Patent application number | Description | Published |
20080240276 | Multi-Input Multi-Output System For Enhancing Transmission Performance - The present invention relates to a multi-input multi-output (MIMO) system for enhancing transmission performance. The MIMO system uses space-time encoding and transmit antenna selection methods, and includes a transmitter ( | 10-02-2008 |
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 |
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 |
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 |
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 |
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 |
20120020425 | APPARATUS 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 |
20120195219 | APPARATUS AND METHOD FOR PRECODING BY LIMITED COOPERATION IN A WIRELESS COMMUNICATION SYSTEM - An apparatus and method are provided for precoding by limited cooperation in a wireless communication system. A method of data precoding by a Base Station (BS) in a wireless communication system includes determining a Channel Quality Indicator (CQI) parameter indicating channel size information between the BS and a User Equipment (UE) served by the BS; transmitting the determined CQI parameter through a backhaul to a central unit; receiving, from the central unit, a weight factor based on a CQI parameter from each cell; and determining a precoding vector based on the weight factor. The weight factor represents a relative ratio of an inter-cell environment that is to be interfered by the BS. | 08-02-2012 |
20140003366 | METHOD AND APPARATUS FOR TRANSMITTING AND RECEIVING SIGNAL | 01-02-2014 |