Patent application number | Description | Published |
20080225895 | Apparatus and Method for Generating Signal According to Ifdma, and Apparatus for Receiving Signal - A signal generation apparatus and signal receiving apparatus according to an Interleaved Frequency Division Multiple Access scheme is provided. The signal generation apparatus generates a plurality of complex symbols by digital-modulating a plurality of data symbols, and rotates the generated plurality of complex symbols in a plurality of each different phase angles. The signal generation apparatus generates a plurality of transmission symbols by repeating a plurality of rotated complex symbols at predetermined times, and rotating the repeatedly generated plurality of transmission chips in phase angles of an orthogonal phase sequence for the respective users. When the signal receiving apparatus receives the plurality of transmission symbols generated as described above, the maximum diversity gain may be obtained. | 09-18-2008 |
20080227498 | Low-Complexity Joint Transmit/Receive Antenna Selection Method For Mimo Systems - Provided is a low-complexity transmit/receive antenna selection method for Multi-Input Multi-Output (MIMO) systems. The method includes the steps of generating a gain matrix of receive channel, calculating norm values of channel gains for each row (receive antennas) and column (transmit antennas) of the generated gain matrix of the receive channel, selecting an antenna with the maximum norm value among the calculated norm values of channel gains, and repeatedly performing the process of alternately selecting transmit and receive antennas having the maximum channel gain value among the channel gain values of the selected antenna until a required number of antennas is all selected. | 09-18-2008 |
20080232500 | Soft Output Sphere Decoding Method - Provided is a soft output sphere decoding method for a MIMO system. The soft output sphere decoding method includes the steps of: detecting a maximum likelihood symbol nearest to a receiving signal; calculating a lattice point nearest to the receiving signal and having a symbol bit opposite to the detected maximum likelihood symbol for all bits of the receiving signal; and calculating a ratio between a distance from the receiving signal to the detected maximum likelihood symbol and a distance from the receiving signal to the calculated lattice points for each bit. | 09-25-2008 |
20080267111 | Data Transmitting Method in Wireless Communication System - In a method for transmitting data from a first node to a second node through first and second relay units in a wireless communication system: a) a first symbol is transmitted from the first node to the second node and the first relay unit during a first time slot section; b) the first symbol, which is received from the first node, is transmitted from the first relay unit to the second node during a second time slot section; c) a second symbol is transmitted from the first node to the second node and the second relay unit during the second time slot section; and d) the second symbol, which is received from the first node, is transmitted from the second relay unit to the second node during a third time slot section. | 10-30-2008 |
20080285677 | Apparatus and Method For Transmitting Signals With Multiple Antennas - An apparatus for transmitting signals with multiple antennas is disclosed. The multiple antenna transmission apparatus performs space-time encoding or space-frequency encoding, and cyclically delays the encoded symbol with a plurality of delay-values to generate a plurality of delayed symbols. The multiple antenna transmission apparatus transmits the plurality of delayed symbols to the channel through a plurality of antennas. By changing the number of space areas for encoding and the number of delay-values for delaying, the number of antennas for the multiple antenna transmission apparatus is easily expanded. | 11-20-2008 |
20080291820 | Method for Allocating Frequency Domain Spread Code in Base Station of Mc-Cdma Communication System - The present invention relates to a method for allocating a frequency domain spread code in a base station of a multi-carrier code division multiple access (MC-CDMA) communication system. A code allocation priority is established based on interference between previously allocated spread codes and a newly allocated spread code so as to minimize the interference caused by channel fading or a synchronization error according to a transmitting or receiving timing offset when a scheduler of the base station in the MC-CDMA communication system allocates a subcarrier group to the plurality of user terminals or channels, and the spread code is allocated to the plurality of user terminals or channels according to the established priority, by the scheduler of the base station. | 11-27-2008 |
20080298225 | Transmitting Apparatus for Transmitting in a Multi-Carrier System Using Multiple Antennas and Receiving Apparatus in the Same System - A transmitting apparatus and receiving apparatus of a multi-carrier system using multiple antennas is proposed. An LCF encoder of the transmitting apparatus performs a liner precoding to input signals to be transmitted to a receiving apparatus using a liner complex matrix considering the number of multiple antennas and the number of subcarriers, and a subcarrier allocator respectively allocates a subcarrier to the signals liner-precoded by the LCF encoder. A transmitter respectively transmits the signals having a subcarrier allocated by the subcarrier allocator through the multiple antennas externally. A subcarrier de-allocator of a receiving apparatus extracts a liner-precoded signal by de-allocating a subcarrier allocated to the received signal. An LCF decoder outputs a bit reliability of the received signal to the liner-precoded signal extracted from the subcarrier de-allocator considering the number m of multiple antennas and the number n of subcarriers. A performance may be improved by using space diversity due to multiple antennas and a frequency diversity due to the OFDMA system, and a complexity may be reduced and a hard decision value of a performance similar to the maximum likelihood detection may be obtained by using a lattice reduction and a 2-branch Chase decoder. | 12-04-2008 |
20090022209 | TRANSMITTING APPARATUS USING SPREAD-SPECTRUM TRANSMISSION METHOD - The present invention relates to a transmitting apparatus using a spread-spectrum transmission scheme. The transmitting apparatus includes a precoder for preceding a data signal by performing a product operation between a first matrix and a diagonal matrix. The preceding outputs a signal responding to the input data by performing a product operation between the first matrix and the diagonal matrix. Such a transmitting apparatus obtains a maximum diversity gain. | 01-22-2009 |
20090161805 | Detection Method of Space Domain Maximum Posteriori Probability in a Wireless Communication System - A detection method of space domain maximum posteriori probability (MAP) in a wireless communication system is a kind of detection technique of space domain MAP in a multi-aerial wireless communication system, which makes the detection of iteration soft interference elimination for the interference signals in the other moments, and makes the MAP detection or the simplified MAP detection for the all signals in current time and space domain. It includes the steps of: taking a fading block as a unit; the received signals are matched and combined in time domain and space domain, and calculating an equivalent channel matrix; making the sequence detection, calculating estimation and variance of the signals before the ending of detecting internal iteration; when the internal iteration detection finishes, the result is outputted, or is outputted after hard decision. | 06-25-2009 |
20090185607 | METHOD FOR CHANNEL STATE FEEDBACK BY QUANTIZATION OF TIME-DOMAIN COEFFICIENTS - The present invention relates to a channel state transmission method using time domain coefficient quantization. A terminal measures channel information in the time domain and transmits it to a base station. In this instance, a multipath frequency selective fading channel is displayed in a tapped delay line format configured with a per-path path delay value and a path gain in the time domain, differentiates a quantization level for each path gain for more efficient transmission, quantizes the same, and transmits it to a transmitter. Therefore, while the amount of bandwidths required for transmitting state information from the terminal to the base station is reduced, the base station can efficiently acquire channel state information on the entire bandwidths. Also, the base station transmits signals to many terminals through beamforming by using the acquired reliable channel state information, thereby increasing the terminal's signal receiving performance. | 07-23-2009 |
20090197624 | APPARATUS AND METHOD FOR RELAYING BETWEEN BASE STATION AND MOBILE STATION, AND METHOD FOR RECEIVING CONTROL INFORMATION - When an event associated with a mobile station occurs, a relay station requests a base station to allocate a dedicated control channel required for transmitting control information on the mobile station to the base station. Next, when the control information on the mobile station is generated, the relay station transmits the control information to the base station through the dedicated control channel. Accordingly, since the base station allocates the dedicated control channel to the relay station in advance before the control information is generated in the relay station, the relay station can transmit the control information to the base station with a minimum of time delay. | 08-06-2009 |
20090252240 | TRANSMITTING APPARATUS AND METHOD, AND RECEIVING APPARATUS AND METHOD IN MULTPLE ANTENNA SYSTEM - Respective codewords of quantization codebooks corresponding to a number of data streams are selected based on channel information estimated by a received training symbol. A stream mode is selected among stream modes to determine a modulation method applied to each data stream. The data stream is detected by using the codeword corresponding to the quantization codebook of the data stream corresponding to the selected stream mode as a precode matrix, and the detected data stream is modulated. In this case, a receiving apparatus performs a feedback operation so that indexes of the selected stream mode and the codeword used as the precode matrix may be transmitted to the transmitting apparatus. The transmitting apparatus selects the number of transmitted data streams and the modulation method based on the transmitted index of feedback streams by the feedback operation. | 10-08-2009 |
20090310725 | Space Domain Filter Detecting Method In A Multi-Antenna Wireless Communication System - A space domain filter detecting method in a multi-antennas wireless communication system, processing differently with the interference from the time domain and the space domain, which proceeds the interference elimination in matched filter manner for the interference signals from all antennas in the other time, and proceeds the filtering in corresponding manner for the interference signals from the other antennas in present time, comprises the following steps: firstly, the received signals are matched-combined in time domain and space domain; secondly, with the combined signals as the observation value for detecting, the filtering is proceeded in space domain in corresponding manner; thirdly, the estimated value is subtracted from the filtered signals, and the result is taken as the detecting result to output, and then is sent to the determiner in non-error control coding system to get the symbol hard determination output or is sent to the determiner in error control coding system to get the symbol soft determination output that finally sent to the coder. The method promotes the transmission rate and the anti-interference ability and advances the spectrum efficiency. | 12-17-2009 |
20100014611 | METHOD FOR DECIDING POSITION OF MAPPING SYMBOLS, AND DEVICE AND METHOD FOR MODULATING BINARY SIGNAL - Disclosed is a binary signal modulator for minimizing deterioration of receiving performance caused by phase error. The binary signal modulator receives binary signals, and converts the binary signals into complex symbols according to a predetermined mapping relation. Here, the mapping relation is generated when a plurality of mapping symbols are arranged on a plurality of trajectories so that the distance between the mapping symbols is greater than or equal to a predetermined distance and the phase between the mapping symbols is greater than or equal to a predetermined angle from among the trajectories starting from a plurality of points on the complex plane, and a distance between the trajectories is greater than or equal to the minimum distance from among the distances between the points. | 01-21-2010 |
20100020892 | APPARATUS AND METHOD FOR GENERATING SYMBOL FOR MULTIPLE ANTENNAS - The present invention relates a symbol generation apparatus for multiple antennas having low receiving complexity and having flexibility with respect to an increase in the number of antennas. The symbol generation apparatus includes a plurality of space-time channel encoders respectively corresponding to a plurality of channels, and an inverse fast Fourier transformer group. The respective space-time channel encoders receive a digital-modulated symbol group from the corresponding channel, perform a space-time encoding operation with respect to a plurality of space areas and at least one time area, shift phases by using a plurality of phase values, and generate a plurality of phase-shifted space-time codewords. The inverse fast Fourier transformer group performs an inverse fast Fourier transform operation by using the plurality of phase-shifted space-time codewords in a plurality of subcarriers respectively corresponding to the plurality of channels, and generates a plurality of inverse fast Fourier transformed signals. | 01-28-2010 |
20100074364 | PRECODING DEVICE AND METHOD IN WIRELESS COMMUNICATION SYSTEM - The present invention relates to a precoder and a precoding method in a multi-user multi-antenna communication system. When a transmission part having a plurality of antennas transmits a plurality of signals to a receiving part having an antenna, the precoder and the precoding method using the same prevents system performance degradation caused by interference signals and efficiently reduces transmission power while changing the constellation rotary angle. When the power is controlled by using the precoder, the system performance is enhanced while not damaging the structural gain of the existing multi-user multi-antenna precoder. | 03-25-2010 |
20100091896 | SIGNAL TRANSMISSION SYSTEM USING MULTIPLE ANTENNA AND SIGNAL TRANSMISSION METHOD THEREOF - The present invention relates to a multiple antenna transmission system and a signal transmission method In the signal transmission method using multiple antennas, a plurality of subcarrier symbols are grouped as a plurality of groups including first and second tiles that are basic resource management units including two or more subcarriers included in a set frequency domain, phases of subcarrier symbols included in a first tile are shifted to be a first phase shifting value, and phases of subcarrier symbols included in a second tile are shifted to be a second phase shifting value that is different from the first phase shifting value. | 04-15-2010 |
20100103900 | BEAMFORMING METHOD AND DEVICE - The present invention relates to a beamforming device in an orthogonal frequency division multiplexing access system, and a method thereof. In the method, a switched beamforming algorithm is applied to perform downlink beamforming, and an adaptive beamforming algorithm is applied to perform uplink receiving beamforming. In addition, a half wavelength array antenna is used to simultaneously allocate the same resource to two terminals separately positioned in two different spaces, so as to support spatial division multiple access (SDMA). In this case, since a base station uses channel status information at transmitter (CSIT) for transmitting beamforming and receiving beamforming, the SDMA may be supported without obtaining additional channel status information at receiver (CSIR) when realizing the uplink receiving beamforming. | 04-29-2010 |
20100128776 | PULSE SHAPING METHOD - Provided is a pulse shaping method. A time interval is predefined so as to shape a pulse used for a transmit pulse and a receive filter response, a parameter is generated by using a weight coefficient and a plurality of cosine functions that are multiplied and added to be output during the predetermined time interval, and 0 is output during another interval, thereby shaping the pulse. The weight coefficient is updated by using the normalized MSE so as to shape the pulse to be optimized for the predetermined time interval. | 05-27-2010 |
20100150034 | SYSTEM AND METHOD FOR SPATIAL DIVISION MULTIPLE ACCESS USING WIRELESS REPEATER HAVING SINGLE TRANSMITTING/RECEIVING ANTENNA - A system for spatial division multiple access using a wireless repeater having a single transmitting/receiving antenna, includes: a base station that selectively transmits a plurality of data stream signals to the wireless repeater within an area through a multi-transmitting antenna for downlink; and at least one wireless repeater that forms a wireless repeater group within the base station area and repeats the data stream signals selectively transmitted from the base station to terminals. | 06-17-2010 |
20100150269 | SIGNAL MODULATING DEVICE, SIGNAL TRANSMITTING METHOD, AND CODE GENERATING METHOD - The present invention relates to a signal modulation device, a transmission method, and a code generation method. The signal modulation device includes a code storage unit including a plurality of n-bit members and storing a code with a number n or n−1 of different bits between two neighboring members, and a mapper for mapping data on symbols according to the code. | 06-17-2010 |
20100153811 | METHOD FOR DECODING USING DYNAMIC SCHEDULING SCHEME FOR LOW DENSITY PARITY CHECK CODES AND APPARATUS THEREOF - Disclosed is a decoding method and device for low density parity check codes using dynamic scheduling. The low density parity check codes are sequentially decoded, and the messages are scheduled in the descending order of the difference between values before and after updating the message transmitted from the variable node to the check node. | 06-17-2010 |
20100157876 | METHOD FOR SELECTIVE TRANSMITTING/RECEIVING ANTENNA REPETITION - Disclosed is a method for selective transmitting/receiving antennal repetition. A repeater performs wireless communication with a terminal located in a jurisdiction repetition area by using one transmitting/receiving antenna, and communicates with a base station by using multiple transmitting/receiving antennas. The repeater, in a downlink, selectively receives a signal transmitted from a specific transmitting antenna of the base station by using a signal process technology, and amplifies and transmits the signal to the repetition area. Further, in an uplink, the repeater receives a signal received from the terminal in the repetition area and then transmits the signal to the base station. In this operation, the signal transmitted to the base station is processed by the repeater such that a specific receiving antenna the base station can receive the signal with the largest strength. | 06-24-2010 |
20100189002 | MULTIPLE BEAMFORMING METHOD AND APPARATUS - The present invention relates to a beamforming method and apparatus. A beamforming method for use in a base station for transmitting a plurality of streams through a plurality of antennas includes: receiving feedback information including information on a first codeword selected from a codebook including a plurality of codewords from each of a plurality of user terminals; grouping the plurality of user terminals by use of the feedback information from each user terminal; determining a user terminal to which a plurality of streams will be assigned of the plurality of user terminals, and determining a second codeword to be used for beamforming from the codebook by use of the feedback information of each user terminal and grouping information; and multiplying data to be transmitted through the plurality of steams by the second codeword and a unitary matrix. | 07-29-2010 |
20100254468 | PILOT DESIGN METHOD, RECORDING MEDIUM, AND TRANSMISSION APPARATUS - In an orthogonal frequency division multiple access (OFDMA) communication system, a transmission apparatus connects a plurality of tiles, which have a 4×3 structure, along a time axis or a frequency axis in an uplink 4-layer PUSC mode, and designs pilots corresponding to one layer at one of a plurality of symbol positions adjacent to a first corner of the plurality of tiles and one of a plurality of symbol positions adjacent to a second corner of the plurality of tiles that face the first corner in a diagonal direction. In this case, null symbols are designed at the rest of the symbol positions adjacent to the first corner or the second corner where the pilots are not designed. Accordingly, a receiving apparatus can obtain n channel values from n tiles. Further, n estimated channel values are applied to a linear interpolation method, so that it is possible to estimate the entire channel value of n tiles. | 10-07-2010 |
20100254470 | APPARATUS AND METHOD FOR SETTING PILOT SUBCARRIER - An apparatus for setting a pilot subcarrier in an antenna selects candidates of power value variables of a pilot subcarrier existing within a predetermined range, and calculates and extracts pilot subcarriers of a predetermined number on the basis of a nonlinear function among the candidates of the selected power value variables. Next, the apparatus removes pilot subcarriers of a predetermined number from the extracted pilot subcarriers of a predetermined number in accordance with a rule and configures the antenna on the basis of position values of final pilot subcarriers except for a virtual subcarrier among the removal result. Further, the apparatus configures the antenna on the basis of the power value by determining the sum total of the power values corresponding to the position values of the final pilot subcarriers to correspond to the number of pilot subcarriers. | 10-07-2010 |
20100265853 | BEAMFORMING METHOD USING MULTIPLE ANTENNAS - A mobile station includes a plurality of mobile station antennas that receive at least one independent training signal from a plurality of base station antennas, and estimates a downlink channel formed by each of a plurality of base station antennas and each of the mobile station antennas by using the at least one independent training signal. The mobile station generates a beam vector by using the downlink channel, and forms transmission beams in the plurality of mobile station antennas for transmitting a signal to an uplink. | 10-21-2010 |
20100265936 | METHOD AND DEVICE FOR ACQUIRING SYNCHRONIZATION BETWEEN NODES AND METHOD FOR ORGANIZING MULTIPLE PHYSICAL CHANNELS - A method for acquiring synchronization between nodes and configuring multiple physical channels in order to improve performance in the ad-hoc/mesh network is disclosed. | 10-21-2010 |
20100275093 | Secure Communication Using Error Correction Codes - Systems and methods for selecting a puncturing pattern for a low density parity check (LDPC) code are disclosed. One such method comprises: selecting a puncture pattern distribution for the LDPC code; calculating a security threshold and a reliability threshold for the LDPC, the LDPC having the selected puncture pattern distribution and also described by a degree distribution; storing the selected puncture pattern distribution responsive to a security gap for the LDPC being a lowest value encountered in any prior iterations; selecting another puncture pattern distribution for the LDPC code; and repeating the calculating, the storing, and the selecting another puncture pattern distribution steps. | 10-28-2010 |
20100279619 | INTER-CELL INTERFERENCE RELIEF METHOD - In a method of mitigating inter-cell interference, terminals are grouped into groups. A base station transmits data to a first terminal belonging to a first group among the groups, without cooperation with a neighboring base station. The base station transmits data to a second terminal belonging to a second group among the groups, through cooperation with the neighboring base station. | 11-04-2010 |
20100291962 | METHOD OF CONTROLLING UPLINK POWER - Provided is that a base station that receives an index and a path attenuation difference of a monitoring sector from a mobile station and receives an amount of interference of the monitoring sector from a base station that corresponds to the monitoring sector. In addition, the base station measures an interference state of the monitoring sector by using the amount of interference and the path attenuation difference and calculates a control value of uplink power based on the interference state of the monitoring sector. Further, the base station transmits the control value of the uplink power to the mobile station. | 11-18-2010 |
20100310001 | TRANSMITTING/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 |
20100316145 | METHOD FOR CHANNEL ESTIMATION AND FEEDBACK IN WIRELESS COMMUNICATION SYSTEM - Disclosed is a method for channel estimation and feedback in a wireless communication system that estimates a channel for each transmission antenna using an orthogonal frequency division multiplexing (OFDM) impulse signal. A method for channel estimation in a wireless communication system includes causing a base station to generate a training signal with a specific waveform for each transmission antenna and to transmit the generated training signal to terminals; causing the terminals to acquire a downlink channel impulse response for each transmission antenna of the base station using the training signal transmitted from the base station; causing the terminals to acquire a downlink channel characteristic for each transmission antenna of the base station using the acquired channel impulse response; causing the terminal to feed back the acquired downlink channel characteristic information to the base station; and causing the base station to perform fast Fourier transform (FFT) on the downlink channel information transmitted from the terminals to indirectly acquire full channel status information (CSI). | 12-16-2010 |
20100322160 | STRUCTURE AND CONSTRUCTION METHOD OF UPLINK CONTROL CHANNEL IN MOBILE WIDEBAND WIRELESS ACCESS SYSTEM - The present invention relates to an uplink control channel configuration in a mobile wideband wireless access system, and an allocation method thereof. An uplink control channel includes a long cyclic prefix used to improve interference and distortion caused by multipath transmission characteristics of an initial ranging or handover ranging signal and a periodic ranging or band request ranging signal. In addition, a short orthogonal frequency division multiple (OFDM) symbol is used to transmit uplink control information when one terminal exists or the number of terminals is small. | 12-23-2010 |
20100322223 | BEAM FORMING METHOD AND APPARATUS - The present invention relates to a method of forming a random beam, and a beam forming apparatus. A quantization preprocessor and a random unitary matrix having a predetermined pattern are used to form a beam on a mobile terminal. A base station forms a beam using a codeword index of a quantization codebook received from a mobile terminal and channel quality information corresponding to the codeword index, and the mobile terminal generates the codeword index and the channel quality information using pilot signals generated by the base station. The number of pilot signals is equal to the number of transmitting antennas. Therefore, a codebook that has been known to both the mobile terminal and the base station is used, and the mobile terminal can select the codeword index for quantization, which makes it possible to selectively give diversity and thus improve the system efficiency. | 12-23-2010 |
20110026628 | APPARATUS AND METHOD FOR MAPPING SYMBOL - In a symbol mapping method, transmission data is encoded to generate information bits and redundancy bits. An average LLR value of bits on which the information bits are mapped is different from an average LLR value of bits on which the redundancy bits are mapped. | 02-03-2011 |
20110033010 | APPARATUS AND METHOD FOR SELECTION OF PRECODING MATRIX - The present invention relates to an apparatus and a method for selection of a precoding matrix. In the present invention, a precoding matrix to enable an effective signal-to-noise ratio (ESNR) to have a maximum value with respect to a signal vector that requires retransmission is selected in a codebook and fed back to a transmitter. Accordingly, since the effective signal-to-noise ratio has the maximum value after the signal vector is retransmitted, it is possible to minimize a reception error probability of retransmission. | 02-10-2011 |
20110039597 | METHOD TO GENERATE POWER CONTROL INFORMATION AND METHOD OF POWER CONTROL FOR UPLINK - In a communication system including a plurality of base stations and a plurality of terminals belonging to each of the base stations, the base station receives information on subcarriers allocated to a terminal that belongs to an adjacent base station from the adjacent base station. Thereafter, the base station generates power control information on the basis of the subcarrier information and transmits the power control information to the terminal, and the terminal controls uplink power on the basis of the received power control information. At this time, the power control information, as information based on estimating hitting between subcarriers used by the terminal that belongs to the base station and subcarriers used by the adjacent base station, may be a ratio found by dividing the total number of subcarriers used by each terminal that belongs to the adjacent base station by the entire number of subcarriers that can be used by the base station. | 02-17-2011 |
20110044301 | DEVICE AND METHOD FOR TRANSMITTING AND RECEIVING SYNCHRONIZATION CHANNEL - A method of transmitting a synchronization channel is provided. A plurality of block sequences for determining at least one block identifier is generated. A plurality of subcarriers of a synchronization channel are divided into a polarity of blocks, and the plurality of block sequences are allocated to the blocks to generate a synchronization signal. | 02-24-2011 |
20110058533 | METHOD OF ALLOCATING RESOURCE AND METHOD OF FORMING RANGING CHANNEL - An access point allocates a resource for ranging to an access terminal included therein, and receives a ranging channel that includes an identifier of the access terminal and a plurality of pilots. The AP checks the access terminal by using the received identifier, and measures a round trip delay of the access terminal based on the received pilots. | 03-10-2011 |
20110116570 | METHOD OF TRANSMITTING SIGNAL AND METHOD OF RECEIVING SIGNAL - In a multicell communication system, a terminal that belongs to a second cell using the same subcarrier as a terminal that belongs to a first cell changes a pilot in an allocated basic resource block. Then, a base station that manages the first cell can estimate a channel of an interference signal transmitted from a second cell from a reception signal even though the reception signal includes an interference signal from the terminal that belongs to the second cell at the time of receiving a signal transmitted from the terminal that belongs to the first cell. Further, the base station that manages the first cell may reduce an interference signal from a reception signal by using a channel estimation value. | 05-19-2011 |
20110122782 | METHOD FOR BEAMFORMING - The present invention relates to a method for random beam-forming based on a codebook. The method includes generating a first random variable corresponding to a Gaussian distribution; generating a second random variable corresponding to a uniform distribution; generating a plurality of beam elements by using the first variable, the second variable, spatial correlation between channels, and indexes of transmitting antennas; and forming a beam by using the plurality of beam elements. | 05-26-2011 |
20110134779 | RANDOM ACCESS METHOD BASED ON NUMBER OF MESSAGES - A base station calculates the number of terminals which have transmitted messages at ith frame, and calculates the number of messages to be transmitted at (i+1)th frame by using the number of terminals which have transmitted the messages in the ith frame. The base station calculates a transmission probability by using the number of messages to be transmitted in the (i+1)th frame and the number of random access slots, and transmits the number of messages to be transmitted in the (i+1)th frame and the transmission probability to the plurality of terminals. The base station receives a message transmitted by a pertinent terminal, whose number of messages to be transmitted in the (i+1)th frame is greater than the number of random access slots, among the plurality of terminals, according to the result obtained by comparing the transmission probability and a random number. | 06-09-2011 |
20110142149 | METHOD AND APPARATUS OF CODEBOOK TRANSFORMATION FOR INTERFERENCE MITIGATION IN CODEBOOK-BASED PRECODING - When a transmitter communicating with a first receiver interferes with an adjacent second receiver, the transmitter receives a reference signal from the second receiver in order to transform a codebook to mitigate interference in the second receiver. A channel with the second receiver is estimated through the received reference signal, and a receiving correlation matrix is calculated based on the estimated channel. The inverse of the receiving correlation matrix is calculated from the calculated receiving correlation matrix, and the codebook is transformed using the calculated inverse of the receiving correlation matrix. | 06-16-2011 |
20110143806 | METHOD FOR CONTROLLING TRANSMISSION POWER IN CELLULAR SYSTEM - A method for controlling transmission power of a base station in a cellular system includes: receiving a reference signal from at least one neighbor base station that is located around the base station; estimating a radio environment between the base station and the neighbor base station by using the receiving power of the reference signal; and controlling cell coverage of the base station by determining the transmission power based on the radio environment. | 06-16-2011 |
20110145671 | METHOD AND APPARATUS FOR ITERATIVE DETERMINATION OF MIMO ITERATIVE RECEIVER - A multiple input multiple output (MIMO) iterative receiver detects a soft log likelihood ratio value from a signal outputted from a transmitter and decodes the detected soft log likelihood ratio value in order to extract a hard value and a soft value from the detected soft log likelihood ratio value. After whether or not a CRC of the hard value is acknowledged is determined, a CRC of a data burst is determined or iteration of signal demodulation of the MIMO iterative receiver is determined by feeding back the soft value or a CRC of data is performed assembling signals of the burst unit in accordance with the determination result. | 06-16-2011 |
20110149910 | METHOD FOR COMMUNICATION CHANNEL CONTROL - A base station designates an identification symbol section in each communication frame in order to identify a plurality of transceivers, transmits a predetermined transceiver identification signal through subcarriers granted to the plurality of transceivers by granting a combination of subcarriers to be used in an identification symbol section to each of the plurality of transceivers, generates and stores terminal connection information for each of the plurality of transceivers by receiving information on evaluation of reception quality for the transceiver from the terminal and using the received information, and allocates a communication resource so as to use the subcarrier of the transceiver connected with the terminal for communicating with the terminal. | 06-23-2011 |
20110150132 | METHOD TO GENERATE BEAMFORMING VECTOR AND PROVIDE THE INFORMATION FOR GENERATING BEAMFORMING VECTOR - A method to generate a beamforming vector by a terminal includes receiving information on a first precoding matrix and a second precoding matrix from a serving base station; and generating a beamforming vector by linearly combining the first precoding matrix and the second precoding matrix. | 06-23-2011 |
20110158347 | METHOD AND TRANSMITTER FOR ITERATIVELY MODIFYING BEAMFORMING VECTOR - The present invention provides data transmission capacity that is optimized in a communication environment by iteratively modifying a beamforming vector by linearly coupling selfish beamforming with unselfish beamforming using feedback information. The transmitter for modifying the beamforming vector iteratively includes: a feedback receiving module that receives feedback information from a receiver: and a vector determination module that determines an initial beamforming vector by coupling a first vector for the selfish beamforming with a second vector for the unselfish beamforming at the time of initial beamforming, and corrects a coupling ratio of the first vector and the second vector of the beamforming vector with reference to the received feedback information whenever the beamforming is modified. | 06-30-2011 |
20110243204 | PRECODING METHOD AND DEVICE - A method for a transmitting terminal in a multi-user multi-antenna environment to perform precoding includes: receiving feedback information from a plurality of receiving terminals; estimating a channel between the transmitting terminal and the plurality of receiving terminals by using the feedback information; and generating a plurality of transmission symbols by applying a first nonlinear precoding method and a second nonlinear precoding method to a plurality of symbols and the estimated channel to be transmitted to the plurality of receiving terminals. The first nonlinear precoding method is used to eliminate interference between subchannels of the same receiving terminal, and the second nonlinear precoding method is used to eliminate interference between the receiving terminals. | 10-06-2011 |
20110243273 | TRANSMITTING APPARATUS IN MULTIPLE INPUT MULTIPLE OUTPUT SYSTEM - Provided are a transmitting apparatus and a transmitting method in a multiple input multiple output system. A power allocation controller includes a block Tomlinson-Harashima precoder (BTHP) that precodes and outputs data to be transmitted to each user in a nonlinear scheme. The BTHP removes and outputs inference signals from data for each user based on the channel information that is fed back from the users. The data for each user output from the BTHP are allocated with power by the power allocation controller. The power allocation controller calculates power allocation parameters so that receiving minimum distances at receiving ends for each user that receive data through the MIMO antennas are the same, and allocates the calculated parameters to data for each user. | 10-06-2011 |
20120039271 | METHOD AND APPARATUS FOR DISTRIBUTED SCHEDULING IN WIRELESS MESH NETWORK BASED ON OFDMA - A method and apparatus for distributed scheduling within an orthogonal frequency division multiple access (OFDMA)-based wireless mesh network may be provided. A requester and a granter in the wireless mesh network may perform three way-handshaking using distributed scheduling messages. A plurality of distributed scheduling messages may use different sub-channels. The request may reserve sub-channels to be used by respective scheduling messages. | 02-16-2012 |
20120155304 | METHOD AND APPARATUS FOR ACCESS CONTROL IN WIRELESS COMMUNICATION SYSTEM - In an orthogonal frequency division multiple access (OFDMA)-based wireless mesh network, a communication node receives information regarding a next transmission time of a 1-hop node and a 2-top node through the 1-hop node, calculates next transmission intervals of the 1-hop node and the 2-hop node, determines a next transmission time of the communication node by using the next transmission intervals of the 1-hop node and the 2-hop node, and then transmits, to an 1-hop node of the communication node, the information of the next transmission time together with the information of the transmission time of the 1-hop node, received from the 1-hop node. | 06-21-2012 |
20120163171 | ROUTING METHOD AND APPARATUS FOR SUPPORTING QoS IN WIRELESS NETWORK - A method for routing and setting up a connection to provide Quality of Service (QoS) required in a wireless network is provided, which allows to use a path capable of providing QoS higher than a certain level between a source node and a destination node. A routing apparatus includes: a connection management unit that receives a connection setup request directed to a destination node, determines a predicted path leading to the destination node and the next node, and transmits a connection setup request to the next node; a resource allocation unit that allocates resources so as to satisfy required QoS; a routing unit that measures available QoS information of a link and enables the exchange of information of the link including the QoS information with the nodes of the network; and a routing information management unit that stores received routing information. | 06-28-2012 |
20120163257 | METHOD AND APPARATUS FOR TRANSMITTING/RECEIVING IN MOBILE WIRELESS NETWORK - In a mobile wireless network system including a plurality of nodes communicating with each other, a node attempting to transmit data finds useable resources through performing carrier sensing on packet data unit (PDU) slots and transmits data through the found resources. A node attempting to receive data finds useable resource through performing carrier sensing on acknowledge (ACK) slots and receives data through the found resources. | 06-28-2012 |
20120163316 | METHOD AND APPARATUS FOR ALLOCATING RESOURCE IN MOBILE WIRELESS NETWORK - In a mobile wireless network system including a plurality of nodes, available resources of a transmitting node and available resources of a receiving node are searched for. Commonly overlapped allocatable resources among available resources of a transmitting node and available resources of a receiving node are searched for, areas corresponding to the calculated allocation resource number according to an allocation condition that is set in the allocatable resource area are selected, and the areas are allocated to the transmitting node or the receiving node. | 06-28-2012 |
20120164949 | METHOD FOR CONTROLLING INTERFACE BETWEEN ADJACENT CELLS IN CELLULAR SYSTEM - A method of transmitting data from a terminal in a cellular system is provided. The data transmission method includes: calculating the transmission capacity of a predetermined number of vectors among pairs of orthogonal vectors; selecting the vector having the largest transmission capacity as a reference vector among the predetermined number of vectors; and transmitting data to a base station using the reference vector. | 06-28-2012 |
20120230216 | COMMUNICATION METHOD - A mobile station and a base station communicate with each other using a frame including one or more downlink subframes and one or more uplink subframes. The base station begins the transmission of a data burst in a subframe corresponding to a downlink subframe index. The mobile station transmits feedback for the data burst to the base station in a subframe corresponding to an uplink subframe index. If the frame uses a time division duplex scheme, the uplink subframe index is determined by at least using the downlink subframe index and the parameter value. | 09-13-2012 |
20120275355 | METHOD AND APPARATUS FOR RESOURCE ALLOCATION AND METHOD AND APPARATUS FOR RECEIVING RESOURCE ALLOCATION INFORMATION SIGNAL - A method of allocating a resource by a base station is provided. The base station allocates a plurality of radio resources for transmitting a plurality of data bursts to a plurality of subframes in one frame, respectively, and generates a resource allocation information signal including allocation information on the plurality of radio resources. The base station transmits the resource allocation information signal to a mobile station through one subframe. | 11-01-2012 |
20120287919 | SYNCHRONIZATION APPARATUS AND METHOD IN WIRELESS NETWORK SYSTEMS - A node synchronization apparatus in a wireless network system sets a fast Fourier transform (FFT) start point and requests a one-hop neighbor node to change its transmission time. The synchronization apparatus sets a signal receiving time and requests a one-hop neighbor node to change a receiving time. In this way, a node synchronizes signal transmission and signal reception. | 11-15-2012 |
20120327882 | BASE STATION, MOBILE STATION, MIMO FEEDBACK RECEIVING METHOD, AND MIMO FEEDBACK TRANSMITTING METHOD - A mobile station receives a MIMO feedback mode bitmap and information on a MIMO feedback period. The mobile station estimates channel information corresponding to at least one MIMO feedback mode indicated by the MIMO feedback mode bitmap. The mobile station generates a MIMO feedback including the MIMO feedback mode bitmap and the channel information corresponding to the at least one MIMO feedback mode indicated by the MIMO feedback mode bitmap. The mobile station transmits the MIMO feedback at the advent of the MIMO feedback period. | 12-27-2012 |
20130250839 | METHOD AND DEVICE FOR ACQUIRING SYNCHRONIZATION BETWEEN NODES AND METHOD FOR ORGANIZING MULTIPLE PHYSICAL CHANNELS - A method for acquiring synchronization between nodes and configuring multiple physical channels in order to improve performance in the ad-hoc/mesh network is disclosed. | 09-26-2013 |
20130260755 | APPARATUS AND METHOD FOR POWER CONTROL USING SMALL BASE STATIONS - In a wireless communication system, a base station to perform power control may include: a user detector to detect a presence of a user terminal by monitoring whether a registration state of the user terminal served by the base station corresponds to a registration complete state, a registration maintain state, or a registration release state; a control signal generator to generate a control signal for controlling power of at least one power device among a plurality of power devices included in a predetermined group, based on the detection result; and a control signal transmitter to transmit the control signal to the at least one power device among the plurality of power devices. | 10-03-2013 |
20130260786 | METHOD AND APPARATUS FOR CONTROLLING FEMTOCELL BASE STATION - Disclosed are a method and an apparatus for controlling a femtocell base station which can effectively solve an inter-cell interference problem. A method of controlling a femtocell base station according to an exemplary embodiment of the present disclosure includes receiving pilot signals from one or more macro cell base stations located in surroundings of a femtocell and measuring intensities of the pilot signals; receiving use frequency information and pilot signal transmission power information from the one or more macro cell base stations; determining a position of the femtocell within a reference macro cell according to an intensity of a reference pilot signal having a maximum signal intensity among the received pilot signals; determining a use frequency of the femtocell according to the position of the femtocell; and determining a transmission power of the femtocell according to the use frequency and the intensity of the reference pilot signal of the femtocell. | 10-03-2013 |
20130331093 | MULTIMODE TERMINAL AND METHOD FOR RELAYING MOBILE COMMUNICATION USING THE SAME - Disclosed are a multimode terminal that may simultaneously enhance utilization of a device and efficiency of a network by enabling a mobile terminal supporting a plurality of communication schemes to additionally support a relay function, and a method of relaying communication using the multimode terminal. A communication relay method of a multimode terminal according to an exemplary embodiment of the present disclosure includes: searching, by a base station, for terminals that support a plurality of communication schemes; selecting, by the base station from among the searched terminals, a relay terminal that satisfies a predetermined condition for performing a multimode relay function; requesting, by the base station, the relay terminal to perform the multimode relay function; and relaying, by the relay terminal in response to the request of the base station, communication between the base station and a target terminal. | 12-12-2013 |
20130344879 | CELLULAR COMMUNICATION SYSTEM AND COMMUNICATION METHOD THEREOF - Disclosed is a cellular communication system allowing direct communication between terminals within a cell or simultaneous transmission and reception of signals between a base station and the terminals through a repeater to be made by introducing a universal link, and a communication method thereof. The communication method of the cellular communication system includes: transmitting, by a base station, universal link setting information and a transmission control signal to a first terminal within a cell, transmitting, by the base station, the universal link setting information and a reception control signal to a second terminal within the cell, and directly transmitting/receiving, by the first and second terminals, signals through the universal link. | 12-26-2013 |
20140317260 | METHOD AND APPARATUS FOR CONTROLLING CLOUD VIRTUAL BASE STATION - Disclosed are a method and apparatus for managing a cloud virtual base station system. The present invention includes setting initial resources and driving or downloading an execution file or environment file of the cloud virtual base station system and monitoring or managing a state for a failure, radio resources, or the execution file or the environment file of the cloud virtual base station system. | 10-23-2014 |
20140355521 | INTELLIGENT MULTIPLE ACCESS COMMUNICATION CONTROL APPARATUS AND METHOD - An intelligent multiple access communication (MAC) control apparatus and method are disclosed. The intelligent MAC control apparatus includes a connection control unit, a resource management unit, a session control unit, a flow control unit, and a determination unit. The connection control unit connects at least one Radio Access Technology (RAT) and a wireless network. The resource management unit collects RAT information including information about available resources and radio state of the RAT. The session control unit checks the QoS of at least one connection target service. The flow control unit determines the priority of the connection target service, and selects a preferential connection target service. The determination unit determines a connection RAT for performing the preferential connection target service based on the QoS and the RAT information. | 12-04-2014 |