading channel can be effectively avoided, and diversity gains can be also improved.12-17-2009
20080267309Apparatus and Method for Handling Broadcast System Information in Telecommunications System User Equipment - A wireless communications device, and a method of operating a wireless communications device, the device operative to receive broadcast system information from a network, the device being arranged to: receive first broadcast system information, said first broadcast system information defining scheduling information for a plurality of items of further broadcast system information; define a subset containing a plurality of items of further broadcast system information; receive an item of further broadcast system information relating to whether transmit diversity is in use; when it is determined that the device has received further broadcast system information relating to whether transmit diversity is in use, wait until one of the following conditions has been met before implementing on the device any changes in transmit diversity as defined by the further broadcast system information relating to whether transmit diversity is in use: i) the device having received all members of the subset of further broadcast system information; or ii) the quality of a signal received by the device being determined to be below a threshold.10-30-2008
20100266061METHOD AND DEVICE FOR PRE-CODING IN MULTIPLE INPUT MULTIPLE OUTPUT SYSTEM - A signal processing method in an MIMO multi-carrier system is disclosed comprising: receiving by a receiver signals of a plurality of sub-carriers transmitted from a transmitter; dividing the sub-carriers into a plurality of sub-carrier blocks according to the correlation between adjacent sub-carriers, each sub-carrier block containing K sub-carriers; selecting a feedback sub-carrier pre-coding matrix ( ) and a rotation matrix ( ) for each sub-carrier block, and then sending the information on the pre-coding matrix and the rotation matrix back to the transmitting end. The present invention provides the method and device for effectively settling the feedback problem in an MIMO/OFDMA system, thereby greatly reducing the number of pre-coding weight matrices needed to feed back to the transmitting device.10-21-2010
20100266060RADIO COMMUNICATION DEVICE AND METHOD FOR DETERMINING DELAY AMOUNT OF CDD - A radio communication device capable of obtaining the frequency diversity effect when a CDD is used for the open-loop transmission. A CDD control information determination section (10-21-2010
20100278279Mimo wireless data transmission system - A MIMO wireless data transmission system including a data arrangement in which data to be sent is divided for each transmission stream of MIMO with adding an error detection code thereto and thereby resending a subframe's worth of data when an error occurred at the time of resending. It therefore becomes to avoid the same frame being sent again at the time of resending.11-04-2010
20100119003COMMUNICATION PROCESSING SYSTEM, OFDM SIGNAL TRANSMITTING METHOD, OFDM TRANSMITTER, OFDM RECEIVER, AND CONTROL STATION - In an OFDM transmitter included in a first service area, an orthogonal-code-pattern multiplication unit multiplies pilot channel signals belonging to any subcarrier group by an orthogonal code which is different from that for one or a plurality of OFDM transmitters adjacent to the OFDM transmitter included in the first service area, or a subcarrier assignment unit assigns pilot channel signals to pilot subcarriers which are common to a plurality of OFDM transmitters and based on a pilot arrangement notified in advance by a control station to all OFDM transmitters included in the first service area.05-13-2010
20090310697MULTIPLE-INPUT MULTIPLE-OUTPUT (MIMO) TRANSMITTER AND COMMUNICATION SYSTEM - A Multiple-Input Multiple-Output (MIMO) transmitter 12-17-2009
20090310698WIRELESS COMMUNICATION SYSTEMS - A method of requesting a plurality of different characteristic indicators from a second communication apparatus (MS) in a wireless communication network comprising a first communication apparatus (BS) and a plurality of such second communication apparatuses (MS) which communicate with the first communication apparatus using a shared communication frame, the method comprising; the first communication apparatus (BS) transmitting (12-17-2009
20100284483PRECODER FOR SPATIAL MULTIPLEXING, MULTIPLE ANTENNA TRANSMITTER - A transmitter (11-11-2010
20100119005RATE ADAPTIVE TRANSMISSION SCHEME FOR MIMO SYSTEMS - A rate adaptive transmission scheme for MIMO systems, which can transmit a variable number of data symbol streams, provide transmit diversity for each data symbol stream, and fully utilize the total transmit power of the system and the full power of each antenna. In one method, at least one data symbol stream is received for transmission from a plurality of antennas. Each data symbol stream is scaled with a respective weight corresponding to the amount of transmit power allocated to that stream. The scaled data symbol stream(s) are multiplied with a transmit basis matrix to provide a plurality of transmit symbol streams for the plurality of antennas. The transmit basis matrix (e.g., a Walsh-Hadamard matrix or a DFT matrix) is defined such that each data symbol stream is transmitted from all antennas and each transmit symbol stream is transmitted at (or near) the full power for the associated antenna.05-13-2010
20100119004MIMO COMMUNICATION SYSTEM AND METHOD FOR DIVERSITY MODE SELECTION - In a MIMO communication system, a method for mode selection comprising: a. measuring communication variables including SNR, Correlation, Interference and Mobility; b. automatic change of mode, according to predefined criteria and responsive to the measured communication variables. The modes from which the selection is made include Spatial Multiplexing, Beamforming, Space-Time Coding and Beamforming.05-13-2010
20100195750 Transmission of Orthogonal Space Time Codes - Implementations of improved transmission of orthogonal space time codes are disclosed.08-05-2010
20090207932WIRELESS COMMUNICATION APPARATUS WITH A PLURALITY OF ANTENNA ELEMENTS - A wireless communication apparatus comprising a memory for storing a group of coefficient values to be applied to processing of orthogonal modulation signals received by a plurality of antenna elements, a coefficient generation unit for detecting a phase shift value of reception timing of specific received signals on the basis of a desired signal and the coefficient values read out from the memory, compensating the group of coefficient values according to the detected phase shift value, and storing the compensated coefficient values in the memory, and a signal processing unit for processing the received signals by applying the compensated coefficient values.08-20-2009
20090207931WIRELESS COMMUNICATION DEVICE AND WIRELESS COMMUNICATION METHOD - A wireless communication device that transmits a wireless signal by carrying out linear precoding processing using a plurality of transmission antennas is provided with: a phase pattern control unit for selecting a phase pattern that reduces peak-to-average power ratio; a phase rotation unit for carrying out phase rotation on a modulation signal using the phase pattern selected in the phase pattern control unit; a control signal generation unit for generating a control signal based on the phase pattern selected in the phase pattern control unit; and a preceding unit for carrying out linear precoding processing on output signals from the phase rotation unit and output signals from the control signal generation unit.08-20-2009
20090086842Unified closed loop SU/MU-MIMO signaling and codebook design - A multi-resolution codebook is used to provide quantization for channel related information in a wireless network that supports both single-user MIMO and multi-user MIMO. The multi-resolution codebook may include a higher resolution “fine” codebook for use with MU-MIMO subscriber stations and a lower resolution “coarse” codebook for use with SU-MIMO subscriber stations. A tracking codebook may also be used to provide quantization for updates to channel related information. In at least one embodiment, the tracking codebook includes a number of unit vectors (or orthogonal matrices) disposed upon a sphere cap.04-02-2009
20100080317SYMBOL MIXING ACROSS MULTIPLE PARALLEL CHANNELS - Symbol mixing across multiple input multiple output (MIMO) parallel channels is disclosed. Each data symbol is transmitted over an effective channel with a weighted sum of the singular values associated with all spatial channels. By averaging the singular values, there is less of a penalty associated with the choice of modulation and coding on the data symbols, since all transmitted symbols experience roughly the same signal to noise ratio (SNR) in transmission.04-01-2010
20110200132MULTI-CELL BASED METHOD FOR APPLYING MULTI-CELL MIMO - The present invention relates a method for transmitting and receiving data in a mobile communication system. More specifically, the invention relates to a method through which a terminal in a cell boundary receives data in a mobile communication system that supports MIMO (Multi Input Multi Output). The method comprises: a step for receiving a first data stream transmitted through multiple transmission antennas from a serving base station, a step for pre-coding a second data stream to make the time delay of the second data stream be different from that of the first data stream and receiving the second data stream from a collaborating base station, and a step for restoring the data based on the first and second data streams.08-18-2011
20110200134SYSTEM AND METHOD FOR CHANNEL ESTIMATION IN A DELAY DIVERSITY WIRELESS COMMUNICATION SYSTEM - A method of controlling downlink transmissions to a subscriber station capable of communicating with a base station of an orthogonal frequency division multiplexing (OFDM) network. The method comprises the steps of: receiving a first pilot signal from a first base station antenna; receiving a second pilot signal from a second base station antenna; and estimating the channel between the base station and subscriber station based on the received first and second pilot signals. The method also comprises determining a set of OFDM symbol processing parameters based on the step of estimating the channel and transmitting the OFDM symbol processing parameters to the base station. The base station uses the OFDM symbol processing parameters to control the relative gains and the relative delays of OFDM symbols transmitted from the first and second antennas.08-18-2011
20110200133RECEIVING APPARATUS AND RECEIVING METHOD - A receiving apparatus includes an inverse matrix multiplying portion which multiplies first and second receiving signal points corresponding to first and second receiving signals by an inverse matrix of a channel matrix based on known signals included in the first and second receiving signals, a first arithmetic portion which determines one or more first sending signal candidate points based on the multiplied first receiving signal points, a second arithmetic portion which determines one or more second sending signal candidate points based on the multiplied second receiving signal points, a determining portion which determines first and second sending signal points, corresponding to first and second sending signals from among the first and second sending signal candidate points so that a total distance based on at least a first distance regarding the first sending signal candidate point and a second distance regarding the second sending signal candidate point satisfies a given condition.08-18-2011
20110200131Low Overhead PMI and CQI Feedback and Pairing Schemes for MU-MIMO - A method is provided for searching for a pairing PMI including estimating a MIMO wireless propagation channel from an access point transmitter to a receiver at a UE; quantizing the estimated channel with a codebook consisting of a plurality of codewords, the result being an actual SU-MIMO PMI currently applicable to the UE; estimating the channel quality corresponding to the actual SU-MIMO PMI, resulting in at least one CQI for the UE; constructing a plurality of subsets from a codebook of codewords, wherein each subset comprises potential MU-MIMO PMIs that represent channels that have reduced interference with a channel represented by one of the potential SU-MIMO PMIs; associating each potential SU-MIMO PMI with the subset that comprises the potential MU-MIMO PMIs that represent channels that have reduced interference with the channel represented by that potential SU-MIMO PMI; searching for an appropriate pairing PMI and the associated CQI for the UE.08-18-2011
20090190686APPARATUS AND METHOD FOR CHANNEL ESTIMATION IN MIMO SYSTEMS - Provided are a preamble structure and a channel estimation algorithm thereof. A communication method for a transmitter for channel estimation in a Multiple Input Multiple Output (MIMO) wireless communication system having N receiving antennas, includes generating a preamble interval having a short training field that includes a predetermined pattern iterated N times on a time domain and is used for compensating for a carrier frequency offset, and transmitting a packet having the preamble interval.07-30-2009
20090274236Wireless Communication Apparatus, Wireless Communication Method, Wireless Communication System, and Computer Program - 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
20090262859Long training sequence for MIMO WLAN systems - A method for configuring a multiple input multiple output (MIMO) wireless communication begins by generating a plurality of preambles for a plurality of transmit antennas. Each of the plurality of preambles includes a carrier detection sequence at a legacy transmit rate, a first channel sounding at the legacy transmit rate, a signal field at the legacy transmit rate, and Z−1 channel soundings at a MIMO transmit rate, where L corresponds to a number of channel soundings. The method continues by simultaneously transmitting the plurality of preambles via the plurality of transmit antennas.10-22-2009
20090262858CONSTELLATION REARRANGEMENT FOR ARQ TRANSMIT DIVERSITY SCHEMES - An ARQ (re-) transmission method of transmitting data in a wireless communication system wherein data packets are transmitted from a transmitter to a receiver, using a first transmission and a second transmission based on a repeat request. The method comprises the steps of modulating data at the transmitter using a first signal constellation pattern to obtain a first data symbol. The first data symbol is transmitted as the first transmission to the receiver using a first diversity branch. Further, the data is modulated at the transmitter using a second signal constellation pattern to obtain a second data symbol. Then, the second data symbol is transmitted as the second transmission to the receive over a second diversity branch. Finally, the received first and second data symbol data symbol are diversity combined at the receiver. The invention further relates to a transmitter and a receiver embodied to carry out the method of the invention.10-22-2009
20090262852Coding for Large Antenna Arrays in MIMO Networks - A method transmits a sequence of symbols in a multiple-input multiple-output (MIMO) network including a transmitter having a set of transmit antennas and a receiver having a set of receive antennas. The sequence of symbols is represented by a vector S=[S10-22-2009
20090262851RADIO TRANSMITTING APPARATUS AND RADIO TRANSMITTING METHOD - A radio transmitting apparatus and a radio transmitting method wherein the loss of transmission efficiency is suppressed to improve the reception quality of pilots received by a receiver apparatus. In the present apparatus and method, in a case of transmitting a pilot block at one of two transmission antennas, the areas of data blocks placed immediately before and after the pilot block are reduced, and the CP of the pilot block is expanded by the amount of that reduction. On the other hand, it is arranged that the interval of transmitting the expanded CP and pilot block be an interval of halting the transmission at the other transmission antenna.10-22-2009
20080279300System and method of transmitting and receiving satellite digital radio signals over an odd number of frequency slots - A system and method for transmitting and receiving data which includes at least one satellite, at least one transmitter in communication with the at least one satellite, and at least one receiver in communication with the at least one satellite. The transmitter modulates source data into a first modulated signal using a first modulation and a second modulated signal using a second modulation, and transmits the first and second modulated signals over an odd number of frequency slots to the satellite. The receiver receives the first and second modulated signals and demodulates at least one of the first and second modulated signals.11-13-2008
20090285322RADIO TRANSMITTER, RADIO COMMUNICATION SYSTEM, AND RADIO TRANSMISSION METHOD - A radio transmitter of the present invention includes a scheduler for assigning a communication time or a communication frequency to each radio receiver based on quality information of a received signal transmitted by the radio receiver, a transmission circuit controller for transmitting either a frequency diversity region or a multiuser diversity region to be selected with respect to each chunk, and a transmission circuit for applying different delay times to signals of a plurality of transmission antennas based on a transmission result of the transmission circuit controller.11-19-2009
20090290656MULTI-USER MIMO METHOD, APPARATUS AND COMMUNICATION SYSTEM FOR TRANSMITTING SIGNAL - A multi-user multi-input multi-output (MIMO) method for transmitting signal with a includes: performing a Tomlinson-Harashima pre-coding (THP) on raw data; decomposing a channel matrix to a product of a block triangular matrix and a unitary matrix, and generating a signal to be transmitted by performing a forward filtering on the THP coded data by using the unitary matrix. A multi-user MIMO apparatus for transmitting signal includes an interference pre-eliminating unit, a modulo unit, a forward filtering unit, and a channel matrix decomposing unit. A multi-user MIMO communication system is further provided.11-26-2009
20090274234USING COVARIANCE MATRICES FOR LINK SELECTION IN MIMO COMMUNICATION SYSTEM - A method of selecting at least one communication link in a wireless communication network is proposed, comprising the steps of transmitting from at least one transmitting node in the network a pilot signal from each of at least two transmitter antennas of the transmitting node, receiving the pilot signals from the at least two transmitter antennas in a receiving terminal, estimating, in the terminal, a covariance matrix of the channel, based on the pilot signals received, determining the pathloss for each antenna based on the covariance matrix, selecting one of at least two possible links for the communication between the terminal and the transmitting nodes. The terminal is enabled to measure on each transmitter antenna individually, which provides a better tool for link selection and cell selection.11-05-2009
20090274235Data transmission method using dirty paper coding in mimo system - A data transmission method for multiple users having multiple receive antennas is provided. The method includes selecting a receive antenna among the multiple receive antennas for each user, performing DPC (Dirty Paper Coding) from the multiple transmit antennas to the receive antenna and transmitting a transmission signal on which the DPC is performed. Since DPC is implemented through a receive antenna selected among multiple receive antennas, complexity is not much increased although the DPC is applied to a MIMO system.11-05-2009
20090274233METHOD AND SYSTEM FOR PHASE TRACKING IN WIRELESS COMMUNICATION SYSTEMS - A method and system phase tracking in a wireless communication system is provided. Phase tracking involves receiving a first Orthogonal Frequency Division Multiplexing (OFDM) symbol and a second OFDM symbol which is a repetition of the first symbol, over a wireless channel, the symbols representing an incoming signal. A phase of the incoming signal is extracted by performing phase tracking across all subcarrier data tones and pilot tones of the symbols.11-05-2009
20090296844METHOD OF TRANSMITTING A PRECODING MATRIX IN A MULTI-INPUT MULTI-OUTPUT (MIMO) SYSTEM - A method of transmitting a precoding matrix in a multi-input, multi-output (MIMO) system is disclosed. In the system, a receiving end determines feedback information by calculating each diagonal sub-matrix of the precoding matrix. Here, the precoding matrix includes a plurality of sub-matrices arranged in a block diagonal format. Thereafter, the receiving end transmits he feedback information of the each calculated sub-matrix.12-03-2009
20090279630JOINT TRANSCEIVER DESIGN FOR MIMO COMMUNICATIONS - A method and apparatus for transmitting data in a MIMO communication system, the method including encoding at least one data symbol by implementing a first precoding scheme, the first preceding scheme including a precoder derived from a first channel state information (CSI). The method further includes selecting at least one antenna that maximizes the first CSI, the at least one antenna being selected by implementing a first selection scheme, and transmitting the at least one data symbol via the at least one antenna.11-12-2009
20090285325MIMO-OFDM Communication System And Communication Method Of Same - A MIMO-OFDM communication method for transmitting and receiving data using MIMO-OFDM communication has, on the transmitting side, a step of performing precoding processing of transmission data using a prescribed precoding method, and a step of performing OFDM modulation of the precoding-processed data and transmitting the data from a plurality of transmission antennas, and has, on the receiving side, a step of performing MIMO decoding processing of reception signals received by a plurality of reception antennas according to a ZF decoding algorithm or an MMSE decoding algorithm, and outputting the data as a transmission data stream, a step of calculating weighting coefficients according to the precoding method, and a step of performing weighted decoding processing of the transmission data obtained by the MIMO decoding processing, by multiplying path metric of the decoding processing by the weighting coefficients.11-19-2009
20090285323ADAPTIVE SOFT OUTPUT M-ALGORITHM RECEIVER STRUCTURES - A method and apparatus is disclosed herein for adaptive soft output M-algorithm receiver structures. In one embodiment, a device for use in a wireless communication system includes a transmitter, and comprises of a receiver to receive information-bearing signals from the transmitter wirelessly transmitted using OFDM and bit interleaved coded modulation, where the receiver comprises an inner decoder structure having a soft output M-algorithm (SOMA) based multiple-in multiple-out (MIMO) joint demapper that uses a SOMA-based MIMO detection process to perform joint inner demapping over each subtone. The SOMA-based MIMO joint demapper is operable to identify a best candidate among a number of candidates by searching a detection tree under control of a parameter representing a total number of paths that are extended from each level, such that only a number of best alternatives from every level of the tree are expanded, wherein the SOMA-based MIMO detection process adapts one or more of the parameters based on tone quality.11-19-2009
20100278277DECODING APPARATUS AND METHOD USING ORTHOGONAL SPACE-TIME BLOCK CODES ROBUST TIMING ERRORS - Provided is a decoding apparatus and method using orthogonal space-time block codes (OSTBCs) robust against timing errors. The decoding apparatus may include: a cyclic prefix removal unit to receive a signal, and to remove a cyclic prefix in the signal; an inverse discrete Fourier transform (IDFT) unit to apply an IDFT to the signal with the removed cyclic prefix; a guard band removal unit to remove a guard band in the inverse discrete Fourier transformed signal, and to generate a complex matrix; a channel estimation unit to transmit a carrier corresponding to the complex matrix and channel status information associated with transmit and receive antennas; and a decoder to calculate a channel status vector with respect to a complex symbol included in the complex matrix, using the channel status information, and to calculate an inner product between the channel status vector and the complex matrix, to restore the complex symbol.11-04-2010
20090290657Continuous Beamforming for a MIMO-OFDM System - A transmitting entity performs spatial processing on data symbols for each subband with an eigenmode matrix, a steering matrix, or an identity matrix to obtain spatially processed symbols for the subband. The data symbols may be sent on orthogonal spatial channels with the eigenmode matrix, on different spatial channels with the steering matrix, or from different transmit antennas with the identity matrix. The transmitting entity further performs beamforming on the spatially processed symbols, in the frequency domain or time domain, prior to transmission from the multiple transmit antennas. A receiving entity performs the complementary processing to recover the data symbols sent by the transmitting entity. The receiving entity may derive a spatial filter matrix for each subband based on a MIMO channel response matrix for that subband and perform receiver spatial processing for the subband with the spatial filter matrix.11-26-2009
20090290655TRANSMISSION MODE AND RATE SELECTION FOR A WIRELESS COMMUNICATION SYSTEM - To select a transmission mode to use for a data transmission via a MIMO channel from station A to station B, station A obtains channel information used for spatial processing and determines the age of this information. Station A selects one of multiple transmission modes based on the age of the channel information and possibly other information (e.g., the fading characteristic of the MIMO channel). To select rate(s) to use for the data transmission, station A obtains channel state information (CSI) indicative of the received signal quality for the MIMO channel, e.g., received SNRs or “initial” rates. Station A determines the age of the CSI and selects one or more “final” rates based on the CSI, the age of the CSI, the selected transmission mode, and possibly other information. Station A processes data in accordance with the selected transmission mode and final rate(s) and transmits the processed data to station B.11-26-2009
20090296845METHOD AND APPARATUS FOR MULTICARRIER COMMUNICATIONS - A data processing device (12-03-2009
20090296847FAULT TOLERANT MODEM REDUNDANCY - A fault tolerant modem system is provided according to some embodiments of the invention. A modem can include modulators and/or demodulators that provide redundancy in the event one of the modulators and/or demodulators fail. Connectivity between modulators and demodulators, for example, can be used to propagate TDMA timing to connected modulators and/or demodulators. Moreover, redundancy can be provided using modulators and/or demodulators with three or more input/output ports.12-03-2009
20090296848JOINT MAXIMAL RATIO COMBINING USING TIME-DOMAUIN BASED SIGNAL PROCESSING - A communication device transmits and receives communication signals with another communication device via a plurality of antennas, a plurality of transmit tapped delay-line filters, a plurality of receive tapped delay-line filters, a combiner/analyzer with a plurality of filters for signal processing; and a plurality of computation blocks. The computation blocks determine complex weights for the tapped delay-line filters for optimizing the received signal-to-noise ratio and the range of communication of the communication device.12-03-2009
20090168916METHOD AND SYSTEM FOR PROVIDING MULTI-INPUT-MULTI-OUTPUT (MIMO) DOWNLINK TRANSMISSION - An approach is provided for supporting transmission in a multi-input-multi-output (MIMO) communication system including a plurality of terminals. A preamble portion of a frame is transmitted by a multiple transmit antennas of a hub using Orthogonal Frequency Division Multiplexing (OFDM) to the terminals over a channel, wherein each of the terminals determines a characteristic of the channel with respect to the transmit antennas as feedback information. The hub receives the feedback information from the terminals. The hub selects, according to the feedback information, a subset of the antennas for transmission of a remaining portion of the frame to the terminal.07-02-2009
20090168915RADIO COMMUNICATION APPARATUS, RADIO COMMUNICATION METHOD AND PROGRAM STORAGE MEDIUM - A radio communication apparatus includes: generation units generating first to mth signals; a storage storing allocation information defining that beams of different quality levels are allocated to first to mth communication apparatuses for each of first to nth subcarriers so that frequencies of respective quality levels are substantially uniform over all the subcarriers among the apparatuses; determining units determining transmission weights by which the signals are multiplied so that the beams according to the allocation information are formed for the apparatuses for each of the subcarriers; generation units performing multiplication processing by using the signals and the weights for each of the subcarriers to generate first to hth weighted signals for each of the subcarriers; transform units performing inverse Fourier transform on the weighted signals for each of the subcarriers to generate first to hth transformed signals; and transmission processing units transmitting the transformed signals via first to hth antennas.07-02-2009
20100220804ASYMMETRICAL MIMO WIRELESS COMMUNICATIONS - A method for asymmetrical MIMO wireless communication begins by determining a number of transmission antennas for the asymmetrical MIMO wireless communication. The method continues by determining a number of reception antennas for the asymmetrical MIMO wireless communication. The method continues by, when the number of transmission antennas exceeds the number of reception antennas, using spatial time block coding for the asymmetrical MIMO wireless communication. The method continues by, when the number of transmission antennas does not exceed the number of reception antennas, using spatial multiplexing for the asymmetrical MIMO wireless communication.09-02-2010
20090041149Multiple input-multiple output communication system - A wireless communication system, and a method of arranging such a system, comprising a transmitter and a receiver. The transmitter includes first means for transmitting a first data stream multiplexed with a carrier wave having a wavelength? and second means for transmitting a second data stream multiplexed with the carrier wave. The receiver comprises third means for receiving the first and second data streams and for providing a first output signal and fourth means for receiving the first and second data streams and for providing a second output signal. The first, second, third and fourth means are arranged to substantially satisfy the equation: Formula (I) where d02-12-2009
20090041148OPEN LOOP MU-MIMO - A unified open loop single-user/multiple-user multiple-input-multiple-output (MIMO) system and method are disclosed. The system and method operate without use of channel state information feedback. Instead, the method utilizes channel quality indicator feedback to schedule users to spatial resource blocks. Both symmetric multi-user MIMO schemes (like 2×2 and 4×4) and asymmetric multi-user MIMO schemes are considered. CQI feedback and reduction proposals are also introduced. The method may be used in a proposed network topology.02-12-2009
20100111216Secure Communication Method, Transmission Apparatus and Reception Apparatus - A transmitting apparatus that transmits signals from a plurality of antennas, and can improve the security of communication compared with a conventional system. In this apparatus, an antenna changing section (05-06-2010
20100111213SINGULAR VALUE DECOMPOSING METHOD AND RELATED SINGULAR VALUE DECOMPOSING DEVICE - A method for performing a singular value decomposition (SVD) upon a matrix. The method includes the steps of: (a) simplifying the matrix to derive a simplified matrix; (b) performing an iterative matrix multiplication upon the simplified matrix to generate an iterated matrix; (c) extracting a vector of the iterated matrix according to an iteration number of the iterative matrix multiplication; (d) de-correlating the simplified matrix from the vector to update the simplified matrix; (e) repeating steps (b), (c), and (d) until a predetermined number of vectors have been derived; and (f) storing a first unitary matrix determined according to the predetermined number of vectors in the singular value decomposition.05-06-2010
20080212706Transmission Method and Transmission System - A transmission device (09-04-2008
20110268211Quantized and Successive Precoding Codebook - A quantized multi-rank beamforming scheme for multiple-antenna systems such as a multiple-input-multiple-output (MIMO) wireless downlink. User equipment (UE) estimates downlink channel and transmit power and determines rank and power allocations. A quantized beamforming matrix is then determined by the UE using successive beamforming. The UE also determines channel quality indices (CQI) which it feeds-back to the wireless downlink base station along with the index of the quantized beamforming matrix. The base station uses the CQI information to select a UE for scheduling of downlink transmission and the quantized beamforming matrix index received from the selected UE to beamform the downlink transmission to the UE. Base station overhead and is minimized while providing near-optimal performance given the constraints of a limited feed-back channel and computational complexity of the UE.11-03-2011
20110268210Restricted Multi-rank Precoding in Multiple Antenna Systems - A quantized multi-rank beamforming scheme for multiple-antenna systems such as a multiple-input-multiple-output (MIMO) wireless downlink User equipment (UE) estimates downlink channel and transmit power and determines rank and power allocations. A quantized beamforming matrix is then determined by the UE using successive beamforming. The UE also determines channel quality indices (CQI) which it feeds-back to the wireless downlink base station along with the index of the quantized beamforming matrix. The base station uses the CQI information to select a UE for scheduling of downlink transmission and the quantized beamforming matrix index received from the selected UE to beamform the downlink transmission to the UE. Base station overhead and is minimized while providing near-optimal performance given the constraints of a limited feed-back channel and computational complexity of the UE.11-03-2011
20110268215Space-Time Precoding and Associated Feedback Generation Methods in Multiple Antenna Systems - A quantized multi-rank beamforming scheme for multiple-antenna systems such as a multiple-input-multiple-output (MIMO) wireless downlink. User equipment (UE) estimates downlink channel and transmit power and determines rank and power allocations. A quantized beamforming matrix is then determined by the UE using successive beamforming. The UE also determines channel quality indices (CQI) which it feeds-back to the wireless downlink base station along with the index of the quantized beamforming matrix. The base station uses the CQI information to select a UE for scheduling of downlink transmission and the quantized beamforming matrix index received from the selected UE to beamform the downlink transmission to the UE. Base station overhead and is minimized while providing near-optimal performance given the constraints of a limited feed-back channel and computational complexity of the UE.11-03-2011
20110268214Feedback Generation in Recursive Multi-Rank Beamforming - A quantized multi-rank beamforming scheme for multiple-antenna systems such as a multiple-input-multiple-output (MIMO) wireless downlink User equipment (UE) estimates downlink channel and transmit power and determines rank and power allocations. A quantized beamforming matrix is then determined by the UE using successive beamforming. The UE also determines channel quality indices (CQI) which it feeds-back to the wireless downlink base station along with the index of the quantized beamforming matrix. The base station uses the CQI information to select a UE for scheduling of downlink transmission and the quantized beamforming matrix index received from the selected UE to beamform the downlink transmission to the UE. Base station overhead and is minimized while providing near-optimal performance given the constraints of a limited feed-back channel and computational complexity of the UE.11-03-2011
20110268213Quantized Precoding For 2TX Multiple Antenna Systems - A quantized multi-rank beamforming scheme for multiple-antenna systems such as a multiple-input-multiple-output (MIMO) wireless downlink. User equipment (UE) estimates downlink channel and transmit power and determines rank and power allocations. A quantized beamforming matrix is then determined by the UE using successive beamforming. The UE also determines channel quality indices (CQI) which it feeds-back to the wireless downlink base station along with the index of the quantized beamforming matrix. The base station uses the CQI information to select a UE for scheduling of downlink transmission and the quantized beamforming matrix index received from the selected UE to beamform the downlink transmission to the UE. Base station overhead and is minimized while providing near-optimal performance given the constraints of a limited feed-back channel and computational complexity of the UE.11-03-2011
20110268212Successive Beamforming Strategies and Methods - A quantized multi-rank beamforming scheme for multiple-antenna systems such as a multiple-input-multiple-output (MIMO) wireless downlink User equipment (UE) estimates downlink channel and transmit power and determines rank and power allocations. A quantized beamforming matrix is then determined by the UE using successive beamforming. The UE also determines channel quality indices (CQI) which it feeds-back to the wireless downlink base station along with the index of the quantized beamforming matrix. The base station uses the CQI information to select a UE for scheduling of downlink transmission and the quantized beamforming matrix index received from the selected UE to beamform the downlink transmission to the UE. Base station overhead and is minimized while providing near-optimal performance given the constraints of a limited feed-back channel and computational complexity of the UE.11-03-2011
20110206155COMMUNICATION APPARATUS AND COMMUNICATION SYSTEM - A communication apparatus that can suppress an increase in circuit size and reduce influence of interference, includes reception array antenna elements, a reception DBF network that generates a reception beam signal for forming M reception beams using a reception signal, and reception FBs that generate frequency split reception beam signals obtained by frequency-splitting the reception beam signal. The communication apparatus includes an interference-source detecting unit that stores, for each reception beam, an interference candidate beam area estimated based on an initial reception beam characteristic, calculates, based on the frequency split reception beam signals, a reception spectrum, and calculates, based on the reception spectrum and a reception spectrum of a reception beam to the interference candidate beam area, an interference source area. The reception DFB network generates a reception beam signal to perform null formation in the direction of the interference source area.08-25-2011
20110206153Channel Quantization for Multiuser Diversity - A method and system for channel quantization for multiuser diversity are provided. A quantizer may utilize quantization levels determined based on an objective function J that corresponds to a performance metric for a finite-rate feedback multiuser downlink communication system. The quantization levels may be obtained based on the results of maximizing the objective function J by means of an optimization algorithm. The optimization algorithm may be a multivariate optimization algorithm that may be implemented utilizing an iterative approach. The quantizer may utilize the quantization levels to quantize channel state information (CSI) to achieve multiuser diversity in the finite-rate feedback multiuser system. The performance metric may be based on signal-to-noise ratio (SNR), bit error rate (BER), and/or system capacity. The quantization levels may be utilized in a multiuser system where distributed quantization is needed for optimal selection.08-25-2011
20110206151MULTI-TERM DEMAPPING FOR MULTI-CHANNEL WIRELESS COMMUNICATION - Providing for reduced complexity or improved accuracy in de-mapping received wireless data streams for multi-channel wireless communication is described herein. By way of example, a low-complexity likelihood algorithm can be employed to de-map data bits from the wireless data streams. In one particular example, the likelihood algorithm can approximate a received bit with a subset of received wireless symbols correlated the bit, reducing algorithm complexity. In other examples, a limited set of received wireless symbols can be employed for the subset, further reducing algorithm complexity. According to at least one other example, logarithmic terms of the algorithm can be approximated with non-logarithmic functions, such as a look-up table, series expansion, polynomial approximation, or the like. These approximations can enhance symbol de-mapping accuracy while maintaining or improving processing overhead for a wireless receiver.08-25-2011
20120294382METHOD AND DEVICE FOR GENERATING PRECODING MATRIX CODEBOOK - Generating precoding matrix codebooks for a communication system that includes: determining at least one correlation antenna group formed by antenna units with correlation of predefined degree among multiple antenna units in the communication system (S11-22-2012
20110268208MU-COMP Channel State Normalization Measure Quantization and Transmission - Uplink overhead is significantly reduced in a MU-COMP wireless communication network by exploiting the dissimilarity of received signal strength in signals transmitted by geographically distributed transmit antennas, as seen by receiving UEs. Each UE calculates a quantized normalization measure of channel elements for a channel weakly received from a first transmitter to that for a channel strongly received from a second transmitter. The quantized normalization measure may be modeled as a ratio of complex Gaussian variables, and quantized in phase and amplitude by making simplifying assumptions. The ratios are quantized, and transmitted to the network using far fewer bits than would be required to transmit the full channel state information. The network uses the quantized normalization measures to set the transmitter weights.11-03-2011
20110268207MULTIPLE INPUT MULTIPLE OUTPUT COMMUNICATION SYSTEM USING CODEBOOK CORRESPONDING TO EACH REPORTING MODE - A multiple input multiple output (MIMO) communication system using a first codebook and a second codebook is provided. The first codebook and the second codebook may independently exist, or may exist in a form of an overall codebook in which the first codebook and the second codebook are integrated with each other. A receiver may extract a first precoding matrix indicator from the first codebook, and may extract a second precoding matrix indicator from the second codebook. The receiver may also extract the first precoding matrix indicator and the second precoding matrix indicator from the overall codebook. The first precoding matrix indicator and the second precoding matrix indicator may be fed back to a transmitter. The transmitter may determine a precoding matrix based on the first precoding matrix indicator and the second precoding matrix indicator.11-03-2011
20100061477DATA TRANSFER METHOD USING PHASE-SHIFT BASED PRECODING AND TRANSMITTER IMPLEMENTING THE SAME - A method of transmitting data using phase-shift-based precoding in a multiple antenna system using a plurality of subcarriers is disclosed. More specifically, the method includes determining a phase-shift-based precoding matrix for transmitting the data by adjusting a transmission phase angle for each antenna, applying an offset for applying offset information fed back from a receiving terminal to the determined precoding matrix, and performing precoding by multiplying the offset applied precoding matrix by a symbol of each subcarrier.03-11-2010
20100220803Training-Based Channel Estimation for Multiple-Antennas - The burden of designing multiple training sequences for systems having multiple transmit antennas, is drastically reduced by employing a single sequence from which the necessary multiple sequences are developed. The single sequence is selected to create sequences that have an impulse-like autocorrelation function and zero cross correlations. A sequence of any desired length N09-02-2010
20090168914Method and System for Utilizing Transmit Local Oscillator for Improved Cell Search and Multi-Link Communication in Multi-Mode Device - A multi-receiver wireless communication device includes a transmitter, a transmit oscillator communicatively coupled to the transmitter, a receive oscillator communicatively coupled to a first receiver and second receiver, and a switching assembly having a first state in which the receive oscillator is coupled to the first and second receivers and a second state in which the receive oscillator is de-coupled from the second receiver and the transmit oscillator is coupled to the second receiver. The first receiver and the second receiver of the wireless communication device are able to operate independent of one another when the switching assembly is in the second state.07-02-2009
20090310702OPERATION FOR BACKWARD-COMPATIBLE TRANSMISSION - The disclosure relates to a transmitter in a transmission system operable to optimize estimates of a quantity at a receiver for improved operation. The transmission system includes a transmitting means connected to a number of antennas (Txm), and to control means. The control means controls the transmitting means to initially transmit an initial training/quantity estimation sequence during an initial training/quantity estimation phase and subsequently transmit a sequence of data symbols such that the information rate of the data symbols is progressively increased.12-17-2009
20090279633SYMBOL VECTOR-LEVEL COMBINING TRANSMITTER FOR INCREMENTAL REDUNDANCY HARQ WITH MIMO - Techniques are provided for transmitting and receiving a mother code in an incremental redundancy hybrid automatic repeat-request protocol. A set of information bits corresponding to a message may be encoded and interleaved to produce the mother code. Each bit position of the mother code may be mapped to an output symbol, and each output symbol may be mapped to an antenna for transmission. One or more transmissions of symbols contained in the output symbols may be performed, where each transmission may include puncturing the mother code by selecting one or more symbols from the of output symbols, and transmitting each symbol in the one or more symbols on an antenna corresponding to that symbol. The mother code may be decoded, in part, by determining combinable bits contained within a set of received symbols, and computing one or more log-likelihood ratio values corresponding to each symbol in the set of received symbols.11-12-2009
20090279631SYSTEMS AND METHODS FOR MULTIPLE-INPUT MULTIPLE-OUTPUT COMMUNICATIONS SYSTEMS - In a multiple input multiple output (MIMO) wireless communication system, there is provided a method for error correction. The method includes receiving an original signal in an initial MIMO format, detecting an error in the original signal, and notifying a transmitter of the error detected in the original signal. The method also includes receiving a new retransmitted signal in a first retransmitted MIMO format, different from the initial MIMO format, the new retransmitted signal including at least a fraction of encoded bits of the original signal. The method also includes correcting the original signal by applying the new retransmitted signal to the original signal.11-12-2009
20110206152METHOD AND SYSTEM FOR BLOCKER ATTENUATION USING MULTIPLE RECEIVE ANTENNAS - Methods and systems for blocker attenuation using multiple receive antennas are disclosed. In this regard, a plurality of signals may be received via a corresponding plurality of antennas and a corresponding plurality of interference-suppressed signals may be generated. The interference-suppressed signals may be generated by adjusting a gain and phase of the plurality of received signals to generate a corresponding plurality of adjusted signals, and combining the corresponding plurality of adjusted signals, respectively, with the plurality of received. The gain of the received signals may be adjusted based on a wide bandwidth signal strength measurement and a narrow bandwidth signal strength measurement. A center frequency of one or more of the plurality of antennas may be adjusted based on received signals strength measurements. A gain and/or phase adjustment of each one of said received signals may be independent of gain and/or phase adjustments of other ones of the receive signals.08-25-2011
20080232502METHOD FOR DETERMINING MIMO TRANSMISSION TECHNIQUES, BASE STATION AND MOBILE TERMINAL - The present invention relates to a method for determining the appropriate combination of at least two MIMO transmission techniques for a radio link in between a transmitter (09-25-2008
20100272207Using Spatial Properties of MIMO Channels for Enhanced Channel Estimation in MIMO Systems - An apparatus for estimating a channel response associated with a multiple input/multiple output (MIMO) system includes an antenna that receives multiple pilot symbols, each of the multiple pilot symbols transmitted from a different one of multiple transmit antennas of a transmitter in the MIMO system. The apparatus further includes a channel estimator that determines spatial, time and frequency correlations of channels of the MIMO system among the multiple transmit antennas when estimating a channel response associated with the MIMO system based on multiple ones of the received plurality of pilot symbols.10-28-2010
20080279301Multiple antennas transmit diversity scheme - A method from transmitting data via multiple antennas. The method contemplates modulating data to be transmitted into a plurality of modulated symbols, encoding each pair of modulated symbols from among said plurality of symbols in accordance with a transmission diversity scheme to result in a plurality of 2 by 2 matrices, with each 2 by 2 matrix corresponding to each pair of modulated symbols, orthogonally spreading the plurality of 2 by 2 matrices to generate an output matrix, and transmitting the symbols in the output matrix via a plurality of antennas by using either a space time transmission diversity scheme, a space frequency transmission diversity scheme, or a combination of a space time transmission diversity scheme and a space frequency transmission diversity scheme.11-13-2008
20080285675Multiple Antenna Transmission with Variable Diversity Gain - A MIMO transmitter has a modulator (11-20-2008
20080304593Transmission symbols mapping for antenna diversity - Methods and apparatus for transmitting data via multiple antennas by using antenna diversity. A transmission diversity scheme is established such that two transmission matrices that are in accordance with the space frequency block code combined with Frequency switched transmit diversity (SFBC+FSTD) scheme, are alternatively applied in either the frequency domain, or the time domain, or both of the frequency domain or then time domain. The symbols in the transmission matrices may be transmitted either as one burst in a primary broadcast channel (PBCH), or as discrete bursts in the primary broadcast channel.12-11-2008
20100002796Adaptive Transmission Method And System For Wireless Communication System - The present invention provides a wireless transmission method and system based on maximum multi-path delay estimation. A wireless transmission method based on an estimation of maximum multi-paths delay, comprising: a communication apparatus involved in wireless communication estimates the maximum multi-paths delay of a currently received frame; the communication apparatus performs a quantization and coding on feedback information related with the estimated maximum multi-paths delay, and then sends the feedback information which has been subjected to the quantization and coding to an opposing communication apparatus which is in wireless communication with the communication apparatus; the opposing communication apparatus recovers the feedback information by demodulating and decoding the feedback information which has been subjected to the quantization and coding; the opposing communication apparatus performs an adaptive adjustment of wireless signals transmitted to the communication apparatus, based on the recovered feedback information. With this method, system parameters can be adaptively adjusted so as to that sufficiently improves the spectrum utilization efficiency of wireless resources (the throughput is increased by about 5%).01-07-2010
20100002797System and Method for Quantization of Channel State Information - A system and method for quantization of channel state information is provided. A method for operating in a wireless communications system includes estimating a communications channel between a controller and a mobile device, thereby producing a channel estimate, parameterizing the channel estimate with principal angle vectors Θ and Φ, quantizing the principal angle vectors, thereby producing quantized values, and transmitting the quantized values to the controller.01-07-2010
20120294383Antenna Selection For Mimo Decoding - A MIMO decoder is configured to obtain a channel matrix and generate a Hermitian transpose of the channel matrix. A product of the Hermitian transpose of the channel matrix and the channel matrix is generated to provide a first product having multiple diagonal elements. A partial matrix inversion of the diagonal elements of the first product is generated to provide a diagonal vector. From the diagonal vector, an antenna layer is selected from the multiple antenna layers and represents the antenna layer selected for a given processing iteration. The selected antenna layer will preferably correspond to that having the lowest inverse channel gain. A partial matrix inversion of the first product along the row corresponding to the selected antenna layer is generated to provide a row vector. A product of the row vector and the Hermitian transpose of the channel matrix is generated to provide an inverse channel gain vector.11-22-2012
20100322334EFFICIENT MULTI-BAND COMMUNICATION SYSTEM - A multi-band communication system (12-23-2010
20080285674Diversity receiver - A diversity receiver includes N number of Fourier transform circuits, N number of channel state estimators, N number of channel equalizers, N number of soft demappers, N number of noise power estimators, N number of multipliers, a combination/selection unit, and a channel decoder. The noise power estimators and multipliers provided in the diversity receiver generate individual channel weights for each channel, which serve as background noise information for the channel decoder.11-20-2008
20080240280Intelligent Iterative Switch Diversity - A method and system to switch among a plurality of antennae used for wireless communications. A first embodiment is a method for using at least one quality metric and at least one time variation indicator of at least one quality metric to selectively switch among a plurality of antennae to maintain wireless communications. A second embodiment is a method using at least one quality metric and at least one time derivative slope of at least one quality metric to selectively switch among a plurality of antennae to maintain wireless communications. These embodiments can be applied in several wireless communication applications using multiple antennae including, but not limited to, WiMAX applications.10-02-2008
20110007833WIRELESS COMMUNICATION SYSTEM, TRANSMISSION APPARATUS AND COMMUNICATION CONTROL METHOD - Provided are a transmission weight generation unit for generating a plurality of transmission weights, a communication quality obtain unit for obtaining information on communication quality of each eigenpath, and a transmission weight determination unit, when a transmission apparatus performs transmission via a plurality of paths, for determining a transmission weight which maximizes communication quality of a path with the lowest communication quality among the plurality of paths.01-13-2011
20080205540WIRELESS COMMUNICATION APPARATUS - Before data is transmitted from a plurality of antennas, a plurality of known symbol sequences are transmitted from these antennas. Each known symbol sequence contains a plurality of known symbols having different subcarrier arrangements. Known symbols transmitted from different antennas have different subcarrier arrangements.08-28-2008
20130010889MIMO Channel Matrix Feedback in OFDM Systems - A method of reporting channel state information (CSI) with reduced feedback overhead in a MIMO-OFDM system is provided. A receiver first estimates CSI of a multiple-input multiple-output (MIMO) channel based on a sounding signal transmitted from a transmitter. The CSI comprises L channel response matrices, and each matrix corresponds to an OFDM tone in the MIMO channel. Each channel response matrix is then decomposed into a first CSI component and a second CSI component. The receiver selects a first subset of the first CSI component based on a first tone group size and a second subset of the second CSI component based on a second tone group size. Finally, the receiver transmits the selected subsets of the first and the second CSI components to the transmitter. The reduced feedback does not have significant loss in the information content of CSI because of the coherent bandwidth in typical OFDM systems.01-10-2013
20100208837WIRELESS COMMUNICATION METHOD AND APPARATUS - The present invention provides a method of processing information prior to an emission from a multi-antenna device in a multi-user network having at least one user, said emission comprising transmission of a plurality of subcarriers comprising pilot symbols and data symbols, and said information being a data vector, the method comprising arranging said pilot symbols and said data symbols such that at least one of said plurality of subcarriers comprises at least one of said pilot symbols and at least one of said data symbols, wherein said data vector corresponds to said at least one of said plurality of subcarriers such that said data vector comprises data elements corresponding to said at least one of said pilot symbols and said at least one of said data symbols, precoding said data vector prior to transmission, and the precoding comprising applying a perturbation to said data vector in order to generate a perturbed data vector in which data elements corresponding to the pilot symbol remain unperturbed, and scaling said data vector by means of a precoding matrix.08-19-2010
20080232503VARIABLE CODEBOOK FOR MIMO SYSTEM - A MIMO wireless communication system employing a variable size preceding codebook is provided. The size of the codebook may be determined by the quality of the wireless transmission channel between a transmitter and a receiver associated with the MIMO wireless communication systems or some other codebook selection criteria. A larger codebook can be employed when the channel quality is high, allowing for significant gains in overall system throughput. In contrast, a smaller codebook can be employed when the cannel quality is poor, so that the added channel overhead associated with a larger code book does not reduce the channel efficiency under circumstances in which a larger codebook would not significantly improve system throughput.09-25-2008
20130215989INFORMATION PROCESSING APPARATUS AND INFORMATION PROCESSING METHOD, AND NON-TRANSITORY COMPUTER READABLE MEDIUM STORING INFORMATION PROCESSING PROGRAM - Transmission channel estimation is performed for NT×NR reception signals and estimated transmission channel values are thereby output. The estimated transmission channel values are divided into N groups of NT×M estimated transmission channel values and a covariance matrix with M rows and N columns is obtained for each of the estimated transmission channel value groups. The N covariance matrixes are averaged over a predetermined range in terms of at least a time or a frequency (first averaging). Eigenvectors are generated based on respective N averaging outputs. Transmission channels between base station antennas and terminal antennas are generated from the eigenvectors and the estimated transmission channel values. Covariance matrixes are obtained for the generated transmission channels. The covariance matrixes are averaged over a different range from the range used in the first averaging (second averaging) and a beam forming weight is obtained by combining the generated eigenvectors.08-22-2013
20090180569Near-Optimal Low-Complexity Decoding of Space-Time Codes for Fixed Wireless Applications - An improved multi-antenna receiver is realized for detecting signals transmitted by a multi-antenna transmitter by summing signals received at the plurality of receiver antennas after multiplying each by a respective constant. The summed signal is applied to a maximum likelihood detector. The respective constants, λ07-16-2009
20090180567TRANSMISSION DEVICE, MIMO COMMUNICATION SYSTEM, AND TRANSMISSION DIVERSITY METHOD - Provided are a transmission device and a transmission diversity method, which can suppress degradation of a transmission diversity performance even under the circumstances having a space correlation, in the case of performing a transmission diversity MIMO communication. The transmission device comprises an orthogonal conversion unit (07-16-2009
20080240279Method and Device For Operating Mimo Air Interfaces in Mobile Communications Systems - The invention concerns a method and device for operating MIMO air interfaces in mobile communications systems, according to which a radio signal is transmitted by a transmitting device via an MIMO channel comprising a number of m subchannels and is received by a receiving device having n antennas. The invention is based on the fact that different polarizations are assigned to the signals to be transmitted on the subchannels, and the signals are supplied to a common antenna.10-02-2008
20090190688Beamforming for Non-Collaborative, Space Division Multiple Access Systems - A wireless communication system noncollaborative, multiple input, multiple output (MIMO) space division multiple access (SDMA) system determines subscriber station combining and weighting vectors that yield a high average signal-to-interference plus noise ratio (SINR). Each subscriber station independently transmits information to a base station that allows the base station to determine a weight vector w07-30-2009
20100142639DATA COMMUNICATION SYSTEM, DATA DECODING APPARATUS AND METHOD THEREFOR - A reception program maps, by PC mapping, the values of message data to symbol x, which describes the combinations of M06-10-2010
20090180568Hybrid Automatic Repeat Requests Coding in MIMO Networks - A method transmits a block of symbols in a multiple-input multiple-output (MIMO) network including a transmitter having a set of transmit antennas and a receiver having a set of receive antennas. A block of symbols is coded with a first code to generate a first block, which is transmitted and received. If a decoding of the first block is incorrect, then block of symbols is coded with the first code and then a second code different than the first code to generate a second block. The second block is transmitted, received and combined with the first block to recover the block of symbols.07-16-2009
20110268209Beamforming In MIMO Systems - A quantized multi-rank beamforming scheme for multiple-antenna systems such as a multiple-input-multiple-output (MIMO) wireless downlink User equipment (UE) estimates downlink channel and transmit power and determines rank and power allocations. A quantized beamforming matrix is then determined by the UE using successive beamforming. The UE also determines channel quality indices (CQI) which it feeds-back to the wireless downlink base station along with the index of the quantized beamforming matrix. The base station uses the CQI information to select a UE for scheduling of downlink transmission and the quantized beamforming matrix index received from the selected UE to beamform the downlink transmission to the UE. Base station overhead and is minimized while providing near-optimal performance given the constraints of a limited feed-back channel and computational complexity of the UE.11-03-2011
20090129499METHOD AND APPARATUS FOR IMPLEMENTING SPACE FREQUENCY BLOCK CODING IN AN ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING WIRELESS COMMUNICATION SYSTEM - The present invention is related to a method and apparatus for implementing space frequency block coding (SFBC) in an orthogonal frequency division multiplexing (OFDM) wireless communication system. The present invention is applicable to both a closed loop mode and an open loop mode. In the closed loop mode, power loading and eigen-beamforming are performed based on channel state information (CSI). A channel coded data stream is multiplexed into two or more data streams. Power loading is performed based on the CSI on each of the multiplexed data streams. SFBC encoding is performed on the data streams for each of the paired subcarriers. Then, eigen-beamforming is performed based on the CSI to distribute eigenbeams to multiple transmit antennas. The power loading may be performed on two or more SFBC encoding blocks or on each eigenmodes. Additionally, the power loading may be performed across subcarriers or subcarrier groups for weak eigenmodes.05-21-2009
20090129497METHOD, DEVICE AND SYSTEM OF MULTI-INPUT-MULTI-OUTPUT WIRELESS COMMUNICATION - Some demonstrative embodiments include devices, systems and/or methods of Multiple-Input-Multiple-Output wireless transmission. One embodiment may include a receiver to receive a wireless transmission via a plurality of receive antennas, and to generate an output including data based on the received wireless transmission, the receiver including a decoder to decode symbols of at least one frequency bin based on at least first and second antenna permutations applied to at least one channel response corresponding to the frequency bin; a correction-step determination module to determine at least first and second correction steps corresponding to the at least first and second antenna permutations, respectively, based on decision errors of decisions corresponding to the decoded symbols; and a channel adaptation module to update the channel response based on the correction steps. Other embodiments are described and claimed.05-21-2009
20110206154WIRELESS COMMUNICATIONS SYSTEM AND PRECODING METHOD - The present invention provides a precoding method for use in a wireless communications system. According to the precoding method of the present invention, a serving base station and cooperative communication base stations employ an identical precoding matrix so as to weight transmission signals and then transmit them. The weighting stands for multiplication of results of overall precoding or each layer precoding process by weight values at the serving base station and the cooperative communication base stations. A user device corresponding to the serving base station and the cooperative communication base stations receives a signal which is obtained by an operation in which the serving base station and the cooperative communication base stations perform an identical precoding process and additively combine results of overall precoding or each layer precoding process with one another. The user device feeds back information which includes (i) precoding matrix information for the serving base station and the cooperative communication base stations, (ii) weight vector information for either overall precoding or layer precoding, and (iii) a quantized value of channel quality. This feedback information is thus advantageous in that its signaling information amount is small.08-25-2011
20090129498MIMO DEMODULATOR AND METHOD FOR THE SAME - Channel estimates calculated by a channel estimator (05-21-2009
20120069926METHOD OF GENERATING CODEBOOK AND TRANSMITTING DATA IN A MULTI-INPUT MULTI-OUTPUT SYSTEM - A method for designing an optimized codebook in a multi-input multi-output communication method using various codebooks is disclosed. In particular, an optimized codebook with respect to eight transmission antennas is devised, and a method for effectively transmitting data by using the optimized codebook is disclosed.03-22-2012
20120069925METHOD 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 03-22-2012
20120069924LINEAR PRECODING IN MIMO BROADCAST CHANNEL WITH ARBITRARY RANK CONSTRAINTS - Methods and systems for transmission are shown that include iteratively generating an optimized precoder matrix and optimized linear filters for multiple receivers, where the optimized precoder matrix is based on a linear filter from a previous iteration and the optimized linear filters the multiple receivers are based on a precoder matrix from a previous iteration, precoding an input stream using the iteratively generated optimized precoder matrix to produce transmission streams for the multiple receivers, where at least one receiver has a plurality of associated transmission streams, and transmitting the transmission streams with multiple antennas to the receivers.03-22-2012
20090135940WIRELESS TRANSMISSION DEVICE AND WIRELESS TRANSMISSION METHOD - A wireless transmission device of the present invention includes n (where n is an integer of two or more) transmission antennas and a delay imparting section for delaying transmission signals supplied to the n transmission antennas by a maximum delay time (n−1)T or less based on a delay time T dependent upon a communication signal, which indicates whether to transmit the transmission signals by way of frequency diversity or multiuser diversity.05-28-2009
20090262855DATA SYMBOL MAPPING FOR MULTIPLE-INPUT MULTIPLE-OUTPUT HYBRID AUTOMATIC REPEAT REQUEST - A system includes an encoding module, a symbol selection module, a subcarrier selection module, and a mapping module. The encoding module receives symbols for transmission over K subcarriers and T antennas, encodes the symbols using a space time code, and generates space time coded (STC) versions of the symbols, where K and T are integers greater than 1. The symbol selection module selects T adjacent ones of the symbols and selects STC versions of the T adjacent ones of the symbols. The subcarrier selection module selects one of the K subcarriers for transmitting the T adjacent ones of the symbols and the STC versions of the T adjacent ones of the symbols. The mapping module maps the T adjacent ones of the symbols onto the T antennas for transmission over the selected one of the K subcarriers, respectively, and maps the STC versions of the T adjacent ones of the symbols onto the T antennas for transmission over the selected one of the K subcarriers.10-22-2009
20090262853MIMO RECEIVING APPARATUS AND RECEIVING METHOD - In a MIMO receiving apparatus, signals of single carriers transmitted from a plurality of transmission antennas are received by a plurality of reception antennas (10-22-2009
20090185635Communication System, Transmitter, Receiver and Multiple Access Method - In a communications system including a transmitter for transmitting signals over a transmission channel and a receiver for receiving the signals, the transmitter includes: a filter for filtering a modulated signal to modify amplitude and phase characteristics of the modulated signal; and a first processor for performing interleaving process and/or scrambling process for the filtered signal. On the other hand, the receiver includes: a second processor for performing deinterleaving process and/or descrambling process for a received signal; and an inverse filter for filtering a signal supplied from the second processor.07-23-2009
20080317156METHOD AND APAPRATUS FOR REDUCING UPDATING RATE OF CHANNEL STATUS IN A COMMUNICATION SYSTEM - A method and apparatus for reducing a channel updating rate in a communication system are provided, in which a channel matrix H representing a channel status of physical channels is acquired, eigenvectors of the channel matrix H are output by a Singular Value Decomposition (SVD) of the channel matrix H, and when at least one of the eigenvectors has a phase inversion, the phase inversion is removed from the eigenvector.12-25-2008
20080317154SEMICONDUCTOR INTEGRATED CIRCUIT DEVICE AND RADIO FREQUENCY MODULE - The present invention provides a semiconductor integrated circuit device and a radio frequency module realizing reduction in high-order harmonic distortion or IMD. For example, a so-called antenna switch having a plurality of transistors between an antenna terminal and a plurality of signal terminals is provided with a voltage supply circuit. The voltage supply circuit is a circuit for supplying voltage from a voltage supply terminal to at least two signal terminals in the plurality of signal terminals via resistive elements. With the configuration, antenna voltage dropped due to a leakage or the like can be boosted and, for example, transistors in an off state can be set to a deep off state.12-25-2008
20080317157Method for Encoding Space-Time Codes in a Wireless Communication System Having Multiple Antennas - A method of transmitting space-time coded data in a wireless communication system having a plurality of antennas is disclosed. More specifically, the method includes allocating data symbols combined with complex weights to at least two transmit antennas during at least one specified time slot, and transmitting the data symbols combined with complex weights to a receiving end via the at least two transmit antennas during the at least one specified time slot.12-25-2008
20090252250APPARATUS AND METHOD FOR BEAMFORMING BASED ON GENERALIZED EIGEN-ANALYSIS IN MULTIPLE INPUT MULTIPLE OUTPUT WIRELESS COMMUNICATION SYSTEM - An apparatus and method for beamforming in a Multiple Input Multiple Output (MIMO) wireless communication system are provided. A Base Station (BS) includes a calculator for generating relational expressions between beamforming vectors of Mobile Stations (MSs) using channel information of each MS, for determining beamforming vector candidates of each MS from the relational expressions using generalized Eigen-analysis, and for selecting beamforming vectors for each MS from the beamforming vector candidates, and a plurality of Transmit (Tx) beamformers for performing Tx beamforming on dedicated pilot symbols to be transmitted to each MS using the beamforming vectors for each MS.10-08-2009
20110222619Method and system for implementing link adaptation based on an application profile - A method comprising establishing a wireless link with at least one endpoint. The wireless link comprises at least one connection. The method also includes determining an application profile associated with a first connection of the wireless link. The method further includes dynamically selecting at least one parameter for the wireless link based on the detected application profile.09-15-2011
20090080559Antenna diversity by means of its through connection for receivers of digital radio signals - The invention relates to an antenna diversity in which high-frequency signals (HF signals) received via a plurality of antennas are fed to a respective tuner (03-26-2009
20090080557Quality of Service Based Antenna Mapping for Multiple-Input Multiple-Output Communication Systems - The teachings presented herein provide methods and apparatus for use in a multiple-input multiple-output (MIMO) system transmitting a plurality of data substreams to a receiver employing ordered successive interference cancellation detection according to a predetermined sequence for decoding the data substreams. In an exemplary method, a quality of service (QoS) requirement is determined for each of two or more application-specific data streams, and the application-specific data streams are assigned to the data substreams according to the determined QoS requirements and the predetermined sequence, so that application-specific data streams having more stringent QoS requirements are decoded earlier than application-specific data streams having less stringent QoS requirements. In some embodiments, the determined QoS requirements comprise maximum delay requirements, and application-specific data streams requiring shorter maximum delays are assigned to earlier-decoded data substreams than application-specific data streams having less stringent maximum delay requirements. In other embodiments, the determined QoS requirements comprise an application-specific robustness, wherein application-specific data streams corresponding to less robust applications are assigned to earlier-decoded data substreams than application-specific data streams corresponding to more robust applications.03-26-2009
20090080560CLOSED-LOOP BEAMFORMING WEIGHT ESTIMATION IN FREQUENCY DIVISION DUPLEX SYSTEMS - A closed-loop beamforming weight estimation process in which, at a first device, respective ones of a plurality of beamforming weight vectors are applied to subcarriers associated with a pattern of subcarriers assigned to a corresponding subcarrier stream such that the plurality of subcarriers assigned to a subcarrier stream is weighted by a corresponding one of the plurality of beamforming weight vectors to produce a plurality of beamformed streams transmitted from a plurality of antennas of the first device to a second device. The second device estimates and analyzes the channel information for each of the received beamformed streams to identify at least one of the beamformed streams that is preferred over the others. The second device transmits to the first device a feedback signal that contains information identifying the preferred beamformed stream. The first device computes a plurality of new beamforming weight vectors based on the information identifying the preferred beamformed stream. The first device applies the new beamforming weight vectors to streams of subcarriers to repeat the process until system parameters or conditions are met.03-26-2009
20090052571METHOD AND APPARATUS OF DATA PROCESSING IN MIMO SYSTEM - A method of data processing includes the steps of: dividing user terminals into groups based on channel attributes and service requirements of the user terminals and setting a precoding code word and a cyclic delay for each of the groups; and determining which group a user terminal corresponding to the data to be processed belongs to and processing the data to be processed by the Cyclic Delay Diversity (CDD) precoding based on the precoding code word and the cyclic delay of the group. A data processing apparatus includes a grouping module and a CDD preceding module. By the method and apparatus above, the signal quality in the MIMO system can be improved.02-26-2009
20090097583APPARATUS AND METHOD FOR SELECTING OPERATION MODE IN MIMO COMMUNICATION SYSTEM - An apparatus and a method for selecting an operation mode to improve a throughput in a mobile communication system are provided. The apparatus includes a Carrier to Interference and Noise Ratio (CINR) predictor for predicting a probable average and dispersion for a CINR measured using a preamble of a received pilot signal or radio signal, a metric calculator for calculating a throughput for each Modulation and Coding Scheme Level (MCS_Level) by using the probable average and dispersion for the predicted CINR and for selecting an MCS_Level having a maximum throughput, and an operation mode selector for selecting an operation mode of the selected MCS_Level having the maximum throughput.04-16-2009
20090080561PILOT PATTERN DESIGN FOR A STTD SCHEME IN AN OFDM SYSTEM - A transmitting device for transmitting data and pilot symbols in an OFDM transmission system having transmission antennas. The device includes symbol generating means for generating data and pilot symbols, means for transmitting the data and pilot symbols using subcarriers of the OFDM system. The symbol generating means generates a first and second type pilot symbol, the second having an inverted value of the first so that a first pilot symbol pattern to be transmitted by using one of said plurality of transmission antennas has a different pattern in the frequency and time dimension from a second pilot symbol pattern to be transmitted by using another transmission antenna. First and second pilot symbols are comprised in respective first and second pilot symbol patterns, where at least some of the first and second pilot symbols have the same time allocation and being alternately identical and inverted to each other.03-26-2009
20130215988FEEDBACK METHOD, MOBILE TERMINAL APPARATUS AND RADIO BASE STATION APPARATUS - The present invention makes it possible to generate precoding weights reliably, even in downlink MIMO transmission using a plurality of transmitting antennas. The present invention includes: a first feedback information selection section (08-22-2013
20090097586Apparatus and method for hybrid automatic repeat request (HARQ) in wireless communication system - A Multiple-Input Multiple-Output (MIMO) wireless communication system is provided. A receiving end includes a selector for selecting at least one stream for a MultiUser (MU) mode; a first generator for generating per stream channel quality information for the at least one selected stream as at least one candidate for channel information for the MU mode; and a determiner for determining one per stream channel quality information of the candidates as channel information for the MU mode.04-16-2009
20090185634RADIO COMMUNICATION SYSTEM, RADIO COMMUNICATION DEVICE, AND CHANNEL CORRELATION MATRIX DECISION METHOD - It is possible to prevent lowering of a throughput of a radio communication system even when propagation path environments of an uplink line and downlink line are asymmetric. A maximum proper value calculation unit (07-23-2009
20090092201Rate-adaptive multiple input/multiple output (MIMO) systems - A rate-adaptive method of communicating over a multipath wireless communication system uses multiple links such that each end of a link uses multiple transmit and receive antennas. A number of independent streams that are to be transmitted for each link is determined based on an overall system performance measure. In addition, the system may also jointly determine the best modulation, coding, power control, and frequency assignment for each link, based on an overall system performance measure. In OFDM systems, the number of independent streams, as well as the modulation, coding, and power control, may be determined on a tone-by-tone basis based on an overall system performance measure.04-09-2009
20090092199Estimating frequency offset at a subscriber station receiver - A method and system of estimating frequency offset at a subscriber station is disclosed. One method includes the subscriber station receiving a composite signal, wherein the composite signal includes multi-carrier signals transmitted from a plurality of base stations. The subscriber station selects a first pair of multi-carrier symbols of the composite signal, wherein each multi-carrier symbol of the first pair of multi-carrier symbols includes a pilot sub-carrier having a common sub-carrier index. The subscriber station selects a second pair of multi-carrier symbols of the composite signal, the second pair having different symbol indices than the first pair, but having a same symbol index separation, wherein each of the multi-carrier symbols of the second pair of multi-carrier symbols includes a pilot sub-carrier having a second common sub-carrier index. The subscriber station estimates a phase based on a first sum of complex conjugate products between received symbols on the pilot sub-carriers of the first pair of multi-carrier symbols, and/or based on a second sum of complex conjugate products between received symbols on the pilot sub-carriers of the second pair of multi-carrier symbols. The subscriber station provides the phase to a filter of a frequency tracking loop of the subscriber station.04-09-2009
20110228870Method and Apparatus for Overlapping MIMO Physical Sectors - MIMO systems communicate with wireless devices. MIMO systems include directional antennas that are oriented so that the physical sectors of the antennas overlap to form areas of overlap. Some physical sectors overlap substantially while others overlap partially. The areas of overlap are oriented in unique directions. Radios are selectively coupled to the portion of the antennas to communicate with the wireless devices. The physical sectors of the antennas that are selectively coupled to the radios overlap. The radios use the antennas to communicate with the wireless devices. The antennas operate as a MIMO antenna.09-22-2011
20130121431APPARATUS AND METHOD FOR JOINTLY SELECTING PRECODING MATRICES IN A MIMO MULTI-FLOW SYSTEM - An apparatus and a method are disclosed for jointly selecting precoding matrices for a plurality of received transmissions, such as those that might be received from a primary serving cell and a secondary serving cell in a multi-flow radio access network wherein each of the serving cells is configured to provide a MIMO transmission. Here, by jointly selecting the precoding matrices, interference from each of the downlink transmissions upon the other transmission can be reduced, thus improving overall performance at the receiving entity.05-16-2013
20130121432METHOD AND APPARATUS FOR CODEBOOK BASED FEEDBACK IN A CLOSED LOOP WIRELESS COMMUNICATION SYSTEM - A method and apparatus are provided for feedback for closed-loop transmitting with multiple transmit antenna elements and multiple receive antenna elements. A base station includes a codebook containing sets of weightings for the multiple transmit antenna elements, with each set of weightings identified by an index and the codebook known to the base station and a served mobile station (MS). The base station pre-codes pilot signals using a precoding matrix, preferably a unitary matrix, to produce pre-coded pilot signals, which precoding matrix may or may not be known to the MS and which precoding matrix may or may not be included in the codebook. The base station then transmits the pre-coded pilot signals to the MS via the multiple transmit antenna elements and, in response, receives an index to a set of weightings in the codebook for use in a subsequent transmission of a data stream.05-16-2013
20130121433MODIFYING A SIGNAL BY CONTROLLING TRANSMIT DIVERSITY PARAMETERS - A method for modifying a signal transmitted from a mobile communication device comprising by perturbing a transmit diversity parameter from its nominal value by modulating the parameter with respect to the nominal value in a first direction for a first feedback interval and then in a second direction for a second feedback interval, receiving a feedback signal including feedback information relating to the perturbed signal as received at a feedback device, and based at least on the feedback information, adjusting the nominal value of the transmit diversity parameter by increasing, decreasing, or preserving the nominal value.05-16-2013
20090245410Method for transmitting signals for reducing feedback overhead and method for transmitting feedback information for the same - A method for transmitting signals to reduce feedback overhead and a method for transmitting feedback information for the same are described. In transmitting signals through precoding, different codebook subsets are used in an open-loop transmission mode and a closed-loop transmission mode, thereby reducing feedback overhead. In this case, it is assumed that the codebook subsets for the respective transmission modes are optimized according to each transmission mode.10-01-2009
20090220022Device, Method and Computer Program for Transmitting an Information Signal Comprising Several Transmit Signals - A device for transmitting an information signal having several transmit signals has a modulator for generating a first and a second transmit signal. The first transmit signal is transmittable via a first spatial emitter, and the second transmit signal is transmittable via a second spatial emitter. The modulator has an OFDM control stage to load a first group of OFDM carriers with first information to generate the first transmit signal, and to load a second group of OFDM carriers with second information to generate the second transmit signal. The first group of OFDM carriers differs from the second group of OFDM carriers, and the first information differs from the second information. The present invention further provides a corresponding method and a computer program for transmitting an information signal.09-03-2009
20090220021METHOD FOR TRANSMITTING/RECEIVING SIGNAL HAVING SPREAD TRAINING SYMBOL IN MOBILE COMMUNICATION SYSTEM - A method for transmitting/receiving signals in a mobile communication system, a pilot configuration of a mobile communication system capable of transmitting much more data using a conventional pilot signal, a channel estimation method, and a receiving method are disclosed. A method for transmitting a signal equipped with a training symbol in a mobile communication system which includes a transmission end capable of transmitting an output signal equipped with a training symbol for channel estimation of a reception end, includes the steps of: a) adding training symbols having the same amplitude to data symbols transmitted via subcarriers, and calculating the output signal transmitted via the subcarriers; and b) transmitting the calculated output signal via the subcarriers.09-03-2009
20090220023METHOD FOR TRANSMITTING SIGNALS IN THE SYSTEM WITH MULTIFUL ANTENNAS - A wireless communication system and more particularly a method for signals in a system using a plurality of antennas are disclosed. In the method for multi-antenna-encoding data symbols to be transmitted through the plurality of antennas, at least two same data symbols multi-antenna-encoded are formed and transmitted repeatedly. Accordingly, it is possible to enhance transmission efficiency.09-03-2009
20090097584WIRELESS TRANSMISSION SYSTEM, WIRELESS TRANSMISSION METHOD, AND WIRELESS STATION AND TRANSMITTING STATION USED THEREIN - The present invention provides a wireless transmission system capable of exerting a maximum path diversity effect by using combinations formed by a plurality of symbol waveforms even when a maximum number of effective branches is limited to a small number. A transmission timing controlling section (04-16-2009
20090154588CHANNEL QUALITY REPORT PROCESSES, CIRCUITS AND SYSTEMS - An electronic device includes a first circuit (06-18-2009
20090245409APPARATUS, METHODS, AND ARTICLES OF MANUFACTURE FOR ADAPTIVE POWER CONTROL - In embodiments, a first wireless device generates symbols for transmission to another wireless device. Adaptive power control is applied to the transmissions, for example, at symbol or frame boundaries. When a transmit power gain adjustment exceeds a threshold, all or part of the required gain adjustment may be performed on the generated symbols before the symbols are combined in an overlap-and-add process. Part of the gain adjustment may also be performed through adjustment of the power amplifier. When the gain adjustment does not exceed the threshold, all of the gain adjustment may be performed through adjustment of the power amplifier. Performing gain adjustment before the overlap-and-add process results in a lower spectral spread of the transmitted waveform and improved bandwidth utilization efficiency. In embodiments, the power adjustment techniques are used in FDD/OFDM systems or other systems where a plurality of symbols or frames is transmitted substantially continuously.10-01-2009
20080260064Cooperative MIMO in Multicell wireless networks - A method and system for cooperative multiple-input multiple output (MIMO) transmission operations in a multicell wireless network. Under the method, antenna elements from two or more base stations are used to from an augmented MIMO antenna array that is used to transmit and receive MIMO transmissions to and from one or more terminals. The cooperative MIMO transmission scheme supports higher dimension space-time-frequency processing for increased capacity and system performance.10-23-2008
20080260063Sequence generating method - This invention provides a sequence generating method, in which the method has steps of generating R sets of orthogonal sequence with each set of the orthogonal sequence including N elements, generating a low-autocorrelation sequence having N elements, and multiplying the N elements of the low-autocorrelation sequence by the N elements of each of R sets of the orthogonal sequence point-to-point. Therefore, a sequence generated by the method of the present invention has low-autocorrelation and low-crosscorrelation in transmission characteristics of a communication system.10-23-2008
20080260062METHOD AND SYSTEM FOR OPTIMIZED REFERENCE SIGNAL DOWNLINK TRANSMISSION IN A WIRELESS COMMUNICATION SYSTEM - A method and system optimizes the transmission of a downlink reference signal (DLRS) in a wireless communication system that uses orthogonal division multiple access (OFDMA) for the downlink. Each Node-B (base station) is capable of transmitting the DLRS reference symbols in different subframes of the OFDM radio frame and changing both the number and location of the subframes in response to changing network conditions. The network conditions include the number of terminals being served by the Node-B and multiple access interference (MAI) from adjacent Node-Bs.10-23-2008
20090316820OFDM RECEIVER HAVING MEMORY CAPABLE OF ACTING IN A SINGLE-CHIP MODE AND A DIVERSITY MODE - An OFDM receiver is provided. The OFDM receiver comprises a Fourier transform (FFT) module, a storage device, an equalizer, and a diversity combiner module. The Fourier transform module transforms a time-domain symbol into an OFDM symbol. The storage device stores OFDM symbols. When operated in a single chip mode, the storage device stores more OFDM symbols outputted from FFT module than operated in a diversity mode. The equalizer retrieves the OFDM symbols from the storage device or the FFT module, estimates the channel frequency response of a transmission channel, and equalizes the OFDM symbol according to the channel frequency response. When operated in the diversity mode, the diversity combiner module receives the OFDM symbols and an alignment signal from a diversity OFDM receiver.12-24-2009
20090252251TRANSFORM-DOMAIN FEEDBACK SIGNALING FOR MIMO COMMUNICATION - The present invention relates to a control method for a communication network that has a transmitter with an array of transmit antennas and that has at least one receiver communicating with the transmitter. The receiver performs a channel measurement for a receive antenna of the receiver using a signal transmitted from the transmitter to the receiver. The receiver further determines channel coefficients for each of an array of transmit antennas at the transmitter from an output of the channel measurement, and then applies a linear, reversible and orthogonal transform to the channel coefficients, thus ascertaining channel component coefficients indicative of the individual weight of respective channel components in a transform domain. The receiver then selects one or more channel components in the transform domain and communicates to the transmitter a control signal indicative of one or more preferred channel components or a magnitude of one or more channel component coefficients, or both, in quantized form. The transmitter receives the control signal and constructs a beam pattern in the transform domain using the information received from the receiver.10-08-2009
20090252248INDIVIDUAL 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.10-08-2009
20100150258NEAR SOFT-OUTPUT MAXIMUM LIKELIHOOD DETECTION FOR MULTIPLE-INPUT MULTIPLE-OUTPUT SYSTEMS USING REDUCED LIST DETECTION - A method and apparatus for generating soft-decision output values for a set of transmitted spatial streams in a multiple-input multiple-output (MIMO) communication system are described. The apparatus includes a processor and memory with executable instructions. A plurality of constellation points for respective transmitted spatial streams are looped over to estimate values for other transmitted streams based at least in part on Reduced List Detection (RLD). The plurality of constellation points is a subset of all possible constellation points determined around a spatial stream where more constellation points are assigned to spatial streams with a weaker signal strength than for spatial streams with a stronger signal strength. A set of distance metrics as values of the plurality of constellation points for the respective transmitted spatial streams are determined. Soft-decision outputs for the respective transmitted streams based at least in part on the set of distance metrics are generated.06-17-2010
20090262854Method for transmitting and receiving downlink control information - A method for efficiently transmitting and receiving downlink control information is disclosed. The method includes, at an base station, receiving feedback information including a preceding matrix index (PMI) from an user equipment (UE) and transmitting precoding information having a predetermined bit number according to the number of antenna ports and a transmission mode of the base station. The preceding information of a predetermined transmission mode in the preceding information includes confirmation information indicating that the base station uses a PMI which is recently received from the UE. At this time, if the confirmation information is transmitted via a specific resource block (RB) of an n10-22-2009
20090257522COMMUNICATION APPARATUS - An exemplary aspect of an embodiment of the present invention is a communication apparatus including an amplifier circuit which adjusts transmit power of a first signal and transmit power of a second signal if the transmit power of the first signal having a first frequency included in a first frequency band is different from the transmit power of the second signal having a second frequency included in a second frequency band, where the second frequency is different from the first frequency. The amplifier circuit includes a variable inductor which varies an inductance value for each of the first signal and the second signal to adjust the transmit power of the first signal and the transmit power of the second signal.10-15-2009
20090122897Method and Apparatus to Improve Performance in a Multicarrier Mimo Channel Using the Hadamard Transform - The Hadamard transform is used to spread data within data blocks in a multicarrier MIMO system, before transmission. In this manner, the negative effects caused by the clustering of bad subcarriers (i.e., subcarriers having a low transmission coefficient due to fading) may be reduced. In at least one embodiment, a MAP-type detection scheme is used in the receiver to extract bit reliabilities from the received signals.05-14-2009
20090116577METHOD AND SYSTEM FOR MULTIPLE INPUT AND MULTIPLE OUTPUT CHANNEL ESTIMATION - The invention relates to a method and system for multiple input and multiple output channel estimation, which can be used to generate and correlate sets of complementary sequences of length N, having a number of elements K greater than or equal to two. According to the invention, a block is used to generate sequences and to convolve same with an input signal, after which they are sent directly, or modulated, to the transmission channel. Once they have been received, and optionally demodulated, they pass through a correlator filter such as to obtain the input signal convolved by the channel, having a noise level reduced by factor KN.05-07-2009
20090116574METHODS AND APPARATUS FOR RECEIVE POWER UNIFICATION FOR MIMO AND NON-MIMO SIGNALING - A method for receive power unification for multiple-input and multiple-output (MIMO) and non-MIMO signaling is described. A data stream may be separated into multiple individual data streams for transmission by multiple transmit antennas. Orthogonal frequency division multiplexing (OFDM) may be applied to the individual data streams to obtain one or more OFDM symbols. Unification processing may be applied to an OFDM symbol. Individual data streams may be transmitted using multiple transmit antennas.05-07-2009
20080232504Methods and Systems For Ofdm Multiple Zone Partitioning - Aspects of the invention include methods and devices for inserting data and pilot symbols into Orthogonal Frequency Division Multiplexing (OFDM) frames having a time domain and a frequency domain. A method involves inserting in at least one zone of a first type a two dimensional array of data and pilot symbols in time and frequency and inserting in at least one zone of a second type a two dimensional array of data and pilot symbols in time and frequency. In some implementations the zone of the first type comprises common pilot symbols that can be detected by all receivers receiving the OFDM frame. In some implementations the zone of the second type comprises dedicated pilot symbols that are only detectable by a receiver that is aware of pre-processing used to encode the dedicated pilot symbols. According to various embodiments of the invention, the zones of the first and second types can be partitioned in the OFDM frame based on time division multiplexing (TDM), frequency division multiplexing (FDM) or combined TDM/FDM. Examples of types of transmissions that could be transmitted in different zones of a single OFDM frame are OFDM multiple input multiple output (MIMO) transmissions and OFDM beam forming transmissions.09-25-2008
20100183088CALIBRATION OF TRANSMIT AND RECEIVE CHAINS IN A MIMO COMMUNICATION SYSTEM - Techniques for calibrating the transmit and receive chains at a wireless entity are described. For a pre-calibration, N first overall gains for a receiver unit and N transmitter units in the transmit chain are obtained, where N>1. Each first overall gain is for a combined response for the receiver unit and the associated transmitter unit. N second overall gains for a transmitter unit and N receiver units in the receive chain are also obtained. Each second overall gain is for a combined response for the transmitter unit and the associated receiver unit. The gain of each transmitter unit and the gain of each receiver unit are determined based on the first and second overall gains. At least one correction matrix is then derived based on the gains of the transmitter and receiver units and is used to account for the responses of these units.07-22-2010
20100183089METHOD FOR SIGNAL TRANSMISSION-RECEPTION IN A MULTI-USER MULTIPLE TRANSMIT AND MULTIPLE RECEIVE ANTENNA RADIO COMMUNICATION SYSTEM - An apparatus and method for signal transmission-reception in a multi-user multiple transmit and multiple receive antenna radio communication system are provided. An aspect of the present invention is to enhance reception performance and increase the communication channel throughput. This is achieved by applying a new sequence of operations including a vector perturbation procedure along with an efficient perturbation vector searching technique based on single-dimensional optimization of a decision function. In addition, the method ensures simple implementation of a subscriber station receiver. The SS receiver is implemented as independent channels for processing signals of different receive antennas. The receiver can be implemented even if each subscriber station has only one receive antenna. Accordingly, the method proves highly efficient in virtually any propagation environment.07-22-2010
20090116576REDUCED COMPLEXITY MULTICARRIER PRECODER - A reduced complexity precoder provides an efficient method and structure to precode a vector-signal-point sequence for transmission through a band-limited channel. The precoder enables a block-oriented receiver to recover an underlying data stream in the presence of inter-symbol interference and noise. The precoder structure is applicable to multicarrier systems such as DMT (discrete multitone) or related transform domain and vector communication systems. The inventive precoder reduces the cost of precoding by an order of magnitude and eliminates the need for a cyclic prefix in DMT and related communication systems. Related multicarrier transmitter and receiver structures and methods which reduce computation, increase transmission bandwidth and reduce transmission power are also developed.05-07-2009
20090116575Method of a receiver estimating a plurality of channels - A method and apparatus of a receiver estimating a plurality of channels is disclosed. The method includes the receiver receiving a composite signal. The composite signal includes a signal from each of a plurality of transmission antennas, wherein the signal of each transmission antenna includes a delay relative to other signals of other antennas. The receiver estimates channels between the receiver and the plurality of transmission antennas based on amplitude and a phase of a received composite signal, at a plurality of frequencies.05-07-2009
20090116573FREQUENCY DIVERSE CONTROL MAPPING OF CHANNEL ELEMENTS TO RESOURCE ELEMENTS - Aspects relate to a flexible interleaving scheme that provides frequency diversity to randomizes interference Frequency diversity groups can be utilized, wherein control channel elements (CCEs) gain greater frequency diversity for a given number of mini-CCEs (e.g., subset of CCEs). A frequency diversity group index is permuted according to a bit reversed scheme to facilitate control channel elements with a small number of mini-CCEs to also gain sufficient frequency diversity.05-07-2009
20090116572COMMUNICATION APPARATUS AND COMMUNICATION METHOD - A communication apparatus in which only a terminal having a specific positional relationship can perform communication through a relatively simple arrangement. When initial setting is performed or communication is started, a timing calculating section (05-07-2009
20090046797Method and System for Retransmitting Data Packets - A method and system are provided for minimizing errors by retransmitting packets in a multiple-input-multiple-output (MIMO) space-time coded packet radio. A packet is transmitted using a first STC code mapping, the mapping including well-known symbol operations, and optional signal weighting. When transmission errors are detected the packet is re-transmitted using STC code mappings selected in turn from a deterministic sequence of STC code mappings. The STC code mappings are chosen in accordance with one or more principles.02-19-2009
20100177837Advanced method for decoding in the mimo system and apparatus for implementing thereof - A mobile station is capable of detecting a signal in the wireless communication systems using the Multiple Input Multiple Output (MIMO). The mobile station includes an apparatus that determines a vector of signals received by several receiving antennas. The apparatus estimates a channel between transmitting antenna and receiving antenna; forms a channel matrix; establishes, based on the channel state data, an order for detecting symbols transmitted by different transmitting antennas; calculates weight coefficients for detecting the symbols in the MIMO system; detects the symbols serially in the established order on the basis of the received signal vector; calculates the Euclidean distance between the detected symbols and the symbol constellation points; determines values of the Logarithmic Likelihood Ratio (LLR) for estimating the soft output bit probability, and forms a group of the most probable candidate symbols from the points of the symbol constellation.07-15-2010
20110103504System and Method for User Specific Antenna Down Tilt in Wireless Cellular Networks - Systems and methods for user specific antenna down tilt in wireless cellular networks are disclosed. A preferred embodiment method comprises synthesizing a plurality of virtual antennas from a single physical antenna, wherein a total number of virtual antennas is less than a total number of antenna elements in the physical antenna, transmitting pilot signals on the plurality of virtual antennas, receiving, from a user equipment, a pre-coding control indicator based on the transmitted pilot signals, determining a multiple-input multiple output pre-coding vector based on the pre-coding control indicator, and transmitting user data modulated by the pre-coding vector to the user equipment via the plurality of virtual antennas.05-05-2011
20110110451TECHNIQUES FOR TRANSFORMATION CODEBOOK ANTENNA BEAMFORMING IN OFDM WIRELESS COMMUNICATION SYSTEM - Methods for a transmitter station and a receiver station to perform beamforming in a wireless communication system, and a transmitter station and a receiver station to perform the corresponding method, are provided. The method for the transmitter station to perform beamforming in the wireless communication system includes estimating and tracking a long-term averaged and normalized channel correlation matrix between the transmitter station and a receiver station, determining beamforming coefficients based on the tracked long-term averaged and normalized channel correlation matrix, and communicating with the receiver station using the determined beamforming coefficients, wherein the receiver station also estimates and tracks the long term averaged and normalized channel correlation matrix, and determines beamforming coefficients based on the tracked long-term averaged and normalized channel correlation matrix.05-12-2011
20090074099CHANNEL AWARE MULTIPLE USER MIMO SCHEME UNIFIED WITH SINGLE USER CLOSED LOOP MIMO - A base station is capable of unifying a single-user MIMO scheme with a multi-user MIMO scheme by receiving a Rank-1 CQI values from one or more subscriber stations. The base station also receives preceding vectors from the subscriber stations, and then determines which of the subscriber stations has a best Rank-1 CQI value. The base station then determines a beam forming matrix to use based at least in part on the vectors received from the subscriber station having the best Rank-1 CQI value. The base station then broadcasts data to the subscriber station using the beam forming matrix corresponding to the subscriber station having the best Rank-1 channel quality indicator to implement single-user MIMO in one or multiple streams to that subscriber station, or to the subscriber stations having the best Rank-2 channel quality indicators to implement multi-user MIMO in multiple streams.03-19-2009
20100239040DATA AND CONTROL MULTIPLEXING FOR UPLINK MIMO WITH CARRIER AGGREGATION AND CLUSTERED-DFT - A method and apparatus for signal processing in a wireless transmit receive unit (WTRU), including generating a plurality of data bits and a plurality of control bits, mapping the data bits and control bits to one or more codewords, multiplexing the data bits and control bits, dividing the bits into layers, allocating control bits to each layer based on a channel quality of each codeword and a channel quality of each layer, and channel interleaving each layer for output to one or more antennas.09-23-2010
20100232533Methods of Selecting Signal Transmitting, Receiving, and/or Sensing Devices with Probabilistic Evolutionary Algorithms in Information Conveyance Systems - Methods are described for near optimal Antenna and/or sensor selection via population-based probabilistic evolutionary algorithms such as estimation of distribution algorithm (EDA) and bio-inspired Optimization (BIO). The aspects of the invention includes a method for joint transmit and receive antenna selection using EDA; and an enhanced EDA, which uses cyclic shift register and biased estimation of distribution; and methods for joint transmit and receive antenna selection using improved population-based optimization. The proposed EDA-based and bio-inspired selection methods results in performances that are close to the ESA (exhaustive search algorithm) and yet impose mush less computational burden than ESA. Another advantage of our methods is that they can be easily implemented on parallel processors.09-16-2010
20100177836Simulation of Multi-Antenna Radio Channel - A radio channel simulation system comprises a plurality of input buses for receiving a beam-specific transmit signal. A transformation module transforms a channel model from antenna domain to beam domain by using a transformation algorithm and beam forming weights. The channel model represented in the beam domain is inputted into a processing module which processes the beam-specific transmit signals according to the channel model represented in the beam domain.07-15-2010
20130215987MIMO SYSTEM AND METHOD OF GENERATING HIERARCHICAL CODEBOOK THEREFOR - Disclosed is a multiple-input multiple-output (MIMO) system including a transmitting end and a receiving end, wherein the transmitting end includes: a hierarchical codebook in which at least one base codebook is designated as the upper matrix and a child codebook generated based on a chordal distance between respective codewords configuring the base codebook is designated as the lower matrix; a scheduler configured to receive channel state information from the receiving end and select precoding matrices from the hierarchical codebook based on the channel state information; and a precoder configured to apply the precoding matrices selected in the scheduler to data to be transmitted to the receiving end and transmit the selected precoding matrices through a plurality of antennas.08-22-2013
20100239043METHOD AND APPARATUS FOR DETECTING SIGNALS OF MULTI-INPUT MULTI-OUTPUT SYSTEM - The embodiments of the present invention disclose a method and an apparatus for detecting signals of a MIMO system, and relate to a MIMO technology. The method includes: performing triangular decomposition on a channel matrix of the MIMO system, and decomposing the MIMO system into multiple MIMO subsystems; detecting the receiving signal vector of the first MIMO subsystem, and obtaining the candidate detection vector list of the first MIMO subsystem; detecting remaining MIMO subsystems consecutively in a SIC mode, and generating candidate detection vector lists of the remaining MIMO subsystems; and combining all the lists, and marking decision or performing calculation to obtain the transmitting signal vector of the MIMO system.09-23-2010
20100226454Method and apparatus for synchronizing a wireless communication system - Techniques for synchronizing a receiver and transmitter in a wireless communication system address synchronization within the context of a detection formulation and provide synchronization statistics used to declare a synchronization detection. A signal is received from a channel at multiple receiving antennas. The receiver and transmitter are synchronized based on the received signal and a channel model incorporating the multiple receiving antennas. The channel model may also incorporate a resolvable delay spread of the received signal with respect to each receiving antenna. Synchronization may be based on a known component of a received signal and further on a channel model incorporating multiple receiving antennas and an interference signal. The known component may be a cyclic prefix or a pilot sequence as in orthogonal frequency division multiplexing (OFDM).09-09-2010
20100226455Closed Loop Mimo Harmonized Feedback - The subject matter disclosed herein provides methods and apparatus for closed loop operation of a wireless system implementing multiple input multiple output (MIMO). In one aspect, there is provided a method. The method may include receiving a payload including channel estimation information. Moreover, one or more bits of the payload may be inserted into a subset of the tiles of a slot. The slot including the subset of the tiles carrying the one or more bits of the payload may be provided as part of a closed loop MIMO-based system. Related systems, apparatus, methods, and/or articles are also described.09-09-2010
20100254473METHOD AND SYSTEM FOR MANAGING PRECODING IN A MULTI-USER WIRELESS COMMUNICATIONS SYSTEM - Operating a wireless communications system that supports multi-user multiple-input multiple-output (MU-MIMO) communications between a base station and multiple mobile stations involves generating a channel estimation, predicting a future channel estimation from the channel estimation, precoding data in response to the predicted future channel estimation, and transmitting the precoded data.10-07-2010
20100254472Full-rate, full-diversity space-time block code technique for multiple transmissions using simple linear decoding complexity - An embodiment of the present invention provides a space-time block code (STBC) transmission method for 4 transmit antennas, comprising adding two 2×2 orthogonal pre-coding before a two Alamouti transmission for a 4 transmit antennas scheme.10-07-2010
20100239042Distance Estimation - A method, comprising: periodically enabling reception of a signal at a receiver, every first time; transforming the received signal in order to determine data in the received signal; comparing the determined data with reference data; and using the difference between the determined data and the reference data to estimate a correction to a multiple of the first time in order to determine a distance between the receiver and an origin of the signal.09-23-2010
20110058621CODEBOOK GENERATING METHOD AND APPARATUS FOR GENERATING A CODEBOOK FOR MULTI-POLARIZED MULTIPLE-INPUT MULTIPLE-OUTPUT (MIMO) SYSTEMS - A communication apparatus and method include: selecting, as a precoding matrix, one of pre-stored at least one matrix W03-10-2011
20110058620 METHOD FOR GENERATING MULTI-ANTENNA SIGNALS - The invention relates to a method for generating multi-antenna signals. Firstly, the propagation conditions between channel coefficients, which each describe one transmitter antenna and one receiver antenna, are generated. Furthermore, weighting factors are generated to weight signals to be transmitted via one transmitter antenna in each case. Taking the channel coefficients (h03-10-2011
20100254476TRAINING 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, power loading information is used to calibrate constellation points for user data.10-07-2010
20100254474Feedback Strategies for Multi-User MIMO Communication Systems - A method for signal processing in a receiver includes receiving in the receiver a Multi-User Multiple-Input Multiple-Output (MU-MIMO) signal. The MU-MIMO signal includes at least a first signal, which is precoded using a first precoding scheme and is addressed to the receiver, and a second signal, which is precoded using a second precoding scheme. An average error rate achievable in decoding the first signal in the presence of the second signal is computed. The average error rate is computed over a set of possible choices of the second precoding scheme. The first precoding scheme is selected from among a plurality of available precoding schemes so as to satisfy a criterion defined over the average error rate. The receiver sends feedback to a transmitter transmitting the first signal. The feedback depends on the selected first precoding scheme and causes the transmitter to control transmission of the first signal.10-07-2010
20100254475RECEIVING APPARATUS, RECEIVING METHOD, AND PROGRAM - A receiving apparatus is disclosed which includes a reception device configured to receive a signal modulated through Orthogonal Frequency Division Multiplexing known as OFDM; and a detection device configured to detect whether or not spectrum inversion has occurred in the OFDM-modulated signal by use of a spectrum inversion presence signal obtained by inverting a subcarrier position of a known signal included in the OFDM-modulated signal.10-07-2010
20100208834METHOD AND APPARATUS FOR ORTHOGONAL PILOT TONE MAPPING IN MULTIPLE-IN AND MULTIPLE-OUT (MIMO) AND SPATIAL DIVISION MULTIPLE ACCESS (SDMA) SYSTEMS - Methods and apparatus for orthogonal pilot tone mapping in Multiple-In and Multiple-Out (MIMO) and Spatial Division Multiple Access (SDMA) systems are disclosed. An aspect of the method includes identifying a plurality of symbol periods within which symbols representing encoded data are to be transmitted in a plurality of spatial streams over a communication channel; identifying a plurality of pilot tone values for a plurality of pilot tones in the plurality of symbol periods to create a pilot tone mapping, wherein the identified pilot tone values are such that a receiver, when receiving at least some of the plurality of pilot tones, is provided with signals enabling the receiver to characterize and mitigate any communication impairments, and potentially obtain transmit spatial stream diversity benefits, wherein at least two of the pilot tone values in the pilot tone mapping are orthogonal when the symbols are combined over at least one dimension; and transmitting the symbols and the plurality of pilot tones over the plurality of spatial streams for the plurality of symbol periods.08-19-2010
20100202552OFDM DEMODULATOR, OFDM DEMODULATION METHOD, OFDM DEMODULATION PROGRAM, AND STORAGE MEDIUM - In a case where there are a plurality of spurious disturbing waves, each of which has a strong peak at a particular frequency, in a transmission band, correlation between the disturbing waves becomes nonconstant so that it becomes difficult to remove the correlation between the disturbing waves. An OFDM demodulator of the present invention includes a symbol integration circuit (08-12-2010
20120140838METHOD AND APPARATUS FOR ANTENNA DIVERSITY IN MULTI-INPUT MULTI-OUTPUT COMMUNICATION SYSTEMS - Transmission schemes that can flexibly achieve the desired spatial multiplexing order, spatial diversity order, and channel estimation overhead order are described. For data transmission, the assigned subcarriers and spatial multiplexing order (M) for a receiver are determined, where M≧1. For each assigned subcarrier, M virtual antennas are selected from among V virtual antennas formed with V columns of an orthonormal matrix, where V≧M. V may be selected to achieve the desired spatial diversity order and channel estimation overhead order. Output symbols are mapped to the M virtual antennas selected for each assigned subcarrier by applying the orthonormal matrix. Pilot symbols are also mapped to the V virtual antennas. The mapped symbols are provided for transmission from T transmit antennas, where T≧V. Transmission symbols are generated for the mapped symbols, e.g., based on OFDM or SC-FDMA. Different cyclic delays may be applied for the T transmit antennas to improve diversity.06-07-2012
20090046802SUCCESSIVE INTERFERENCE CANCELLATION RECEIVER PROCESSING WITH SELECTION DIVERSITY - Techniques are provided to support successive interference cancellation (SIC) receiver processing with selection diversity whereby each of N02-19-2009
20100266063SYSTEM, METHOD AND APPARATUS FOR MOBILE TRANSMIT DIVERSITY USING SYMMETRIC PHASE DIFFERENCE - Communication is performed for a first communication device having a set of antenna elements. A quality-indication signal is received from a second communication device (e.g., a basestation). A complex weighting is calculated based on the quality-indication signal. A pre-transmission signal is modified based on the complex transmit diversity weighting to produce a set of modified-pre-transmission signals, wherein the modifications are symmetric by making approximately half the magnitude of the transmit diversity modification to one signal in a first direction, and approximately half the magnitude of the transmit diversity modification to the other signal in a second direction, opposite the first direction. Each modified pre-transmission signal from the set of modified-pre-transmission signals is uniquely associated with an antenna element from the set of antenna elements. The set of modified-pre-transmission signals is sent from the set of antenna elements to produce a transmitted signal.10-21-2010
20090279632Method for achieving transmission diversity in a multiple antenna system - A method for achieving transmission diversity in a multiple antenna system is disclosed. The transmission diversity method includes selecting a column vector from a matrix DETERMINED according to a resource index and a current rank, and multiplying the selected column vector by a transmission symbol.11-12-2009
20090252247TRANSMITTER, RECEIVER AND METHOD FOR CONTROLLING MULTIPLE INPUT MULTIPLE OUTPUT SYSTEM - Provided is a method of controlling a multiple input multiple output (MIMO) system. One embodiment of the method includes the steps of: estimating, at a receiver, a MIMO channel and detecting data streams using a successive interference cancellation scheme; calculating, at the receiver, S and P using the estimated channel and then feeding back information corresponding to (P10-08-2009
20090245412Method and Apparatus for Multiplexing Data and Control Information in Wireless Communication Systems Based on Frequency Division Multiple Access - An apparatus for transmitting data in a frequency division multiple access based communication system is disclosed. The apparatus includes a symbol block generator for generating a symbol block in a predetermined symbol block period within one TTI when control information to be transmitted exists in the TTI, an FFT unit for performing FFT on the symbol block, and an IFFT unit for performing IFFT on signals output from the FFT unit and then transmitting the signals. The symbol block includes the control information and data to be transmitted. The TTI includes multiple symbol block periods.10-01-2009
20120033756Multi-User Downlink Linear MIMO Precoding System - Multi-user (MU-) MIMO systems with quantized feedback are designed to maximize the sum-rate via scheduling and linear precoding. To maximize throughput over the network, quantized CSIT is sent through a low-rate feedback link feedback from a plurality of users back to a base station. The base station then determines a subset of the plurality of users to transmit one or more signals to based on the received feedback and determines a preceding matrix based on the received feedback from the plurality of users wherein the precoding matrix maximizes a sum-rate throughput for the subset of the plurality of users. Additionally, based on the received feedback, the base station designs a quantization codebook. This codebook may be designed off-line and/or online. The codebook and/or precoding matrix are used to transmit signals to the users.02-09-2012
20120033755Transmit Mode Switching for MIMO Base Stations - In a transmitter using at least two transmitting antennas a STTD transmitter is used in combination with a common pre-coding transmitter for power amplifying power balancing. A selector can be provided for selecting data/channels transmitted using STTD and common pre-coding such that for one channel type, STTD or common pre-coding is used whereas the combination of both STTD and common pre-coding is used for a different data/channel type. By selectively using both STTD and common pre-coding for power amplifier power balancing, an improved power balancing is achieved. At the same time, the STTD gain is obtained in the relevant cases but the STTD loss in other cases is avoided.02-09-2012
20090074100APPARATUS AND METHOD FOR DETECTING CYCLIC PREFIX LENGTH IN MOBILE COMMUNICATION SYSTEM - An apparatus and method for detecting a Cyclic Prefix (CP) length in a mobile communication system are provided. The apparatus includes first, second, third and fourth correlators, an average unit, and a length detector. The first, second, third and fourth correlators respectively correlate first, second, third and fourth CP parts within a frame boundary. The average unit averages the correlation values of the first, second, third and fourth correlators. The length detector determines the CP as an extended CP if the average value minus the correlation value of the fourth correlator is greater than a first threshold value. Accordingly, less memory may be required to determine a CP length as compared to the conventional art.03-19-2009
20100266062DISTRIBUTED MAXIMAL RATIO COMBINING RECEIVER ARCHITECTURE - A wireless communication system in which each receiver is configured synchronize to a received waveform using only its local received signal without requiring any information about other receivers in the system. The local receiver is configured to remove frequency and/or phase error based on information encoded in the received waveform. In some examples, the local receiver uses channel probe information embedded in the received waveform to provide channel estimates for each communication channel over which the signals are received and, based on the estimates, adjusts the received signals for phase shift and amplitude scaling caused by the channel. Signal acquisition (in time and frequency), as well as partial demodulation (for channel estimation), is done independently for each channel. Signals from each channel are combined using a maximal ratio combiner.10-21-2010
20100220802METHOD FOR TRANSMITTING OPTIMALLY DIVERSIFIED INFORMATION IN A MIMO TELECOMMUNICATION SYSTEM - A method for transmitting data in a telecommunication system including at least one transmitter comprising at least two transmitting antennas and at least one receiver comprising at least one receiving antenna, the method including: transforming a plurality of bits of the data to be transmitted into a plurality of symbols by modulating the plurality of bits of the data at the transmitter; generating a first vector formed by the plurality of symbols at the transmitter; preparing a modified matrix by modifying an original matrix based on the number of rows of the first vector, the original matrix being predefined at the transmitter; generating a second vector by multiplying the first vector with the modified matrix at the transmitter; and transmitting symbols forming the second vector over communication channels established between the at least two transmitting antennas of the transmitter and the at least one receiving antenna of the receiver.09-02-2010
20090190687METHOD AND APPARATUS FOR ALLOCATING FEEDBACK CHANNEL IN MULTIPLE ANTENNA COMMUNICATION SYSTEM - A method and apparatus for allocating a feedback channel in a multiple antenna communication system are provided. In a method of operating a Base Station (BS) for allocating a feedback channel in a Multi-User Multiple-Input Multiple-Output (MU-MIMO) communication system, the method includes measuring a MIMO transmission environment, determining an amount of feedback according to the MIMO transmission environment, and allocating a feedback channel according to an amount of the feedback.07-30-2009
20090323848Spatial sub-channel selection and pre-coding apparatus - A spatial sub-channel selection and pre-coding apparatus for being operative in a first communication device, the first communication device being adapted for communicating with a second and a third communication device using MIMO (Multiple-Input-Multiple-Output) radio channels, a first MIMO radio channel extending between the first communication device and the second communication device having at least one spatial sub-channel, a second MIMO radio channel extending between the first communication device and the third communication device having at least one spatial sub-channel, wherein one of the first MIMO radio channel or the second MIMO radio channel has at least two spatial sub-channels.12-31-2009
20110211647CLOSED-LOOP MULTIPLE-INPUT-MULTIPLE-OUTPUT SCHEME FOR WIRELESS COMMUNICATION BASED ON HIERARCHICAL FEEDBACK - The present invention provides methods implemented in a base station having a plurality of antennas and one or more user terminals. One embodiment of the method includes receiving feedback from at least one user in response to transmitting a first frame to said at least one user. The first frame is formed by pre-coding at least one symbol using at least one first code word selected from at least one first code book associated with the at least one user. The method also includes transmitting at least one second frame to the user(s). The second frame(s) are pre-coded using at least one second codeword selected from at least one second codebook. The second codebook(s) determined based on the feedback and the first codeword(s).09-01-2011
20100220800SIGNALING OF DEDICATED REFERENCE SIGNAL (DRS) PRECODING GRANULARITY - A method for communication includes receiving in a receiver signals, which include one or more dedicated reference signals and are transmitted from a transmitter over a communication channel in multiple blocks. The signals in each block, including the dedicated reference signals, are transmitted on a respective group of subcarriers over a respective time interval and are precoded using a respective preceding scheme that maps the signals onto multiple antenna ports of the transmitter. Two or more of the blocks whose respective preceding schemes differ from one another by no more than a predefined distance are identified. One or more parameters of the communication channel are estimated over the dedicated reference signals included in the identified blocks. The signals are decoded based on the estimated parameters.09-02-2010
20100220801UPLINK PRECODING METHOD IN 4-Tx SYSTEM - A method for a user equipment to precode and transmit an uplink signal efficiently in a 4-antenna system and a method for a base station to receive the transmitted signal efficiently are disclosed. Four antennas of a user equipment can be grouped by a 2-antenna unit. In consideration of this antenna group, it is able to perform precoding using antenna selection/DFT matrix of the antenna group unit. Moreover, a rank-3 codebook can be configured to include a precoding matrix of a type in consideration of power balance per antenna and a precoding matrix including one non-zero component only in one row for maintaining a good CM property.09-02-2010
20080279299MULTIPLE-INPUT MULTIPLE-OUTPUT (MIMO) DETECTOR INCORPORATING EFFICIENT SIGNAL POINT SEARCH AND SOFT INFORMATION REFINEMENT - A novel and useful apparatus for and method of multiple input multiple output (MIMO) detection for use in MIMO based communication systems. The mechanism of the invention performs a simplified tree search utilizing a single stage expansion of the most likely first symbol candidates, in the case of a 2×2 MIMO system. The invention also provides a refinement mechanism that is operative to significantly improve the soft information (i.e. log likelihood ratio) of the list of candidates. To improve the soft information, the mechanism applies one or more refinements rounds to generate additional candidates for both first and second detected symbols.11-13-2008
20130129003TRANSMISSION CONTROLLING METHOD, SENDER APPARATUS AND RECEIVER APPARATUS FOR WIRELESS COMMUNICATION SYSTEM - A wireless communication system including a sender apparatus having a plurality of transmitting antennas that transmits a plurality of data blocks; and a receiver apparatus that receives the plurality of data blocks, wherein the sender apparatus transmits a process number via a control channel different from a data channel to the receiver apparatus, and wherein the receiver apparatus performs HARQ processing of received data blocks based on the received process number which prevents the data blocks from competing.05-23-2013
20110235736Method and Apparatus for Cancellation of Partially Known Interference Using Transmit Diversity Based Interference Cancellation - In wireless communication networks, potentially significant interference arises at a given targeted receiver because of unrelated transmissions from a neighboring, interfering transmitter. According to apparatuses and methods described and claimed herein, a first transmitter provides for cancellation of partially known interference at a targeted receiver by employing a transmit diversity based interference cancellation method, wherein it transmits diversity combinations of desired and interfering symbols. Correspondingly, the targeted receiver employs diversity combining of the received signals to cancel interference attributable to the interfering symbols.09-29-2011
20100278278METHOD FOR SETTING PRECODER IN OPEN LOOP MIMO SYSTEM - A feedback method of a user equipment in an open loop Multiple-Input Multiple-Output (MIMO) system is disclosed. The method includes, receiving one of a plurality of modes determined according to types of resources to be used for performing feedback from a base station, and selecting a precoding matrix from a codebook subset corresponding to the received mode, applying the selected precoding matrix, and transmitting feedback information. Different codebook subsets are configured with respect to the plurality of modes, and the codebook subset is configured by extracting a predetermined number of elements from a base codebook based on a predetermined criterion considering the characteristics of the modes.11-04-2010
20100310001TRANSMITTING/RECEIVING METHOD FOR MULTI-USER MULTIPLE-INPUT MULTIPLE-OUTPUT SYSTEM - Disclosed is a transmitting/receiving method in a multi-user multiple-input multiple-output (MU-MIMO) channel. The transmitting method includes: performing QR decomposition on a Hermitian transpose matrix of a channel matrix to obtain a first matrix and a second matrix as a triangular matrix; obtaining a preprocessing matrix by using the first matrix; and forming an effective channel based on the preprocessing matrix by a block triangulation technique.12-09-2010
20100296599MULTI-ANTENNA COMMUNICATION METHOD AND SYSTEM THEREOF - A multiple antenna communication method and a multiple antenna communication system are provided. The multiple antenna communication method includes: determining a weighting vector with respect to a plurality of transmit antennas, using a spread spectrum code; determining a target transmission rate of each of the transmit antennas using the determined weighting vector; transmitting information associated with the target transmission rate to a multiple antenna reception apparatus; receiving, from the multiple antenna reception apparatus, channel information including information regarding whether to accept the transmitted target transmission rate information; and transmitting data to the multiple antenna reception apparatus using the received channel information.11-25-2010
20100310002ADAPTIVE AND SELECTIVE FRAME FORMATS WITHIN MULTIPLE USER, MULTIPLE ACCESS, AND/OR MIMO WIRELESS COMMUNICATIONS - Adaptive and selective frame formats within multiple user, multiple access, and/or multiple input multiple output (MIMO) wireless communications. A reconfigurable channel circuitry, that may be implemented to communicate with one, a subset, or all of various blocks within a communication device provides for adaptive and selective frame formatting of communications between the communication device and other communication devices. In a wireless communication device context, and also in the context of multiple user, multiple access, and/or MIMO communications (e.g., multi-user multiple input multiple output (MU-MIMO) and/or orthogonal frequency division multiplexing (OFDM), etc.), frame formatting may be adapted in accordance with a number of parameters including: the one or more users with which communications are to be made, the clusters (e.g., channel, band, frequency, etc.) employed for such communications, the one or more antennae (e.g., within a multi-antenna architecture) employed for such communications, and/or any other parameters.12-09-2010
20100303167HIERARCHICAL MODULATION SYSTEM AND TRANSMITTER AND METHOD THEREOF - An exemplary embodiment of the present invention proposes a transmitter including a hierarchical modulator. The hierarchical modulator receives, jointed encodes, and maps a high-priority and low-priority bit-stream signals, so as to generate multiple mapping signal, wherein each mapping signal is the summation of a low-priority and high-priority mapping signals. The low-priority mapping signal is the complex number signal on the frequency domain to which part bits of the low-priority bit-stream signal are mapped, and the high-priority mapping signal is the complex number signal on the frequency domain to which part bits of the high-priority bit-stream signal are mapped. The p12-02-2010
20090290654APPARATUS FOR TRANSMITTING AND RECEIVING DATA TO PROVIDE HIGH-SPEED DATA COMMUNICATION AND METHOD THEREOF - In the present invention, data generated from a source unit are distributed to at least one bandwidth; the data distributed to the respective bandwidths are encoded in order to perform an error correction; the encoded data are distributed to at least one antenna; a subcarrier is allocated to the data distributed to the respective antennas, and an inverse Fourier transform is performed; a short preamble and a first long preamble corresponding to the subcarrier are generated; a signal symbol is generated according to a data transmit mode; and a frame is generated by adding a second long preamble between the signal symbol and a data field for the purpose of estimating a channel of a subcarrier which is not used.11-26-2009
20100322336Beamforming to a Subset of Receive Antennas in a Wireless MIMO Communication System - In a method for controlling transmission of an information signal to a multiplicity of receive antennas associated with one or more receivers a steering matrix is developed using a subset of receive antennas, wherein the subset of receive antennas includes less than all of the multiplicity of receive antennas. Transmission of the information signal via a plurality of transmit antennas is controlled using the steering matrix.12-23-2010
20100322335BEAMFORMING BY ANTENNA PUNCTURING - Beamforming is provided for a wireless MIMO device by using antenna puncturing to reduce the number of transmit antennas that are used to transmit data for certain subcarriers. In a conventional approach, if N spatial streams are being used to provide spatial multiplexing, then N transmit antennas would be used to transmit for each subcarrier. In at least one embodiment of the invention, enhancements in channel capacity are achieved by using less than N transmit antennas for one or more subcarriers.12-23-2010
20100322337CLOSED LOOP FEEDBACK SYSTEM FOR IMPROVED DOWN LINK PERFORMANCE - A method includes receiving at least two space-time coded signals from an antenna system associated with a first station, determining complex channel state information based on the received space-time coded signals, and sending the complex channel state information to the first station. In an alternative embodiment, a method includes transmitting at least two space-time coded signals in respective beams of a multi-beam antenna array, measuring a channel impulse response for each space-time coded signal at a second station, and sending an indicia of a selected set of least attenuated signals from the second station to the first station. The multi-beam antenna array is associated with a first station. The beams transmit a signature code embedded in each respective space-time coded signal, and the signature codes are orthogonal so that the second station can separate and measure the channel impulse response corresponding to each space-time coded signal.12-23-2010
20090067531METHOD FOR REPORTING CHANNEL INFORMATION IN MULTIPLE ANTENNA SYSTEM - There is provided a method of reporting downlink channel information to a base station in a multiple antenna system. The method includes reporting a single rank for overall subband, the overall subband comprising a plurality of subbands and reporting a CQI for the single rank for at least one subband. Radio resources required for reporting channel information can be reduced and signaling overheads can be minimized.03-12-2009
20090067529QUANTIZED CHANNEL STATE INFORMATION PREDICTION IN MULTIPLE ANTENNA SYSTEMS - A CSI vector quantizer (VQ) system is provided for time-correlated channels. The VQ system operates a receiver forwarding quantized channel state information in the form of indices and a transmitter predicting channel state change. The VQ system is aimed at feedback channels, in which bit errors, erasures and delays can occur. The VQ system uses transmitter-side channel prediction algorithms that work with the quantized CSI information and allow the system to recover from feedback channel transmission errors, erasures and delays. Moreover, the techniques can be used to lower the required feedback rate, while keeping the system's throughput at the required level.03-12-2009
20090067532METHODS AND SYSTEMS FOR DIVERSITY COMBINING OF SYNCHRONIZATION STATISTICS IN OFDM SYSTEMS - 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.03-12-2009
20090067533MIMO BASED NETWORK CODING NETWORK - A wireless communication system includes an intermediate node, a first node and a second node. There is described a method for implementing MIMO based network coding, comprising the first node transmitting first data to the intermediate node, and the second node transmitting second data to the intermediate node. Both the first node and the second node may use spatial multiplexing or time division multiplexing or frequency division multiplexing on a common/different resource. The intermediate node receives the transmissions from the first node and second node, and performs network coding on the first data and second data using a predefined network coding scheme to produce network coded information. The intermediate node transmits the network coded information to the first node and second node using multi-user MIMO; and; each first or second node receives the MIMO transmissions from the intermediate node and applies network decoding procedures to recover the first data and second data. Network coding schemes include Decode and Forward (DF), Map and Forward (MF) and Amplify and Forward (AF). The first node and second node may be members of groups of nodes all within the same coverage area. A method for scheduling MIMO-based network coded transmissions is also described. Hybrid Automatic Repeat Request (HARQ) transmission may also be network encoded.03-12-2009
20090067530Providing feedback in a MIMO system - There is provided a system and method of operating a multiple-input multiple-output (MIMO) receiver with N antennas in a wireless communication system. The method includes measuring N vectors, each vector defining channel transfer coefficients between M antennas of a transmitter and a corresponding antenna of the receiver. Additionally, a vector in a linear space generated by the N measured vectors is selected and quantized values of less than M components of the selected vector are fed back to the transmitter.03-12-2009
20090067534WIRELESS 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 a multiple of 9 subcarriers in the frequency domain and further allocated in two contiguous OFDM symbols.03-12-2009
20100166097Wireless Communication System And Wireless Communication Method - There is provided a MIMO wireless communication system, which comprises at least one base station having plural transmitting antennas and at least one user equipment having at least one receiving antennas, the base station being capable of accommodating plural user equipments by precoding based on a codebook, wherein, each of the plural user equipments comprises: a channel estimation unit for conducting a channel estimation based on a pilot signal transmitted from the base station, to obtain a channel information; a codeword determination unit for determining a first codeword that results in the maximum signal-noise-ratio, and at least one second codeword that results in the minimum signal-noise-ratio, based on the channel information; and a transmission unit for feedbacking the first codeword and the second codeword(s) to the base station, the base station is configured to schedule the user equipments based on the first codeword and the second codeword so that a predetermined system performance metric is optimized.07-01-2010
20110019760Methods and Systems for Reducing Supply and Termination Noise - A transmitter expresses continuous-time signals on alternate, parallel channels with reference to different supply voltages such that the signals on alternate channels have different common-mode voltages. At the transmitter, expressing the symbols using alternate supply voltages limits the maximum supply current used to express the signals and to transition between adjacent symbol sets. Limiting supply current ameliorates problems associated with simultaneous switching noise (SSN). At the receiver, the different common-mode voltages tend to balance the current to and from termination nodes, and consequently place reduced stress on a reference voltage. Providing different common-mode voltages on alternate channels may additionally reduce cross-talk between channels.01-27-2011
20100080315MIMO TRANSMISSION MODE SELECTING METHOD AND WIRELESS COMMUNICATION EQUIPMENT - In a radio communication apparatus, a MIMO system deciding section of a transmitter unit decides an object MIMO communication system with reference to a CQI value and a measured rate table while an AMC table controlling section selects an object MCS value according to the decided MIMO communication system and CQI value. The AMC table controlling section changes the MCS value step by step according to a transmission count and a result (success/failure) of the communication. If the communication (receiving) is successful or if the transmission count reaches the maximum value, the controlling section updates the mean value of the measured rate table. At this time, based on a value estimated from the combination of the MIMO communication system, the encoding system, and the modulating system that are used currently, the controlling section changes the reference for selecting another combination that are not used currently.04-01-2010
20110026630Power Allocation of Spatial Streams in MIMO Wireless Communication System - Multiple-input multiple-output (MIMO) wireless communication techniques are provided that involve mapping multiple spatial streams to corresponding modes of a wireless channel between a plurality of antennas of a first wireless communication device and a plurality of antennas of a second wireless communication device so as to allocate or distribute power unequally to the plurality of modes. In addition, techniques are provided herein to cyclically shift a mapping of spatial streams to modes of the channel.02-03-2011
20110026631PHYSICAL UPLINK CONTROL CHANNEL (PUCCH) RESOURCE MAPPING WITH TRANSMIT DIVERSITY - Certain aspects of the present disclosure relate to techniques for control channel resource mapping with transmit diversity. In an aspect, a method for wireless communications is provided with includes transmitting a signal associated with a downlink control channel, where the downlink control channel spans at least one group of resource elements (REs), and the group of REs indicates a first orthogonal resource to be used by a user equipment (UE). The method also includes signaling a second orthogonal resource to be used by the UE.02-03-2011
20110026629SYSTEM AND METHOD FOR ENCODING AND DECODING OF SPACE-TIME BLOCK CODES IN DATA COMMUNICATION - A wireless data communication system. The system includes: a transmitter having a unitary rotation matrix processor for processing incoming information data stream and outputting a plurality of transmission symbols; an encoder for encoding the plurality of transmission symbols; M number of mapper units for mapping the symbols outputted from the encoder into a two dimensional constellation having M data symbols, where M is an integer greater than 1; M number of pulse shaper units to modulate the respective signals from the two dimensional constellation; and M number of antennas to transmit the M data symbols in M time slots. Each antenna transmits a respective symbol from the M symbols in a respective time slot of the M time slots and the encoder is configured to determine which symbol to be transmitted from each antenna in each time slot.02-03-2011
20110026633Wireless Communication Method, Wireless Communication System, Base Station and Mobile 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 modulation scheme. A mobile station (02-03-2011
20090034644MIMO COMMUNICATION SYSTEM AND METHOD FOR COMMUNICATING WITH SINGLE ANTENNA AND MULTI-ANTENNA MOBILE STATIONS - In a wireless local area network (WLAN) that includes high-throughput communication devices with multiple antennas and legacy communication devices with single antennas, training tones are transmitted over a plurality of spatial channels during a first portion of an orthogonal frequency division multiplexed (OFDM) packet-training preamble. The training tones are interspersed among subcarrier frequencies of the spatial channels. The training tones are retransmitted during a second portion of the packet-training preamble. The training tones are shifted among the subcarrier frequencies of the spatial channels during the retransmission allowing a high-throughput receiving station to perform a channel estimation on different subcarrier frequencies of the spatial channels. The legacy communication devices may receive and process the training tones and may set their network allocation vector to refrain from communicating during a subsequent interval.02-05-2009
20090034643Communication System, Transmitter, Receiver, Transmitting Method, Receiving Method, and Program - A transmitter 02-05-2009
20100172430PRECODING CODEBOOKS FOR MIMO COMMUNICATION SYSTEMS - A method for communication includes configuring a communication system that includes a transmitter and a receiver with first precoding matrices for mapping up to N data streams onto N transmit antenna ports of the transmitter. Each of at least some of the first precoding matrices are derived from respective second and third precoding matrices configured for mapping onto respective numbers of transmit antenna ports that are less than N. The data streams are mapped onto the N transmit antenna ports using a precoding scheme based on one of the first precoding matrices. The mapped data streams are transmitted over the N transmit antenna ports from the transmitter to the receiver.07-08-2010
20110044395MIXED MODE PREAMBLE FOR MIMO WIRELESS COMMUNICATIONS - A preamble of a frame for a multiple input multiple output (MIMO) wireless communication for a first transmit antenna of the MIMO communication includes a legacy preamble portion in accordance with a legacy wireless communication protocol. The preamble of the frame for the MIMO wireless communication for the first transmit antenna also includes a current protocol preamble portion in accordance with a protocol of the MIMO wireless communication. The preamble of a frame for at least a second antenna of the MIMO communication includes a cyclically shifted legacy preamble portion for the frame. The preamble of the frame for the MIMO wireless communication for the second transmit antenna also includes a second current protocol preamble portion in accordance with a protocol of the MIMO wireless communication.02-24-2011
20110044394Adaptive time diversity and spatial diversity for OFDM - An adaptable orthogonal frequency-division multiplexing system (OFDM) that uses a multiple input multiple output (MIMO) to having OFDM signals transmitted either in accordance with time diversity to reducing signal fading or in accordance with spatial diversity to increase the data rate. Sub-carriers are classified for spatial diversity transmission or for time diversity transmission based on the result of a comparison between threshold values and at least one of three criteria. The criteria includes a calculation of a smallest eigen value of a frequency channel response matrix and a smallest element of a diagonal of the matrix and a ratio of the largest and smallest eigen values of the matrix.02-24-2011
20110116566WIRELESS COMMUNICATION SYSTEM, TRANSMITTER AND RECEIVER - According to the present invention, a transmitter includes: multiple antennas 15-1, 15-2; a DFT unit 04 configured to transform a time domain signal into a frequency domain signal; a cluster mapping unit 05 configured to divide the frequency domain signal into clusters and to assign the clusters to frequencies on the basis of cluster assignment information; an IDFT unit 06 configured to transform a mapped frequency domain signal into a time domain signal; and cyclic delay setting units 11-1, 11-2 configured to set, for the respective multiple antennas, a cyclic delay amount to the IDFT-transformed time domain signal.05-19-2011
20110129029METHOD FOR TRANSMIT DIVERSITY ENCODING - Transmit diversity coding of symbols employing four antennas is disclosed. An example embodiment of the invention comprises providing blocks of symbols to four transmit antennas, the blocks of symbols being determined by transforming input blocks and extending the blocks by adding zeroes in groups before or after groups of elements in the blocks.06-02-2011
20110080969MULTI-GRANULAR FEEDBACK REPORTING AND FEEDBACK PROCESSING FOR PRECODING IN TELECOMMUNICATIONS - A communications system comprises a second device (04-07-2011
20110085614Selecting Transmission Technology for Communications in Wide Area Mobile Networks - Method and RNC for selecting transmission technology when a UE enters the network, which checks whether the UE is MIMO and, if so and only one carrier is available, allocates its traffic to said carrier and uses a S-CPICH to provide all MIMO traffic with a diversity pilot and Virtual Antenna Mapping for balance. If more than one carrier is available, the number of UEs, their radio conditions and load of carriers are checked periodically. If the carrier is busy only with MIMO and its load is higher than the load of the remaining carriers, diversity CPICH of STTD is selected; otherwise and only if the UEs vulnerable to STTD with good radio conditions exceed a certain number, the S-CPICH is selected. The RNC can reconfigure the network from transmitting MIMO traffic with STTD to using MIMO with S-CPICH or vice versa dynamically by periodical check of the load and UEs criteria for configuration change.04-14-2011
20100166100MULTIPLE-INPUT, MULTIPLE-OUTPUT (MIMO) SYSTEMS WITH MULTIPLE TRANSMISSION MODES - Techniques to transmit data on a number of transmission channels in a multi-channel communication system using multiple transmission schemes requiring less channel-state information (CSI). These schemes may include a partial-CSI transmission scheme that transmits a single data stream on each transmit antenna selected for use and a “beam-forming” transmission scheme that allocates all transmit power to a single transmission channel having the best performance. Each transmission scheme may provide good or near-optimum performance for a specific range of operating conditions (or operating SNRs). These multiple transmission schemes may then be combined in a piece-wise fashion to form a “multi-mode” transmission scheme that covers the full range of operating conditions supported by the MIMO system. The specific transmission scheme to be used for data transmission at any given moment would then be dependent on the specific operating condition experienced by the system at that moment.07-01-2010
20090323851METHOD AND APPARATUS FOR UTILIZING CHANNEL STATE INFORMATION IN A WIRELESS COMMUNICATION SYSTEM - Techniques for transmitting data from a transmitter unit to a receiver unit in a multiple-input multiple-output (MIMO) communication system. In one method, at the receiver unit, a number of signals are received via a number of receive antennas, with the received signal from each receive antenna comprising a combination of one or more signals transmitted from the transmitter unit. The received signals are processed to derive channel state information (CSI) indicative of characteristics of a number of transmission channels used for data transmission. The CSI is transmitted back to the transmitter unit. At the transmitter unit, the CSI from the receiver unit is received and data for transmission to the receiver unit is processed based on the received CSI.12-31-2009
20090323849METHOD AND APPARATUS FOR PERFORMING MULTIPLE-INPUT MULTIPLE-OUTPUT WIRELESS COMMUNICATIONS - A method and an apparatus for performing multiple-input multiple-output (MIMO) wireless communications are disclosed. A Node-B may receive an index to a pre-coding matrix in a single user MIMO (SU-MIMO) pre-coding codebook from wireless transmit/receive units (WTRUs) and adaptively perform one of SU-MIMO or multi-user MIMO (MU-MIMO) based on a predetermined criterion. Channel information for performing MU-MIMO may be obtained based on the pre-coding matrix of the SU-MIMO pre-coding codebook. A rank requested by the WTRU may be overridden if the unitary MU-MIMO codebook is a subset of the SU-MIMO pre-coding codebook. If not, a MU-MIMO pre-coding matrix with a largest correlation to the pre-coding matrix may be selected. A WTRU may send a pre-coding matrix for transmission to the WTRU along with a preferred interference matrix. A WTRU may send rank information and multiple right singular vectors for MU-MIMO.12-31-2009
20130156122WIRELESS TRANSMISSION METHOD, AND WIRELESS TRANSMITTER AND WIRELESS RECEIVER - A wireless transmission method capable of transmitting a data stream between a wireless transmitter having a plurality of transmitting antennas and a wireless receiver, the wireless transmission method includes controlling to increase the number of transmission beams to be formed for transmitting said data stream depending on the number of data streams to be transmitted from said transmitting antennas becoming small, and receiving any one or more transmission beam from said transmission beams by said wireless receiver, wherein said transmission beams are formed by predetermined number of the plurality of transmitting antennas.06-20-2013
20130156123EFFICIENT 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.06-20-2013
20130156125METHOD AND APPARATUS FOR TRANSMITTING SIGNALS USING CODEBOOKS IN A WIRELESS COMMUNICATION SYSTEM THAT SUPPORTS MULTIPLE ANTENNAS - The present invention relates to a wireless communication system, and more particularly, to a method and apparatus for transmitting signals using codebooks in a wireless communication system that supports multiple antennas. A method in which a base station transmits downlink signals according to one embodiment of the present invention comprises the following steps: receiving a first precoding matrix indicator (PMI) and a second precoding matrix indicator from a terminal; determining a first matrix (W1) from a first codebook including precoding matrixes indicated by the first PMI, determining a second matrix (W2) from a second codebook, including precoding matrices indicated by the second PMI, and determining a precoding matrix (W) based on the first matrix (W1) and second matrix (W2); performing precoding on one or more layers, to which the downlink signals are mapped, using the determined precoding matrix (W); and transmitting the precoded signals to the terminal. Each of the precoding matrices included in the first codebook is a block diagonal matrix, and one block has, as compared to the other block, a form multiplied by a predetermined phase value.06-20-2013
20120243631SYSTEMS AND METHODS FOR CREATING A DOWNLINK PRECODE FOR COMMUNICATION SYSTEM WITH PER-ANTENNA POWER CONSTRAINTS - Systems and methods for a downlink precode filter directed towards both wired and wireless MIMO communication systems. Systems and methods of the invention can provide close to optimal capacity (similar to the water-filling solution) while requiring power amplifiers associated with transmit antennas to operate at a fixed power level. In particular, systems and methods of this invention can improve the performance of MIMO wireless devices such as 802.11n, WiMax, LTE, LTE-Advanced etc.09-27-2012
20110080972METHOD AND APPARATUS FOR MULTI-ANTENNA TRANSMISSION IN UPLINK - Method and apparatus for uplink transmission using multiple antennas are disclosed. A wireless transmit/receive unit (WTRU) performs space time transmit diversity (STTD) encoding on an input stream of a physical channel configured for STTD. Each physical channel may be mapped to either an in-phase (I) branch or a quadrature-phase (Q) branch. The WTRU may perform the STTD encoding either in a binary domain or in a complex domain. Additionally, the WTRU may perform pre-coding on at least one physical channel including the E-DPDCH with the pre-coding weights, and transmitting the pre-coded output streams via a plurality of antennas. The pre-coding may be performed either after or before spreading operation.04-07-2011
20090245411WIRELESS COMMUNICATION METHOD AND APPARATUS FOR FORMING, STEERING AND SELECTIVELY RECEIVING A SUFFICIENT NUMBER OF USABLE BEAM PATHS IN BOTH AZIMUTH AND ELEVATION - A wireless communication method of exploiting the radio frequency (RF) physical environment to establish a sufficient number of usable multiple paths of RF propagation for facilitating communications. The method is implemented in a wireless communication system including at least one transmitter and at least one receiver. The receiver's antenna is directed towards one of a plurality of reception paths and receives a data stream from the transmitter via the reception path that the receiver antenna is directed towards. The receiver decodes the data stream, reconstructs a modulation pattern of the decoded data stream, and subtracts the reconstructed data stream from a sum of all of the signals received by the receiver via the reception paths. The receiver provides received signal direction information associated with reception paths to the transmitter. The transmitter adjusts and/or eliminates one or more of the reception paths that are unusable based on the signal direction information.10-01-2009
20110142153MULTIPLE-INPUT MULTIPLE-OUTPUT SYSTEM, RECEIVING APPARATUS AND METHOD OF RECEIVING SIGNALS - A multi-input multi-output system, receiving apparatus and method of receiving signals are provided. The multi-input multi-output system includes a transmitting apparatus configured to send signals coded through a double space time transmit diversity scheme while changing a phase and an antenna, and a receiving apparatus configured to, if a signal is received from the transmitting apparatus, estimate predetermined symbols by use of a maximum likelihood estimation scheme, estimate remaining symbols by use of a decision feedback equalization scheme, and to calculate a Log Likelihood Ratio (LLR) of each of the predetermined symbols and the remaining symbols, in which the LLR of the remaining symbol is calculated by switching a channel matrix vector (H) of the receiving signal.06-16-2011
20110211648METHOD, APPARATUS AND SYSTEM FOR PROVIDING FEEDBACK TO A TRANSMIT DIVERSITY DEVICE - A method and system for improving closed loop feedback in transmit diversity communication. In one embodiment of the invention, a predetermined variation of one or more transmit diversity parameters is performed at the transmit diversity transmitter. The receiver compares the transmit diversity parameter values of the received signals to the predetermined variation and transmits to the transmitter a value of a transmit diversity correction parameter. The transmitter may use this correction value to modify the transmit diversity parameter in a subsequent transmission.09-01-2011
20110249765PORTABLE TERMINAL AND METHOD FOR OPERATING OF MIMO ANTENNA THEREOF - A portable terminal and a method operate multiple input multiple output (MIMO) antennas. Received signal strength indications (RSSIs) of the MIMO antennas are measured through a wireless communication unit that transmits and receives a wireless signal using the MIMO antennas. A path between a MIMO antenna with a greatest RSSI and a broadcast receiving unit is connected during a broadcast mode.10-13-2011
20100008444Method and apparatus to balance maximum information rate with quality of service in a MIMO system - In a wireless MIMO communication system for N symbols of a frame of information, allocating N01-14-2010
20110085615SYSTEM OF SHARING DATA USING TRANSMISSION ORDER - A data transmission apparatus and a data reception apparatus, are provided. The apparatuses may share data in a Peer-to-Peer (P2P) scheme via a network. The data transmission apparatus divides data into a plurality of segments, and determines a transmission order with respect to each of the divided segments. The data transmission apparatus and the data reception apparatus share data based on the transmission order of the divided segments.04-14-2011
20100008443CHANNEL ESTIMATION OF MULTI-CARRIER SIGNAL WITH SELECTION OF TIME OR FREQUENCY DOMAIN INTERPOLATION ACCORDING TO FREQUENCY OFFEST OF CONTINUOUS PILOT - The invention relates to a method of estimating the transmission channel of a received multi-carrier signal (y) in a mobile environment, which method comprises identifying pilots (P01-14-2010
20090147879ADAPTIVE SIGNALING IN MULTIPLE ANTENNA SYSTEMS - Briefly, in accordance with one embodiment of the invention, a wireless communication system may adaptively switch between a multiple input, multiple output mode and a spatial division, multiple access mode based at least in part on channel conditions and traffic conditions.06-11-2009
20110176631COMMUNICATION METHOD FOR MIMO COMMUNICATION SYSTEM - A communication method for a MIMO communication system comprises the steps of: transmitting a plurality of first streams modulated in a non space division multiplexing manner from a transmitter to a plurality of receiving stations; and transmitting a plurality of second streams following the plurality of first streams modulated in a space division multiplexing manner from the transmitter to the plurality of receiving stations. Each of the first streams comprises a legacy short training field, a legacy long training field, a legacy signal field and at least a very high throughput signal field, and each of the first streams has the same length. Each of the second streams comprises a very high throughput short training field, a plurality of very high throughput long training fields and a data field, and each of the second streams has the same length.07-21-2011
20090323850ADVANCED MIMO INTERLEAVING - A MIMO transmitter including an interleaving system for parsing encoded bits to a plurality of spatial streams and a plurality of interleavers to interleave bits for spatial streams such that at least a first spatial stream uses a first stream interleaver that interleaves with a pattern distinct from a second stream interleaver interleaving for a second spatial stream.12-31-2009
20100008440LINK ADAPTATION IN WIRELESS COMMUNICATIONS - A wireless communication system with link adaptation is provided. The wireless communication system may include a channel k-factor estimator estimating a Rician k-factor of a channel based on a signal received from a transmitter, a frequency band grouping unit determining a size of frequency band grouping based on the Rician k-factor, a transmission mode selector determining a transmission mode for each frequency band group based on the Rician k-factor, and a modulation and coding scheme selector determining a modulation and coding scheme for the each frequency band group.01-14-2010
20100034310Transmit diversity schemes in OFDM systems - A transmission diversity device is provided. The transmission diversity device includes physical channel processing configured to map a plurality of modulation symbols onto one or more layers. Thereafter a precoder is configured to perform beamforming on the one or more layers. The output of the precoder is obtained by at least one of two base equations. The mapper and precoder are configured to perform code word-to-layer mapping for transmit diversity for two layers, four layers, six layers, eight layers and sixteen layers. Further, the mapper and precoder are configured to perform code word-to-layer mapping for 8 transmit diversity schemes.02-11-2010
20080310539SYSTEMS AND METHODS FOR GENERATING AN ORTHOGONAL SIGNAL FROM SEQUENCES THAT ARE NOT MULTIPLES OF 2 - A method for generating orthogonal signals is described. A sequence is chosen. A determination is made if the chosen sequence is orthogonal. The sequence is converted from a time domain to a frequency domain if the sequence is not orthogonal. A determination is made if the length of the sequence is a multiple of a first quantity. An Inverse Fast Fourier Transform that is a multiple of the length of the sequence is chosen if the length of the sequence is not a multiple of the first quantity.12-18-2008
20090213955RADIO COMMUNICATION APPARATUS AND A RADIO COMMUNICATION METHOD - The radio communication apparatus includes 08-27-2009
20100054356INTERFERENCE AVOIDING MIMO - Method and apparatus for communicating a radio signal between a first station and a second station, including estimating at least one characteristic of a radio channel from the first station including a first plurality of weightable transceiving elements, to the second station including a second plurality of weightable transceiving elements; calculating a receive weighting of at least one weightable transceiving element at the second station, responsive to the estimate; calculating a transmit weighting of at least one weightable transceiving element at the first station; and then communicating the radio signal by transmitting from the transmit-weighted transceiving elements at the first station, over the radio channel, to the receive-weighted transceiving elements at the second station, while reducing the response to unwanted interfering signals.03-04-2010
20100054357RADIO COMMUNICATION SYSTEM - A transmission device (03-04-2010
20100316157MULTI-CELL PROCESSING ARCHITECTURES FOR MODELING AND IMPAIRMENT COMPENSATION IN MULTI-INPUT MULTI-OUTPUT SYSTEMS - The present invention relates to a method for multiple-input multiple-output impairment pre-compensation comprising: receiving a multiple-input signal; generating a pre-distorted multiple-input signal from the received multiple-input signal; generating a multiple-output signal by feeding the pre-distorted multiple-input signal into a multiple-input and multiple-output transmitter; estimating impairments generated by the multiple-input and multiple-output transmitter; and adjusting the pre-distorted multiple-input signal to compensate for the estimated impairments. The present invention also relates to a pre-compensator for use with a multiple-input and multiple-output transmitter, comprising: a multiple-input for receiving a multiple-input signal; a matrix of pre-processing cells for generating a pre-distorted multiple-input signal from the received multiple-input signal; and a multiple-output for feeding the pre-distorted multiple-input signal to the multiple-input and multiple-output transmitter. The pre-processing cells are configured so as to estimate impairments generated by the multiple-input and multiple-output transmitter and adjust the pre-distorted multiple-input signal to compensate for the estimated impairments.12-16-2010
20110176629DOWNLINK TRANSMISSION IN A MULTIPLE-USER MULTIPLE-INPUT MULTIPLE-OUTPUT ("MU-MIMO") WIRELESS COMMUNICATION SYSTEM - Information transmission in a multiple-input multiple-output (“MIMO”) wireless communication system is provided. In one embodiment, a method for transmitting information in a MIMO wireless communication system, comprising updating channel quality information (“CQI”) values of a plurality of wireless devices, wherein updating said CQI values consider the effects of interference from transmissions to those wireless devices associated with a pre-assigned companion codeword set; pairing said plurality of wireless devices using at least said CQI values, a precoding matrix index (“PMI”) value and said pre-assigned companion codeword set, wherein said pre-assigned companion codeword set, pre-assigned companion codewords associated with said pre-assigned companion codeword set and said PMI value are updated for each of said plurality of wireless devices; precoding the information for each of said plurality of wireless devices using said PMI value; and transmitting said precoded information to each of said plurality of wireless devices.07-21-2011
20110176632METHOD OF TRANSMITTING UPLINK DM-RS MULTIPLEXED WITH DATA IN UPLINK MIMO TRANSMISSION - Provided is a multi-layer transmission method of multiplexing and transmitting data and a demodulation reference signal (DM-RS) sequence in an uplink digital Fourier transform-spread-orthogonal frequency division multiplexing (DFT-S-OFDM) transmission employing multiple-input multiple-output (MIMO). The method includes allocating one DM-RS sequence as a DM-RS sequence of a first transmission layer for uplink transmission; allocating a DM-RS sequence whose cyclic shift (CS) value having the same sequence as the DM-RS sequence of the first transmission layer is configured to differ from that of the DM-RS sequence as a DM-RS sequence of a second transmission layer; and multiplexing layer-specific data and the layer-specific DM-RS sequences according to each of the first and second transmission layers. Accordingly, an RS can be transmitted in more OFDM symbols of a slot or subframe without an increase in overhead. Consequently, it is possible to satisfy requirements of LTE-advanced that a high frequency spectrum and a high mobile velocity should be supported, and transmit and receive a DM-RS multiplexed with data while maintaining orthogonality.07-21-2011
20110176630WIRELESS COMMUNICATION APPARATUS AND WIRELESS COMMUNICATION METHOD - Provided is a wireless communication apparatus which prevents deterioration of communication characteristics because of a transmission weight of a greatest common factor and enhances the communication characteristics of feedback MIMO. A wireless communication apparatus having a plurality of antennas includes a reception unit for obtaining channel state information of channels of signals received from another wireless communication apparatus, a channel state information calculation unit for calculating an average value of the channel state information, selecting channels having the channel state information equal to or higher than a threshold based on the average value and calculating representative channel state information of the predetermined frequency band overall from the channel state information of the selected channels, 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.07-21-2011
20100239041 METHOD FOR TRANMITTING FEEDBACK INFORMATION IN MULTI INPUT MULTI OUT PUT SYSTEM BASED ON CODEBOOK AND A METHOD FOR TRANSMITTING PRECODING INFORMATION IN MULTI INPUT MULTI OUTPUT SYSTEM USING CODEBOOK- BASES PRECODING SCHEME - A method for transmitting feedback information in a codebook-based multiple-input multiple-output (MIMO) system is disclosed. To transmit the feedback information, a signal is received to discern channel characteristics of the received signal, and a codebook is updated using an extended matrix including a plurality of vector components and using previous feedback information. Feedback information is selected for transmission from the updated codebook in consideration of the channel characteristics of the received signal.09-23-2010
20110080971MULTIPLE-INPUT MULTIPLE-OUTPUT COMMUNICATION SYSTEM USING EXPLICIT FEEDBACK - A multiple input multiple output (MIMO) communication system using an explicit feedback is provided. In the MIMO communication system using the explicit feedback, a receiver may generate an explicit feedback vector by calculating an explicit channel matrix, and by vectorizing the explicit channel matrix or an explicit channel matrix processed using a predefined function. Feedback information generated based on the explicit feedback vector may be provided to a transmitter. The transmitter may reconfigure the explicit channel matrix or the processed explicit channel matrix based on the feedback information. The transmitter and the receiver may share the explicit channel matrix or the processed explicit channel matrix using an adaptively transformed codebook.04-07-2011
20110080968 METHOD FOR TRANSMITTING CHANNEL QUALITY INFORMATION IN A MULTIPLE INPUT MULTIPLE OUTPUT SYSTEM - A method for transmitting a CQI in a MIMO system is disclosed. A method for allowing a receiver to feed back a CQI value to a transmitter in a Multiple Input Multiple Output (MIMO) system includes, receiving a transmission (Tx) pilot signal for each Tx antenna from a base station (BS), measuring a first CQI value of a first codeword and a second CQI value of a second codeword on the basis of the pilot signal, and transmitting the first CQI value of the first codeword and the second CQI value of the second codeword to the base station (BS), wherein at least one of the first and second CQI values includes specific information capable of indicating a transmission restriction status of a corresponding codeword.04-07-2011
20110103503METHOD AND APPARATUS FOR CONTROLLING DYNAMIC CHANNEL FEEDBACK IN A MIMO NETWORK - A communication method and apparatus for coordinated multi-point (CoMP) transmission, is provided. Sizes of codebooks for a plurality of base stations may be adjusted based on a status of channels between a target terminal and a plurality of base stations. The terminal feeds back, to at least one of the plurality of base stations, channel direction information (CDI) including a number of bits of feedback.05-05-2011
20090028265Apparatus and method for detecting signal by maximum likelihood - An apparatus and method for detecting a signal in a receiver by maximum likelihood (ML) are provided, in which symbols are detected according to the number of transmit antennas of a transmitter and a modulation scheme, channels are estimated, an equivalent channel matrix corresponding to the estimated channels is determined, a permuted equivalent channel matrix is determined by multiplying the equivalent channel matrix by a predetermined permutation matrix, the permuted equivalent channel matrix is QR decomposed, a hard decision is performed on predetermined symbols among the detected symbols using a received signal resulting from the QR decomposition, and the log likelihood ratios (LLRs) of the hard-decided symbols are determined.01-29-2009
20090028262RADIO COMMUNICATION METHOD, RADIO COMMUNICATION SYSTEM, AND RADIO COMMUNICATION DEVICE - There are disclosed a radio communication device and others capable of generating in a short time a secret key common to a base station and a mobile station in a radio communication system using the MIMO technique and starting the encrypted communication at an early stage. In this device, in ST01-29-2009
20110103506APPARATUS FOR TRANSMITTING A SYNCHRONOUS SIGNAL IN A MULTI-ANTENNA SYSTEM - An apparatus for transmitting a synchronization signal using a plurality of transmit (Tx) antennas is provided. The apparatus includes a synchronization signal generator for generating a synchronization signal used for tracking timing or frequency synchronization, a transmission processor for allocating different subcarriers to a plurality of Tx antennas without overlapping, mapping the synchronization signal to the subcarriers, and generating an orthogonal frequency division multiplexing (OFDM) symbol by performing inverse fast Fourier transformation (IFFT), a control signal coupler for controlling codes as a resource not to overlap among the plurality of Tx antennas, and the plurality of Tx antennas for transmitting the OFDM symbol.05-05-2011
20110249766METHOD FOR FRAME AGGREGATION IN MOBILE COMMUNICATION SYSTEM - A staggered frame aggregating method for multi-band time-division duplex mobile communication system. By relatively shifting the frame in each frequency band in turn, a new frame configuration is formed by aggregating and it is used for transmitting and receiving data, and it makes the frames in different bands stagger in time.10-13-2011
20110080970Data Transmission in a Wide Area Mobile Network - Method and system for data transmission in a wide area mobile network supporting both MIMO User Equipments and non MIMO User Equipments, comprising: 04-07-2011
20100246706METHOD FOR RESOURCE ALLOCATION IN WIRELESS COMMUNICATION SYSTEM - The present invention provides a method for resource allocation in a wireless communication system. In the method for resource allocation, a scheduler of a base station decides on a modulation scheme and an encoding scheme according to channel quality information (CQI), and decides on a number of allocated resource blocks according to transmission data size referring to a table of resource block allocation. The table of resource block allocation presents a number of allocated resource blocks and a number of transmission bits according to the number of allocated resource blocks.09-30-2010
20100246705METHOD AND APPARATUS FOR UPLINK POWER CONTROL IN MULTIPLE-INPUT MULTIPLE-OUTPUT - A method and apparatus for uplink power control in multiple-input multiple-output (MIMO) includes setting a transmit power level for a physical uplink shared channel (PUSCH) transmission.09-30-2010
20110075752NON-UNITARY PRECODING SCHEME FOR WIRELESS COMMUNICATIONS - Techniques for a non-unitary precoding scheme for wireless communications are described. An apparatus may comprise a mobile device for a mobile broadband communications system utilizing an orthogonal frequency-division multiple access technique. The mobile device may have a channel state information module operative to generate channel state information for a fixed device using a non-unitary precoding scheme for a closed loop multi-user multiple-input and multiple-output scheme. The channel state information may comprise channel quality information and a codeword index. Other embodiments are described and claimed.03-31-2011
20110069775SIGNAL PROCESSING METHOD AND APPARATUS FOR MIMO SYSTEM - A signal processing method for a MIMO system comprises the steps of: arranging a plurality of frequency domain MIMO data streams into a plurality of groups, wherein each group comprises at least a frequency domain MIMO data stream; partitioning sub-carriers of each of the plurality of frequency domain MIMO data streams into a plurality of sub-channels; performing phase rotation for the plurality of frequency domain MIMO data streams, wherein the phases of the sub-carriers in a sub-channel are rotated the same amount, and different phase rotations are performed on different groups of the plurality of frequency domain MIMO data streams; transforming the plurality of frequency domain MIMO data streams into a plurality of time domain MIMO data streams; and performing CSD for the plurality of time domain MIMO data streams if each group comprises more than one frequency domain MIMO data stream, wherein the amount of CSD is different for each time domain MIMO data stream in a group.03-24-2011
20110069776MIMO DETECTION METHOD AND SYSTEM BASED ON CHANNEL CORRELATION - An OFDM symbol detection method is disclosed, which includes: receiving OFDM modulated symbols transmitted from multiple transmitting antennas; receiving information on correlation time and/or correlation bandwidth; performing channel estimation on each of a plurality of channels for the multiple transmitting antennas, and conducting smoothing processing on each channel estimation result according to said information on correlation time and/or correlation bandwidth, so as to obtain channel estimation averages of respective channels; and performing signal detection on the received OFDM symbols by using the channel estimation averages. Both time correlation and frequency correlation are considered in the method.03-24-2011
20120201321CHANNEL FEEDBACK TO SUPPORT EFFICIENT RANK OVERRIDE - A method can include providing channel feedback to support efficient rank override For example, in such a method, a rank−r precoder index corresponding to a rank−r precoder is determined, and performance for each rank−1 precoder within the rank−r precoder is measured Based on the measured performance, a rank−1 precoder that maximizes performance is selected08-09-2012
20120201320Sparse Channel Estimation Using Order Extension for Frequency and Time Selective MIMO Wireless Communication Networks - A channel matrix is estimated for a channel subject to frequency and time selective fading in a multiple-input multiple-output (MIMO) wireless communication network. The method uses a recursive least-squares (RLS) process and an expectation-maximization (EM) process, based on a L08-09-2012
20120201319METHOD AND ARRANGEMENT FOR POLARIZATION CONTROL IN A COMMUNICATION SYSTEM - Controlling the polarization state of signals to be transmitted from a MIMO capable radio base station node to a plurality of user equipment, which radio base station node comprises a precoder unit connecting a first and a second virtual antenna port to a respective first and second transmit antenna port, by the steps of controlling (S08-09-2012
20110150120Reference signal resource randomization with SU-MIMO - For an integer number R (greater than one) of demodulation reference signal DM RS resources that are reserved for SU-MIMO transmissions by a UE, there is associated in a memory a) for a first transmission instance each of the R DM RS resources with a unique one of R spatial layers or R transmit antennas, and b) for a second transmission instance each of the R DM RS resources with a different unique one of the R spatial layers or transmit antennas. The first and second transmission instances (slots or sub-frames) are consecutive. A UE transmission to a network in the first slot/sub-frame comprises each DM RS resource on the respective spatial layer or transmit antenna with which they are associated for the first slot/sub-frame, and a UE transmission to the network in the first slot/sub-frame comprises each DM RS resource on the respective spatial layer or transmit antenna with which they are associated for the second slot/sub-frame.06-23-2011
20110150119METHOD AND SYSTEM FOR CHANNEL ESTIMATION IN AN OFDM BASED MIMO SYSTEM - Upon receiving spatially independent OFDM signals from multiple transmit antennas coupled to a single transmitter, a receiver comprising multiple receive antennas operably coupled to multiple RF chains adjusts phase and/or gain of a portion of signal components received over multiple receive antennas coupled to the same RF chain. A combined channel estimate for the RF chain is generated using corresponding frequency domain samples of the adjusted signal components. Individual channel estimates are generated from the generated combined channel estimate. Phase rotation and/or gain adjustment information are determined to adjust signal components received over additional receive antennas coupled to the RF chain. The phase and/or gain adjusted signal components are combined with signal components over a selected reference receive antenna coupled to the RF chain for RF processing. The RF processed signal components are converted into corresponding frequency domain samples to generate individual channel estimates for the phase rotation and/or gain adjustment.06-23-2011
20100310003TRANSMISSION ACKNOWLEDGMENT WITHIN MULTIPLE USER, MULTIPLE ACCESS, AND/OR MIMO WIRELESS COMMUNICATIONS - Transmission acknowledgement within multi-user wireless communication systems. Within multi-access wireless communication systems such as those operating in accordance with multi-user multiple input multiple output (MU-MIMO), orthogonal frequency division multiple access (OFDMA), and/or MU-MIMO/OFDMA, acknowledgement of receipt (e.g., using ACKs) is provided back to the sending or transmitting wireless communication device from each (or a subset) of the intended recipient wireless communication devices. Appropriate coordination of these ACKs from the respective, receiving wireless communication devices may be performed using instructions embedded within a multi-user packet that is provided to the receiving wireless communication devices. Alternatively, polling as effectuated by the sending or transmitting wireless communication device may be used to give explicit direction to the respective, receiving wireless communication devices of the manner by which their respective ACKs should be provided to the transmitting wireless communication device.12-09-2010
20100303166Apparatus and Method for Inserting a Cyclic Postfix for a Time-Rotated Symbol in a Communication System - An apparatus and method for inserting a cyclic postfix for a time-rotated symbol in a communication system. In one embodiment, the apparatus includes a time pre-rotation module configured to time shift bits of at least one of ending samples of a symbol to a beginning of the symbol to form a time-rotated symbol. The apparatus also includes an interpolator configured to construct an up-sampled symbol from the time-rotated symbol and a cyclic postfix module configured to insert a cyclic postfix at an end of the up-sampled symbol to form an expanded up-sampled symbol.12-02-2010
20090010354COMMUNICATION DEVICE AND COMMUNICATION METHOD - There is provided a communication device capable of transmitting a transfer rate request signal while reducing it and reducing the interference and power consumption when the transfer rate request signal is transmitted substantially without lowering the transmission efficiency in the MIMO communication method. In this device, a modulation encoding unit (01-08-2009
20100266064MIMO WIRELESS COMMUNICATION GREENFIELD PREAMBLE FORMATS - A method for multiple input multiple output wireless communication begins by determining protocols of wireless communication devices within a proximal region. The method continues by determining whether the protocols of the wireless communication devices within the proximal region are of a like protocol. The method continues by determining the number of transmit antennas. The method continues, when the protocols of the wireless communication devices within the proximal region are of the like protocol, formatting a preamble of a frame of the wireless communication utilizing at least one of cyclic shifting of symbols, cyclic shifting of tones, sparse tone allocation, and sparse symbol allocation based on the number of transmit antennas.10-21-2010
20100260280DATA TRANSMISSION IN WIRELESS COMMUNICATION SYSTEM - Embodiments of the disclosure set forth methods for transmitting data in a wireless communication system. Some example methods include converting a data stream to a symbol set and selecting a first plurality of symbols from the symbol set. The first plurality of symbols includes at least a first symbol, a second symbol, a third symbol, a fourth symbol, a fifth symbol, a sixth symbol, a seventh symbol, and a eighth symbol. The methods include generating one or plurality of symbols of a second plurality of symbols based on interleaving two symbols selected from the first plurality of symbols. The methods further include weighting some symbols of the second plurality of symbols and generating a matrix based on symbols selected from the second plurality of symbols and the weighted symbols. The methods also include encoding the data stream based on the matrix.10-14-2010
20100260279DATA TRANSMISSION IN WIRELESS COMMUNICATION SYSTEM - Embodiment of the disclosure set forth methods for transmitting data in a wireless communication system. Some example methods include converting a data stream to a symbol set; selecting a first plurality of symbols from the symbol set, wherein the first plurality of symbols includes at least a first symbol, a second symbol, a third symbol, and a fourth symbol; generating a second plurality of symbols having at least a fifth symbol and a sixth symbol, wherein the fifth symbol includes a first part of the first symbol and a second part of the second symbol and the sixth symbol includes a first part of the third symbol and a second part of the fourth symbol; weighting the sixth symbol to form a first weighted symbol; and transmitting in a first time slot the fifth symbol with a first antenna and the first weighted symbol with a second antenna.10-14-2010
20100098186UWB AMPLIFIER - A wireless communication device comprises an integrated circuit comprising electronic circuitry for performing wireless control functions. An external circuit, separate from the integrated circuit, is provided for performing a predetermined stage of a wireless control function, the external circuit comprising at least one discrete component. The at least one discrete component of the external circuit is controlled by one or more control signals received from the integrated circuit. As such, the invention makes use of a low cost external device as the input device in an integrated solution, thus benefiting from the improved performance of the external device while gaining the control and system benefits of a complex integrated solution.04-22-2010
20100098184TRANSMISSION METHOD FOR MULTIPLE ANTENNA SYSTEM - A transmission method for a multiple antenna system including a first device having M (>1) transmitting antennas and a second device having N (>1) receiving antennas is disclosed. The method includes determining whether there is a multiple-input multiple-output (MIMO) transmission scheme satisfying a condition that it consumes less energy than a single-input single-output (SISO) transmission scheme to transmit a frame at a given transmission power, among one or more MIMO transmission schemes available to the first device and the second device, the one or more MIMO transmission schemes being determined by the numbers of activated transmitting and receiving antennas, and MIMO code; determining a transmission mode as a MIMO mode when there is the at least one MIMO transmission scheme satisfying the condition, and otherwise determining the transmission mode as a SISO mode; and performing frame transmission from the first device to the second device in the determined transmission mode. Thus, frame transmission with power saving can be performed.04-22-2010
20100098185WIRELESS COMMUNICATIONS SYSTEM, TRANSMITTING APPARATUS AND RECEIVING APPARATUS - In a transmitter 04-22-2010
20100080316INFORMATION PROCESSING APPARATUS, INFORMATION PROCESSING METHOD, DISPLAY APPARATUS AND INFORMATION PROCESSING PROGRAM - Disclosed herein is an information processing apparatus including: a demodulation FFT processing section configured to carry out an FFT process on a demodulation-related signal extracted by making use of a demodulation FFT window from every symbol of a received OFDM signal and output the frequency-domain signal; a control FFT processing section configured to carry out a process equivalent to an FFT process on a control-related signal extracted by making use of a control FFT window from every symbol of the received OFDM signal and output the frequency-domain signal; a transmission-line information estimation section; an equalization section; a reception-quality computation/comparison section; and an FFT-window position control section configured to control the demodulation FFT window to be used by the demodulation FFT processing section and the control FFT window to be used by the control FFT processing section on the basis of a comparison result produced by the reception-quality computation/comparison section.04-01-2010
20100098187DIVERSITY TRANSMITTER AND DIVERSITY TRANSMISSION METHOD - The present invention concerns a diversity transmitter, comprising: transmit symbol input means (04-22-2010
20090190684WIRELESS COMMUNICATION METHOD, RADIO RECEIVING APPARATUS, RADIO TRANSMITTING APPARATUS, AND WIRELESS COMMUNICATION SYSTEM - A wireless communication system capable of achieving adaptive STTD (Space-time Transmit Diversity). In this system, a receiving apparatus uses a channel estimation to calculate SINR (Signal to Interference and Noise Ratio) of each of substreams in all the combinations of transmission antennas and also calculate the performance of the whole system in all the combinations of transmission antennas, thereby deciding a particular combination, which provides the best performance of the whole system, and obtaining a parameter for antenna selection. The SINR of each substream in the decided particular combination is used to decide an AMC parameter. A transmitting apparatus performs STTD and AMC based on the AMC parameter fed back from the receiving apparatus, and further selects, based on the antenna selection parameter fed back from the receiving apparatus, a particular combination of transmission antennas for performing a transmission.07-30-2009
20090141824METHOD AND SYSTEM FOR GENERATING CANDIDATE BEAMFORMING COEEFICIENTS FOR TRANSMISSION OF DATA OVER A WIRELESS MEDIUM - A method and system for generating a number of candidate beamforming vectors for transmission of data over a wireless medium, is provided. One implementation involves determining the number (N) of transmitter antennas; determining the number (n) of candidate beamforming vectors to be constructed as an algebraic function of N; providing a Fourier transform matrix W comprising (n+1) rows and (n+1) columns; selecting N rows from the Fourier transform matrix W; and generating an abridged matrix using the selected N rows, wherein each column of the abridged matrix is configured to be used as a candidate beamforming vector for transmission of a data signal, such that the abridged matrix comprises a N×n sub-matrix of the Fourier transform matrix W.06-04-2009
20080273621Method and apparatus for estimating frequency offset and timing offset of one or more mobile stations (MSs) - A method and apparatus for estimating frequency offset and timing offset of a first Mobile Station (MS) in a communication system is provided. The method includes receiving a composite signal at a plurality of receiver antennas of a Base Transceiver Station (BTS). The composite signal includes a first signal transmitted from a first MS and a second signal transmitted from a second MS. The composite signal includes one or more tiles. Each tile includes a plurality of data sub-carriers, a plurality of first pilot sub-carriers, and a plurality of second pilot sub-carriers. A total phase offset of the first MS is estimated based on a complex conjugate product of pilot symbols of the plurality of first pilot sub-carriers. Thereafter, a first phase offset corresponding to the timing offset of the first MS is estimated based on a Power Delay Profile (PDP) of one or more first pilot sub-carriers. Finally, a second phase offset corresponding to the frequency offset of the first MS is determined based on the total phase offset and the first phase offset.11-06-2008
20080273620APPARATUS, AND ASSOCIATED METHOD, FOR PROVIDING OPEN LOOP DIVERSITY IN A RADIO COMMUNICATION SYSTEM - Apparatus, and an associated method, for providing transmit diversity to an open-loop MIMO communication scheme, such as a point to multipoint broadcast service in a cellular system. Multiple data streams of the broadcast data are broadcast by way of transmit diversity antennas of a sending station. The data symbols of the separate data streams are phase-shifted to be offset in phase from one another. The data streams, once the data symbols thereof are selectably phase-shifted by a phase shifter, are applied by an applier to sending nodes of the respective cells.11-06-2008
20080267312MULTICARRIER COMMUNICATION APPARATUS AND PEAK SUPPRESSING METHOD FOR THE SAME - A multicarrier communication apparatus includes: a scheduler operable to schedule transmission opportunities of the plurality of series of transmission data in accordance with predetermined scheduling information; a peak evaluator to evaluate whether or not the peak of the multicarrier signal exceeds a predetermined threshold value; and a peak suppressing unit operable to halt transmission of at least some of the plurality of series of transmission data based on the scheduling information upon decision by said peak evaluator that the result of the evaluation exceeds the threshold value. This construction makes it possible to accomplish peak suppression with ease without increasing the arithmetic scale, like in the previous art, while maintaining communication of users high in scheduling precedence.10-30-2008
20080267311RADIO COMMUNICATION METHOD, RADIO TRANSMISSION APPARATUS AND RECEIVING APPARATUS - A radio communication method including, generating a first transmit RF signal and a second transmit RF signal from a data signal to be transmitted, wherein the first transmit RF signal and the second transmit RF signal being subjected to a code spread by a first spreading code and a second spreading code, respectively forming a symmetric power spectrum in the frequency domain, transmitting the first transmit RF signal and the second transmit RF signal from a transmit antenna at a different time, receiving the first transmit RF signal and the second transmit RF signal to generate a first received RF signal and a second received RF signal, and reproducing the data signal from the first received RF signal and the second received RF signal.10-30-2008
20080267310Transmit diversity in a wireless communication system - A method for transmitting data via multiple antennas by modulating data to be transmitted into a plurality of modulated symbols, encoding each pair of modulated symbols from among said plurality of symbols in accordance with a transmission diversity scheme to result in a plurality of N by N matrices, with each N by N matrix corresponding to each pair of modulated symbols, generating a M by M code matrix comprised of the plurality of N by N matrices, orthogonally spreading the M by M code matrix to generate an output matrix, generating a plurality of row-permuted matrices by exchanging at least one pair of rows in the output matrix, and transmitting the symbols in the plurality of row-permuted matrices via a plurality of antennas by using either a space time transmission diversity scheme, a space frequency transmission diversity scheme, or a combination of a space time transmission diversity scheme and a space frequency transmission diversity scheme.10-30-2008
20110255624MULTIUSER MIMO SYSTEM, RECEIVER, AND TRANSMITTER - Even when respective transmitters use different transmission schemes, signals of the respective transmitters are separated. A receiver that is applied to a multiuser MIMO system in which a plurality of transmitters performs transmission to at least one receiver, includes a MIMO separation part 10-20-2011
20110255625CODEBOOK-BASED MULTI-BASE STATION UNITE PRE-CODING METHOD, MOBILE TERMINAL, AND BASE STATION - The present invention provides a novel codebook-based multi-base station unite pre-coding scheme. In this invention, multiple cooperating base stations commonly transmit signals to a mobile terminal. The mobile terminal estimates a channel matrix of a unite MIMO channel from the multiple cooperating base stations, and selects the optimal pre-coding matrix index from the pre-coding matrix codebook based on the unite MIMO channel matrix and feeds it back to the multiple cooperating base stations. Each cooperating base station selects the optimal pre-coding matrix based on the received pre-coding matrix index and uses the corresponding portion of the pre-coding matrix to perform unite pre-coding on the data. Namely, the respective partial pre-coding matrixes as employed by all cooperating base stations together form the pre-coding matrix that is optimal to the mobile terminal, and the pre-coding matrix as used by respective cooperating base stations is a part of the optimal pre-coding matrix. By using the codebook-based multi-base station unite pre-coding scheme according to the present invention, the user performance is improved, the complexity of implementation is low, and the demand on network connecting the base stations is very low.10-20-2011
20080205539Method and System for Achieving Spatial Diversity of a Wireless Communications Network - A method and system are provided for achieving spatial diversity of a wireless communications network. The method comprises arranging antennas on a transmitting wireless station into a plurality of antenna subgroups, wherein each of the antenna subgroups forms a virtual antenna, creating a plurality of beamformed MIMO channels using the plurality of virtual antennas, wherein each of the beamformed MIMO channel comprises a plurality of sub-carriers and corresponds to a virtual antenna, dividing sub-carriers in each of the plurality of beamformed MIMO channels into at least a first and second cluster, distributing a first amount of transmitting power to the first cluster and a second amount of transmitting power to the second cluster, wherein the first amount of transmitting power is substantially larger than the second amount of transmitting power.08-28-2008
20080205537Method For Selecting Optimal Beam And Apparatus For Receiving Digital Broadcasting Signal Using The Same - There are provided a method for selecting an optimal beam to improve digital broadcasting receiving performance, and a digital broadcasting receiving apparatus using the same. The method includes the steps of: a) calculating a mainpath Signal to Multipath signal and Noise Ratio (SMNR) based on a channel impulse response for a plurality of beams which are formed according to steering directions from output signals of antennas, wherein the output signal of each antenna has different phase shift according to location of antenna element; b) selecting a predetermined number of beams having a high SMNR value by comparing the calculated SMNR value for respective beam; c) calculating a mainpath Signal to Dominant Multipath signal Ratio (SDMR) based on a channel impulse response corresponding to the selected beam; and d) selecting a beam output signal having the biggest SDMR value by comparing SDMR values calculated in selecting a predetermined number of beams.08-28-2008
20110164700CLOSED FORM SINGULAR VALUE DECOMPOSITION - The subject matter disclosed herein provides methods and apparatus for determining a singular value decomposition, providing feedback from a client station to a base station, and closed loop operation of a wireless system implementing multiple-input multiple-output (MIMO). The method may include determining one or more singular vectors using a closed form singular value decomposition. The one or more determined singular vectors may be provided to a precoder at the base station as feedback. The method may include aligning a phase of one or more singular vectors. The method may also include determining, at a client station, a plurality of singular vectors for channels used in a MIMO transmission from a base station to a client station. The client station may provide an indication to the base station regarding whether to use a singular value decomposition or a uniform channel decomposition. Related systems, apparatus, methods, and/or articles are also described.07-07-2011
20110164699METHOD AND SYSTEM FOR AN ITERATIVE MULTIPLE USER MULTIPLE INPUT MULTIPLE OUTPUT (MU-MIMO) COMMUNICATION SYSTEM - A method and system for an iterative multiple user multiple input multiple output (MU-MIMO) communication system are presented. In one aspect, a current iteration beamforming matrix may be generated based on a current iteration matched filter matrix for each of a plurality of user devices. A subsequent iteration matched filter matrix may be generated based on the current iteration beamforming matrix for each of the plurality of user devices. A subsequent iteration beamforming matrix may be generated based on the subsequent iteration matched filter matrix for each of the plurality of user devices. A succeeding iteration beamforming matrix may be generated based on an iteration count value and/or based on one or more difference values. The one or more difference values may be computed based on the plurality of subsequent iteration beamforming matrices and the plurality of current iteration beamforming matrices generated for the plurality of user devices.07-07-2011
20110069773Method of identifying a precoding matrix corresponding to a wireless network channel and method of approximating a capacity of a wireless network channel in a wireless network - A method of identifying a precoding matrix corresponding to a wireless network channel comprises the steps of identifying a capacity metric that includes an identity matrix, approximating the capacity metric using an approximation metric that ignores the identity matrix, using the approximation metric to search over all matrices in a matrix codebook in order to identify a particular precoding matrix that increases a capacity of the wireless network channel, and transmitting across the wireless network channel a matrix index that corresponds to the particular precoding matrix. Additional techniques for identifying precoding matrices are also described herein, as is a method of approximating a capacity of a wireless network channel in a wireless network.03-24-2011
20100329378MULTIPLE ANTENNA SPATIAL MULTIPLEXING OPTIMAL DETECTION - MIMO detection is described that reduces the complexity of computations for finding the soft bit output. The detection process includes QR factorization splitting the distance calculations into two groups, subset lookup using a last cross constellation set (LCCS) lookup, and minimal distance lookup with soft bit output calculation. By grouping the distance calculations into a first group that has one antenna transmitting using a modulation scheme with a generally square constellation diagram and a second group for all of the other antenna constellation diagrams, the LCCS lookup process may be used which substantially reduces the number of calculations to be made in the detection process. Moreover, in the special case of 2×2 antenna, QR factorization is performed by applying a scaled Givens rotation to the channel matrix. The application of the scaled Givens rotation operator eliminates any square root operations that would be performed in a standard QR factorization.12-30-2010
20100329379ESTIMATING CHANNEL CONDITIONS IN A MIMO OFDM COMMUNICATION SYSTEM - A method of estimating channel conditions for use in a MIMO communication system includes the steps of, at a receiver: computing a SINR metric for all pre-coding matrices; computing a first capacity metric for the bandwidth from the SINR metrics, and selecting a rank which maximizes the first capacity metric; computing a second capacity metric for each frequency channel from the SINR metrics and the selected rank, and selecting one or more pre-coding matrices which maximize the second capacity metric; computing a third capacity metric from the second capacity metric, selected rank and selected pre-coding matrices for each transmission layer within each frequency channel, and selecting one or more frequency channels which maximize the third capacity metric; and transmitting the selected rank, selected pre-coding matrices and selected frequency channels to the transmitter for use in subsequent data transmissions.12-30-2010
20110033005MIMO wireless data communication system, MIMO wireless data communication method and MIMO wireless data communication apparatus - In a MIMO wireless communication system, the transformation process synthesizes the eigenmodes having a large singular value (i.e. a high effective SNR) and the eigenmodes having a small singular value (i.e. a low effective SNR). Thereby, the former eigenmodes are converted into modes having suppressed effective SNR which do not require a large number of levels of modulation, and the latter eigenmodes are converted into modes having increased effective SNR instead. In a MIMO wireless communication system for eigenmode transmission, a large communication capacity is realized without increasing the number of levels of modulation even in a communication environment capable of achieving a high SNR.02-10-2011
20110135026Orthogonal frequency coding for surface acoustic wave devices - Methods and systems for coding SAW OFC devices to mitigate code collisions in a wireless multi-tag system. Each device producing plural stepped frequencies as an OFC signal with a chip offset delay to increase code diversity. A method for assigning a different OCF to each device includes using a matrix based on the number of OFCs needed and the number chips per code, populating each matrix cell with OFC chip, and assigning the codes from the matrix to the devices. The asynchronous passive multi-tag system includes plural surface acoustic wave devices each producing a different OFC signal having the same number of chips and including a chip offset time delay, an algorithm for assigning OFCs to each device, and a transceiver to transmit an interrogation signal and receive OFC signals in response with minimal code collisions during transmission.06-09-2011
20110135025MULTI-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.06-09-2011
20110261893WIRELESS COMMUNICATION APPARATUS AND WIRELESS COMMUNICATION METHOD - Provided is a wireless communication apparatus which prevents deterioration of a 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 a plurality of antennas includes a reception unit for receiving signals of channels in a predetermined frequency band from another wireless communication apparatus and obtaining channel state information of the channels, a channel state information calculation unit for calculating a weighted average of the channel state information as representative channel state information of the predetermined frequency band overall based on power of the channel state information, 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.10-27-2011
20120147982Methods and Apparatus for Overlapping MIMO Physical Sectors - A system for communicating with wireless devices. The systems includes radio groups whose MIMO physical sectors overlap. The MIMO physical sectors communicate using different channels. The MIMO physical sectors overlap to form an area of overlap. Each radio group includes directional antennas and radios. Radios are selectively coupled to the antennas. The antennas that are oriented so that the physical sectors of the antennas overlap to operate as MIMO antennas and form the MIMO physical sector for the radio group. The antennas operate as a MIMO antenna.06-14-2012
20110142154SEQUENTIAL TRANSMISSION MULTI-BEAMFORMING METHOD WITH LOW COMPLEXITY USING HADAMARD MATRIX - Provided is a sequential transmission multi-beamforming apparatus and method with a low complexity based on a Hadamard matrix. A simple codebook may be generated based on the Hadamard matrix and thus, a number of weighted-vectors is reduced and a complexity of hardware is decreased. A diversity gain may be maximized based on a spatial diversity processing apparatus and a beamforming weighted vector may be systematically generated.06-16-2011
20090202014Adaptation Techniques in MIMO - A method of the multiple input multiple output feedback is disclosed. In accordance with an embodiment of the invention, the multiple input multiple output feedback method includes a receiver receiving a reference signal from a base station and calculating a signal to interference and noise ratio from the received reference signal. The method further includes determining a modulation and coding scheme based on the signal to interference and noise ratio and a receiver type.08-13-2009
20110096860Multi-Antenna Communication Systems Utilizing RF-Based and Baseband Signal Weighting and Combining - A receiver operatively coupled to an antenna structure capable of receiving a first plurality of RF signals is disclosed herein. The receiver includes an RF processing network operative to perform weighting and combining operations within the RF domain using the first plurality of RF signals so as to produce a second plurality of RF signals. Also provided is a downconverter configured to downconvert the second plurality of RF signals into a second plurality of down-converted signals. In alternate implementations certain of the weighting and combining operations are performed at baseband and the remainder effected within the RF domain. A transmitter of corresponding architecture is also disclosed.04-28-2011
20110096859METHOD FOR FEEDBACK AND METHOD FOR CONFIGURING A CODEBOOK IN MULTI-ANTENNA SYSTEM - A feedback method for a multi-antenna system is disclosed. The feedback method for use in the multi-antenna system can reduce an amount of transmission (Tx) feedback information associated with a precoding matrix (i.e., a codebook). For example, a single codebook may include precoding matrixes associated with several ranks. A basic matrix constructing the precoding matrix is extended to a frequency axis, such that it can be used as a Cyclic Delay Diversity (CDD) structure.04-28-2011
20110096858MIMO DECODING SYSTEM AND METHOD - A method for decoding Spatial-Multiplexing MIMO in a system with 2 transmit (Tx) antennas, comprising: A. The baseband signal model is written using vector-notation, wherein, in the case of a system with 2 Tx antennas, the equation can be written with separated channel-matrix columns; B. For all M possibilities of the first symbol vector-element component s04-28-2011
20100215111METHODS AND APPARATUS FOR POWER CONTROL BASED ANTENNA SWITCHING - A method for selecting an antenna is described. The method may include transmitting using a first antenna with a first metric and a radio frequency (RF) chain for a first dwelling period. The method may include switching to transmitting using a second antenna with a second metric for a first testing period. The second antenna may use the same RF chain as the first antenna. The first metric may be compared with the second metric to determine an optimal antenna. The optimal antenna may be selected.08-26-2010
20110176628SYMBOL TIMING RELATIVE OFFSET MULTI ANTENNA SYSTEM AND METHOD - A multi-antenna communication method. A transmitter accepts a plurality of n data sources, and a plurality of MT independent data streams are prepared for transmission through a plurality of MT different antennae. The transmitter introduces a sub-symbol offset between symbols in the plurality of MT independent data streams transmitted by adjacent ones of the plurality of MT different antennae. Receivers for receiving and processing the Mτ independent data streams are also provided.07-21-2011
20110103505METHOD AND SYSTEM FOR A SIMPLIFIED USER GROUP SELECTION SCHEME WITH FINITE-RATE CHANNEL STATE INFORMATION FEEDBACK FOR FDD MULTIUSER MIMO DOWNLINK TRANSMISSION - A method for processing signals in a communication system includes selecting, from a plurality of users, a first user having a channel gain that is greater than a channel gain corresponding to a remaining portion of the plurality of users. At least a second user may be selected from a portion of the remaining portion of the plurality of users, based on a feedback channel gain of the second user. The selected second user may have a channel direction that is approximately orthogonal to a channel direction of the first user. System capacity may be determined based on the selecting of the first user and the selecting of the second user. The channel gain may be defined by a quantized channel gain. A quantized channel direction of the selected first user may be determined for the selecting of the second user.05-05-2011
20100215113Method and System for Pre-Coding For Frequency Selective Radio Communication Channel - A method for processing signals to be transmitted in a MIMO system from a transmitter having at least two transmitting antennas to a receiver having at least two receiving antennas on a frequency selective communication channel. The method comprises estimating elements of a channel matrix H(q08-26-2010
20100215114METHOD FOR TRANSMITTING SOUNDING REFERENCE SIGNAL IN MIMO WIRELESS COMMUNICATION SYSTEM AND APPARATUS THEREFOR - A method for transmitting a sounding reference signal in a MIMO wireless communication system and an apparatus therefor are disclosed. The method for transmitting sounding reference signals (SRSs) in a MIMO wireless communication system comprises receiving sounding reference signal parameters from a base station; receiving information of the number of sounding reference signals which will be transmitted at a transmission time instant from the base station; if a plurality of sounding reference signals are provided, generating the sounding reference signals corresponding to each of the plurality of antennas by using the sounding reference signal parameters; and transmitting the generated sounding reference signals to the base station through their corresponding antennas at a specific transmission instant.08-26-2010
20100166093METHOD FOR ESTIMATING PHASE ERROR IN MIMO OFDM COMMUNICATIONS SYSTEM - A method for estimating a phase error existing in a receiver of a MIMO OFDM communications system is disclosed. The method includes executing Hermitian transpose on channel coefficient matrix of the MIMO OFDM communications system for generating Hermitian-transposed channel coefficient matrix, multiplying received signal matrix of the receiver with the Hermitian-transposed channel coefficient matrix for generating converted signals, summing products of the converted signals and complex conjugates of pilot signals corresponding to the converted signals for generating a sum result, and generating the phase error according to the sum result, the converted signals, and the complex conjugates of the pilot signals. The pilot signals are extracted from the received signal matrix.07-01-2010
20100166096TRANSMISSION METHOD AND MULTIPLE INPUT MULTIPLE OUTPUT WIRELESS COMMUNICATION SYSTEM USING THE SAME - A transmission method executed in a multiple input multiple output wireless communication system may include the following steps: receiving a transmitting bit sequence; providing an X level pulse amplitude modulation (X-PAM) signal set, wherein distances between any two adjacent signal points in the X-PAM are the same; generating M signal sets according to the X-PAM signal set, wherein the i07-01-2010
20100166094Method for transmitting and receiving signals in open-loop spatial multiplexing mode - A method for transmitting and receiving signals in an open-loop spatial multiplexing transmission mode is described. If the number of transmit antennas is 2 and a rank is 2, a base station performs precoding according to a cyclic delay diversity scheme by a matrix in which a first matrix corresponding to an identity matrix, a second matrix corresponding to a diagonal matrix, and a third matrix corresponding to a unitary matrix are sequentially multiplied and transmits the precoded signals. This may be substantially the same as the case where the base station performs precoding using a matrix in which the second matrix corresponding to the diagonal matrix and the third matrix corresponding to the unitary matrix are multiplied and transmits the precoded signals. A user equipment estimates a transmission mode according to the received rank indicator and the number of transmit antennas and receives signals.07-01-2010
20100166099METHOD FOR TRANSMITTING AND ESTIMATING SYMBOLS CODED WITH A CODING MATRIX, AND CORRESPONDING RECEIVER AND TRANSMITTER - An embodiment of a method for transmitting a sequence of symbols through at least a channel in a wireless communication system comprises at least the steps of: 07-01-2010
20100166098METHOD AND APPARATUS FOR ANTENNA SELECTION AND POWER CONTROL IN A MULTIPLE INPUT MULTIPLE OUTPUT WIRELESS COMMUNICATION SYSTEM - A MIMO base station is provided that includes a multi-channel transmitter having an input Fourier Transform Matrix (FTM) and an output FTM that are each coupled to an intervening signal processing section having multiple radio frequency (RF) amplifiers. A signal applied to an input port of the input FTM is distributed to all RF amplifiers of the transmitter by the input FTM and then is recombined by the output FTM such that the signal is routed to a single antenna of the multiple antennas of an antenna array. Thus, for both MIMO and non-MIMO transmissions, all RF amplifiers are used to amplify each input signal, but the non-MIMO transmission signal then is recombined such that only a single transmit antenna then is used to transmit the signal. The base station further provides antenna selection for a single antenna transmission and gain allocation among the multiple antennas for a MIMO transmission.07-01-2010
20100158151SYSTEM AND METHOD FOR COMBINATION MULTIPLE INPUT, MULTIPLE OUTPUT (MIMO) AND BEAMFORMING - Specifically, a method and system that performs MIMO and beamforming at a base station based on an uplink channel sounding (ULCS) from only one of the mobile station antennas and closed-loop multiple input, multiple output (MIMO) schemes based on the singular value decomposition (SVD) of the channel matrix. The ULCS is limited to sounding and the channel uses fewer than an optimal number of transmit antennas (e.g. one for WiMAX). The base station arrays may be configured for a full array transmitting mode or a sub-array transmitting mode.06-24-2010
20100119002MIMO ANTENNA SYSTEM - A wireless local area network (“WLAN”) antenna array (“WLANAA”) includes a circular housing having a plurality of radial sectors and a plurality of primary antenna elements configured as Multiple-Input, Multiple-Output (MIMO) antennas. Each primary antenna element, which includes multiple antennas connected to a single radio, being positioned within a radial sector of the plurality of radial sectors.05-13-2010
20100195754APPARATUS AND METHOD FOR ANTENNA SWITCHING DIVERSITY IN AN OFDM SYSTEM - Methods, systems, and apparatus, including computer programs encoded on computer storage media, for antenna switching diversity comprising: identifying the start of an OFDM symbol period; switching from an original antenna to an alternative antenna; calculating a signal quality metric associated with the original antenna and the alternative antenna; and selecting either the original antenna or the alternative antenna for demodulation of a current OFDM symbol based on the calculated signal quality metric. In one aspect, the antenna switching diversity is based on either symbol rate switching or block rate switching, and a selection of one or the other is made.08-05-2010
20100195753MINO ANTENNA APPARATUS CAPABLE OF DIVERSITY RECEPTION USING ONE RADIATING CONDUCTOR - A MIMO antenna apparatus is provided with: an upper housing having slits; first feed points through which the upper housing itself is excited as first antennas; second feed points through which the slits are excited as second antennas; switch circuits, each of which is connected to one of the first feed points and one of the second feed points, and connects one of the two feed points to an A/D converter circuit-; a signal level detector circuit detecting signal levels of received radio signals; and a controller that controls the switches to change a feed point connected to the A/D converter circuit, when the detected signal level is less than or equal to a predetermined threshold value. The slits are located between the first antennas.08-05-2010
20100067605Method and Arrangement for Adapting a Multi-Antenna Transmission - A method in a first node for adapting a multi-antenna transmission to a second node over a wireless channel is provided. The wireless channel has at least three inputs and at least one output. The first node and the second node are comprised in a wireless communication system. The method comprising the steps of: Obtaining (03-18-2010
20100067603Radio Communication Systems And Transmitting Method - A radio transmitter includes a signal generating unit that generates first and second OFDM (Orthogonal Frequency-Division Multiplexing) signals carrying the same information, and a phase shifter that controls a phase of the second OFDM signal based on a spectrum of a composite signal of the first and second OFDM signals.03-18-2010
20110051835UPLINK MIMO TRANSMISSION FROM MOBILE COMMUNICATIONS DEVICES - A method of uplink transmission from a mobile device having multiple antennas to a base station having multiple antennas includes transmitting in an open-loop single-user MIMO mode when the mobile device is at high speed, transmitting in a closed-loop single-user MIMO mode when the mobile device is at low speed, and, upon request, transmitting in a multi-user collaborative MIMO mode. The method also includes controlling uplink transmissions in a selected one of the open-loop single-user MIMO, the closed-loop single-user MIMO and the multi-user collaborative MIMO modes. Uplink transmissions from the mobile device may be transmitted using multiple antennas of the mobile device. Upon request, the mobile device may switch to transmitting in multi-user collaborative MIMO mode with a subset of the multiple antennas.03-03-2011
20110051834METHOD OF TRANSMITTING OF DATA AND CONFIGURING A CODEBOOK IN MULTI ANTENNA SYSTEM - Methods of controlling a transmission power and configuring a codebook in a multi-antenna system to solve a transmission power unbalance between antennas are disclosed. The method of transmitting data in a multi-antenna system includes (A) transmitting one or more pilot signals within a first symbol region through a first antenna unit, and (B) transmitting one or more pilot signals within a second symbol region through a second antenna unit, wherein data within the first symbol region is transmitted through the second antenna unit, and data within the second symbol region is transmitted through the first antenna unit. According to the present invention, since a transmission power unbalance between antennas is solved, a transmission power can be uniformly assigned to each antenna and channel estimation can be easily performed. Moreover, a power amplifier having a uniform amplification range can be used and designed.03-03-2011
20110051833TRANSMITTER SIGNAL INJECTION COMPENSATION - A transceiver mitigates signal leakage into a receive path from a transmit path. A subtraction circuit determines a difference between a receive signal and a compensation signal to produce a compensated receive signal prior to demodulation by a demodulator. An equalizer both amplitude adjusts and phase adjusts orthogonal baseband transmit signals based on the difference from the subtraction circuit to produce the compensation signal. A digital tuning circuit determines at least one amplitude adjust coefficient to be used by the equalizer. The equalizer can have a polarity switch or a variable attenuator or a variable delay.03-03-2011
20110051832METHODS FOR DETERMINING RECONSTRUCTION WEIGHTS IN A MIMO SYSTEM WITH SUCCESSIVE INTERFERENCE CANCELLATION - Certain aspects provide a method for determining decoding order and reconstruction weights for decoded streams to be cancelled in a MIMO system with successive interference cancellation, based on estimates of the channel characteristics, the received composite signal and parameters of the system.03-03-2011
20090262857OFDM Receiving Apparatus and Mode Detecting Method Thereof - Provided are an orthogonal frequency division multiplexing (OFDM) receiving apparatus and a mode detecting method thereof. The mode detecting method includes: detecting a first mode of a received signal by using first delay signals obtained by delaying the received signal, and first correlation values of the received signal; and detecting a second mode of the received signal by using second delay signals obtained by delaying a first correlation value corresponding to the first mode from among the first correlation values, and the first correlation value corresponding to the first mode. According to the OFDM receiving apparatus and the mode detecting method, a fast Fourier transform (FFT) mode is detected first and then a guard interval (GI) mode is detected based on a result of detecting the FFT mode from the same signal, and thus mode detection is accurately and quickly performed and the OFDM receiving apparatus has a reduced chip size.10-22-2009
20110182378PILOT PATTERN DESIGN FOR A STTD SCHEME IN AN OFDM SYSTEM - A transmitting device for transmitting data and pilot symbols in an OFDM transmission system having transmission antennas. The device includes symbol generating means for generating data and pilot symbols, means for transmitting the data and pilot symbols using subcarriers of the OFDM system. The symbol generating means generates a first and second type pilot symbol, the second having an inverted value of the first so that a first pilot symbol pattern to be transmitted by using one of said plurality of transmission antennas has a different pattern in the frequency and time dimension from a second pilot symbol pattern to be transmitted by using another transmission antenna. First and second pilot symbols are comprised in respective first and second pilot symbol patterns, where at least some of the first and second pilot symbols have the same time allocation and being alternately identical and inverted to each other.07-28-2011
20110188599METHOD AND APPARATUS FOR PRE-SCHEDULING IN CLOSED-LOOP MU-MIMO ANTENNA SYSTEM - A method and an apparatus for pre-scheduling in a closed-loop multiple user multiple input multiple output (MU-MIMO) antenna system. A base station receives channel information representing a downlink channel condition of each mobile station from mobile stations in a cell, and determines a candidate user group for each of frequency bands included in an entire frequency band, based on the channel information, the candidate user group including mobile stations to which resources can be simultaneously allocated. The base station also instructs a mobile station included in each candidate user group to transmit a sounding signal through a corresponding frequency band. If the sounding signal is received through the corresponding frequency band, the base station performs a scheduling with regard to the mobile station included in each candidate user group.08-04-2011
20110188597APPARATUS FOR GENERATING AT LEAST ONE DIVERSE SIGNAL BASED ON AT LEAST ONE ASPECT OF AT LEAST TWO RECEIVED SIGNALS - An apparatus for generating at least one signal based on at least one aspect of at least two received signals is provided. The apparatus comprises: a diverse antennae array of M antennae, where M is greater than or equal to two; at least one multiple-input and multiple-output capable transceiver in communication with each antenna in the diverse antennae array of M antennae; encoding circuitry capable of causing first data to be encoded; decoding circuitry capable of causing second data to be decoded; and processing circuitry capable of causing diversity combining, where the processing circuitry is in communication with the multiple-input and multiple-output capable transceiver, the encoding circuitry, and the decoding circuitry. In operation, the processing circuitry is capable of causing the apparatus to: receive at least two first signals, combine at least two of the at least two first signals, generate at least two second signals based on at least one aspect of the at least two first signals, and simultaneously transmit the at least two second signals. Additionally, the apparatus is configured such that at least one of the at least two second signals is capable of being received by a multiple-input capable node.08-04-2011
20110188596METHOD AND APPARATUS FOR DISTRIBUTED SPACE-TIME CODING IN WIRELESS RADIO NETWORKS - A method and apparatus is disclosed herein for performing distributed space-time coding. In one embodiment, the distributed space-time coding is used for downlink communications in wireless radio networks. In one embodiment, the method comprises storing information-bearing sequence at two or more base stations in a group of base stations; and transmitting data corresponding to the information-bearing sequence from a number of base stations for receipt by a receiver of a user, where the number of base stations is not globally known a priori and indicates a diversity of order, such that the diversity of order M is obtained if a total of M number of antennas spread over multiple base stations transmit the information-bearing sequence, where M is an integer.08-04-2011
20110188595Simulation of Multi-Antenna Radio Channel - A radio channel simulation system comprises a plurality of input buses for receiving a beam-specific transmit signal. A transformation module transforms a channel model from antenna domain to beam domain by using a transformation algorithm and beam forming weights. The channel model represented in the beam domain is inputted into a processing module which processes the beam-specific transmit signals according to the channel model represented in the beam domain.08-04-2011
20100166095COOPERATIVE DIVERSITY METHOD AND COOPERATIVE DIVERSITY SYSTEM USING OPPORTUNISTIC RELAYING - There are provided a cooperative diversity method and a cooperative diversity system using opportunistic relaying. In cooperative diversity wireless communications, an optimum relay is selected considering an interference effect between adjacent cells, and the selected relay transmits a data signal received from a transmitter to a receiver. Accordingly, an optimum relay is selected considering interference between channels not only in a single cell environment but also a multi cell environment, and a signal is transmitted to a receiver through the selected relay, thereby increasing transmission efficiency and improving reliability.07-01-2010
20090175375Joint Optimization of Linear Pre-Filtering and Nonlinear Vector Perturbation for MIMO Multiuser Precoding - A method includes jointly optimizing a vector perturbation and a linear pre-filter, applying said vector perturbation to a transmit data vector (s) to produce an output vector, applying said linear pre-filter (G) to said output vector to produce a transmit signal (x), and computing a scaling factor (γ).07-09-2009
20090175376DATA COMMUNICATION IN A WIRELESS COMMUNICATION SYSTEM USING SPACE-TIME CODING - A method of controlling data communication in a wireless communication system comprises measuring channel quality from data received from a base station having multiple antennas, wherein the base station and a mobile station are in a closed loop space-time coding (STC) communication. The method also comprises determining a first weight matrix based on a number of the multiple antennas of the base station, the weight matrix comprising weight elements. The method also comprises determining a second weight matrix from the first weight matrix in response to a predetermined condition, wherein the second weight matrix is associated with controlling data output using the multiple antennas of the base station for subsequent transmission. The method also comprises providing a number of STC outputs to the base station, wherein the number of STC outputs is associated with the second weight matrix.07-09-2009
20110188598METHOD AND APPARATUS OF TRANSMITTING A SPATIAL STREAM FOR MU - MIMO IN A WIRELESS LOCAL AREA NETWORK SYSTEM - A method of transmitting a spatial stream for multi user (MU)-multiple input multiple output (MIMO) in a wireless local area network system, performed by a transmitter is provided. the method includes transmitting, to a receiver, a management frame including group information to assign or change a position of a plurality of spatial streams corresponding to each of a plurality of groups, and transmitting, to the receiver, a frame including at least one spatial stream, wherein the group information includes a plurality of group indicators and a plurality of spatial stream (SS) indicators, each of the plurality of group indicators indicating whether or not the receiver is a member of each of the plurality of groups, each of the plurality of SS indicators indicating a position of the plurality of spatial streams corresponding to each of the plurality of groups.08-04-2011
20090285324APPARATUS AND METHOD FOR SPATIAL MULTIPLEXING IN MULTI INPUT MULTI OUTPUT SYSTEM - Methods and apparatus for spatial multiplexing in a closed-loop Multi Input Multi Output (MIMO) system are provided. In a method of operating a receiver in an MIMO system, a signal transmitted by a transmitter is received. Blockwise-Orthogonalized Spatial Multiplexing (B-OSM) is performed on the received signal. Feedback information determined by performing the B-OSM on the received signal is fed back to the transmitter.11-19-2009
20100027702Stream 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
20100027704Method and Apparatus for Data Transmission Based on Signal Priority and Channel Reliability - Various methods for data transmission based on signal priority and channel reliability are provided. One example method includes encoding a number of bits into coded bits including systematic bits and respective associated parity bits, the bits being encoded for transmission via channels of a multi-channel communications system including a more reliable channel and a less reliable channel. The example method also includes allocating the systematic bits to bit locations within a first stream corresponding to the more reliable channel, allocating the systematic bits to bit locations having a higher signal priority within a second stream corresponding to the less reliable channel, and allocating the parity bits to bit locations within the second stream. Similar and related example methods and apparatuses for allocating the systematic and parity bits to the respective bit locations in both the more and less reliable channels are also provided.02-04-2010
20100027703MULTIPLE-INPUT MULTIPLE-OUTPUT DETECTOR AND DETECTION METHOD USING THE SAME - A multiple-input multiple-output detector and a detection method using the same are provided. The detection method includes following steps. First, a plurality of candidate results is provided by a plurality of detectors. Next, a channel condition and a detected criterion are provided. Finally, one of the candidate results is selected to serve as a detected result according to the channel condition and the selection criterion.02-04-2010
20100020893RADIO COMMUNICATION APPARATUS AND RESENDING CONTROLLING METHOD - A synthesized gain in a resending operation can be improved significantly by relatively simple control when resending control is applied upon executing of a transmission diversity using CDD. A radio communication apparatus equipped with a plurality of antennas and for performing communication by MIMO, includes a phase shift amount assigning section 01-28-2010
20100239039WIRELESS TRANSMISSION SYSTEM, AND WIRELESS STATION AND METHOD USED FOR SAME - A wireless transmission system capable of performing multi-station simultaneous transmission of data by wireless is provided. The wireless transmission system includes a plurality of wireless stations for transmitting and receiving data. Transmitter-side wireless stations, a multipath channel, and receiver-side wireless stations constitute a system for path diversity. At least one wireless station among the wireless stations determines, depending on a response packet with respective to a multi-station simultaneous transmission request packet transmitted by itself or other stations, a plurality of delay amounts from a reference timing during multi-station simultaneous transmission in the wireless transmission system, and a plurality of symbol waveforms that are a basis for a modulated waveform. A difference between each delay amount is set to be larger than or equal to a predetermined delay resolution for each symbol waveform, and a difference between maximum and minimum values of the delay amounts is set to be smaller than or equal to a predetermined maximum delay.09-23-2010
20100061478METHOD FOR SYMBOL SYNCHRONIZATION OF RECEIVED DIGITAL SIGNAL AND DIGITAL SIGNAL RECEIVER USING THE SAME METHOD - A method for symbol synchronization of received digital signal and a digital signal reception apparatus are provided. The method comprises steps of correlating the received digital signal with the received signal delayed by one symbol so as to obtain a first correlation value result as a combined effort of a strongest path and other paths; removing substantially effect of the strongest path from the first correlation result so as to obtain a second correlation result which exhibits contribution of a fastest path; searching a maximum correlation value and its position of the fastest path so as to determine symbol synchronization timing for initiating FFT processing. The digital signal reception apparatus is characterized by a symbol timing detecting unit for determining symbol synchronization timing of the fastest path through substantially removing the effect of a strongest path.03-11-2010
20100195751Method for Estimating Channels in Two-Hop MIMO AF Networks - A method estimates interim channels in a two-hop multi-input-multi-output (MIMO) amplify-and-forward (AF) relay network including a source station (SS), a relay station (RS), and a destination station (DS). The estimate is according to the overall channel obtained at the DS or the SS. By varying an amplifying matrix of the RS over time, the method establishes a linear equation group with respect to the elements of the interim channels over the first (SS-RS) and second (RS-SS) hops, based on which low-complexity estimation of the interim channels is performed.08-05-2010
20100054358METHOD OF TRANSMITTING CONTROL INFORMATION IN WIRELESS COMMUNICATION SYSTEM - A method of transmitting control information in a wireless communication system is provided. The method includes configuring downlink control information including a plurality of information fields according to a format of scheduling for transmission of a single codeword in a spatial multiplexing mode, wherein the plurality of information fields include a preceding matrix indicator (PMI) confirmation filed for indicating whether preceding is performed on downlink data by using a PMI reported by a user equipment and a transmitted preceding matrix indicator (TPMI) information field for indicating a codebook index, and at least one of the PMI confirmation field and the TPMI information field indicates an offset value of power for the downlink data transmission or interference information for the downlink data transmission, and transmitting the downlink control information.03-04-2010
20120307930Scattered Pilot Pattern And Channel Estimation Method For MIMO-OFDM Systems - A method and apparatus are provided for reducing the number of pilot symbols within a MIMO-OFDM communication system, and for improving channel estimation within such a system. For each transmitting antenna in an OFDM transmitter, pilot symbols are encoded so as to be unique to the transmitting antenna. The encoded pilot symbols are then inserted into an OFDM frame to form a diamond lattice, the diamond lattices for the different transmitting antennae using the same frequencies but being offset from each other by a single symbol in the time domain. At the OFDM receiver, a channel response is estimated for a symbol central to each diamond of the diamond lattice using a two-dimensional interpolation. The estimated channel responses are smoothed in the frequency domain. The channel responses of remaining symbols are then estimated by interpolation in the frequency domain.12-06-2012
20120307929FEEDBACK METHOD FOR INTERFERENCE ALIGNMENT IN WIRELESS NETWORK - A feedback method for interference alignment in wireless network having K transmitters and K receivers is provides. The method comprising: transmitting, performed by transmitter n−1, a precoding vector of transmitter n−1 (n is a integer between 2 and K−1) to receiver n+1; calculating, performed by the receiver n+1, a precoding vector of transmitter n using the precoding vector of transmitter n−1; and transmitting, performed by the receiver n+1, the precoding vector of transmitter n to transmitter n.12-06-2012
20120307928SIGNALING AND CHANNEL ESTIMATION FOR UPLINK TRANSMIT DIVERSITY - In a method of transmitting a data stream from a transmitter in a multiple-input-multiple-output (MIMO) wireless communication system, where the transmitter comprises a plurality of transmit antennas, a discrete Fourier transform (DFT) is applied to the data stream to generate a plurality of symbol sequences; symbols of a first symbol sequence from the plurality of symbol sequences are paired with symbols of a second symbol sequence from the plurality of symbol sequences to generate a plurality of symbol pairs, wherein the pairing results in an orphan symbol; a space-time block code (STBC) is applied to the symbol pairs to generate a plurality of sets of STBC symbols, each set of STBC symbols being associated with a corresponding one of the plurality of antennas; a cyclic delay diversity (CDD) operation is applied to the orphan symbol to generate a plurality of CDD symbols, each CDD symbol being associated with a corresponding one of the plurality of antennas; and each one of the antennas transmits the corresponding set of STBC symbols and the corresponding CDD symbol.12-06-2012
20120307926BEAM-FORMER SEARCHING METHOD AND CENTRAL UNIT USING THE METHOD - A beam-former searching method and a central unit using the method are proposed. The proposed method is adapted for a coordinated multi-point transmission for macro-diversity or an interference alignment scheme, and includes following steps. A metaheuristic algorithm is used to search for precoders and postcoders respectively for B of collaborative transmitters and U of receivers, where U=B for interference alignment and U=1 for coordinated multi-point transmission for macro-diversity. Memory is initialized by generating solution vectors randomly Utility functions is computed respectively for the generated solution vectors and the generated solution vectors are sorted respectively according to the computed utility functions. A new solution vector is improvised iteratively until the number of iterations reaches a pre-configured algorithm termination upper limit. In addition, a solution vector is selected as an output according to the computed utility functions.12-06-2012
20120307927METHODS OF DETERMINING RANK INFORMATION AND RELATED COMMUNICATIONS DEVICES AND SYSTEMS - A method of operating a wireless terminal communicating with a base station over a wireless channel may include determining whether the wireless terminal is in an edge area or an interior area of coverage of the base station. Responsive to determining that the wireless terminal is in an edge area of coverage of the base station, a transmit diversity communications rank indicator may be selected to select diversity communications over the wireless channel between the wireless terminal and the base station. Related wireless terminals are also discussed.12-06-2012
20080205538METHOD FOR SER APPROXIMATION FOR OSTBC IN DISTRIBUTED WIRE COMMUNICATION SYSTEMS - A method for Symbol Error Rate (SER) approximation of an SER-based transmission power allocation operation for an Orthogonal Space Time Block Code in a DWCS equipped with multiple transmission Distributed Antennas (DA) geographically dispersed at random. The method for SER approximation includes the steps of: setting multiple combinable antenna subsets from the multiple DAs; selecting a quasi-optimal antenna subset A08-28-2008
20080317158TIME-DOMAIN TRANSMIT AND RECEIVE PROCESSING WITH CHANNEL EIGEN-MODE DECOMPOSITION FOR MIMO SYSTEMS - Techniques for processing a data transmission at the transmitter and receiver. In an aspect, a time-domain implementation is provided which uses frequency-domain singular value decomposition and “water-pouring” results to derive time-domain pulse-shaping and beam-steering solutions at the transmitter and receiver. The singular value decomposition is performed at the transmitter to determine eigen-modes (i.e., spatial subchannels) of the MIMO channel and to derive a first set of steering vectors used to “precondition” modulation symbols. The singular value decomposition is also performed at the receiver to derive a second set of steering vectors used to precondition the received signals such that orthogonal symbol streams are recovered at the receiver, which can simplify the receiver processing. Water-pouring analysis is used to more optimally allocate the total available transmit power to the eigen-modes, which then determines the data rate and the coding and modulation scheme to be used for each eigen-mode.12-25-2008
20100086073SYSTEM AND METHOD TO IMPLEMENT CONCURRENT ORTHOGONAL CHANNELS IN AN ULTRA-WIDE BAND WIRELESS COMMUNICATIONS NETWORK - A system and method for media access control are disclosed. The method comprises providing concurrent orthogonal channels to access media using pulse division multiple access to define pulse positions, wherein the pulse division multiple access includes a time hopping sequence and an offset to distinguish the concurrent orthogonal channels. In addition, the method comprises processing signals associated with at least one of the orthogonal channels.04-08-2010
20090202016OPEN-LOOP TRANSMIT DIVERSITY SCHEMES WITH FOUR TRANSMIT ANTENNAS - In a wireless communication system, SFBC-based (Space-Frequency Block-Code) transmission diversity schemes provide enhancement for multiple antennas, such as the illustrative four, in order to achieve better performance than SFBC-FSTD (SFBC-Frequency Switching Transmit Diversity) alone. SFBC-PFSTD (Precoded Frequency Switching Transmit), which is multiplying a precoding matrix to the SFBC-FSTD signals, opens up the possibility of utilizing the pilot tones in synchronization channels (SSC and/or PSC) to enhance the channel estimation performance for antenna 08-13-2009
20110305291MIMO System Having A Plurality Of Service Antennas For Data Transmission And Reception And Method Thereof - Embodiments provide a MIMO system having a plurality of service antennas and method for data transmission and reception. The system includes a plurality of service antennas, where each service antenna is configured to simultaneously serve a plurality of terminals and independently receive a pilot sequence from the plurality of terminals. The system further includes a plurality of channel estimation units configured to independently generate an antenna-specific channel estimate based on the received pilot sequence and a plurality of pre-coding units configured to independently generate a coded signal to be transmitted to the plurality of terminals via a respective service antenna based on a set of data symbols and the antenna-specific channel estimate.12-15-2011
20110305290DEVICE AND METHOD SUPPORTING MULTI-CARRIER WAVES - Provided are a device and method supporting multi-carrier waves. The device comprises: a multi-carrier control unit for receiving carrier wave allocation data including data relating to allocated carrier waves and deactivating a portion of the carrier waves included in the carrier wave allocation data or else receiving carrier wave control data including data relating to additional carrier waves; and a multi-carrier operation unit which operates using multiple carrier waves allocated on the basis of the carrier wave allocation data and the carrier wave control data. The base station scheduling burden can be reduced and the power consumption of the terminal can be reduced.12-15-2011
20110110450ASYMMETRICAL FEEDBACK FOR COORDINATED TRANSMISSION SYSTEMS - A method includes, in a mobile communication terminal, receiving from at least first and second base stations, which cooperate in a coordinated transmission scheme, signals that are transmitted over respective first and second communication channels. Respective channel measures are calculated for the communication channels based on the received signals. First and second feedback data, which are indicative of the respective channel measures of the first and second communication channels, are formulated such that the first feedback data has a first data size and the second feedback data has a second data size, different from the first data size. The first and second feedback data are transmitted from the mobile communication terminal to at least one of the base stations.05-12-2011
20110110452HIGH-FREQUENCY CIRCUIT, HIGH-FREQUENCY DEVICE, AND COMMUNICATIONS APPARATUS - A high-frequency circuit comprising first and second antenna terminals, a transmitting terminal and first and second receiving terminals for first and second communications systems, and first and second switch circuits each having a common terminal and at least first and second switching terminals; the first antenna terminal being connected to a common terminal of the first switch circuit, the transmitting terminal for the first communications system being connected to the first switching terminal of the first switch circuit, the second antenna terminal being connected to a common terminal of the second switch circuit, the transmitting terminal for the second communications system being connected to the first switching terminal of the second switch circuit, each first receiving terminal for the first and second communications systems being connected to the second switching terminal of the first switch circuit via a first receiving-side multiplexer circuit, each second receiving terminal for the first and second communications systems being connected to the second switching terminal of the second switch circuit via a second receiving-side multiplexer circuit.05-12-2011
20110075753TRANSMISSION/RECEPTION APPARATUS AND METHOD FOR IMPROVING THROUGHPUT IN A MULTI-INPUT MULTI-OUTPUT COMMUNICATION SYSTEM - A method and apparatus for transmitting at least two transport blocks in a Multi-Input Multi-Output (MIMO) communication system, in which a transmitter determines whether a type of a receiver receiving the at least two transport blocks is a Successive Interference Cancellation (SIC) receiver, determines a Modulation and Coding Scheme (MCS) level for the at least two transport blocks depending on whether the type of the receiver is an SIC receiver, and transmits the at least two transport blocks using the determined MCS level.03-31-2011
20120057644INFORMATION PROCESSING METHOD, DEVICE, AND SYSTEM - In the field of communications, an information processing method, device, and system are provided. The information processing method includes: receiving Precoding Control Indications (PCIs); determining a target PCI according to statistics of the PCIs and/or sources of the PCIs; and performing uplink Multiple Input Multiple Output sending control according to the target PCI. A User Equipment and an information processing system are also provided.03-08-2012
20080310541METHOD AND SYSTEM FOR SFBC/STBC IN A DIVERSITY TRANSMISSION SYSTEM USING ALAMOUTI CODES - Aspects of a system for SFBC and/or STBC in a diversity transmission system using a plurality of Alamouti codes may include a transmitting station that enables reception of signals via a wireless communication medium. The transmitting station may enable determination of a plurality of channel estimate values that are based on signal propagation characteristics of the wireless communication medium. A plurality of N weighting factor phase angles may be computed based on the plurality of channel estimate values, where N is an integer that is greater than 1. The transmitting station may enable transmission of a plurality of 2·N signals based on the plurality of N weighting factors. The plurality of 2·N signals may be encoded utilizing Alamouti coding.12-18-2008
20110158341METHOD AND APPARATUS FOR PHASE QUANTIZATION AND EQUAL GAIN PRECODING USING LATTICES - A method and apparatus are disclosed for phase quantization and equal gain precoding in a wireless communication system. The method includes scaling, by a receiving device, a phase vector based on a predetermined scaling factor to determine a first lattice point. The method also includes determining, by the receiving device, a second lattice point based on the determined first lattice point. In addition, the method includes determining, by the receiving device, a quantized phase vector based on the determined second lattice point and the predetermined scaling factor.06-30-2011
20110158340VIRTUAL ANTENNA ARRAY FOR WIRELESS DEVICES - A system for wireless communication is disclosed. The system includes a plurality of antenna nodes configured to receive an incoming signal, extract versions of an incoming packet from the incoming signal, and send the versions on a packet-based network. The system also includes a receive processing node configured to receive the versions of the incoming packet from the antenna nodes, determine if any of the versions are complete packets, and recover a complete version of the incoming packet based on the versions if none of the versions is complete. The system also includes a transmit processing node configured to transmit an outgoing packet on one or more of the antenna nodes based on quality feedback data.06-30-2011
20110158339ANTENNA DIVERSITY SYSTEM WITH MULTIPLE TUNER CIRCUITS HAVING MULTIPLE OPERATING MODES AND METHODS - In an embodiment, a tuner circuit includes an inter-chip receiver circuit configurable to couple to a first inter-chip communication link to receive a first data stream and includes an analog-to-digital converter configured to convert a radio frequency signal into a digital version of the radio frequency signal. The tuner circuit further includes a digital signal processor coupled to the inter-chip receiver circuit and the analog-to-digital converter. The digital signal processor is configurable to generate an output signal related to at least one of the first data stream and the digital version of the radio frequency signal based on a selected operating mode.06-30-2011
20110090981Method and Apparatus For Communication Site Planning - The present invention relates to a solution for determining wireless communication cell characteristics related to wireless MIMO transmission mode and dynamically selecting suitable communication transmission mode for certain parts of the wireless communication cell. The solution uses a flatness spectrum analysis of received impulse response from a plurality of measurement points in the cell using a plurality of antennas in a wireless network access gateway, e.g. a base station.04-21-2011
20110090980CHANNEL INFORMATION PREDICTION SYSTEM AND CHANNEL INFORMATION PREDICTION METHOD - Provided is a channel information prediction system which uses a low ray element in a transformation MIMO CSI to calculate a first prediction filter coefficient. By using the obtained first prediction filter coefficient, the system executes a first prediction for predicting channel information upon a radio signal transmission in the future and suppresses a component of the ray contained in the low ray element. By using the low ray component in which the ray component is suppressed, the system executes a second prediction for predicting channel information upon a radio signal transmission in the future.04-21-2011
20100208836MULTIPLICATIVE NETWORK CODING - Network coding may be performed with encoding and/or decoding that involves a multiplication operation. In an example embodiment, a communication node is adapted to perform multiplicative network coding. The communication node includes an encoder and a decoder. The encoder is arranged to perform an encoding operation by multiplying two or more signals that bear information to form a composite signal. The decoder is arranged to perform a decoding operation by multiplying a received composite signal with one or more complex-conjugated signals, with the decoder yielding a decoded signal that bears information. With the encoding operation, the communication node is adapted to at least partially perform multiplicative-network-coding encoding for a sending communication mode. With the decoding operation, the communication node is adapted to at least partially perform multiplicative-network-coding decoding for a receiving communication mode.08-19-2010
20120045007INSERTING AND DECODING REPLICATED DATA SYMBOLS IN WIRELESS COMMUNICATIONS - Examples are generally described that include transmission methods including inserting at least a portion of data from a first data stream into a second data stream to be transmitted over a communications channel. On receipt of the two data streams, examples of receiving methods include receiving the replicated data, decoding the replicated data using an estimated channel matrix, and generating an updated estimate of the channel matrix based, at least in part, on the replicated data.02-23-2012
20120045006RADIO FREQUENCY FRONT END CIRCUIT - A RF front end circuit includes a processor, a main receiving (Rx) path and an adjustment path connected between the processor and an external antenna array in parallel, and a coupling module coupled with the main Rx path. The adjustment path includes an adjustment transmitting (Tx) path, an adjustment Rx path, and a DSP. The adjustment Tx path includes a coupling switch. When the circuit operates in an adjustment mode, the switch is connected to the coupling module, the adjustment Rx path receives and demodulates a first analog signal, the DSP converts the first analog signal to a digital signal, clipping a peak of the digital signal, and converts the digital signal to a second analog signal, the adjustment Tx path modulates and reverses the phase of the second analog signal, and the coupling module couples the second analog signal to the main Rx path to counteract noise received thereby.02-23-2012
20120002743Statistical Joint Precoding in Multi-Cell, Multi-User MIMO - A network node jointly precodes multi-user (MU) multiple-input multiple-output (MIMO) transmissions simultaneously sent from geographically distributed base stations to a plurality of mobile terminals over associated downlink MU-MIMO channels. The node receives feedback that describes statistics of the downlink MU-MIMO channels, including channel mean and covariance. The node then computes, based on the channel means and covariances, uplink input covariances for the mobile terminals that would collectively maximize a first or second-order approximation of the ergodic capacity of dual uplink MU-MIMO channels, subject to a global transmit power constraint that comprises the sum of individual transmit power constraints for the base stations. Notably, the node also adjusts the uplink input covariances as needed to satisfy the individual transmit power constraints for the base stations, maps the uplink input covariances to corresponding downlink input covariances, and jointly precodes MU-MIMO transmissions sent over the downlink MU-MIMO channels based on those downlink input covariances.01-05-2012
20120002742MIMO CHANNEL STATE INFORMATION ESTIMATION WITH COUPLED ITERATIVE TWO-STAGE RANKING - A plurality of wireless channels link a transmitter and a receiver, each channel corresponding to a different transmit-receive antenna pair. Channel state information is estimated for the plurality of wireless channels by grouping the plurality of channels into one or more groups, each group including the channels associated with two or more collocated transmit and/or receive antennas. A set of delay tap values is iteratively estimated in the time domain for each group of channels so that the channels included in the same group are associated with the same delay tap values. A frequency domain channel response of each of the channels included in the same group of channels is estimated based on the set of delay tap values estimated for the group.01-05-2012
20120002744Methods and Systems for Transmitting an Information Signal in a Multiple Antenna Communication System - Methods and systems are provided for transmitting a plurality of information signals in a multiple antenna communication system. One or more information signals are coded using a plurality of coders to generate the plurality of coded information signals and an Inverse Fast Fourier Transformation is performed on each of the plurality of coded information signals to create a corresponding output signal. Each of the corresponding output signals are transmitted on a different antenna. Each of the plurality of coded information signals can optionally be separated into K signals, On the receiver side, a signal comprising K different frequencies is received on at least N receive antennas and a Fast Fourier Transformation is applied to each of the at least N received versions of the signal comprising K different frequencies to generate N*K low frequency signals. The N*K separate low frequency signals are then combined to recover a transmitted information signal, based on one or more transfer functions from each of a plurality of transmit antennas to each of the N receive antennas.01-05-2012
20120207236APPARATUS AND METHOD FOR RECEIVING DATA IN COMMUNICATION SYSTEM - Disclosed is an apparatus for receiving data in a communication system, including: a receiving unit configured to receive data transmitted from an access point (AP) by a multi-input multi-output (MIMO) scheme; a detecting unit configured to detect a data stream of the received data using an LQ decomposition scheme; a generating unit configured to generate channel information regarding the data stream; and a transmitting unit configured to feedback the channel information to the AP.08-16-2012
20120207238METHOD AND APPARATUS FOR PROCESSING PRECODER - The present invention provides a method and an apparatus for processing a precoder. The method comprises: step A: a base station determining whether the number of received effective precoders reported by a certain UE is greater than or equal to a threshold a, if so, executing step B, otherwise, executing step D; step B: the base station determining whether each received effective precoder is according to the same number of layers, if so, executing step C, otherwise, executing step D; step C: the base station determining whether a variation speed of each effective precoder is fast, if so, applying a transmit diversity transmission mode to the UE, otherwise, applying a MIMO transmission mode to the UE; and step D: applying the MIMO transmission mode to the UE. Therefore, the present invention can reasonably predict the transmission mode and the precoder that should be employed in the transmission mode at current time for a certain UE.08-16-2012
20110064156METHOD OF TRANSMITTING FEEDBACK INFORMATION FOR PRECODING AND PRECODING METHOD - Precoding methods and method for performing precoding and methods of transmitting feedback information for precoding or transmitting a signal using a multi-codebook and method of transceiving precoding information in a multi-antenna system, where a signal transmitting method in a multi-antenna system, and more particularly, a method of transceiving precoding matrix information for a multi-input multi-output (MIMO) system is disclosed. The present invention proposes a method of performing communications using an expanded unitary matrix generated from shifting a phase of a base unitary matrix. The present invention is applicable to single user MIMO, multi-user MIMO, beam forming, etc.03-17-2011
20120008703COMMUNICATION APPARATUS, COMMUNICATION SYSTEM AND CHANNEL FEEDBACK METHOD THEREOF FOR USE IN MULTI-INPUT MULTI-OUTPUT NETWORK - A communication apparatus, a communication system and a channel feedback method thereof for use in multi-input multi-output network are provided. The communication apparatus and the communication system communicate with each other via first antenna and second antenna respectively. The communication apparatus and the communication system transmit sounding signals via two high-related sounding channels and determine phase information of the signal transmitted in the channel between the communication apparatus and the communication system accordingly.01-12-2012
20120114057WIRELESS COMMUNICATION DEVICE, WIRELESS COMMUNICATION SYSTEM AND INFORMATION NOTIFYING METHOD - A wireless communication device or an access point includes: a main unit; an external antenna unit; a throughput check module; and a notification controller, a notice applying circuit and a notice generating circuit. The main unit is for including a communication control circuit. The external antenna unit is for including an antenna and is electrically connected with the main unit via a cable. The throughput check module is for checking throughput of communication with another wireless communication device or a station. The notification controller, the notice applying circuit and the notice generating circuit are for notifying a user of system information based on check result by the throughput check module, by using the external antenna unit. This configuration improves the work efficiency of antenna adjustment at the wireless communication device using the external antenna unit.05-10-2012
20120014469WIRELESS COMMUNICATION SYSTEM, DEVICE AND METHOD - A wireless communication system includes an inverse matrix calculating unit which uses an inverse matrix of a channel matrix of a first combination of L antennas (where L is an integer, 1≦L≦N) selected from the N antennas, so as to calculate an inverse matrix of a channel matrix of a second combination of L antennas selected from the N antennas through an arithmetic operation, and an antenna selecting unit which selects a combination of L antennas from the N antennas as L antennas to be used for communication, the selected combination determining a reference value for antenna selection related to the inverse matrix calculated by the inverse matrix calculating unit so that the reference value for antenna selection fits a successive interference cancellation process carried out for a signal transmitted from the L antennas of the selected combination.01-19-2012
20120057645 METHOD FOR COMMUNICATING IN A NETWORK - The present invention relates to a method for operating a communication system in a network, the system comprising a primary station and at least one secondary station, the primary station comprising a plurality of transmit antennas and the secondary station comprising a plurality of receive antennas, the method comprising the steps of the primary station selecting a first communication scheme among a plurality of communication schemes, the primary station computing a transmission vector on the basis of the first communication scheme, the secondary station computing a reception vector on the basis of a second communication scheme, the second communication scheme being selected among the plurality of communication schemes by the secondary station on the assumption that a predetermined communication scheme is being used by the primary station.03-08-2012
20120057643MULTIPLE INPUT, MULTIPLE OUTPUT WIRELESS COMMUNICATION SYSTEM, ASSOCIATED METHODS AND DATA STRUCTURES - Briefly, in accordance with one or more embodiments, in response to receiving a wireless communication signal, a non-uniform codebook is generated based at least in part on one or more characteristics of the received wireless communication signal for quantization and communication back to a source of the received signal. The non-uniform codebook may be generated by selecting a suitable uniform codebook based at least in part on the one or more characteristics of the received wireless communication signal, and supplementing the uniform codebook with additional codewords to generate the non-uniform codebook.03-08-2012
20110064160Method for Transmitting Data in a MIMO System and Communication System for Transmitting Data in a MIMO System - Method for transmitting data in a MIMO system and communication system for transmitting data in a MIMO system. A method for transmitting data in a communication system is provided. The method includes the steps of selecting a first channel (C03-17-2011
20110064159METHOD AND APPARATUS FOR TRANSMITTING DOWNLINK SIGNAL IN A MIMO WIRELESS COMMUNICATION SYSTEM - A method and apparatus for transmitting a downlink signal in a multiple input multiple output (MIMO) wireless communication system is disclosed. A method for receiving a downlink signal from a base station to a user equipment in a multiple input multiple output (MIMO) system, which supports dual layer transmission based on first and second antenna ports, comprises receiving downlink control information (DCI) through a downlink control channel; and receiving downlink data through a downlink data channel, the downlink data including one or more of a first transport block and a second transport block, wherein the downlink control information includes a new data indicator (NDI) for each of the first and second transport blocks, and if the first transport block is disabled and the second transport block is enabled, the new data indicator for the first transport block indicates an antenna port through which the second transport block is received.03-17-2011
20110064158DIFFERENTIAL FEEDBACK SCHEME FOR CLOSED-LOOP MIMO BEAMFORMING - A first N×M codebook of a first rank M may be used to generate a second N×(N−M) codebook of a second rank (N−M). This second codebook is both orthogonal and complementary to the first codebook. In practice, this may reduce storage requirements in closed-loop MIMO beamforming, because the second codebook may be dynamically generated as needed by a base station and/or a mobile station. In some cases, a higher rank beamforming matrix or precoding matrix may be formed from a lower rank (e.g., one or two) beamforming matrix or precoding matrix. Also, a novel way to generate the rotation matrix Q03-17-2011
20110064157Spectrally flat delay diversity transmission - Delay diversity is implemented within a wireless system in a manner that can achieve a relatively flat spectrum in a receiving device. In at least one embodiment, phase shift values from an orthogonal P×N matrix A are used to provide phase shifts to a data packet to be transmitted from N transmit antennas, in a single spatial stream, to a remote wireless device. The matrix A is an orthogonal matrix with A·A03-17-2011
20120114056METHOD AND APPARATUS FOR INTERFERENCE CANCELLATION AND DETECTION USING PRECODERS - A method to achieve full diversity without sacrificing bandwidth and with a linear complexity in a wireless system includes the steps of orthogonally transmitting a plurality of signals utilizing multiple antennas using a corresponding plurality of precoders in a plurality of time slots, which precoders are designed using the channel information to cancel interference among the plurality of signals while achieving a maximum possible diversity of NM with low complexity for at least two users each having N transmit antennas and one receiver with M receive antennas, separating the signals in the receiver using the orthogonality of the transmitted signals, and decoding the signals independently to provide full diversity to the at least two users.05-10-2012
20120063530COMMUNICATION DEVICE - The configuration of a system for conventional MIMO-OFDM transmission is complicated because different phase rotations are applied to respective subcarriers and antennas. Therefore, a system includes: a copy unit that copies a group composed of a predetermined number of symbols and a predetermined number of subcarriers to produce a plurality of groups; a phase rotation unit that applies different phase rotations to the plurality of copied groups; and a plurality of transmitting antennas that transmits, to a receiver, the plurality of respective groups to which the phase rotations have been applied.03-15-2012
20120027116MULTICARRIER TECHNIQUES FOR WIRELESS SYSTEMS - Multicarrier techniques for wireless communications system are described. An apparatus may comprise a carrier management module to define a primary carrier for use by a multicarrier communications system to communicate control information, and a secondary carrier for use by the multicarrier communications system to communicate media information, with the secondary carrier having a communication parameter and technology that is potentially different from the primary carrier. Other embodiments are described and claimed.02-02-2012
20120027113STRUCTURED MIMO CODEBOOK - Provided is a method of wireless communication which includes selecting a codebook from a plurality of codebooks in accordance with an antenna characteristic, and transmitting an indication of the selected codebook. Each of the plurality of codebooks is associated with one of a plurality of antenna characteristics. In some designs, channel state information is received from a user equipment. The channel state information may be used to determine downlink scheduling and/or precoding. In some designs, the channel state information may include feedback elements associated with different subband granularity. The feedback elements may also indicate a selection of a subset of precoder column vectors and/or a phase offset between two groups of transmit antennas.02-02-2012
20120027115Method and Apparatus for Impairment Correlation Estimation in a Wireless Communication Receiver - A wireless communication receiver improves signal impairment correlation estimation in MIMO/MISO systems by considering different transmit power allocations and different transmit antenna power distributions in its impairment correlation calculations. The receiver may be implemented in according to a variety of architectures, including, but not limited to, Successive Interference Cancellation (SIC) Generalized RAKE (G-RAKE), Joint Detection (JD) G-RAKE, and Minimum Mean Squared Error (MMSE) G-RAKE. Regardless of the particular receiver architecture adopted, the improved impairment correlations may be used to calculate improved (RAKE) signal combining weights and/or improve channel quality estimates for reporting by receivers operating in Wideband CDMA (W-CDMA) systems transmitting HSDPA channels via MIMO or MISO transmitters. A transmitter may be configured to facilitate impairment correlation determinations by wireless communication receivers operating in MIMO/MISO environments, by signaling one or more values, e.g., data-to-pilot signal transmit power ratios and/or transmit antenna power distributions for the data and pilot signals.02-02-2012
20120027112Antenna Switching in a Closed Loop Transmit Diversity System - A method for closed loop transmit diversity is disclosed. Data from user equipment (UE) that was transmitted using multiple transmit antennas is received. A new transmit antenna is selected for the UE. A new cycle period for the UE is determined. A new transmit antenna index and a testing indication based on the new cycle period are sent to the UE.02-02-2012
20120027111METHOD AND APPARATUS FOR MAJOR GROUP SCHEDULING IN A FIXED BEAM COMMUNICATION SYSTEM - An OFDMA communication system is provided that schedules partial usage of subchannels (PUSC) major groups by assigning a beam matrix of a plurality of beam matrices to each major group of multiple PUSC major groups, receiving an uplink signal from each user equipment of multiple users equipment, which uplink signal provides an indication of a channel response associated with the user equipment, determining, for each user equipment of the multiple users equipment and based on the indication of channel quality received from the user equipment, a beam matrix and major group to which to assign the user equipment, and based on the determination of a beam matrix and major group to which to assign each user equipment of the multiple users equipment, assigning two or more users equipment of the multiple users equipment to a same beam matrix and major group during a same time slot.02-02-2012
20120027114BEAMFORMING BY ANTENNA PUNCTURING - Beamforming is provided for a wireless MIMO device by using antenna puncturing to reduce the number of transmit antennas that are used to transmit data for certain subcarriers. In a conventional approach, if N spatial streams are being used to provide spatial multiplexing, then N transmit antennas would be used to transmit for each subcarrier. In at least one embodiment of the invention, enhancements in channel capacity are achieved by using less than N transmit antennas for one or more subcarriers.02-02-2012
20120106667SYSTEMS AND METHODS OF TRANSMITTER PROTECTION FOR WIRELESS COMMUNICATIONS - Various embodiments provide for systems and methods for wireless communications that implement transmitter protection schemes using spatial combining. The protection scheme implemented by some embodiments provides for a number of benefits, including without limitation: hitless protection; constant power monitoring for each wireless channel being utilized; extra gain to wireless signals transmitted; beam steering, beam hopping, and beam alignment capabilities; and varying levels of transmission path protection (e.g., 1+1 protection, or 1+N protection). Additionally, the features of some embodiments may be applied to a variety of wireless communications systems including, for example, microwave wireless systems, cellular phone systems and WiFi systems.05-03-2012
20120063528SYSTEM AND METHOD FOR POWER CONTROL IN MIMO SYSTEMS - The return channel in a multiple-input and multiple-output (MIMO) communication system is used to provide signal information on an individual-channel basis. In one embodiment, in a controlled factory environment, this information may be used to incrementing up or down the variable gain amplifier and/or the power amplifier of a MIMO transmitter and/or receiver so as to generate a default signal power offset to be used during normal operation. Thereafter, such signal information may similarly be provided via the return channel and used to further adjust the transmit parameters to account for location-specific signal conditions.03-15-2012
20120063529INTER-CELL INTERFERENCE MITIGATION METHOD USING SPATIAL COVARIANCE MATRIX ESTIMATION METHOD FOR INTER-CELL INTERFERENCE MITIGATION OF MIMO ANTENNA OFDM SYSTEM - Disclosed is an inter-cell interference mitigation method using a spatial covariance matrix (SCM) estimation method in a multi-input multi-output (MIMO) orthogonal frequency division multiplexing (OFDM) communication system for mitigating interference between asynchronous cells. The inter-cell interference mitigation method includes extracting a reference symbol (RS) of a received OFDM symbol and performing channel estimation, estimating an initial SCM using the RS signal and the channel estimation result, applying time-domain sinc type weighting to the initial SCM and applying an SCM, and demodulating a data symbol with mitigated inter-cell interference using the channel estimation result and the estimated SCM. By applying time-domain sinc type weighting to SCM estimation, it is possible to reduce an SCM estimation error occurring due to a spectral leakage induced by an abrupt change in a signal at a border point between an effective sub carrier zone and a guard band zone, and a simple design of a moving average filter form for a frequency domain signal can be made instead of frequency-time-frequency domain transformation using an inverse fast Fourier transform (IFFT) and fast Fourier transfer (FFT).03-15-2012
20120170677COORDINATED LINEAR BEAMFORMING IN DOWNLINK MULTI-CELL WIRELESS NETWORKS - System and methods are disclosed for optimizing wireless communication for a plurality of mobile wireless devices. The system uses beamforming vectors or precoders having a structure optimal with respect to the weighted sum rate in a multi-cell orthogonal frequency division multiple access (OFDMA) downlink. A plurality of base stations communicate with the mobile devices and all base stations perform a distributed non-convex optimization exploiting the determined structure.07-05-2012
20120170676Robust 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.07-05-2012
20120170675PRE-CODING METHOD AND APPARATUS - The present invention provides a pre-coding method in a multi-user macro-diversity transmission system. The method comprises: obtaining, for a mobile station in the multi-user macro-diversity transmission system, a first sub-precoder that guarantees orthogonality between equivalent channels of users; obtaining a second sub-precoder by performing QR decomposition based on equivalent channels precoded through the first sub-precoder; obtaining a final pre-coder with respect to the mobile station by combining the first sub-precoder and the second sub-precoder; and performing pre-coding on data of the mobile station with the final precoder The present invention further provides a corresponding base station and a multi-user macro-diversity transmission system. Through the technical solution of the present invention, the multi-user macro-diversity transmission system may achieve more macro-diversity gain, thereby greatly enhancing the performance of the multi-user macro-diversity transmission.07-05-2012
20120170674APPARATUS AND METHOD FOR TRANSMITTING/RECEIVING DATA IN A MULTI-ANTENNA SYSTEM, AND SYSTEM USING THE SAME - A data reception apparatus and method for generating and transmitting feedback information in a multi-antenna system using grouped antennas, and a data transmission apparatus and method for transmitting a data stream of a user according to a transmission mode selected depending on the feedback information is disclosed. The reception apparatus generates feedback information depending on maximum channel quality information, an antenna group index associated with the maximum channel quality information, rank information, and remaining channel quality information associated with the rank information, and transmits the feedback information to the transmission apparatus. The transmission apparatus selects one of a multi-user mode and a single-user mode as a transmission mode depending on the feedback information and transmits a data stream of a user via multiple antenna groups or one antenna group, according to the selected transmission mode.07-05-2012
20090135944Cooperative-MIMO Communications - Spatial subchannel codes for wireless devices operating in a cooperative antenna array are generated using an asymptotically optimal decoding algorithm, such as a trellis-exploration algorithm similar to the Viterbi algorithm. A trellis may be constructed using a number of desired subchannels, at least one code length, and a number of code-chip parameters. A fitness function is derived from a mathematical relationship between codes, and may include some measure of correlation of the codes. The selected codes correspond to paths having optimal path metrics derived from the fitness function. Multiple iterations through the trellis may be performed to refine a selection of the codes.05-28-2009
20090135943COMMUNICATION APPARATUS AND CONTROLLING METHOD THEREOF - To determine an appropriate transmission rate more efficiently in communication which uses multiple-input multiple-output technique, a communication apparatus which selects one of a plurality of transmission rates determined by a set of modulation schemes for streams and communicates with an external device using the MIMO technique of performing transmission using a plurality of streams includes a change unit which changes the transmission rate, and a determination unit which determines, based on a transmission power to be allocated to each stream and the modulation scheme of each stream, the transmission rate to be changed by the change unit so as to make the power per bit of each stream at the transmission rate after change remain unchanged or increase.05-28-2009
20090135942APPARATUS AND METHOD FOR TRANSMITTING DATA USING MULTI-ANTENNA - Provided are an apparatus and method for transmitting data using a multi-antenna. The apparatus includes a transmission buffer selecting unit for selecting transmission buffer of an antenna group corresponding to characteristics of each aggregated Medium access control Protocol Data Units (MPDU) when a list of aggregated MPDUs to transmit is received; a data transmitting unit for generating a list of aggregated MPDUs to transmit with storage information of the aggregated MPDUs, transferring the generated list to the transmission buffer selecting unit and transmitting corresponding aggregated MPDUs through the selected transmission buffer; and a timing controlling unit for controlling a transmission timing of each aggregated MPDU.05-28-2009
20090135939APPARATUS AND METHOD FOR SPACE-TIME CODING IN MULTIPLE-ANTENNA SYSTEM - Disclosed is a space-time coding apparatus and method to flexibly adjust diversity/multiplexing orders in a multiple-antenna system. The transmitting apparatus for the multiple-antenna system includes a space-time code controller, an encoder, a demultiplexer, and a space-time encoder. The space-time code controller generates space-time codes by determining bases according to a multiplexing order required by a receiver. The encoder modulates and encodes data destined for the receiver in accordance with a predetermined modulation level. The demultiplexer demultiplexes data received from the encoder in order to transmit the data through at least one antenna. The space-time encoder space-time-codes the demultiplexed data using the space-time codes.05-28-2009
20130170572Mobility-Resilient Multi-Antenna Communications - The antenna weight selection solution disclosed herein selects antenna weights for a multiple antenna communication system that transmits uplink or downlink data using multiple radiation patterns based on channel variability metrics determined for two or more sets of candidate antenna weights. In so doing the antenna weight selection solution disclosed herein reduces the channel variability associated with data transmissions, and therefore reduces the amount of feedback and/or the feedback rates required for the multiple antenna communication system.07-04-2013
20120155562MULTI-ANTENNA COMMUNICATION SYSTEM - A system is provided for communications between at least two telecommunications devices, at least one being onboard an aircraft, said devices comprising means for sending and/or receiving digital data, said data being classed in at least two categories, the first category corresponding to critical data, the second category corresponding to non-critical data. The data are sent on M antennas and received on N antennas. A matrix H of dimension M×N representative of the multi-antenna propagation channel is estimated and the data are sent according to a mode of transmission selected from among at least two multi-antenna modes. A first robust mode uses a scheme of Alamouti type, a second high-speed mode uses a scheme of BLAST type. The critical data are transmitted using the robust mode, the non-critical data being transmitted using one of the two multi-antenna modes. The high-speed mode is selected when the rank RH of the matrix H exceeds a previously chosen threshold value SR.06-21-2012
20120207237WIRELESS COMMUNICATION SYSTEM USING PILOT SUBCARRIER ALLOCATION - A method of transmitting pilot signals by a transmitter in a multiple-input multiple-output (MIMO) antenna system using an orthogonal frequency division multiplexing (OFDM) scheme includes allocating pilot subcarrier locations within a resource block including OFDM symbols in a time domain and subcarriers in a frequency domain based on variables of ‘18k’, ‘9mi’ and ‘floor (ns/2)’, wherein ‘k’ indicates a subchannel index, ‘ns’ indicates a symbol index, ‘mi’ corresponds to ‘(ns+i)mod 2’, ‘i’ indicates an antenna index, wherein ‘floor (n)’ denotes a greatest integer that is not greater than ‘n’; and transmitting the pilot signals to a receiver based on the allocated pilot subcarrier locations.08-16-2012
20120207234Method for Transmitting Digital Data, and Transmitter Base Implementing Such a Method - A method for transmitting digital data on a communication channel, between a transmitter base comprising N transmission antennas and K receivers. A signal carrier of frequency f08-16-2012
20110069774Methods and Systems for Providing Feedback for Beamforming and Power Control - Methods and systems for providing feedback for beamforming and power control are provided. In some embodiments, the methods comprise: calculating a threshold associated with a subcarrier; receiving the subcarrier containing an information symbol at the receiver; determining a channel estimate of the subcarrier and a weighting vector for the information symbol; based at least on the channel estimate and the weighting vector, determining a power level of the subcarrier; comparing the power level to the threshold; generating a feedback signal indicating a first energy level to be used for the subcarrier based on the comparison; subsequent to generating the feedback signal, determining a second power level of the subcarrier; comparing the second power level to the threshold; and generating a second feedback signal to the transmitter indicating a second energy level to be used for the subcarrier.03-24-2011
20120300868Method and System for MIMO Channel Information Feedback - The present invention discloses a method for Multiple Input Multiple Output (MIMO) channel information feedback, and the method includes: a terminal selecting part of column vectors for MIMO system feedback from a codebook matrix W corresponding to a Precoding Matrix Indicator (PMI) and marking the selected part of column vectors as W11-29-2012
20120300867MODEL-BASED CHANNEL ESTIMATOR FOR CORRELATED FADING CHANNELS AND CHANNEL ESTIMATION METHOD THEREOF - A model-based channel estimator for correlated fading channels adapted to a multiple-input multiple-output (MIMO) system, estimates a coefficient vector of a channel matrix for a given angle of departure (AoD) according to a plurality of received signals, a plurality of transmit pilots, a plurality of known model orders, and a plurality of predetermined bases for exploiting time, frequency, spatial channel correlation among a transmit antenna array, and spatial channel correlation among a receive antenna array, then estimates a mean AoD based on the estimated channel matrix. The channel estimator estimates iteratively the coefficient vector and the mean AoD until a stop criterion is met. Then, it reconstructs a channel estimate by using the plurality of predetermined bases, the coefficient vector, and the mean AoD.11-29-2012
20090262856HIGH DATA RATE UPLINK TRANSMISSION - A user equipment device has a control information decoder configured to receive and decode an uplink scheduling grant. A transmit module is configured to receive a rank indicator (RI) extracted by the decoder and adapt a transmission rank in response to the RI. At least two transmit antennas are configured to transmit according to the RI.10-22-2009
20120106668METHOD AND SYSTEM FOR AN ALTERNATING CHANNEL DELTA QUANTIZER FOR MIMO PRE-CODERS WITH FINITE RATE CHANNEL STATE INFORMATION FEEDBACK - Aspects of a method and system for an alternating channel delta quantizer for MIMO pre-coders with finite rate channel state information feedback may include quantizing a change in channel state information in a MIMO pre-coding system onto a codebook using a cost function and selecting the codebook from a set of codebooks; and generating the set of codebooks from a plurality of codebooks, where each may comprise one or more unitary matrices. The channel state information may be a matrix V that may be generated using Singular Value Decomposition (SVD) and/or Geometric Mean Decomposition (GMD). The selecting of the codebooks may be enabled by alternating between the elements of the set of codebooks. The cost function f(A) may be defined by the following relationship:05-03-2012
20100172429DIGITAL BROADCASTING RECEIVING APPARATUS - A digital broadcasting receiving apparatus is characterized in that the digital broadcasting receiving apparatus is provided with an antenna combination determination processing unit for selecting at least two antennas from among a plurality of antennas which have directivities in different directions and each of which receives a digital broadcasting wave transmitted from outside the digital broadcasting receiving apparatus, and for providing an instruction for switching among the above-mentioned plurality of antennas on the basis of a state of reception of the digital broadcasting waves received by the selected antennas, and switches for switching among the above-mentioned plurality of antennas according to the instruction from the above-mentioned combination determination processing unit.07-08-2010
20120121032COMMUNICATION STATION AND METHOD FOR TRANSMITTING OFDM SYMBOLS WITH CYCLIC-DELAY DIVERSITY (CDD) - A communication station uses a plurality of antennas for transmission of orthogonal frequency division multiplexed (OFDM) symbols. The communication station includes an interleaver to interleave a block of encoded bits of an associated input bit stream for use in generating an output bit stream having a desired code rate. The communication station also includes circuitry to modulate the bits of the output bit stream to generate complex-valued modulation symbols, circuitry to map the modulation symbols for transmit diversity to layers for each of the antennas based on a number of antennas used and to further map the modulation symbols for each antenna onto resource elements, circuitry to cyclically shift the mapped modulation elements, circuitry to provide the cyclically-shifted modulation symbols for transmission by an associated one of the antennas, and circuitry to add a cyclic prefix to the modulation symbols prior to transmission.05-17-2012
20120121031Method and Apparatus for Demodulation of a Reference Signal - A method for wireless network communication is provided. The method comprises determining, by a transmitter including a quantity of antennas, a quantity of transmitted layers; mapping a quantity of data symbols to the antennas using a quantity of precoders; generating a quantity of demodulation reference signal (DMRS) antenna ports based on the quantities of the antennas, the transmitted layers, and the precoders; and determining whether to precode at least one of the DMRS antenna ports with the precoders. The method further maps the precoded data symbols and the DMRS antenna ports to a quantity of resource elements. The method then modulates a signal comprising the resource elements and transmits the modulated signal to a receiver. Subsequently, the method estimates a channel received by the receiver over the DMRS antenna ports.05-17-2012
20100290552WIRELESS COMMUNICATION SYSTEM, RECEIVER, TRANSMITTER, WIRELESS COMMUNICATION METHOD, RECEIVING METHOD, AND TRANSMITTING METHOD - A system that combines MIMO spatial multiplexing and dual polarization transmission is provided. The system is constructed with a simple circuit configuration, whereby a wireless communication system which accurately demodulates signals that are multiplexed doubly, both spatially and in polarization, is provided. The wireless communication system is a MIMO communication system that uses a plurality of antennas to form a plurality of fixed transmission channels, and includes a transmitting section and a receiving section. The transmitting section performs MIMO spatial multiplexing as well as dual polarization transmission of transmitting two independent signals in the same band by using two mutually orthogonal polarizations of radio waves as signals to be transmitted from respective antennas on a transmitting side. The receiving section includes an inference canceller and a MIMO signal processing circuit that is connected to the interference canceller. The interference canceller performs signal processing for eliminating an interference component between the polarizations by adaptive control on signals received by respective antennas on a receiving side. The MIMO signal processing circuit performs signal processing for MIMO spatial demultiplexing independent of the signal processing of the interference canceller.11-18-2010
20120163486Method of Selecting Antennas in a Wireless Communicating Network for High Reliability and Low Latency - A network includes a transmitter and a receiver, wherein the transmitter includes a set of transmit antennas and the receiver includes a set of receive antennas. The transmitter duplicates a packet as copies of the packet, and selects subsets of the set of transmit antennas independent of channel characteristics between the subsets of transmit antennas and the set of receive antennas, wherein combinations of the antennas in the subsets of the transmit antennas are different. The receiver selects subsets of the set of receive antennas independent of channel characteristics between the subsets of receive antennas and the set of transmit antennas, wherein combinations of the antennas in the subsets of the receive antennas are different. The selected subsets are used to transmit the packet, and retransmit the packet in case of a failure in a previous transmission.06-28-2012
20100246704METHOD 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.09-30-2010
20120128090METHOD FOR PROVIDING INFORMATION OF ACCESS POINT SELECTION - A method for providing information of access point (AP) selection in a wireless local area network (WLAN) system is provided. The method includes: receiving from candidate APs the AP selection information comprising channel correlation information for other stations associated with the candidate APs; and selecting one AP from candidate APs according to the channel correlation information corresponding to the candidate APs. Accordingly, a gain of multi-user multiple input multiple output (MIMO) can be increased, and an AP suitable for a terminal can be selected.05-24-2012
20120128089WIRELESS COMMUNICATION SYSTEM, TRANSMITTING APPARATUS, WIRELESS COMMUNICATION METHOD, AND CONTROL METHOD FOR TRANSMITTING APPARATUS - A wireless communication system includes a transmitting apparatus, and a plurality of receiving apparatuses. A first receiving apparatus among the plurality of receiving apparatuses includes, a first receiver that receives wireless signals transmitted from a plurality of antennas of the transmitting apparatus, a first processor that selects, from among a plurality of transmission weights, a transmission weight that allows a quality of a wireless signal to satisfy specified criteria, and a first transmitter that transmits weight information concerning the selected transmission weight to the transmitting apparatus. The transmitting apparatus including a second receiver that receives the weight information from the first receiving apparatus, and a second processor that corrects for a phase difference among the plurality of antennas based on the weight information, the weight information relating to positional information concerning a position of the first receiving apparatus.05-24-2012
20100215115RECEIVER SPATIAL PROCESSING FOR EIGENMODE TRANSMISSION IN A MIMO SYSTEM - For eigenmode transmission with minimum mean square error (MMSE) receiver spatial processing, a transmitter performs spatial processing on NS data symbol streams with steering vectors to transmit the streams on NS spatial channels of a MIMO channel. The steering vectors are estimates of transmitter steering vectors required to orthogonalize the spatial channels. A receiver derives a spatial filter based on an MMSE criterion and with an estimate of the MIMO channel response and the steering vectors. The receiver (1) obtains NR received symbol streams from NR receive antennas, (2) performs spatial processing on the received symbol streams with the spatial filter to obtain NS filtered symbol streams, (3) performs signal scaling on the filtered symbol streams with a scaling matrix to obtain NS recovered symbol streams, and (4) processes the NS recovered symbol streams to obtain NS decoded data streams for the NS data streams sent by the transmitter.08-26-2010
20100208839CLOSED-LOOP RATE CONTROL FOR A MIMO COMMUNICATION SYSTEM - In a MIMO system, rate control is achieved with an inner loop that selects rates for data streams sent via a MIMO channel and an outer loop that regulates the operation of the inner loop. For the inner loop, SNR estimates are obtained for each data stream based on received pilot symbols and/or received data symbols. An effective SNR is derived for each data stream based on the SNR estimates, a diversity order, a MIMO backoff factor, and an outer loop backoff factor for the data stream. The rates are then selected for the data streams based on the effective SNRs for the data streams. The outer loop adjusts the outer loop backoff factor for each data stream based on the performance (e.g., packet errors and/or decoder metrics) for the data stream.08-19-2010
20100208838UPLINK PRECODING METHOD IN 4-Tx SYSTEM - A method for a user equipment to precode and transmit an uplink signal efficiently in a 4-antenna system and a method for a base station to receive the transmitted signal efficiently are disclosed. Four antennas of a user equipment can be grouped by a 2-antenna unit. In consideration of this antenna group, it is able to perform precoding using antenna selection/DFT matrix of the antenna group unit. Moreover, a rank-3 codebook can be configured to include a precoding matrix of a type in consideration of power balance per antenna and a precoding matrix including one non-zero component only in one row for maintaining a good CM property.08-19-2010
20100208835DIVERSITY RECEIVER AND DIVERSITY RECEPTION METHOD - An orthogonal signal from a modulated signal of the digital terrestrial broadcast is produced. Then, an adder carrier-combines the orthogonal signal and an interpolated signal into an interpolated orthogonal signal, which is in turn demodulated by a DQPSK demodulation section. A demodulated signal is produced from a modulated signal of the digital satellite broadcast. A transmission path coding section produces transport stream data. A DQPSK mapping section re-demodulates the transport stream data to produce an orthogonal signal. A sync detection section asynchronously detects a demodulated signal demodulated by the DQPSK demodulation section and a demodulated signal produced by a time deinterleave section in the transmission path coding section. The detected time difference is set as a delay time of a delay circuit so as to delay the orthogonal signal, thereby producing the interpolated signal to be carrier-combined by the adder in order to provide improved reception quality.08-19-2010
20100080314Reconfigurable orthogonal frequency division multiplexing (OFDM) chip supporting single weight diversity - A method and system for a reconfigurable orthogonal frequency division multiplexing (OFDM) chip supporting single weight diversity are provided. The reconfigurable OFDM chip may be configured to process signals such as IEEE 802.11, 802.16, and digital video broadcasting (DVB). The OFDM chip may generate channel weights to be applied to signals received in receive antennas. The weighted signals may be combined into a single received signal and channel estimates may be generated from the single received signal. Updated channel weights may be generated from the generated channel estimates. Updates to the channel weights may be performed dynamically. The configurable OFDM chip may be utilized to provide collaborative cellular and OFDM-based communication. The reconfigurable OFDM chip and the cellular chip may communicate data and/or control information via a memory coupled to a common bus. 04-01-2010
20100067601REDUCTION OF OVERHEAD IN A MULTIPLE-INPUT MULTIPLE-OUTPUT (MIMO) SYSTEM - A multi-access multiple-input multiple-output (MIMO) system comprises a base station (BS) and a number of user equipment (UE), N, for serving N users. The BS divides the N users into L mobility groups, where each mobility group is associated with a certain range of channel dynamics. Those mobility groups having lower channel dynamics—that is, the channel dynamics change less rapidly—are updated with beamforming information less frequently than those mobility groups having higher dynamics—that is, the channel dynamics change more rapidly.03-18-2010
20100067602COMMUNICATION RECEIVER WITH MULTIPLEXING OF RECEIVED SIGNAL, FOR RECEIVE SPACE DIVERSITY - A communication receiver implements receive space diversity to combine or select signals received from a same source on at least two spatially separated antennas in which the signals may vary in their fading characteristics at a given time. The receiver includes a RF processing module for down-converting and multiplexing the signals and a baseband processing module for converting the signals into digital signals, generating code sequences, producing despreaded and demultiplexed in-phase signals, and retrieving data initially contained within the received signals.03-18-2010
20110182377RADIO COMMUNICATION SYSTEM - The second radio communication system selects one or more of the sub-carriers S07-28-2011
20120163488MIMO-OFDM Wireless Communication System - A MIMO channel frequency response matrix is decomposed into a frequency-related par and a constant part. The constant part is independent of subcarrier index and of number of subcarriers in one symbol interval. Separated QR decomposition and either SVD or GMD is applied to the two parts. A right unitary matrix (R) is obtained from the SVD or GMD applied to the constant part. QR decomposition is applied to the constant part to generate a beamforming matrix (V). In another embodiment, a selection criterion based on a correlation matrix distance is used to select a beamforming matrix that is independent of subcarrier, the selected matrix is retrieved from a local memory and applied to a received signal. Noise covariance is computed for a noise expression which considers interference generated from the applied beamforming matrix. Data detection is performed on the received signal using the noise covariance.06-28-2012
20120314793SIGNAL TRANSMISSION METHOD IN DISTRIBUTED ANTENNA SYSTEM - The present invention relates to a method for a random terminal to receive a signal from a base station in a distributed antenna system (DAS), and more specifically, to a method for a terminal for receiving a signal from a base station, comprising: selecting a precoding matrix corresponding to a terminal-specific, numbered antenna from a codebook for the DAS, which is based on control information about the terminal-specific antenna to be used for communication with the terminal from among a plurality of antennas which includes antennas that are isolated from each other by a predetermined distance; and processing the received signal by using the selected precoding matrix.12-13-2012
20120314792METHOD OF GENERATING A CODEBOOK - A precoding codebook matrix/vector of length 2L is generated by the selection of two matrices/vectors, each from one of a predetermined set of L×L matrices and multiplying each column of one of the matrices/vectors by a complex coefficient.12-13-2012
20120314791SYSTEMS AND METHODS FOR COMPRESSED FEEDBACK AND SUBCARRIER GROUPING FOR BEAMFORMING - Methods and apparatuses are provided for providing compressed feedback channel state information for beamforming. A beam transmitted by a transmission source is received at a receiving device. The receiving device computes a channel state matrix H of the transmission channel based on the received beam. Using the channel state matrix H, the receiving device performs a singular value decomposition procedure that produces a steering matrix V. The singular value decomposition procedure generates a set of angles (θ12-13-2012
20120314790TRANSMISSION AND RECEIVING APPARATUS AND METHOD IN A MULTI CARRIER TRANSMISSION SYSTEM - A transmission apparatus and method for transmitting signals in a multi carrier transmission system comprises a modulator, a band information generator that generates band information defining the frequency bands corresponding to all of the data streams carried within that frequency channel, said band information including a tuning frequency indicator indicating a tuning frequency and a tuning frequency type indicator indicating the type of tuning frequency indicated by said tuning frequency indicator, wherein said type is selected from a group comprising at least a first type indicating a tuning frequency of a frequency band and a second type indicating a center frequency of a frequency channel, and a transmitter.12-13-2012
20120213302MULTI-ANTENNA TRANSMISSION FOR SPATIAL DIVISION MULTIPLE ACCESS - An uplink channel response matrix is obtained for each terminal and decomposed to obtain a steering vector used by the terminal to transmit on the uplink. An “effective” uplink channel response vector is formed for each terminal based on its steering vector and its channel response matrix. Multiple sets of terminals are evaluated based on their effective channel response vectors to determine the best set (e.g., with highest overall throughput) for uplink transmission. Each selected terminal performs spatial processing on its data symbol stream with its steering vector and transmits its spatially processed data symbol stream to an access point. The multiple selected terminals simultaneously transmit their data symbol streams via their respective MIMO channels to the access point. The access point performs receiver spatial processing on its received symbol streams in accordance with a receiver spatial processing technique to recover the data symbol streams transmitted by the selected terminals.08-23-2012
20120134437RADIO 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.05-31-2012
20120134434METHOD AND SYSTEM FOR PRECODING AND METHOD FOR CONSTRUCTING PRECODING CODEBOOK - A pre-coding method and system and a method for constructing pre-coding codebook are disclosed, including: a transmitting end and a receiving end storing information of a pre-coding codebook together, the receiving end selecting a codeword from the pre-coding codebook according to an estimated channel matrix and feeding back a serial number of the codeword to the transmitting end, and the transmitting end finding out the codeword according to the serial number and pre-coding, by using the codeword, a symbol block sent to the receiving end; wherein, at least eight codeword vectors or column vectors in at least eight codeword matrixes in the pre-coding codebook are obtained based on 8-dimensional vectors selected from a 8-dimensional vector set, and this 8-dimensional vector set is obtained by calculating from the part or all of 4-dimensional vectors in u05-31-2012
20120134436Combined Channel Coding and Space-Time Block Coding in a Multi-Antenna Arrangement - Enhanced performance is achieved by combining channel coding with the space-time coding principles. With K synchronized terminal units transmitting on N antennas to a base station having M≧K receive antennas, increased system capacity and improved performance are attained by using a concatenated coding scheme where the inner code is a space-time block code and the outer code is a conventional channel error correcting code. Information symbols are first encoded using a conventional channel code, and the resulting signals are encoded using a space-time block code. At the receiver, the inner space-time block code is used to suppress interference from the other co-channel terminals and soft decisions are made about the transmitted symbols. The channel decoding that follows makes the hard decisions about the transmitted symbols. Increased data rate is achieved by, effectively, splitting the incoming data rate into multiple channels, and each channel is transmitted over its own terminal.05-31-2012
20120134435Method And Apparatus For Interference Suppression In Orthogonal Frequency Division Multiplexed (OFDM) Wireless Communication Systems - A method and apparatus for interference suppression in wireless communication systems, especially Orthogonal Frequency Division Multiplexed (OFDM) systems, is presented. The array apparatus includes a two-tier adaptive array system, which provides for both spatial diversity and beamforming at the uplink The adaptive array and includes sub-arrays spaced at a distance sufficient to provide spatial diversity and support beamforming or scanning A Direction of Arrival (DOA) of signals impinging upon the array can be calculated by comparing signals from sub-array elements. Each sub-array can be filtered or beamformed to provide high gain to desired signals received from the DOA (which may be a multipath signal) while simultaneously dampening-out undesired signals, such as co-channel interference (CCI) in the frequency band of operation. The DOA is also used for allocating frequency bins for data signals, such as in an OFDM system, to provide weighted guidelines for bin allocation to maximize received signal power.05-31-2012
20100195752TRANSMITTER/RECEIVER FOR CONTROLLING MULTIUSER MULTIPLE INPUT MULTIPLE OUTPUT SYSTEM AND METHOD THEREOF - Provided are a method of controlling a multi-user multiple input multiple output (MIMO) system and a transmitter/receiver used in the method. In the method, it can be determined whether feedback information is fed back according to the feedback information type rather than being indiscriminately provided to a transmitter, and then only a necessary feedback information type is transmitted, thereby increasing system capacity while reducing feedback load.08-05-2010
20100189189RADIO COMMUNICATION SYSTEM, RADIO COMMUNICATION APPARATUS, AND RADIO COMMUNICATION METHOD - The signaling amount in selecting a plurality of beams is reduced in pre-coding to thereby enhance the throughput. To select a plurality of beams when the pre-coding is applied, when notification of a beam number is provided in a feedback signal from a user equipment 07-29-2010
20120163487BASE STATION AND FEEDBACK INFORMATION CONTROL METHOD IN RADIO COMMUNICATION SYSTEM - A base station includes: a subset information generation section which selects M precoding matrices from among N precoding matrices and sets the M precoding matrices as a precoding matrix subset; a transmission section which transmits the precoding matrix subset to a radio communication device; and a reception section which receives feedback information from a radio communication device that is generated by the radio communication device, wherein the feedback information includes information about at least one precoding matrix which is selected from the precoding matrix subset based on reception quality at the radio communication device.06-28-2012
20090060082WIRELESS COMMUNICATION APPARATUS, AND FEEDBACK INFORMATION GENERATING METHOD - A wireless communication apparatus that allows channel information to be reproduced with high precision at a transmitting end without increasing feedback information amount. In this apparatus, a channel estimating part (03-05-2009
20090060081Systems and methods for ofdm channelization - Systems and methods for OFDM channelization are provided that allow for the co-existence of sub-band channels and diversity channels. Methods of defining diversity sub-channels and sub-band sub-channels are provided, and systematic channel definition and labeling schemes are provided.03-05-2009
20090060080METHODS AND APPARATUS FOR LOCATION-BASED RATE LIMITING IN WIRELESS NETWORKS - Methods and systems are provided for location-based network rate limiting The system allows an administrator to logically partition an environment into a plurality of spatial regions. The method then includes specifying, for each of the spatial regions, a rate limit for that spatial region, then performing a locationing procedure to determine in which spatial region the mobile unit is located. Rate limiting is applied based on the location of the mobile unit. The systems and methods are applicable, for example, to networks operating in accordance with 802.11, RFID, WiMax, WAN, Bluetooth, Zigbee, UWB, and the like.03-05-2009
20120213305METHOD AND APPARATUS FOR TRANSMITTING AND RECEIVING DATA IN A MIMO SYSTEM - The present invention relates to a method and apparatus for transmitting and receiving data. A data transmission method from a sender terminal to a receiver terminal in a MIMO system using a variable frequency band according to one embodiment of the present invention comprises: repeatedly generating a signal field depending on a frequency band that is applied to the transmission of a data frame; generating a data field including the data; generating a data frame including the signal field and the data field; and transmitting the data frame to the receiver terminal. The present invention is advantageous in that a signal field which is transmitted together with the data being transmitted from the sender terminal to the receiver terminal in the MIMO system can be sent more efficiently.08-23-2012
20120250779Method for Transmitting an Information Sequence - Methods and apparatus are disclosed for applying successive multi-rank beamforming strategies (e.g., successive precoding strategies) for the design of precoders over a set of parallel channels. Successive beamforming is applied to a narrow band channel model and is also applied for finer quantization of a single beamforming vector (e.g., recursive beamforming). A first embodiment provides the optimal approach with high complexity. An alternative embodiment provides successive beamforming for near optimal precoding selection with medium complexity. A low complexity method for precoder selection is also provided wherein a channel representative matrix for the set of parallel channels is determined and successive beamforming on the calculated channel representative is applied.10-04-2012
20120213303COMPATIBLE SUBSET GENERATION TO FACILITATE MULTI-RADIO COEXISTENCE - Radios in a multi-radio device may be represented by parameter nodes, each parameter node representing a communication configuration of a particular radio. A coexistence manager may determine compatible subsets of parameter nodes. The subsets represent communication configurations of the radios that are compatible for simultaneous operation which reduces interference. Compatible subset generation may occur during an evaluation phase of a coexistence manager of a multi-radio device. Compatible subsets are generated based on resolvability of radio events or other potential collisions of the subsets, such as by use of a progressive resolution (PR) graph, associated compatibility graphs, and instructions and logic corresponding to such graphs.08-23-2012
20120213304DATA TRANSFERRING DEVICE, DATA TRANSFERRING METHOD AND DATA RECEVING METHOD - Disclosed is a data transmitting device which includes an input symbol mapping unit converting serial data symbols to parallel data symbols and generating null signals; and a conversion unit converting the parallel data symbols and the null signals to a plurality of subcarriers and a plurality of null subcarriers using sub frequency bands overlapped with one another, wherein the plurality of subcarriers is transformed using sub frequency bands separated from one another.08-23-2012
20100278280Apparatus for transmitting and receiving data to provide high-speed data communication and method thereof - In the present invention, data generated from a source unit are distributed to at least one bandwidth; the data distributed to the respective bandwidths are encoded in order to perform an error correction; the encoded data are distributed to at least one antenna; a subcarrier is allocated to the data distributed to the respective antennas, and an inverse Fourier transform is performed; a short preamble and a first long preamble corresponding to the subcarrier are generated; a signal symbol is generated according to a data transmit mode; and a frame is generated by adding a second long preamble between the signal symbol and a data field for the purpose of estimating a channel of a subcarrier which is not used.11-04-2010
20120076228Adaptive Time Diversity and Spatial Diversity for OFDM - An adaptable orthogonal frequency-division multiplexing system (OFDM) that uses a multiple input multiple output (MIMO) to having OFDM signals transmitted either in accordance with time diversity to reducing signal fading or in accordance with spatial diversity to increase the data rate. Sub-carriers are classified for spatial diversity transmission or for time diversity transmission based on the result of a comparison between threshold values and at least one of three criteria. The criteria includes a calculation of a smallest eigen value of a frequency channel response matrix and a smallest element of a diagonal of the matrix and a ratio of the largest and smallest eigen values of the matrix.03-29-2012
20120076227RADIO BASE STATION APPARATUS AND METHOD FOR SELECTING MODULATION AND CODING SCHEME - Provided is a radio base station apparatus capable of selecting an optimal modulation and coding scheme for each transmission stream easily. The radio base station apparatus has a CQI information decoder (03-29-2012
20120177140WIRELESS COMMUNICATION SYSTEM AND WIRELESS COMMUNICATION METHOD - A base station includes: a MIMO precoding section (07-12-2012
20100272206TRANSMITTING/RECEIVING APPARATUS AND METHOD THEREOF IN CODEBOOK BASED MULTIPLE ANTENNA SYSTEM - A transmission/reception apparatus and a method thereof in a codebook-based multiple antenna system is provided. In a transmission method in a codebook-based Multiple Input Multiple Output (MIMO) system, control information is received from a receiver. A codeword is determined within an Open-Loop (OL)-MIMO codebook where a Closed-Loop (CL)-MIMO codebook is reused based on the control information. At least one data stream is transmitted via at least one antenna using the determined codeword.10-28-2010
20100272205METHOD FOR DETECTING SIGNAL, DEVICE FOR DETECTING SIGNAL, AND RECEIVING DEVICE - The present invention relates to a method for detecting a signal, a device for detecting a signal, and a receiving device. A method for detecting a signal according to the present invention is a method for detecting a signal from a receiving device in a communication system including a multi-output multi-input antenna, including: estimating a channel matrix of a signal received from a plurality of receiving antennas; generating at least one channel matrix groups by aligning the channel matrix and generating at least one transmitting signal group by aligning a transmitting signal to be estimated to correspond thereto; determining a first candidate vector in consideration of all constellation points for a first layer of the at least one transmitting signal group; determining a second candidate vector in consideration of all constellation points for a second layer of the at least one transmitting signal group; generating a final candidate vector including the first candidate vector and the second candidate vector; and calculating a soft output using the final candidate vector.10-28-2010
20120177139DATA RESOURCE MAPPING FOR FREQUENCY-CODED SYMBOLS - A device and method for communicating frequency-coded symbols that include data elements and reference symbols are disclosed. In one aspect, a carrier frequency band includes a plurality of subcarrier frequency bands. Data elements are transmitted and received on respective pairs of adjacent subcarrier frequency bands to provide diversity. Reference symbols are transmitted and received on predetermined subcarrier frequency bands. Muting is applied to selected subcarrier frequency bands based on the number and frequency configuration of the reference symbols.07-12-2012
20100034309MULTIPLE INPUT MULTIPLE OUTPUT ANTENNA SYSTEM, SIGNAL TRANSMISSION METHOD, SIGNAL TRANSMISSION APPARATUS, AND COMPUTER PROGRAM PRODUCT FOR THE MULTIPLE INPUT MULTIPLE OUTPUT ANTENNA SYSTEM - A multiple input multiple output (MIMO) antenna system, a signal transmission method, a signal transmission apparatus and a computer program product for the MIMO antenna system are provided. The signal transmission method comprises the following steps of transmitting a signal with a first signal transmission mode and a first transmission power via a signal transmission channel; receiving a signal to noise ratio (SNR) of the signal; receiving an interference value of the signal transmission channel; obtaining a power weight value according to the interference value; determining a system threshold of the signal transmission channel to the SNR of the signal; determining a second signal transmission mode of the signal transmission channel based on the system threshold; and determining a second transmission power of the signal transmission channel according to the power weight value.02-11-2010
20100008439SYSTEM AND METHOD FOR QUASI-ORTHOGONAL SPACE-TIME BLOCK CODING - The present invention relates to a quasi-orthogonal space-time block coding system and method. The system does not become particularly complicated since the encoding rate is given as 1 and it is possible to decode the encoded signal by using a simple linear algorithm, and system performance is increased since there is no interference component of an adjacent signal in the estimate01-14-2010
20100008442Method for Limiting Local Bandwidth Impairment Using Tone Reservation - The present invention relates to a method of limiting local bandwidth impairment in a telecommunications system, wherein tone reservation is used to reduce peak power of a multi-carrier signal using successive processing stages. The present invention also relates to an apparatus for limiting local bandwidth impairment and to a base station including such an apparatus. The method according to the present invention comprises the steps: generating a first peak reduction signal using reserved frequencies or tones of a first subset of frequencies or tones; generating a second peak reduction signal using reserved frequencies or tones of a second subset of frequencies or tones; extracting the In-phase components, I-components, of the first peak reduction signal and extracting the Quadrature components, Q-components, of the second peak reduction signal; and generating a third peak reduction signal by combining or adding, in the frequency domain, the I-components of the first peak reduction signal and the Q-components of the second peak reduction signal.01-14-2010
20100008441MULTIANTENNA RECEIVING DEVICE - A multiantenna receiving device is provided to make it possible to cope with both improvement in error rate characteristic and simplification in structure. The multiantenna receiving device is comprised of soft judgement output units (01-14-2010
20090196370ITERATIVE INTERFERENCE CANCELLATION - An exemplary method of communicating includes determining a first user channel estimate from a communication comprising first and second user reference sequences. The first user reference sequence is reconstructed using the determined first user channel estimate. The communication is revised based upon the reconstructed first user reference sequence. Then determining a second user channel estimate is based on the revised communication.08-06-2009
20120263252Systems and Methods of Power Line Transmission of Solar Panel Data - Statistical analysis may be requested for a solar panel system. Each section of the panel may be assigned to a particular slice of an OFDM transmission scheme. The photovoltaic (PV) modules are divided into strings of modules and a spectrum of frequencies is divided into sub-channels. Then each string is assigned into a timeslot data related PV modules is transmitted on a particular sub-channel during the assigned timeslot.10-18-2012
20120257685Codebook With Nested Structure - A multi-rank beamforming (MRBF) scheme in which the downlink channel is estimated and an optimal precoding matrix to be used by the MRBF transmitter is determined accordingly. The optimal precoding matrix is selected from a codebook of matrices having a recursive structure which allows for efficient computation of the optimal precoding matrix and corresponding Signal to Interference and Noise Ratio (SINR). The codebook also enjoys a small storage footprint. Due to the computational efficiency and modest memory requirements, the optimal precoding determination can be made at user equipment (UE) and communicated to a transmitting base station over a limited uplink channel for implementation over the downlink channel.10-11-2012
20120189074Diversity for Digital Distributed Antenna Systems - Techniques are provided for a base station to transmit and receive wireless signals via a plurality of remote transceiver stations deployed in a coverage area. The remote transceiver stations are coupled to the base station in order to communicate with wireless mobile devices. A transmission time delay is determined for a message to be transmitted from corresponding remote transceiver stations to a wireless mobile device. Transmission of the message to be wirelessly transmitted from the two or more remote transceiver stations is delayed by a corresponding transmission time delay. The delayed transmissions appear as a resolvable multipath transmission to receivers in the wireless mobile user devices. Techniques are also provided for delaying the processing of uplink transmissions at the base station receiver. Delays associated with downlink or uplink transmissions may also be programmed into individual remote transceiver stations.07-26-2012
20120189077METHOD AND APPARATUS FOR MODE SWITCHING BETWEEN A MULTI-CELL COORDINATED COMMUNICATION MODE AND A SINGLE-CELL MIMO COMMUNICATION MODE - A method for dynamically switching a communication mode includes generating and transmitting first feedback information in accordance with a first communication mode; switching the first communication mode into a second communication mode interlocked with the first communication mode; and generating and transmitting second feedback information in accordance with the second communication mode. The first communication mode is one of a multi-cell coordinated multi-point (CoMP) communication mode and a single-cell multi-input multi-output (MIMO) communication mode, and the second communication mode is the other of the multi-cell coordinated multi-point (CoMP) communication mode and the single-cell multi-input multi-output (MIMO) communication mode. The switching step can be performed without signaling from a base station.07-26-2012
20120189076MULTIPLE ANTENNAS TRANSMIT DIVERSITY SCHEME - A method from transmitting data via multiple antennas. The method contemplates modulating data to be transmitted into a plurality of modulated symbols, encoding each pair of modulated symbols from among said plurality of symbols in accordance with a transmission diversity scheme to result in a plurality of 2 by 2 matrices, with each 2 by 2 matrix corresponding to each pair of modulated symbols, orthogonally spreading the plurality of 2 by 2 matrices to generate an output matrix, and transmitting the symbols in the output matrix via a plurality of antennas by using either a space time transmission diversity scheme, a space frequency transmission diversity scheme, or a combination of a space time transmission diversity scheme and a space frequency transmission diversity scheme.07-26-2012
20120189075METHOD AND APPARATUS FOR OBTAINING PRECODING MATRIX INDICATOR - The present disclosure discloses a method and an apparatus for obtaining a precoding matrix indicator, and relates to the field of communication technologies. The method includes: obtaining a first rotation matrix according to first channel information; obtaining a first differential matrix according to the first rotation matrix and a currently-obtained instantaneous beam forming matrix/precoding matrix; and quantizing, according to a first differential codebook, a pre-acquired first rank indicator, and preset quantization criteria, the first differential matrix to obtain a differential precoding matrix indicator. The apparatus includes: a first rotation matrix obtaining module, a first differential matrix obtaining module, and a differential precoding matrix indicator obtaining module. In the present disclosure, the differential PMI is obtained according to the channel information, and the differential PMI is used for feedback, which not only reduces an overhead, but also improves feedback accuracy.07-26-2012
20120328038TRANSMISSION SYSTEM, TRANSMISSION DEVICE AND METHOD FOR CONTROLLING TRANSMISSION DEVICE - A transmission system includes a first device; and a second device that is connected to the first device through a plurality of transmission paths, wherein the first device includes a plurality of request storage units that are provided for the transmission paths and each store a request to be transmitted to the second device, a request determining unit that determines whether a request to be transmitted to the second device is of a type that causes a redundant request, a request resource determining unit that counts the number of the requests stored in each of the plurality of request storage units and determines the number of request storage units, a request storing unit that causes a plurality of requests, generated by copying the request to be transmitted, and a plurality of request transmitters that transmit the requests stored in the plurality of storage units.12-27-2012
20120328040Detecting the Number of Transmit Antennas in a Base Station - Data is scrambled at a transmitter according to one of a number of predetermined scrambling sequences which are associated with a particular one of a number of predetermined transmit antenna diversity schemes (i.e., a specific number of transmit antenna ports). Received data is decoded using one or more of the known transmit antenna diversity schemes and the scrambled data is descrambled according to a corresponding descrambling sequence (related to the scrambling sequence). Based on the descrambled data, the receiver determines which transmit antenna diversity scheme (i.e., the number of antenna ports) is used by the transmitter. In one specific embodiment, CRC parity data is scrambled in the transmitter and the receiver descrambles the recovered CRC parity data according to a descrambling sequence, computes CRC parity data from the received data, and compares the descrambled CRC parity data to the newly computed CRC parity data.12-27-2012
20120328036Method And Apparatus for Channel Bonding Using Multiple-Beam Antennas - A system is provided that enhances the throughput and reliability of wireless communications by providing multi-beam user terminals that exhibit directional discrimination. Multiple wireless communication channels are matched with multiple beams created from an array antenna by a beam-forming processor. The multiple wireless communication channels are bonded into a single virtual channel, thereby increasing data bandwidth while reducing interference and multi-path effects that can degrade communications. The beam-forming function may be performed in a dedicated beam-forming processor or may reside within a general-purpose microprocessor located in the user terminal. In addition, a wireless communications system with access points featuring multiple beams that exhibit directional discrimination that can concurrently support multiple users with multi-beam terminals via a common frequency channel. Both forward and return links feature multiple-folded frequency reuse, enabling multiple users with higher throughput and improved reliability. The spectrum utility of the communications system has been enhanced with multiple folds.12-27-2012
20120082257Method and System for Channel Estimation in a Single Channel MIMO System with Multiple RF Chains for WCDMA/HSDPA - Aspects of a method and system for channel estimation in a MIMO communication system with multiple RF chains for WCDMA/HSDPA may comprise receiving a plurality of communication signals from a plurality of transmit antennas. A plurality of vectors of baseband combined channel estimates may be generated based on phase rotation of the received plurality of communication signals. A matrix of processed baseband combined channel estimates may be generated based on the generated plurality of vectors of baseband combined channel estimates. A plurality of amplitude and phase correction signals may be generated based on the generated plurality of vectors of baseband combined channel estimates. An amplitude and a phase of at least a portion of the received plurality of communication signals may be adjusted based on the generated plurality of amplitude and phase correction signals, respectively.04-05-2012
20090016460Apparatus and method for beamforming with limited feedforward channel in multiple input multiple output wireless communication system - An apparatus and method are provided for beamforming in a MIMO wireless communication system. A base station includes a first calculator that repeatedly calculates downlink beamforming vectors of the user terminals to calculate the optimal beamforming vectors for the user terminals, a quantizer that quantizes the downlink beamforming vectors in order to transmit information of the downlink beamforming vectors, a control channel transmitter that feeds forward information of the quantized downlink beamforming vectors to the user terminals, a second calculator that calculates the final downlink beamforming vectors of the user terminals, and a beamforming transmitter that sums the beamformed TX signals of the user terminals and transmits the summed TX signals through a plurality of TX antennas.01-15-2009
20090016461BASE STATION AND MIMO-OFDM COMMUNICATION METHOD THEREOF - When performing communication with a mobile station using MIMO-OFDM communication, a base station uses multiple input multiple output (MIMO) communication, which is multiple data stream transmission, to transmit data and pilot signals in a case where the communication environment of the mobile station is good, or uses single input multiple output (SIMO) communication, which is single data stream transmission, in a case where the communication environment of the mobile station is poor. When performing that SIMO communication, the base station performs control so that pilot signals from a specified cell that are used in channel estimation in single data stream transmission and pilot signals from adjacent cells that are used in channel estimation in single data stream transmission do not overlap in the frequency direction and/or time axis direction.01-15-2009
20120230445RECEPTION DEVICE, RECEPTION METHOD, AND RECEPTION PROGRAM - A propagation channel estimation unit estimates a propagation channel estimated value. A symbol replica generation unit generates a symbol replica which is a modulated symbol from demodulated information. A signal extraction unit extracts each subcarrier component from a received signal from which interference has been removed, based on the propagation channel estimated value and the symbol replica. A demodulation unit demodulates the signals of the subcarrier components extracted by the signal extraction unit.09-13-2012
20120230444BEAMFORMING IN MIMO COMMUNICATION SYSTEMS - A communication terminal includes first and second transmitters, which are coupled to produce respective first and second Radio Frequency (RF) signals that are phase-shifted with respect to one another by a beamforming phase offset, and to transmit the RF signals toward a remote communication terminal. The terminal includes a reception subsystem including first and second receivers and a phase correction unit. The first and second receivers are respectively coupled to receive third and fourth RF signals from the remote communication terminal. The phase correction unit is coupled to produce, responsively to the third and fourth RF signals, a phase correction for correcting an error component in the beamforming phase offset.09-13-2012
20110122962PHASE DIFFERENCE IN A MOBILE COMMUNICATION NETWORK - A system and method are described for detecting and controlling the phase difference introduced to radio signals by transmission branches of a transmission system in a mobile communication network. Periodically a calibration signal is generated at an input of the transmission branches during a phase calibration mode. The phase difference introduced by the two transmission branches is detected by detecting the phase difference between the calibration signal, which has at least partly passed through the first transmission branch and the calibration signal, which has at least partly passed through the second transmission branch. The phase difference between the radio signals is controlled based on the detected phase difference.05-26-2011
20110122961COMMUNICATION DEVICE ADOPTED FOR MULTI-INPUT MULTI-OUTPUT ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING SYSTEM AND METHOD THEREOF - A communication device adopted for a multi-input multi-output orthogonal frequency division multiplexing (MIMO-OFDM) system and a method thereof are provided. The MIMO-OFDM system comprises the communication device and a corresponding communication device, and they communicate with each other. The communication device comprises a transceiving module, a singular value decomposition (SVD) operation module, and an interpolation operation module. The transceiving module receives a channel state information (CSI) from the corresponding communication device, wherein the CSI comprises CSIs of a plurality of selected subcarriers. For each of the selected subcarriers, the SVD module performs an SVD decomposition operation on the channel matrix representing the CSI of the selected subcarrier to obtain a decomposed result, wherein the decomposed result comprises a beamforming matrix, an SVD matrix, and a decoding matrix. The interpolation operation module performs interpolations on the beamforming matrices of the selected subcarriers to derive beamforming matrices of the unselected subcarriers. The interpolation operation module performs interpolations on the decoding matrixes of the selected subcarriers to derive obtain decoding matrices of the unselected subcarriers.05-26-2011
20080298494METHODS AND APPARATUS FOR IMPROVED UTILIZATION OF AIR LINK RESOURCES IN A WIRELESS COMMUNICATIONS SYSTEM - Methods and apparatus for improving the utilization of air link resources in a wireless communications system, e.g., an OFDM MIMO system, including a base station with multiple transmit antennas are described. Superposition signaling in the downlink is employed. The superimposed signal includes a first transform result signal and a second lower power signal. The first transform result signal is generated from a first signal, which uses position modulation, e.g., including null components and high power non-null components. Different components of the first transform result signal are directed to different transmit antennas. The first transform result signal communicates information to a first wireless terminal, e.g., a weak receiver. The non-null received elements of the first transform result signal are utilized by a second wireless terminal, e.g., a superior receiver, as pilots to determine a channel estimate. The second wireless terminal uses the determined channel estimate to demodulate received second signals.12-04-2008
20110002412METHOD FOR DETERMINING DEMODULATION REFERENCE SIGNAL IN THE UPLINK, UE AND UPLINK SYSTEM - The present invention discloses a method for determining an uplink demodulation reference signal (DMRS), which includes: taking one of multiple transmit antennas in the uplink as a base transmit antenna, taking other transmit antennas as subordinating transmit antennas and setting a DMRS for the base transmit antenna; establishing DMRS subordinating relationships between the base transmit antenna and each of the subordinating transmit antennas; and setting a DMRS for each of the subordinating transmit antennas according to the DMRS of the base transmit antenna and the DMRS subordinating relationship between the base transmit antenna and each of the subordinating transmit antennas. The present invention also provides a user equipment (UE) and an uplink system for providing DMRSs for multiple transmit antennas. The method, UE and system are applicable in both SU-MIMO transmission and MU-MIMO transmission.01-06-2011
20110002410System and method for power control and antenna grouping in a distributed-input-distributed-output (DIDO) network - A system and machine-implemented method are described for adjusting communication with a first distributed-input-distributed-output (DIDO) client. For example, a method according to one embodiment of the invention comprises: applying DIDO weights to one or more data streams to generate one or more DIDO precoded data streams; receiving input channel quality information (CQI) and/or channel state information (CSI) related to DIDO communication channels over which the DIDO precoded data streams are to be transmitted; determining a power scaling factor based on the CQI and/or CSI; and applying the power scaling factor to each of the DIDO precoded data streams.01-06-2011
20120269278DOWNLINK MULTIPLE INPUT MULTIPLE OUTPUT ENHANCEMENTS FOR SINGLE-CELL WITH REMOTE RADIO HEADS - A base station selects a subset of at least one geographically separated antennas for each of the plurality of user equipments. The base station forms at least layer of data stream including modulated symbols, precodes the data stream via multiplication with the NT-by-N precoding matrix where N is the number of said layers and NT is the number of transmit antenna elements and transmits the precoded layers of data stream to the user equipment via the selected geographically separated antennas. The base station signals the subset of the plurality of geographically separated antennas via higher layer Radio Resource Control or via a down link grant mechanism. The base station optionally does not signal the subset of the plurality of geographically separated antennas to the corresponding mobile user equipment.10-25-2012
20120269281METHOD AND SYSTEM FOR UTILIZING TONE GROUPING WITH GIVENS ROTATIONS TO REDUCE OVERHEAD ASSOCIATED WITH EXPLICIT FEEDBACK INFORMATION - Aspects of a method and system for utilizing tone grouping with Givens rotations to reduce overhead associated with explicit feedback information are presented. In one aspect of the invention, Givens matrices may be utilized to reduce a quantity of information communicated in explicit feedback information via an uplink RF channel. The explicit feedback information may include specifications for a feedback beamforming matrix that may be utilized when transmitting signals via a corresponding downlink RF channel. The feedback beamforming matrix may represent a rotated version of an un-rotated matrix. The Givens matrices may be utilized to apply one or more Givens rotations to un-rotated matrix. The rotated matrix may reduce the quantity of information communicated in the explicit feedback information. The quantity of information communicated in the explicit feedback information may be further reduced by utilizing tone grouping.10-25-2012
20120269280RECURSIVE REDUCTION OF CHANNEL STATE FEEDBACK - Feedback bandwidth may be reduced in a closed loop MIMO system by Householder transformations and vector quantization using codebooks.10-25-2012
20120321011ADAPTATION TO MILLIMETER-WAVE COMMUNICATION LINK USING DIFFERENT FREQUENCY CARRIERS - To realize quick adaptation to a communication link between a transmitter and a receiver by using two different frequency carriers. A receiver detects a preamble from a transmission bit string. When determining that a total sum of the number of modified bits exceeds a certain threshold in a range of a payload following the preamble (when detecting that a reception state of a communication link has been degraded), the receiver issues, to a transmitter, a request for changing a transmission parameter (four parameters may be used for enhancement/lowering) for the transmission bit string by using a communication link, which is a relatively-low-frequency carrier. On the other hand, the transmitter receives the request for change, and executes the request for changing the transmission parameter for the transmission bit string while maintaining transmission of a payload in the transmission bit string.12-20-2012
20120321010FULL SPECTRUM MODULATOR FOR DIGITAL TELEVISION SIGNALS - A full spectrum modulator processes a plurality of CATV channels from separate paths. Each path has (i) a first filter for pulse shaping an input channel signal and upsampling a channel frequency thereof, (ii) an interpolator for interpolating the output of the first filter to a common sample rate, and (iii) a decimator for centering the output of the interpolator on a predetermined channel bandwidth. An IDFT processor receives channel signal outputs from the decimators. A polyphase filter bank receives IDFT processed parallel channel signals from the IDFT processor. A commutator converts the processed parallel channel signals from the polyphase filter bank to a single stream of data. A second filter upsamples the single stream of data to a fixed output sampling rate and low pass filters alias signals therefrom. Both standard and harmonically related carrier CATV channel frequency plans are accommodated.12-20-2012
20120321009MULTIPLE INDEPENDENT NARROW CHANNELS IN WIRELESS NETWORKS - A multiple independent narrow-channel wireless network and method for transmitting and received data over a wireless network using a fragmented frequency spectrum. The system and method uses a plurality of narrow wireless channels obtained from splitting a wide wireless channel. Each narrow channel performs sending, receiving, and carrier sensing. Moreover, each narrow channel is independent such that data can be sent or received without any interference from other narrow channels and without synchronization. Embodiments of the system and method include a compound radio having a compound receiver and a compound transmitter. The compound transmitter includes an inter-radiolet symbol synchronization module, to permit use of a single inverse fast Fourier transform block, and a dynamically configurable filter array, to mitigate leakage between channels. The compound receiver uses fraction data rate processing to optimize efficiency. A throughput maximal metric technique is used to determine its frequency of operation in white spaces.12-20-2012
20120321008COOPERATIVE DATA TRANSPORT - Various arrangements for cooperative data transport are presented. These arrangements may include a first mobile device configured to receive, via a first wireless network, a first set of shared data. The first set of shared data may be shared among a plurality of mobile devices using a second wireless network. The first mobile device may also receive, via the first wireless network, a first set of private data, wherein the first set of private data is intended for the first mobile device. The first set of private data may not be shared among the plurality of mobile devices.12-20-2012
20100226456METHOD AND SYSTEM FOR TRANSMITTER BEAMFORMING FOR REDUCED COMPLEXITY MULTIPLE INPUT MULTIPLE OUTPUT (MIMO) TRANSCEIVERS - Aspects of a method and system for transmitter beamforming for reduced complexity multiple input multiple output (MIMO) transceivers are presented. Aspects of the system may include a MIMO transmitter that computes a channel estimate matrix and decomposes the computed channel estimate matrix based on singular value decomposition (SVD). Singular values in a singular value matrix may be rearranged and grouped to generate a plurality of submatrices. In one aspect, each of the submatrices may be decomposed based on GMD at a MIMO transmitter, while a MIMO receiver may utilize a vertical layered space time (VLST) method. In another aspect, the MIMO transmitter may utilize Givens rotation matrices corresponding to each of the submatrices, while the MIMO receiver may utilize maximum likelihood (ML) detection.09-09-2010
20090147876ROBUST WIRELESS MULTIMEDIA TRANSMISSION IN MULTIPLE IN MULTIPLE-OUT (MIMO) SYSTEM ASSISTED BY CHANNEL STATE INFORMATION - A system and method is provided wherein channel state information assisted MIMO transmission based on singular value decomposition (SVD) (06-11-2009
20110235735METHOD AND APPARATUS FOR OPTIMIZING TRANSMISSION DIVERSITY - A method and apparatus are provided for transmission in a communication system. The system includes a transmitter having at least one first and second antenna and a receiver, which includes at least one receiving antenna. The method includes determining a transmit diversity scheme for at least one group of symbols from among a plurality of modulated symbols. This step includes at least one step of obtaining a phase shift of at least one symbol of the at least one group of symbols. The phase shift is based on: at least one phase shift parameter N; and responses (h09-29-2011
20110235734ACTIVE ANTENNA ARRAY HAVING A SINGLE DPD LINEARISER AND A METHOD FOR PREDISTORTION OF RADIO SIGNALS - An active antenna array comprises: a digital signal processor connected to a plurality of digital-to-analogue conversion blocks; a plurality of antenna elements; a plurality of transmission paths, whereby an individual one of the plurality of transmission paths is connected between an individual one of the digital-to-analogue conversion blocks and an individual one of the plurality of antenna elements, whereby an individual one of the plurality of transmission paths comprises a correction signal combiner and a feedback coupler; a plurality of paths connected between individual ones of the feedback couplers and a single feedback combiner; a single feedback path connected between the single feedback combiner and a correction signal calculation unit; and a single correction signal path connected between the correction signal calculation unit and at least two of the correction signal combiners.09-29-2011
20100232535Apparatus and Method for Multilayer Space-Time-Frequency Precoding for a MIMO-OFDM Wireless Transmission System - In a wireless wideband MIMO-OFDM transmission system, a method includes converting a coded bit sequence to parallel data layers, responsive to channel encoding and interleaving of an information sequence to provide the coded bit sequence; passing each data layer through a respective repetition encoder, independently interleaving respective spread data sequences from the respective repetition encoder, and amplifying the respective interleaved outputs responsive to power allocation of a respective layer of multiple layers for both I and Q channels for being combined to form complex symbols for transmission through respective multiple antennas.09-16-2010
20100232534TRANSMITTING AND RECEIVING APPARATUS HAVING PLURAL ANTENNA IN MULTI-USER ENVIRONMENTS AND METHOD THEREOF - The present invention provides a radio transmitting and receiving apparatus having multiple antennas that can decrease an influence due to interference between cells that exists in a multi-cell environment, by using a transmission method that not only considers performance of a corresponding cell but also an influence due to interference on adjacent cells and an influence due to interference from the adjacent cells in a multi-user and multi-cell environment, effectively use limited radio resources, and increase a data rate of a radio communication system, and a method thereof.09-16-2010
20100232532METHOD AND APPARATUS OF SPACE-TIME-FREQUENCY CODING - The invention relates to a space-time-frequency encoding for use in wireless communication systems. According to the encoding scheme provided by the invention, it first transforms a plurality of input element pairs into a plurality orthogonal element pairs respectively, each of the plurality of input element pairs and corresponding orthogonal element pair forming an orthogonal matrix; and then maps the first element, second element and the redundancy of the second element in each of the plurality of input element pairs and corresponding orthogonal element pair as channel elements to three predetermined time-frequency cells in a first and second two-dimension time-frequency matrix so as to make the channel elements in the first and second matrixes suitable for being transmitted via different antennas. As the redundant input element pairs and corresponding orthogonal element pairs transmitted via different antenna are orthogonal in both space-time domain and space-frequency domain at the same time, and thus two-dimension space-time transmit diversity gain and space-frequency transmit diversity gain can be achieved at the same time.09-16-2010
20100232531Optimum perturbation apparatus and method in a multi-antenna multi-user communication system - An optimum perturbation apparatus and method in a multi-antenna, multi-user communication system are provided. In the optimum perturbation method, upon receipt of modulation symbols, channel responses are decomposed into eigenvalues and eigenvectors by Single Value Decompositin (SVD) and a distortion value of the modulation symbols is estimated using the eigenvectors and the eigenvalues to minimize noise and interference power. The modulation symbols are precoded by combining the modulation symbols with the estimated distortion value.09-16-2010
20100232538Transmitting Apparatus, Transmission Control Method, And Communication Apparatus - A transmitting apparatus multiplexes transmit signals to receiving apparatuses according to weight vectors, and transmits the multiplexed transmit signals wirelessly using antennas. Here, a controller of the transmitting apparatus first selects a first receiving apparatus and allocates a weight vector to it. Next, the controller outputs, to a second receiving apparatus, data on candidates of a weight vector available in parallel with the weight vector allocated to the first receiving apparatus. Then, the controller allocates the weight vector to the second receiving apparatus based on feedback data from the second receiving apparatus.09-16-2010
20100232537APPARATUS FOR TRANSMISSION THROUGH MULTIPLE ANTENNAS - A space-time coding apparatus receives two groups of inputs and outputs two groups of outputs. A configuration of each output group is based on spatial diversity and a configuration between the groups of outputs is based on spatial multiplexing. The space-time coding apparatus may include two spatial diversity coders whose outputs are each connected two spatial multiplexing coders. A plurality of antennas may be respectively connected to outputs of each spatial multiplexing coder. Coding coefficients are configured so that a first wireless receiving terminal corresponding to a first group of outputs receives only input signal components of a first group of inputs, and a second wireless receiving terminal corresponding to a second group of outputs receives only input signal components of a second group of inputs.09-16-2010
20100232536PRECODING APPARATUS FOR MULTI-USER, MULTI-ANTENNA, WIRELESS TRANSMISSION SYSTEM - A multi-antenna wireless transmission apparatus for multiple receiving terminals includes a channel characteristic acquiring unit to acquire characteristic parameters of a wireless transmission channel between a transmitting party antenna and a receiving party antenna, a coefficient calculator to use the characteristic parameters of the wireless transmission channel to calculate coefficients configured such that the transmitting party sets a ratio of received power for a transmission signal at the receiving party to intensity of interference and noise of the transmission signal, and a precoder to multiply an input signal by a matrix whose elements are the coefficients calculated by the coefficient calculator and to output an output signal. The output signal is to be transmitted from the transmitting party antenna to the receiving party antenna.09-16-2010
20120087434Method and System for Pre-Equalization in a Single Weight Spatial Multiplexing MIMO System - Certain aspects of the method may comprise receiving a plurality of spatially multiplexed communication signals from a plurality of transmit antennas at a base station. A plurality of vectors of baseband combined channel estimates may be generated based on phase rotation of the received plurality of spatially multiplexed communication signals. A plurality of pre-equalization weights may be generated based on the generated plurality of vectors of baseband combined channel estimates. The received plurality of spatially multiplexed communication signals may be modified based on the generated plurality of pre-equalization weights. At least a portion of the generated plurality of pre-equalization weights may be fed back to the base station for modifying subsequently transmitted spatially multiplexed communication signals which are transmitted from at least a portion of the plurality of transmit antennas at the base station.04-12-2012
20120087433COMMUNICATIONS APPARATUS AND COMMUNICATIONS SYSTEM USING MULTICARRIER TRANSMISSION MODE - A communications apparatus accommodated in a communications system for exchange of information between a communications apparatuses by a multicarrier transmission mode using a plurality of subcarriers. The communications apparatus includes a dedicated transmission data generator for each communications apparatus, configured to generate frequency band information indicating which frequency band is to be used for transmission of data information between each communications apparatus; and a transmitter configured to transmit the dedicated frequency band information with dedicated control channel for each communications apparatus by using a specific frequency band which is set from among a plurality of frequency bands assigned to the communications system, in which the specific frequency band is set as a primary band in a frequency band assigned to the communication system.04-12-2012
20120087432WIRELESS RECEPTION DEVICE, WIRELESS RECEPTION METHOD, AND WIRELESS COMMUNICATION SYSTEM - A wireless reception device includes a determination section to determine, based on reception power of each of subcarriers of a multicarrier signal and a transfer function of each of the subcarriers, a value relating to an interference component between subcarriers, the interference component being from another subcarrier for each of the subcarriers, with respect to each of the subcarriers, and a removal section to remove the interference component from each of the subcarriers, based on the value relating to the interference component.04-12-2012
20120087431ANTENNA DIVERSITY APPARATUS AND ANTENNA DIVERSITY METHOD - The present invention provides an antenna diversity apparatus and an antenna diversity method. The antenna diversity apparatus comprises: a plurality groups of antennas, a switching unit, a demodulating unit, an antenna switch selecting unit, and a control unit, wherein each group of the plurality groups of antennas comprises at least an antenna, and the control unit can comprises: a receiving signal quality detecting unit, a packet detecting unit, and an antenna decision unit. The antenna decision unit can be realized by hardware, firmware, or software, and the antenna switch selecting unit can be realized by hardware. The antenna diversity apparatus and the antenna diversity method provided by the present invention can switch antennas fast to avoid the defect of occurring burst error to reduce transmitting data rate, and switch to proper antennas fast when variation of the data transmission channels occurs.04-12-2012
20120087430SYSTEMS AND METHODS TO EXPLOIT AREAS OF COHERENCE IN WIRELESS SYSTEMS - Non-linear or linear precoding is used to create separate areas of coherence to different users. Limited feedback techniques may also be employed to send channel state information (CSI) from the plurality of users to the MU-MAS. In some embodiments, a codebook is built based on basis functions that span the radiated field of a transmit array. Additionally, the precoding may be continuously updated to create non-interfering areas of coherence to the users as the wireless channel changes due to Doppler effect. Moreover, the size of the areas of coherence may be dynamically adjusted depending on the distribution of users.04-12-2012
20120328039METHOD AND SYSTEM FOR PRECODING DATA - The present disclosure relates to channel state feedback in a communication system. The method includes obtaining a reference signal from an access point; deriving a rank indication, a codebook subset selection indication and a precoding matrix index based on the obtained reference signal; sending a first feedback message conveying the rank indication and the codebook subset selection indication, and sending a second feedback message conveying the precoding matrix index, to the access point; and receiving, from the access point, data precoded by a matrix derived based on the rank indication, the codebook subset selection indication and the precoding matrix index.12-27-2012
20110280329CHANNEL ESTIMATION FOR LOW-OVERHEAD COMMUNICATION IN A NETWORK - A system for communicating between stations over a shared medium comprises: a first station comprising one or more antennas that transmit a waveform, the waveform including at least a first symbol, having a predetermined symbol length, comprising a first set of frequency components at predetermined carrier frequencies modulated with preamble information stored in a second station and a second set of frequency components at predetermined carrier frequencies modulated with information to be communicated to at least one station, with the carrier frequencies of the first and second sets of frequency components being integral multiples of a frequency interval determined by the inverse of the symbol length, wherein each of the one or more transmitting antennas transmits at least some carrier frequencies from each of the first and second sets; and at least a second station. The second station comprises one or more antennas, configured to: process sampled values from the first symbol received by each of the one or more antennas based on channel characteristics estimated from the first set of frequency components to decode information encoded on a first subset of the second set of frequency components, and process sampled values from the first symbol received by each of the one or more antennas based on channel characteristics estimated from the first set of frequency components and the first subset of the second set of frequency components to decode information encoded on a second subset of the second set of frequency components.11-17-2011
20110293030ORTHONORMAL TIME-FREQUENCY SHIFTING AND SPECTRAL SHAPING COMMUNICATIONS METHOD - A wireless combination time, frequency and spectral shaping communications method that transmits data in convolution unit matrices (data frames) of N×N (N12-01-2011
20120328037ANTI-GEOLOCATION - Methods, apparatus, and articles of manufacture make Geolocation of a source transmitter more difficult or impossible. Scatterers common to a source transmitter and an intended receiver are identified using a variety of techniques, such as iterative time reversal (ITR) and Singular Value Decomposition (SVD) of a scatter matrix. The source transmitter then uses time reversal and knowledge of the signatures of the scatterers to focus its transmissions on one or more of the scatterers, instead of the intended receiver. The source transmitter may have multiple antennas or antenna elements. The source transmitter and/or the intended receiver may include antenna elements with Near-Field Scatterers to enable spatial focusing below the diffraction limit at the frequencies of interest. The source transmitter may be a plurality of ad hoc nodes cooperating with each other.12-27-2012
20090122899Method, Device, Arrangement, Transmitter Unit and Receiver Unit for Generating Data Characterising Mimo Environment - A method and arrangement for generating data for transmitter or receiver simulations where the generated data includes Multiple Input Multiple Output radio environment (MIMO) characteristics. The arrangement includes a model data (05-14-2009
20100202553MIMO Precoding Enabling Spatial Multiplexing, Power Allocation and Adaptive Modulation and Coding - In a closed-loop wireless communication system, a codebook-based feedback mechanism is provided to enable non-unitary precoding for multi-stream transmission, where in each stream is optimized with suitable transmission power allocation and AMC. The codebook-based feedback mechanism uses a precoding codebook having a power allocation matrix which is constrained to specify that beamforming always applies full power to a predetermined beam. With this constraint, a one-bit power allocation feedback index may be used to switch between beamforming and spatial multiplexing.08-12-2010
20130010888METHOD FOR OPERATING A SECONDARY STATION - The invention relates to a method for operating a secondary station, the secondary station communicating with at least one primary station by means01-10-2013
20130010887SCATTERED PILOT PATTERN AND CHANNEL ESTIMATION METHOD FOR MIMO-OFDM SYSTEMS - Methods and apparatus are provided for inserting data symbols and pilot symbols in an OFDM (orthogonal frequency division multiplexing) transmission resource utilizing frequency hopping patterns for the data symbols and/or the pilot symbols. Data symbols and pilot symbols are allocated for down link (base station to mobile station) and up link (mobile station to bases station) transmission resources in a two-dimensional time-frequency pattern. For each antenna of a MIMO-OFDM (multiple input multiple output OFDM) communication system, pilot symbols are inserted in a scattered pattern in time-frequency and data symbols are inserted in an identical frequency-hopping pattern in time-frequency as that of other antennas.01-10-2013
20130010886TECHNIQUES TO ENHANCE DIVERSITY FOR A WIRELESS SYSTEM - A system, apparatus, method and article to manage diversity for a wireless multicarrier communication system are described. An apparatus may include a diversity agent to couple to a transmitter, the diversity agent to convert a determined number of input bits into symbols, interleave the symbols across multiple spatial streams, and map the symbols to tones for each spatial stream. Other embodiments are described and claimed.01-10-2013
20130010885MULTIPLE-INPUT MULTIPLE-OUTPUT WIRELESS COMMUNICATION APPARATUS AND METHOD - Disclosed herein is a multiple-input multiple-output (MIMO) wireless communication apparatus including: a plurality of radio frequency (RF) modules each processing RF signals input; a plurality of local area communication modules processing a local area communication signal input; a plurality of switches; and a control block determining whether there is an idle RF module in the plurality of RF modules at the time of the MIMO mode operation and switching a corresponding switch so that the local area communication module operating in the MIMO mode and a corresponding RF antenna corresponding to the idle RF module are connected to each other. Therefore, the MIMO mode is implemented without adding the local area communication dedicated antenna, thereby making it possible to maximize space utilization and reduce a cost.01-10-2013
20130010884MULTIPLE-INPUT, MULTIPLE-OUTPUT TELECOMMUNICATIONS SCHEMES - This disclosure concerns beam-forming vectors and beam-forming matrices for multiple-input, multiple-output (MIMO) communications systems. These systems, from the method perspective, provide, according to one embodiment, a method of feeding back, to a transmitter from a receiver in a MIMO communications system, at least part of a beam-forming vector of a beam-forming matrix, wherein: the vector relates to a spatial stream of the MIMO system; the vector comprises a series of elements; each element specifies a beam-forming weight for a respective transmit antenna of the transmitter; and the method comprises: calculating a scaling factor that would scale a first element of the vector to a value of one; scaling the other element or elements of the vector with the scaling factor; and feeding back the scaled other element or elements to the transmitter to inform a beam-forming process. These systems, from the method perspective, provide, according to another embodiment, a method of processing a beam-forming matrix, wherein: the beam-forming matrix is for adjusting signals that are to issue from the transmit antennae of a MIMO communications system; the MIMO communications system comprises a transmitter and a receiver; the beam-forming matrix is capable of being decomposed into a series of beam-forming vectors; each beam-forming vector relates to a spatial stream of the MIMO system; each beam-forming vector comprises a series of elements; each element specifies a beam-forming weight for a transmit antenna of the transmitter; and the method comprises: obtaining a beam-forming matrix in which the elements are quantised; and orthogonalising the beam-forming vectors with respect to one another.01-10-2013
20100150260METHOD AND SYSTEM FOR MINIMIZING EFFECTS OF TRANSMITTER IMPAIRMENTS IN MULTIPLE INPUT MULTIPLE OUTPUT (MIMO) BEAMFORMING COMMUNICATION SYSTEMS - Aspects of a method and system for minimizing effects of transmitter impairments in multiple input multiple output (MIMO) beamforming communication systems are presented. In one aspect of a system for minimizing effects of transmitter impairments, a MIMO transmitter may enable nulling of transmitter-induced noise by adjusting at least a portion of a plurality of signals transmitted based on a transmitter error vector magnitude (EVM). The transmitter may enable transmission of the plurality of signals subsequent to the nulling. In another aspect of a system for minimizing effects of transmitter impairments a MIMO receiver may enable nulling of transmitter-induced noise contained in a plurality of received signals based on a transmitter EVM. Each of the plurality of received signals may include information contained in a plurality of spatial streams. The receiver may enable detecting estimated values for the information contained in the plurality of spatial streams based on the nulling.06-17-2010
20100150259METHOD AND A DEVICE FOR DETERMINING SHIFTING PARAMETERS TO BE USED BY AT LEAST A FIRST AND A SECOND TELECOMMUNICATION DEVICES - The present invention concerns a method for determining shifting parameters p06-17-2010
20130022146METHOD AND APPARATUS FOR FEEDING BACK AND CONSTRUCTING CORRELATION MATRIX IN MULTI-INPUT MULTI-OUTPUT SYSTEMS - The present invention provides a method for feeding back a correlation matrix in a multi-input multi-output system, comprising: constructing codebooks for the correlation matrix based on a conjugation nature of the correlation matrix and based on a predetermined relationship between diagonal elements and off-diagonal elements in the correlation matrix; selecting a codeword from the constructed codebook; and feeding back a corresponding index of the selected codeword in the codebook. Through the present invention, the throughput of the multi-input multi-output system can be enhanced, while reducing the encoder complexity or transfer load.01-24-2013
20130022145DECIDING THE ORDER OF SIC DETECTION BY ADJUSTING MCS - Method, receiver and computer program product for processing a signal, wherein the signal is received over a wireless network from a transmitter, the signal comprising a plurality of data streams. A selected one of the data streams is preferentially treated by reporting an adjusted value of a characteristic of the selected data stream to the transmitter and the received signal is decoded using a technique of successively decoding data streams in which the selected data stream is the first data stream to be decoded, a signal corresponding to the selected data stream being removed from the received signal prior to decoding at least one of the unselected data streams in the received signal.01-24-2013
20130022144MIMO PRECODING ENABLING SPATIAL MULTIPLEXING, POWER ALLOCATION AND ADAPTIVE MODULATION AND CODING - In a closed-loop wireless communication system, a codebook-based feedback mechanism is provided to enable non-unitary precoding for multi-stream transmission, where in each stream is optimized with suitable transmission power allocation and AMC. The codebook-based feedback mechanism uses a precoding codebook having a power allocation matrix which is constrained to specify that beamforming always applies full power to a predetermined beam. With this constraint, a one-bit power allocation feedback index may be used to switch between beamforming and spatial multiplexing.01-24-2013
20130022142BASE STATION AND METHOD FOR IMPLEMENTING AN ADAPTIVE CLOSED-LOOP MIMO AND OPEN-LOOP MIMO TECHNIQUE IN A WIRELESS COMMUNICATION SYSTEM - A base station and a method are described herein that implement an adaptive closed-loop MIMO and open-loop MIMO technique which accounts for all channel conditions and improves the performance of communications with a user equipment. In one example, the base station and method analyze a current user equipment report and a previous user equipment report received from a user equipment to determine if at least one channel condition parameter has a rate of change greater than a corresponding at least one threshold and if yes then use an open-loop MIMO technique and if no then use a closed-loop MIMO technique when interacting with the user equipment.01-24-2013
20130022143BEAMFORMING APPARATUS AND METHOD IN MULTI-ANTENNA SYSTEM - The present invention relates to a symbol-wise beamforming apparatus and method in an OFDM communication system using multiple antennas. A weight vector calculator calculates a transmit weight vector using a signal received through the multiple antennas as an input on the basis of channel information in the time domain and covariance matrix information about interference and noise and computes a receive weight vector using the calculated transmit weight vector. At least one of the calculated transmit weight vector and receive weight vector is transmitted to a transmission apparatus through a transmitter.01-24-2013
20130136201METHOD AND APPARATUS FOR GENERATING A FEEDBACK CODEBOOK IN A NETWORK DEVICE - The invention provides a method of generating a 2M-antenna feedback codebook for l data streams in a network device, wherein l=1, . . . , 2M. The method includes the steps of: acquiring an M-antenna feedback codebook W05-30-2013
20080247483Space Time Coded Mb-Ofdm Uwb System - A system, apparatus, and method is provided for space-time coding a multiband OFDM UWB system that employs a scheme that transmits channel symbols corresponding to an incoming signal on the same sub-carrier (10-09-2008
20080240281ORTHOGONAL REFERENCE SIGNAL PERMUTATION - A method for a wireless communication system is provided. The method includes analyzing a set of signal sources that are operably associated with a set of time domain windows. Often, the method periodically switches the association between the set of time domain windows and the set of signal sources in order to facilitate a determination of one or more signal paths generated by the signal sources.10-02-2008
20080232505Frequency-domain method for joint equalization and decoding of space-time block codes - Space-time block coding is combined with single-carrier, minimum-mean-square-error, frequency-domain equalization for wireless communication through a medium characterized by multi-paths. The transmitter encodes incoming symbols into two or more streams that are transmitted over a corresponding number of transmitting antennas. The encoding employs modulo arithmetic. Decoding in the receiver proceeds by converting received signals to frequency domain, linearly combining the signals to separate contribution of the signals from the two or more transmitting antennas equalizing the separated signals, converting the equalized signals to time domain, and applying the converted signals to a decision circuit.09-25-2008
20080232501STATIC AND DIFFERENTIAL PRECODING CODEBOOK FOR MIMO SYSTEMS - Systems and methods are disclosed to generate a codebook for channel state information by generating a random codebook; partitioning channel state information into a set of nearest neighbors for each codebook entry based on a distance metric; and updating the codebook by finding a centroid for each partition.09-25-2008
20100086075Parallel Generation and Matching of a Deskew Channel - In one embodiment, a method includes receiving input data bits at a collective data rate, the input data bits being grouped into a plurality of input data words, the input data bits of each of the input data words being received from n parallel input-data-bit streams, each of the n parallel input-data-bit streams having a stream data rate that is 1/n of the collective data rate, each of the input data words comprising n consecutive ones of the input data bits; selecting particular input data bits; and generating a k-bit deskew channel with the selected input data bits, the deskew channel comprising a number of frames, each of the frames comprising x input data bits from one or more input data words and one or more framing bits. In another embodiment, a method includes using such a deskew channel to determine relative delays between data channels and the deskew channel.04-08-2010
20080225978METHOD AND APPARATUS FOR SYNCHRONIZATION FOR MIMO TDS-OFDM SYSTEM - In an orthogonal frequency division multiplexing (OFDM) multiple-input multiple-output (MIMO) wireless communication system where both a transmitter and a receiver include a plurality of antennas, a method comprising the step of: a receiver using at least one pseudo noise (PN) to correlate desired information relating to a received symbol.09-18-2008
20080225977METHOD AND APPARATUS FOR MIMO CHANNEL ESTIMATION IN A TDS-OFDM SYSTEM DOWNLINK USING A SUB-SPACE ALGORITHM IN THE FREQUENCY DOMAIN - In an orthogonal frequency division multiplexing (OFDM) multiple-input multiple-output (MIMO) wireless communication system, a method is provided for channel estimation using a sub-space method suitable for computer implementation. The system has both a transmitter and a receiver including a plurality of antennas. The method comprising the step of: a receiver using at least one pseudo noise (PN) to correlate desired information relating to a received symbol; transforming the correlated information into frequency domain; and performing channel estimation using a sub-space method suitable for computer implementation.09-18-2008
20080225976METHOD FOR MULTIPLE-INPUT-MULTIPLE-OUTPUT SYSTEM DEMODULATION - A MMSE-based deterministic sequential Monte Carlo (SMC) method for MIMO demodulation exhibiting square root complexity in terms of constellation size. Further extensions to the method reduce the search space resulting in significant reduction in computational requirements while minimally impacting performance. As a hard decision algorithm, the methods achieve sphere decoder performance while imposing a much smaller computational load.09-18-2008
20080225975Structured Space-Time Code Achieving the Full Diversity and Full Rate and Generating Method Thereof, and Multi-Input Multi-Output System - A space-time code used for a transmitter to transmit a plurality of data symbols to a receiver in a MIMO system, the space-time code including a code word matrix for transmitting an amount of data symbols corresponding to a product of the number of transmit antennas and a spatial multiplexing rate during one block period, wherein a row index indicates combined signals transmitted through different transmit antennas and a column index indicates time slots that correspond to the number of transmit antennas, and wherein the number of data symbols allocated to each transmit antenna in a code block corresponds to the spatial multiplexing rate, and the data symbols are combined by different combining coefficients for each transmit antenna at every time slot, and simultaneously transmitted through different transmit antennas, and each transmit antenna transmits a different set of data symbols at every time slot.09-18-2008
20110261895Calibration Correction for Implicit Beamforming In a Wireless MIMO Communication System - A transmitter beamforming technique for use in a MIMO wireless communication system determines a partial description of a reverse channel without determining a full dimensional description of the reverse channel. A correction matrix is developed from the partial description of the reverse channel and a description of the forward channel. The correction matrix is used to process signals to be transmitted via the forward channel, and a steering matrix is used to perform beamforming in the forward channel.10-27-2011
20110261894WIRELESS COMMUNICATION APPARATUS, WIRELESS COMMUNICATION SYSTEM AND WIRELESS COMMUNICATION METHOD - In a MIMO system using a cross-polarized antenna structure, even if no ideal XPD can be obtained, the interference between different polarized waves can be reduced to allow an effective precoding to be executed. When a MIMO communication is performed between a transmitter (10-27-2011
20130170573Adaptive Transmit Beamforming - Embodiments of a method and apparatus for selecting one of several different power constraints under which sets of complex, beam weights are normalized are described herein. The embodiments of the method and apparatus specifically select the power constraint based on a code rate used to encode information carried by a transmit signal weighted by the sets of complex, beam weights. Appropriate selection of the power constraint can improve the bit error rate (BER) or block error rate (BLER) of the decoded transmit signal at a receiver.07-04-2013
20130170574Cell Clustering and Aperture Selection - A method is disclosed that includes accessing baseband information for a number, N (N>1), of antennas accessible by a number of baseband units, where the baseband information correspond to a transmission by a user equipment and is received at the N antennas. The method includes determining values for one or more metrics for the baseband information for the N antennas. The method includes selecting, based on the determined values, a subset k of the N antennas and corresponding baseband information to use to determine output data for the transmission by the user equipment. The method includes determining the output data for the user equipment using the baseband information from the k antennas. Apparatus and computer program products are also disclosed.07-04-2013
20130142271METHOD FOR DETERMINING PRECODING WEIGHTS - The present invention relates to a method for determining precoding weights between a base station and one user equipment in a communication network. The base station is provided with an antenna structure having multiple antennas, and the antenna structure provides coverage in a coverage area. The precoding weights are stored in a codebook available to the base station and the user equipment. The method comprises: selecting to use a part of the coverage area; determining, at the base station, a subset of precoding weights stored in the codebook generating at least one precoding beam within the selected part of the coverage area; and informing the one user equipment of the determined subset of pre-coding weights generating the at least one precoding beam within the selected part of the coverage area.06-06-2013
20130142270MULTIPLE-INPUT MULTIPLE-OUTPUT SPATIAL MULTIPLEXING SYSTEM WITH DYNAMIC ANTENNA BEAM COMBINATION SELECTION CAPABILITY - A spatial diversity receiver for wirelessly receiving a modulated RF signal and a method for wirelessly transmitting and receiving the modulated RF signal. The spatial diversity receiver includes at least two antenna arrays and an antenna beam selection control unit. Each antenna array of the spatial diversity receiver includes at least two fixed beam antennas with distinct radiation patterns, and combinations of the fixed beam antennas are selectable for wireless receipt of the modulated RF signal. The antenna beam selection control unit is configured to control at least one antenna switching and/or combining unit in order to select a specific combination of fixed beam antennas from each antenna array.06-06-2013
20130177097Interference Alignment Method and Device and Multi-Channel Communication System - An interference alignment method, an interference alignment device, and a multi-channel communication system are provided. The method includes: obtaining channel matrix in a multi-channel communication system; determining a first desired signal and a second desired signal of the multi-channel communication system according to the channel matrix; obtaining precoding vectors and receive vectors, after a first receive signal is filtered by a receive vector corresponding to the first desired signal, a signal formed by superposing interference signals included therein has a feature of a lattice constellation pattern, and that at a receiver corresponding to the second desired signal, after a second receive signal is filtered by a receive vector corresponding to the second desired signal, interference signals included therein are canceled, where the first receive signal and the second receive signal are transmit signals sent to the corresponding receivers after precoding processing is performed at transmitters by using corresponding precoding vectors.07-11-2013
20130177098METHOD AND DEVICE FOR SELECTING ANTENNA IN MULTI- ANTENNA SYSTEM - Provided is a method for selecting an antenna performed by a receiver in a multi-antenna system. The method for selecting the antenna performed by the receiver in the multi-antenna system, comprises: a subcarrier group setting step for setting subcarrier groups by grouping subcarriers; a channel information acquisition step for acquiring channel information between a receiving end antenna and each of a plurality of transmission end antennas; an antenna selecting step for determining said subcarrier groups, which are to be transmitted to each of the plurality of said transmission end antennas on the basis of said channel information; and an antenna selection information transmission step for transmitting antenna selection information, which contains the result of said antenna selection, to a transmission end.07-11-2013
20130177094PRECODER FOR SPATIAL MULTIPLEXING, MULTIPLE ANTENNA TRANSMITTER - A method of spatially precoding data includes determining a transmission rank of a communication channel and selecting a set of one or more precoding filters derived from a single generator matrix based on said transmission rank. The method also includes precoding data for transmission to a remote device using said precoding filters in a predetermined order according to a predetermined precoding sequence. The precoding may include using different ones of said precoding filters during different precoding intervals in a predetermined precoding period of the predetermined precoding sequence. Additionally, precoding data for transmission may involve traversing an Orthogonal Frequency Division Multiplexing (OFDM) resource block in an alternating pattern during said predetermined precoding period.07-11-2013
20130177095Multiple-Input Multiple-Output System And Method - A multiple-input multiple-output (MIMO) system can transmit on multiple antennas simultaneously and receive on multiple antennas simultaneously. Unfortunately, because a legacy 802.11a/g device is not able to decode multiple data streams, such a legacy device may “stomp” on a MIMO packet by transmitting before the transmission of the MIMO packet is complete. Therefore, MIMO systems and methods are provided herein to allow legacy devices to decode the length of a MIMO packet and to restrain from transmitting during that period. These MIMO systems and methods are optimized for efficient transmission of MIMO packets.07-11-2013
20130177096METHOD AND APPARATUS FOR TRANSCEIVING DATA IN A MIMO SYSTEM - The present invention relates to a method and apparatus for transceiving data. A method in which a transmitting terminal transmits data to a receiving terminal in a MIMO system according to one embodiment of the present invention comprises the following steps: generating a data field containing the data; generating a signal field containing information on the data field; generating a data frame containing the data field and the signal field; and transmitting the data frame to the receiving terminal. According to the present invention, an end of the frame being transmitted is accurately notified to the receiving terminal in a communication system in which the frame is transmitted using MIMO, thereby decoding the frame in a more efficient manner at the receiving terminal.07-11-2013
20090268842MULTIPLE STREAMS USING PARTIAL STBC WITH SDM WITHIN A WIRELESS LOCAL AREA NETWORK - A method of communicating data to M receiving antennas from N transmitting antennas, where M and N are integers, the method includes the steps of receiving M data signals from M receive antennas, applying the M data signals to a space/time decoder to produce M decoded streams and reconstructing original data transmitted via N transmit antennas from the M decoded streams. At least P transmitting antennas transmit space-time block-coded signals and (N-P) transmitting antennas transmit code signals through spatial division multiplexing, where P is an integer.10-29-2009
20110274198SYSTEM AND METHOD FOR SIGNALING CONTROL INFORMATION IN A MOBILE COMMUNICATION NETWORK - A method of transmitting control information from a wireless communication terminal to an access network includes generating control information comprising a plurality of control bits. The method also includes encoding the control bits using a block code that outputs an encoded bit sequence comprising encoded bits b(11-10-2011
20110274197METHOD FOR TRANSMITTING MIMO RELATED INFORMATION - The present invention provides a method for transmitting MIMO related information. The method includes: encoding MIMO related information of a user equipment (UE) by a base station, and transmitting downlink control signaling including a result of the encoding; receiving by the UE the downlink control signaling transmitted by the base station, obtaining the result of the encoding, and obtaining the MIMO related information of the UE by decoding the result of the encoding. By adopting the method, the base station is enabled to transmit MIMO related information required by the UE to the UE with small signaling overhead.11-10-2011
20080219375APPARATUS AND METHOD FOR SPATIAL MULTIPLEXING WITH BACKWARD COMPATIBILITY IN A MULTIPLE INPUT MULTIPLE OUTPUT WIRELESS COMMUNICATION SYSTEM - An apparatus and method for supporting both a receiver using a single antenna and a receiver using multiple antennas in a Multiple Input Multiple Output (MIMO) wireless communication system are provided. The apparatus and method in a MIMO wireless communication system include a first synthesizer for generating a first Transmit (Tx) signal by adding a first signal and a second signal, a second synthesizer for generating a second Tx signal by subtracting the second signal from the first signal and a plurality of transmitting units for transmitting the first Tx signal and the second Tx signal through corresponding antennas. Accordingly, receivers having either a single antenna or multiple antennas may be employed in the same communication system.09-11-2008
20130202056CODEBOOK GENERATION SYSTEM AND ASSOCIATED METHODS - A codebook generation system and associated methods are generally described herein.08-08-2013
20130114753RADIO BASE STATION AND COMMUNICATION CONTROL METHOD - A radio base station (eNB 05-09-2013
20130114752TRANSMISSION METHOD, TRANSMITTER APPARATUS, RECEPTION METHOD AND RECEIVER APPARATUS - Transmission quality is improved in an environment in which direct waves dominate in a transmission method for transmitting a plurality of modulated signals from a plurality of antennas at the same time. All data symbols used in data transmission of a modulated signal are precoded by hopping between precoding matrices so that the precoding matrix used to precode each data symbol and the precoding matrices used to precode data symbols that are adjacent to the data symbol in the frequency domain and the time domain all differ. A modulated signal with such data symbols arranged therein is transmitted.05-09-2013
20130094602METHOD AND SYSTEM FOR REDUCTION OF PEAK-TO-AVERAGE POWER RATIO OF TRANSMISSION SIGNALS COMPRISING OVERLAPPING WAVEFORMS - The present invention provides a method and system for reducing the peak to average power ratio (PAP) of a signal with low computational complexity. According to one embodiment, the present invention is applied to reduce the PAP of an OFDM signal. According to an alternative embodiment, the present invention, is applied to reduce the PAP of a CDMA signal. Rather than seeking the optimum solution, which involves significant computational complexity, the present invention provides for a number of sub-optimal techniques for reducing the PAP of an OFDM signal but with much lower computational complexity.04-18-2013
20130101060SYSTEMS AND METHODS FOR SUPPRESSING INTERFERENCE IN A WIRELESS COMMUNICATION SYSTEM - Systems and methods are provided for suppressing interference from a received data signal. A characteristic of a channel is estimated, the channel being configured for transmission of data between a transmitting device and a receiving device having two or more receive antennas. A spatial correlation of interference is determined for the two or more receive antennas based on the channel characteristic. The received data signal is filtered based on the spatial correlation.04-25-2013
20130129002TRANSMISSION CONTROLLING METHOD, SENDER APPARATUS AND RECEIVER APPARATUS FOR WIRELESS COMMUNICATION SYSTEM - A wireless communication system including a sender apparatus having a plurality of transmitting antennas that performs MIMO transmission of a plurality of data blocks; and a receiver apparatus that receives the plurality of data blocks. The sender apparatus transmits a process number via a control channel different from a data channel to the receiver apparatus, and wherein when the MIMO diversity transmission is performed, the receiver apparatus performs HARQ processing in the received data blocks based on not a process number which prevents the data blocks from competing but the received process number from the sender apparatus.05-23-2013
20130129000Feedback of Channel Information in a Closed Loop Beamforming Wireless Communication System - A method for feeding back transmitter beamforming information from a receiving wireless communication device to a transmitting wireless communication device includes a receiving wireless communication device receiving a preamble sequence from the transmitting wireless device. The receiving wireless device estimates a channel response based upon the preamble sequence and then determines an estimated transmitter beamforming unitary matrix based upon the channel response and a receiver beamforming unitary matrix. The receiving wireless device then decomposes the estimated transmitter beamforming unitary matrix to produce the transmitter beamforming information and then wirelessly sends the transmitter beamforming information to the transmitting wireless device.05-23-2013
20130128999MIMO CODEBOOK GENERATION - Particular codebook entries used for a MIMO system of a lower dimension (i.e., having a relatively low number of antennas) can be used to generate a codebook for a MIMO system of a higher dimension (i.e., having a relatively high number of antennas). The entries in rank 1 of the codebook related to the MIMO system having four transmit antennas are used to newly construct entries for rank 1 through rank 8 of two base matrices for a MIMO base codebook related to eight transmit antennas.05-23-2013
20130129001TRANSMISSION METHOD, TRANSMITTER, AND RECEIVER FOR MULTI ANTENNA WIRELESS COMMUNICATION SYSTEM - A transmitter includes first generator to generate pilot source signal by modulating pilot sequence, second generator to generate data source signal with time length longer than that of pilot source signal by modulating data sequence, first cyclic shifter to perform cyclic shift of first shift amount to pilot source signal to generate first pilot signal, second cyclic shifter to performs cyclic shift of second shift amount to data source signal to generate first data signal, third cyclic shifter to perform cyclic shift of third shift amount to pilot source signal to generate second pilot signal, fourth cyclic shifter to perform cyclic shift of fourth shift amount to data source signal to generate second data signal, first transmit antenna to transmit first pilot signal and first data signal, and second transmit antenna to transmit second pilot signal and second data signal.05-23-2013
20110222620Method and System for Frame Formats for MIMO Channel Measurement Exchange - A method and system for frame formats for MIMO channel measurement exchange is provided. Aspects of a method for communicating information in a communication system may comprise transmitting data via a plurality of radio frequency (RF) channels utilizing a plurality of transmitting antenna, receiving feedback information via at least one of a plurality of RF channels, and modifying a transmission mode based on the feedback information. Aspects of a method for communicating information in a communication system may also comprise receiving data via a plurality of receiving antenna, transmitting feedback information via at least one of the plurality of RF channels, and requesting modification of a transmission mode for the received data in transmitted response messages comprising the feedback information.09-15-2011
20080198943SYSTEMS AND METHODS FOR LATTICE ENUMERATION-AIDED DETECTION - Embodiments provide systems and methods for improved multiple-input, multiple-output (MIMO) detection comprising generating at least one list of candidate vectors by employing lattice enumeration which approximates hyperellipsoid detection search space and calculating a reliability of the candidate vectors. At least one advantage to embodiments is that improved detection occurs because detection can be performed in a search space defined by the eigenvectors (which define the general shape of an ellipsoid/hyperellipsoid, depending upon number of dimensions) and eigenvalues (which provide the appropriate scaling in each direction of the eigenvectors) of the effective channel.08-21-2008
20130156121INTER-BASE-STATION COOPERATED MIMO TRANSMITTING METHOD AND BASE STATION APPARATUS - A decrease in a transmission capacity is suppressed even when CSI is not fed back from a mobile station apparatus to all cooperating base station apparatuses. A base station apparatus (BS06-20-2013
20130148755PRECODING CODEBOOKS FOR MIMO COMMUNICATION SYSTEMS - A method for communication includes configuring a communication system that includes a transmitter and a receiver with first precoding matrices for mapping up to N data streams onto N transmit antenna ports of the transmitter. Each of at least some of the first precoding matrices are derived from respective second and third precoding matrices. The second and third precoding matrices are configured for mapping data onto respective numbers of transmit antenna ports that are less than N. The data streams are mapped onto the N transmit antenna ports using a precoding scheme based on one of the first precoding matrices. The mapped data streams are transmitted over the N transmit antenna ports from the transmitter to the receiver.06-13-2013
20130148754Performance for a multiple antenna beamforming cellular network - The present disclosure provides for an improved application of signal strength weightings in an SDMA sectored cellular network. The improved signal strength weightings application is conducted through the improved selection of weightings from a new codebook subset or by the selection of weightings from a larger codebook subset. In a further embodiment, an antenna beam index or bit map can be used to select the best beam(s) in an SDMA sectored cellular network. In another embodiment, a field or factor in an uplink or downlink transmission packet can designate which directional transmission beam is best suited for the transmission or when the directional transmission beam should be activated.06-13-2013
20130148756DATA TRANSMISSION METHOD, TRANSMITTER AND RECEIVER IN COORDINATED COMMUNICATION SYSTEM - The present invention provides a data transmission method, a transmitter, and a receiver in a coordinated communication system, including: precoding, by a first transmitter, its payload data by using a first precoding matrix to obtain first precoded data; precoding, by the first transmitter, coordinated data by using a second precoding matrix to obtain second precoded data to cancel interference with the first precoded data at a receiver caused by data transmitted by another transmitter; and transmitting the first precoded data and the second precoded data after the precoding to the receiver. According to the method, the first transmitter codes its payload data by using the first precoding matrix; and codes the coordinated data by using the second precoding matrix to cancel, by using different precoding matrices, the interference with the first precoded data at the receiver caused by the data transmitted by another transmitter.06-13-2013
20130148757WIRELESS TRANSMISSION METHOD, AND WIRELESS TRANSMITTER AND WIRELESS RECEIVER - A wireless transmitter capable of transmitting a data stream to a wireless receiver, the wireless transmitter includes a plurality of transmitting antennas; and a scheduler controls to increase the number of candidate beams selectable for transmitting said data stream depending on the number of data streams to be transmitted from said transmitting antennas becoming small, wherein said beams are formed by predetermined number of the plurality of transmitting antennas.06-13-2013
20120275530OPEN LOOP SPATIAL PROCESSING - Methods and apparatus for multiple-input multiple-output (MIMO) transmissions are disclosed. A base station may precode wireless transmit/receive unit (WTRU)-specific reference signals and data that are transmitted to a WTRU using a randomly selected precoder. The precoder may be selected based on a predefined precoder selection sequence or by the base station. A different precoder may be applied to different resource blocks (RBs). In addition, a large delay cyclic delay diversity (CDD) or discrete Fourier transform (DFT) spreading may be applied on the WTRU-specific reference signals and the data. For heterogeneous deployed antennas, spatial diversity gain is achieved by dynamically scheduling resources between transmission points. A hopping scheme may be applied across the transmission points as the resources are dynamically partitioned between the transmission points. A different randomly selected precoder may be applied to each RB transmitted from a different transmission point.11-01-2012
20120275536Codebook With Nested Structure - A multi-rank beamforming (MRBF) scheme in which the downlink channel is estimated and an optimal precoding matrix to be used by the MRBF transmitter is determined accordingly. The optimal precoding matrix is selected from a codebook of matrices having a recursive structure which allows for efficient computation of the optimal precoding matrix and corresponding Signal to Interference and Noise Ratio (SINR). The codebook also enjoys a small storage footprint. Due to the computational efficiency and modest memory requirements, the optimal precoding determination can be made at user equipment (UE) and communicated to a transmitting base station over a limited uplink channel for implementation over the downlink channel.11-01-2012
20120275535 Codebook 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 k11-01-2012
20120275534MITIGATION OF TRANSMISSION ERRORS OF QUANTIZED CHANNEL STATE INFORMATION FEEDBACK IN MULTI ANTENNA SYSTEMS - Methods are disclosed for improving communications on feedback transmission channels, in which there is a possibility of bit errors. The basic solutions to counter those errors are: proper design of the CSI vector quantizer indexing (i.e., the bit representation of centroid indices) in order to minimize impact of index errors, use of error detection techniques to expurgate the erroneous indices and use of other methods to recover correct indices.11-01-2012
20120275533Method, Apparatus and Communication Unit - A method, an apparatus and a communication unit for generating precoding feedback information in a multiple frequency radio transmission system are disclosed. A rank for precoding matrices, wherein the rank is constant over the multiple frequencies, is selected and a plurality of precoding matrices having the selected rank are selected. A different precoding matrix is selected for each frequency subset of the multiple frequencies.11-01-2012
20120275532METHOD AND DEVICE FOR LAYER MAPPING AND METHOD AND DEVICE FOR GENERATING LAYER MAPPING PATTERNS - A device for mapping code words to layers in a Multi-Input Multi-Output (MIMO) system, and for generating layer mapping patterns that include a mapping step, wherein each code word of multiple code words is mapped by mapping different code words of the multiple code words to different layer pairs of L layers on each symbol of multiple symbols, each layer pair is composed of two layers of the L layers, wherein L=2M and M is an integer that is larger than 1; in the method, each code word is circularly mapped on the multiple symbols to all layer pairs that can be generated by the L layers. Accordingly, the diversity performance can be improved through mapping each code word circularly on the multiple symbols to all layer pairs that can be generated by the multiple layers, thus the decoding performance is improved.11-01-2012
20120275531METHOD AND DEVICE FOR SELECTING THE ANTENNAS AT THE BASE STATION - In order to solve the technical problem in the prior art that different spatial correlation modes are applicable for the transmission antennas in the base station under different working modes is not considered, the present invention provides a method and device for selecting the antenna at the base station. Wherein, the spatial correlation mode information among the multiple transmission antenna elements is determined by the base station according to the working mode; then, multiple transmission antenna elements are selected from several antenna elements to transmit the signal, according to the spatial correlation mode information. With the solution in the present invention, the base station may flexibly choose channel characteristic of strong spatial correlation and/or high DoF. When the base station is working under a closed-loop mode, transmission antennas may be selected to satisfy the strong spatial correlation, thereby the feedback over-head is reduced, and the robustness against the feedback delay is increased, and the quantization error is reduced. When the base station is working under an open-loop mode, transmission antennas may be selected to satisfy the weak spatial correlation, thereby the spatial DoF is increased, and the diversity and/or multi-plexing gain is introduced.11-01-2012
20100296598SORTED QR DECOMPOSITION METHOD USED IN DETECTION OF MIMO ANTENNA SYSTEM AND DETECTOR USING THE SAME - A sorted QR decomposition method used in a detection of a multiple input multiple output (MIMO) communication system is provided. First, whether a sorting-stop parameter of a channel transformation matrix of the MIMO communication system is greater than or equal to a sorting-stop threshold is determined. Then, whether energy of elements in a leftmost column within a process area of the channel transformation matrix is completely transferred to a top element in the leftmost column is determined. If the energy of the elements in the leftmost column within the process area is not yet completely transferred to the top element in the leftmost column, a unit process area of a process unit set is expanded.11-25-2010
20100067599MIMO PREAMBLE FOR INITIAL ACCESS WITH AN UNKNOWN NUMBER OF TRANSMIT ANTENNAS - For certain embodiments, a preamble sequence associated with a particular number of transmit antennas may allow a receiving mobile station to determine the number of transmit antennas used for transmission. The preamble sequence may be selected from one of a set of Constant Amplitude and Zero Auto Correlation (CAZAC) sequences corresponding to all of the supported number of transmit antennas. As a result, a receiving station may be able to determine the sequence sent by correlation and, thereby determine the number of antennas used for transmission. Given the number of transmit antennas, the mobile station may then perform MIMO channel estimation during initial synchronization to recover the channel taps between each transmit and each receive antenna.03-18-2010
20100316156BASE STATION APPARATUS AND METHOD IN MOBILE COMMUNICATION SYSTEM - A base station apparatus used in a mobile communication system where user terminals with various numbers of reception antennas may be situated includes a providing unit configured to provide plural reference signals according to the number of transmission antennas; a precoding unit configured to replicate each of a predetermined number of input signal sequences according to the number of transmission antennas, apply a predetermined precoding vector to each of the replicated sequences, and generate output signal sequences corresponding to the number of transmission antennas; and a transmitting unit configured to transmit transmission signals including the output signal sequences from plural transmission antennas; wherein at least one of the input signal sequences includes a control signal and one of the plural reference signals.12-16-2010
20100316155SCANNING AVAILABLE WIRELESS-DEVICE SERVICES IN MULTIPLE WIRELESS-RADIO TECHNOLOGY COMMUNICATION SYSTEMS - In one embodiment, a wireless device having two or more antennas. The wireless device substantially concurrently determines (a) using a first antenna, whether a first communications service is available for data transfer, and (b) using a second antenna, whether a second communications service is available for data transfer. After determining that at least one communications service is available for data transfer, the wireless device uses both antennas to transfer data using a selected communications service.12-16-2010
20100316154METHOD FOR PERFORMING VIRTUAL MULTIPLE ANTENNA TRANSMISSION IN UPLINK USING FEEDBACK INFORMATION AND MOBILE TERMINAL SUPPORTING THE SAME - A method and apparatus for performing virtual multiple antenna transmission using feedback information in a closed-loop multiple antenna system is provided. Virtual multiple antenna control information is fed back from a receiving end that has determined the virtual multiple antenna control information taking into consideration a communication condition of a transmitting end. Virtual multiple antenna transmission is performed in uplink using the feedback information. The transmitting end may also primarily determine at least part of the virtual antenna control information and transmit the determined information to the receiving end. This method allows adaptive virtual multiple antenna transmission suitable for a channel condition in closed-loop uplink, thereby improving the communication performance.12-16-2010
20130182785SYSTEM AND METHODS FOR NULL STEERING IN A MULTICARRIER SYSTEM - A system and methods for cancelling spatial interference associated with an original multi-carrier signal carrying at least one data transmission sent by a transmitter to an antenna array comprising a plurality of antennae and having a receiver operatively associated therewith, the system receiving a plurality of received signals respectively including interference and the original signal as received by a respective individual antenna from among the plurality of antennae, the system comprising a spatial nulling device for generating a cleaner signal by reducing at least one spatial component of the interference; and a signal manipulator operative to manipulate a derivative of the received signal so as to cause the at least one data transmission to be more concentrated in a subset of frequency bands in which the spatial nulling device is more effective and to be less concentrated in frequency bands which do not belong to the subset of frequency bands.07-18-2013
20130182786Reporting of Channel State Information - A receive node device includes a processor coupled to a memory. The processor is configured to report a first sub-index and to report at least one additional second sub-index for each one of one or more matrices. Each one of the one or more matrices is indexed by the first sub-index and the second sub-index. The first sub-index and the second sub-index have different time-frequency reporting granularity.07-18-2013
20130182787COMMUNICATION CONTROL METHOD, BASE STATION APPARATUS AND MOBILE STATION APPARATUS - In order to suppress deterioration of the throughput performance of the whole system in the MIMO system performing MIMO transmission, the present invention is characterized in that in a codebook in which there are defined a plurality of precoding weights and a plurality of PMIs (Precoding Matrix Indicators) assigned to the precoding weights, bit information of the PMIs assigned to the precoding weights is adjusted in such a manner as to suppress an effect of feedback error from a mobile station apparatus. The bit information of the PMIs assigned to the precoding weights is adjusted in such a manner as to suppress an effect of a transmission beam formed with a PMI in which feedback error is detected.07-18-2013
20130182788DOUBLE-ITERATIVE METHOD OF TRANSMITTING MULTIPLE STREAMS PER USER IN A MULTI-USER MIMO SYSTEM, AND A CORRESPONDING TRANSMITTER, COMPUTER PROGRAM PRODUCT, AND DATA MEDIUM - A multi-stream transmission method and device are provided for transmitting N data streams allocated to K different users. The method is implemented by a transmitter for a multi-user MIMO system having N07-18-2013
20130182789METHOD AND DEVICE FOR EFFICIENT FEEDBACK IN WIRELESS COMMUNICATION SYSTEM THAT SUPPORTS MULTIPLE ANTENNAS - The present invention relates to a method for allowing a terminal to transmit CSI for downlink transmission from a base station through an uplink comprises the steps of: receiving a downlink signal through a downlink channel; generating CSI that contains one or more indicators among an RI, a PMI, and CQI for the downlink channel; and transmitting the CSI through an uplink channel, wherein the CSI can contain one or more pieces of information among a first type of CSI which is determined on the basis of a rank N that is determined by the terminal and a second type of CSI which is determined on the basis of a rank that is restricted by a reference value M.07-18-2013
20120281781Method and System for Transmitting Data Using Collaborative Multiple Input Multiple Output Beamforming - The present invention discloses a method and a system for transmitting data using the collaborative multiple input multiple output (MIMO) beamforming. The method comprises: selecting an MIMO mode according to channel quality information (CQI) (S11-08-2012
20120281780PARTIAL INTERFERENCE ALIGNMENT FOR K-USER MIMO INTERFERENCE CHANNELS - Systems, methods, and apparatus are described that employ a partial interference alignment scheme in conjunction with an interference detection scheme to mitigate interference in quasi-static multiple input multiple output (MIMO) channels. In an aspect, sets of transmitter and receiver pairs are determined based on feasibility of alignment of the transmitters at the receivers of the sets in accordance with an interference alignment scheme and path loss associated with signal transmissions between the transmitter and receiver pairs, wherein the sets include different alignment assignments of the respective transmitters at the respective receivers of the sets. The alignment assignments can include different numbers of the transmitters aligned at the receivers of the sets. A set is then selected from the sets that contributes to an interference profile at the receivers that facilitates interference detection at the receivers. Interference detection at a receiver is further simplified using semi-definite relaxation techniques.11-08-2012
20120281779METHODS AND ENTITIES FOR MODULATION SYMBOL TRANSPORT - A method and entity for controlling the transmission and reception of modulation symbols over a communication network capable of MIMO operation is described. The transmission involves generating a block bundle consisting of at least two distinguishable blocks of modulation symbols, wherein each of the at least two distinguishable blocks of the block bundle is configured according to a single set of one or more block configuration parameters, assigning the modulation symbols of each of the at least two distinguishable blocks of the block bundle to distinguishable layers of a corresponding layer bundle for transmitting the modulation symbols, wherein the number of distinguishable layers in the layer bundle is equal to the number of blocks in the block bundle, and transmitting said modulation symbols and signalling only the single set of one or more block configuration parameters for the block bundle. The reception involves the corresponding inverse operation for reconstructing the modulation symbols.11-08-2012
20120281778DYNAMIC INTERFERENCE ALIGNMENT FOR PARTIALLY CONNECTED QUASI-STATIC MIMO INTERFERENCE CHANNEL - Systems, methods, and apparatus are described that employ specially designed interference patterns to build an in-band side channel without degrading the effective throughput of the main channel. Transmitter and receiver pairs implement a two-stage dynamic interference mitigation scheme based on the partial connections in limited dimension MIMO interference channels. The first stage determines the stream assignments and the subspace constraints for beamforming vectors and zero-forcing vectors based on the partially connected topology such as the path loss, shadowing and spatial correlation. The second stage determines the beamforming vectors and the zero-forcing vectors based on the instantaneous channel state information over the subspaces obtained from the first stage. In an aspect, a controller device implements the first and second stage and assigns the transmitter and receiver pairs to perform interference alignment using the stream assignments and beamforming and zero-forcing vectors respectively.11-08-2012
20120281777ADAPTIVE MULTI-CHANNEL TRANSMITTER LINEARIZATION SYSTEM USING A SHARED FEEDBACK RECEIVER - Pre-distortion techniques, devices and systems for a multi-channel transmitter are described. An adaptation time is provided for each of the transmit chains in the multi-channel transmitter. During each adaptation time an output of a transmit chain is coupled to a shared feedback receiver. The shared feedback receiver generates a feedback signal that is used to vary pre-distortion for that transmit chain. A commutation controller varies at least one of: (a) an amount of the adaptation time for a transmit chain and (b) an order in which each of the transmit chains receives its adaptation time.11-08-2012
20130156124SYSTEM 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.06-20-2013
20090279634STTD ENCODING FOR PCCPCH - A circuit is designed with a measurement circuit (11-12-2009
20130114751USER EQUIPMENT AND CHANNEL STATE INFORMATION FEEDBACK METHOD - The present invention provides a user equipment and channel state information feedback method. The channel state information feedback method used in a coordinated multi-point system includes acquiring small-scale channel state information H′=[H′05-09-2013
20120020425APPARATUS AND METHOD FOR MINIMIZING ERRORS BY A CELL EDGE USER IN A MULTI-CELL COMMUNICATION SYSTEM - The present invention relates to performance improvement in a cell edge, particularly, to a method for selecting a precoder for a terminal in a multiple antenna system, wherein the method comprises: performing channel estimation for reference signals of a serving base station and another base station; determining a minimum singular value by using the channel estimation result; and if a complete collaborative feedback structure is used, feeding back a table of the determined, minimum singular value to the base stations.01-26-2012
20130195213Methods and Systems for Peak-to-Average Power Reduction Without Reducing Data Rate - A transmitter for performing multicarrier modulation comprising a processing unit configured to generate a multicarrier data signal comprising a plurality of subcarriers, wherein each of the plurality of subcarriers represents at least one data bit of a plurality of data bits, select a subset of the subcarriers based on signal quality information about one or more of the subcarriers, construct a kernel signal comprising the subset of subcarriers, and create a digital signal comprising combining the multicarrier data signal and a peak-to-average ratio (PAR) reduction signal based on the kernel signal, wherein a PAR of the digital signal is less than a PAR of the multicarrier data signal.08-01-2013
20130195214METHOD AND DEVICE FOR GENERATING PRECODING MATRIX CODEBOOK AND METHOD FOR DESIGNATING PRECODING MATRIX - The present invention discloses a method and device for generating precoding matrix codebook and a method for a base station designating precoding matrix in multi-antenna communication system. The method for generating a precoding matrix codebook includes the following steps: the step of obtaining a selection probability: obtaining a selection probability allowed for each Rank by the multi-antenna communication system in the case of a certain Signal Noise Ratio (SNR); the step of determining a codebook size: determining a precoding matrix codebook size for a corresponding Rank according to the selection probability for each Rank in the case of the certain SNR; and the step of determining a codebook: determining a precoding matrix codebook for each Rank from the precoding matrix complete set according to the codebook size for each Rank in the case of the certain SNR.08-01-2013
20090202015TRANSMITTER HAVING FULL-DIVERSITY AND FULL-RATE, A LINEAR SPACE-TIME CODE GENERATING METHOD FOR THE TRANSMITTER, AND A MIMO SYSTEM USING SAME - A space-time code has a codeword matrix. The codeword matrix is a square matrix with dimension equal to the number of the transmit antennas, wherein a row of the codeword matrix represents combined signals transmitted by each transmit antenna and a column of the codeword matrix represents timeslots of the number of the transmit antennas. Signals are transmitted through the rows of the number of spatial multiplexing rate, in each column of the matrix. Further, the symbols of the number of the transmit antennas are combined by way of utilizing complex weights, in each row of the matrix. With this space-time code, a delay is minimized, so that change of channels can be managed efficiently. Also, the space-time code has minimum number of data symbols, and thus its complexity is minimized.08-13-2009
20120039412ENFORCING CONSTANT MODULUS AND FINITE ALPHABET PROPERTIES IN ADAPTIVE AND DUAL-STAGE CODEBOOKS - Methods and apparatus for enforcing codebook properties (e.g., constant modulus and/or finite alphabet) in adaptive and dual-stage codebooks are described. One example method generally includes receiving multiple feedback aspects of a channel for wireless communications determining multiple codewords based on the multiple feedback aspects, determining a final precoding matrix based on the multiple codewords, enforcing at least one codebook property in at least one of the multiple codewords or the final precoding matrix, applying the final precoding matrix to a plurality of spatial streams to form precoded spatial streams, and transmitting the precoded spatial streams. For certain aspects, enforcing the at least one codebook property includes quantizing elements in each of the multiple codewords and/or the final precoding matrix to the nearest value in a finite alphabet or to increase a performance metric.02-16-2012
20120039411FEED-FORWARD CONTROL SIGNALING AND DECODING SCHEMES - Systems and methods for conveying wireless transmission allocation information are disclosed. In accordance with one method, an index indicating selected data stream parameters is received. In addition, an indication of a number of transmit antennas at a transmitter from which the data stream is transmitted is also received. Further, the selected parameters are determined from the index based on the number of transmit antennas at the transmitter. Moreover, data signals are received and processed with a processor in accordance with the selected data stream parameters.02-16-2012
20120045008PILOT PATTERN FOR MIMO OFDM - In an embodiment, a transmitter includes a transmission path that is configurable to generate first pilot clusters each including a respective first pilot subsymbol in a first cluster position and a respective second pilot subsymbol in a second cluster position such that a vector formed by the first pilot subsymbols is orthogonal to a vector formed by the second pilot subsymbols. For example, where such a transmitter transmits simultaneous orthogonal-frequency-division-multiplexed (OFDM) signals (e.g., MIMO-OFDM signals) over respective channels that may impart inter-carrier interference (ICI) to the signals due to Doppler spread, the pattern of the pilot symbols that compose the pilot clusters may allow a receiver of these signals to estimate the responses of these channels more accurately than conventional receivers.02-23-2012
20130202057METHOD AND SYSTEM FOR ACQUIRING CHANNEL INFORMATION - A method and system for acquiring channel information are disclosed in the present document, wherein the method includes: a base station and a User Equipment (UE) jointly saving a first codebook and at least a second codebook, and the first codebook being used for channel information quantization in various scenarios; the UE performing feedback of at least 2 Precoding Matrix Indicators (PMIs) to the base station, wherein, one PMI corresponds to one code word in the first codebook, all the other PMIs respectively correspond to different code words in a second codebook used currently, and all the code words corresponding to the fed back PMIs are used for representing channel information of one or multiple or all subbands; and after receiving the PMIs fed back from the UE, the base station finding corresponding code words from the first codebook and the second codebook used currently, and acquiring the channel information.08-08-2013
20120093251RADIO COMMUNICATION SYSTEM, TRANSMISSION APPARATUS, AND RECEPTION APPARATUS - To provide a radio communication system, a transmission apparatus, a central control unit, and a reception apparatus, which can enhance transmission performances without giving more interference than necessary. The radio communication system in which a plurality of transmission apparatuses 04-19-2012
20120093250METHOD AND APPARATUS FOR DATA TRANSMISSION BASED ON DISTRIBUTED DISCRETE POWER CONTROL IN COOPERATIVE MULTI-USER MULTI-INPUT MULTI-OUTPUT SYSTEM - Disclosed are a method and apparatus capable of enhancing a closed loop multi-input multi-output (MIMO) capacity through distributed discrete power control in the case of cooperatively transmitting information to multiple users through a downlink.04-19-2012
20130208820COMMUNICATION OVERHEAD REDUCTION APPARATUS, SYSTEMS, AND METHODS - An apparatus and a system, as well as a method and article, may operate to transmit a first number of training symbols corresponding to a first number of communication chains to solicit a response including a second number of training symbols corresponding to a second number of communication chains. The first and second number of communication chains may form a portion of a multiple-input, multiple-output (MIMO) system.08-15-2013