Patent application number | Description | Published |
20080225962 | APPARATUS FOR GENERATING PRECODING MATRIX CODEBOOK FOR MIMO SYSTEM AND METHOD OF THE SAME - An apparatus for generating a precoding matrix codebook includes a matrix group generator to generate a first group of unitary matrices based on a vector-based codebook for precoding of a multiple input multiple output (MIMO) communication scheme; a matrix group extender to extend the first group of unitary matrices to generate a second group of unitary matrices; and a matrix group selector to select a group of columns corresponding to a communication rank from each of the unitary matrices that are elements of the second group so that the columns are optimized based on a distance between the columns corresponding to the communication rank. | 09-18-2008 |
20080242332 | DECENTRALIZED CONTROL OF FEEDBACK FOR MULTI-USER DIVERSITY - A communication apparatus includes a mobile terminal to measure a downlink channel state of a downlink between a base station and the mobile terminal, and to determine whether to transmit feedback information about the downlink channel state to the base station based on the measured downlink channel state. | 10-02-2008 |
20080247475 | METHOD FOR CODEBOOK DESIGN AND BEAMFORMING VECTOR SELECTION IN PER-USER UNITARY RATE CONTROL (PU2RC) SYSTEM - A base station includes a storage unit to store a codebook, wherein the codebook includes a plurality of matrices; a control unit to perform beamforming using the codebook to generate a signal; and a multi-antenna to transmit the signal. For all of the plurality of matrices, all column vectors of a same matrix of the plurality of matrices are orthogonal to each other. For all columns of the plurality of matrices, all column vectors of a same column of all of the plurality of matrices satisfy a Grassmannian line packing (GLP) criterion. | 10-09-2008 |
20080256163 | APPARATUS AND METHOD OF GENERATING CODEBOOK FOR MULTIPLE INPUT MULTIPLE OUTPUT COMMUNICATION SYSTEM - An apparatus and method of generating a codebook. The codebook generation apparatus includes a matrix extender to generate a candidate matrix set by multiplying a base matrix and at least one diagonal matrix, wherein the at least one diagonal matrix includes elements of a constrained set as diagonal elements; and a codebook generator to generate the codebook where a minimum distance between the elements is maximized, based on the candidate matrix set. According to aspects of the present invention, it is possible to provide a precoding codebook that can reduce an amount of feedback from a terminal. | 10-16-2008 |
20090268827 | SYSTEM FOR FEEDING BACK INDEX OF CODEWORD MATRIX - A system is provided for performing downlink beamforming based on information fed back by a mobile station. The mobile station includes a channel matrix generation unit to generate a channel matrix with respect to channels ranging from a base station to a mobile station, the base station including multiple transmission antennas, a codebook updating unit to generate a second codebook including a plurality of second codeword matrixes based on the generated channel matrix and a first codebook including a plurality of first codeword matrixes, a codeword selection unit to select at least one transmission codeword matrix from among the plurality of second codeword matrixes, a transmission unit to transmit an index of the selected transmission codeword matrix to the base station, and a receiving unit to receive data transmitted from the base station via the multiple transmission antennas. | 10-29-2009 |
20090268840 | MULTIPLE 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 |
20090285342 | PERTURBED DECODER, PERTURBED DECODING METHOD AND APPARATUS IN COMMUNICATION SYSTEM USING THE SAME - A decoder adopted to receive a signal transmitted in a communication system, includes one or more of a module adopted to pre-process a received signal to reduce the effect of interference-plus-noise on the received signal before filtering the received signal, and a module adopted to post-process the result of filtering the received signal. | 11-19-2009 |
20100045494 | USER TERMINAL AND BASE STATION USING ADAPTED CODEBOOK ACCORDING TO POLARIZATION - A terminal and a base station using an adaptive codebook for a polarization are provided. The terminal includes a rotation matrix generator to generate rotation matrices corresponding to a cross polarization discrimination value (XPD) of a transmission signal and a codebook generator to generate a codebook including result matrices that are generated based on pre-stored block diagonal matrices and the rotation matrices. | 02-25-2010 |
20100054351 | METHOD FOR DEMODULATING SIGNAL AND TERMINAL AND BASE STATION FOR EXECUTING THE METHOD - A method of modulating and/or demodulating a signal in a communication system and a terminal for demodulating a signal received from a base station are provided. A terminal includes a singular value extractor to extract at least one singular value of a channel matrix associated with a channel that is formed between a base station and the terminal, a modulation order determination unit to determine a modulation order based on the at least one singular value, and a received signal demodulator to demodulate a received signal according to the determined modulation order. | 03-04-2010 |
20110064051 | CLUSTERED MULTI-CELL MULTI-USER MULTIPLE INPUT MULTIPLE OUTPUT COMMUNICATION SYSTEM USING CELL-EDGE USER SELECTION SCHEME - Provided is a control method of a control apparatus for a multi-cell communication system including a plurality of cells, the method including determining a cell edge terminal or an inner cell terminal from each of terminals included in each of the cells, and selecting, from base stations included in the plurality of cells, a first base station and a second base station. The first base station may serve all of a corresponding cell edge terminal and a corresponding inner cell terminal, and the second base station may serve only the corresponding inner cell terminal between the corresponding cell edge terminal and the corresponding inner cell terminal. | 03-17-2011 |
20110096755 | CODEBOOK FOR MULTIPLE INPUT MULTIPLE OUTPUT COMMUNICATION AND COMMUNICATION DEVICE USING THE CODEBOOK - In a multi-user multiple input multiple output (MIMO) communication, each of receivers may use a different channel codebook and a transmitter may determine beamforming vectors using a beamforming codebook corresponding to each of the receivers. | 04-28-2011 |
20110164696 | MULTIPLE-INPUT MULTIPLE-OUTPUT (MIMO) COMMUNICATION SYSTEM USING A CODEBOOK AND METHOD OF DESIGNING THE CODEBOOK - Provided is a multiple input multiple output (MIMO) communication system using a codebook. A transmitter and a receiver included in the MIMO communication system may generate a codebook having a different size for each eigenvector of a channel matrix or a channel covariance matrix, based on eigenvalues of the channel matrix or the channel covariance matrix. | 07-07-2011 |
20110222625 | METHOD AND APPARATUS FOR SHARING CHANNEL STATE INFORMATION (CSI) IN A MULTIPLE-USER MULTIPLE-INPUT MULTIPLE-OUTPUT (MU-MIMO) ENVIRONMENT - Provided is a channel state information (CSI) sharing method and apparatus in a Multiple User Multiple Input Multiple Output (MU-MIMO) environment. Each node may use network-coding to reduce overhead necessary for sharing CSI between all nodes in the MU-MIMO environment. A transmitter may dynamically select, based on the CSI between receivers, a path used for transmitting data to each receiver and a receiver to be used as a relay based on the global CSI. A decoding performance may be improved based on the CSI between the transmitter and the receivers. | 09-15-2011 |
20110292926 | MULTIPLE INPUT MULTIPLE OUTPUT COMMUNICATION SYSTEM AND COMMUNICATION METHOD OF CONFIGURING CODEBOOK - A multiple input multiple output (MIMO) communication system and communication method of configuring a codebook are provided. A channel may be formed between a transmitter and a receiver, and a cross-polarization discrimination value (XPD) may be detected. The XPD may vary based on a location of the transmitter and the receiver, a mobility thereof, or a peripheral environment, among other factors. The codebook may be configured based on the XPD. | 12-01-2011 |
20120140834 | METHOD OF GENERATING ADAPTIVE CODEBOOK AND MULTIPLE INPUT MULTIPLE OUTPUT COMMUNICATION SYSTEM USING THE ADAPTIVE CODEBOOK - Provided is a method of generating an adaptive codebook and a multiple input multiple output (MIMO) communication system using the adaptive codebook. A transmitter and a receiver may generate, from a base codebook based on a matrix associated with statistics of a channel matrix, the adaptive codebook maintaining a unitary characteristic. The transmitter may perform scheduling, transmit filter design, and precoding using adaptive codebook based feedback information. | 06-07-2012 |
20130229309 | BEAM ALIGNMENT METHOD UTILIZING OMNI-DIRECTIONAL SOUNDING AND USE THEREOF - A method includes transmitting a training signal from each of N omni-directional beams corresponding to N entries in an omni-directional codebook, receiving feedback including indication(s) corresponding to an entry from a narrow beam codebook entry to use to transmit, determining, based on the indication(s), the entry from a narrow beam codebook entry to use to transmit, and transmitting a data signal using the entry from the narrow beam codebook. Another method includes receiving at a receiver a training signal including N omni-directional beams corresponding to N entries in an omni-directional codebook, determining a best entry from a narrow beam codebook to use by a transmitter in transmissions to the receiver, where the best entry is determined as a function of the received training signal including the N omni-directional beams, and transmitting to the transmitter indication(s) corresponding to the best entry of the narrow beam codebook. | 09-05-2013 |
20130336233 | METHOD AND APPARATUS FOR OPPORTUNISTIC USER SCHEDULING OF TWO-CELL MULTIPLE USER MIMO - An apparatus and a method for opportunistic user scheduling of two-cell multiple user Multiple Input Multiple Output (MIMO) by a base station, the method comprising: broadcasting signals through random beams to users; and receiving Channel Quality Information (CQI) from best K user set. The CQI is calculated based on all possible combinations of transmit beamforming vectors. | 12-19-2013 |
20140112272 | METHOD AND APPARATUS FOR USING CHANNEL OUTPUT FEEDBACK IN MULTI USER WIRELESS SYSTEMS AND HYBRID-ARQ - A method and apparatus for transmitting and receiving a signal using a channel output feedback in a wireless communication system and Hybrid-Automatic Repeat Request (ARQ) are provided. The method and apparatus include a transmitter configured to transmit to a base station and a first packet on a precoder received from the base station. A receiver configured to receive, from the base station, a Channel Output Feedback (COF) of the transmitted first packet and information for transmitting a second packet. A controller configured to prepare a variant of the second packet using the COF and the received information for transmitting the second packet, and to control to transmit the prepared variant to the base station. | 04-24-2014 |
20140112413 | DIFFERENTIAL CODEBOOK FOR TEMPORALLY-CORRELATED MISO DUAL-POLARIZATION ANTENNA - A code word selection method performed by a User Equipment (UE) in a wireless communication system is provided. The method includes generating a rotation matrix using previously selected codeword; generating a new differential code book using the rotation matrix and a differential code book; selecting a code word from the new differential code book; and performing data transmission using the selected code word. | 04-24-2014 |