Samsung Electronics Co., Ltd.

Korea Advanced Institute of Science and Technology

Yonsei University

Seoul National University

Seung-Hoon Nam

Jae-Hak Chung

Chan-Soo Hwang

Yung-Soo Kim

Young-Ho Jung

Yong-Hoon Lee

Vahid Tarokh

Chan-Byoung Chae

Jong-Hyeuk Lee

Won-Il Roh

Myeon-Kyun Cho

Chung-Yong Lee

Hong-Sil Jeong

Sung-ryul Yun

Jeong-Tae Oh

Dong-seek Park

Jong-Ho Lee

Young-soo Park

Young-Soo Kim

Ho-Jin Kim

Hak-Ju Lee

Sung-Ryul Yun

Young-Soo Park

Eung-sun Kim

Eun-Yong Kim

Sung-Hyun Cho

Seijoon Shim

Sae-Young Chung

Kyeongyeon Kim

Cheol-Woo You

Chungyong Lee

In-Soo Hwang

Jihoon Choi

Jae-kwon Kim

Dong-Seek Park

Kwang-Bok Lee

Kyun-Byoung Ko

Jae-Yeun Yun

Chang-Soo Hwang

Joo-Hwan Chun

Soong-Yoon Choi

Ye-Hoon Lee

Seong-Cheol Kim

Myeong-Cheol Shin

Jin-Gon Joung

In-Hyoung Kim

Hui-won Je

Kyeong-Yeon Kim

Sei-Joon Shim

Do-Young Kwak

Hong-Sun Park

Ji-Won Kang

Woo-Seok Nam

Gun-Chul Hwang

Chang-Soon Park

Tarokh Vahid

Koo-Chul Jung

Woo-Hyuk Chang

Yoon-Ok Cho

In-Soon Park

Jae-Choong Han

Chan Byoung Chae

Vahid Samsung Electronics Co Ltd Tarokh

Chan-Soo Samsung Electronics Co Ltd Hwang

Jae-Kwon Kim

Sung-Ryul 811-806 Byeokjeokgol Yun

Chang-Byoung Chae

An adaptive subchannel and bit allocation method in a wireless communication system. A mobile station analyzes channel quality information of a subchannel at a predetermined period and determines a feedback band index with a maximum decision criterion. The mobile station feeds back the determined feedback band index with the maximum decision criterion to a base station. The base station generates band allocation information using the feedback information from the mobile station, and transmits the band allocation information to the mobile station. The mobile station transmits AMC information using the band allocation information received from the base station. The base station estimates a channel using the AMC information transmitted from the mobile station and allocates bits to the allocated band according to the channel estimation result.

Adaptive subchannel and bit allocation method using partial channel information feedback in an orthogonal frequency division multiple access communication system

A transmitter in a multiple input multiple output (MIMO) communication system is provided. The transmitter includes a multiplexer for multiplexing an input bit stream into a plurality of bit streams, and outputting the bit streams in parallel; a bit-order rearranger for reordering bits constituting the bit streams, which are output from the multiplexer in the same time period, and outputting the reordered bits as reordered bit streams; and a modulator for modulating the parallel reordered bit streams output from the bit-order rearranger according to their associated modulation schemes, and transmitting the modulated symbols via their associated antennas.

Transmission apparatus and method for MIMO 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.

Optimum perturbation apparatus and method in a multi-antenna multi-user communication system

A method for transmitting to one cell a frame including broadcast channels in a cellular wireless communication system in which a base station supports a plurality of physical channels corresponding to the broadcast channels. The base station generates the frame and transmits the generated frame to a mobile station. The frame includes separate broadcast channels for the respective physical channels. A position, in the frame, of a first broadcast channel for a physical channel capable of supporting a mobile station having the worst channel state is fixed in all of transmission frames. The first broadcast channel includes positional information of the remaining broadcast channels except for the first broadcast channel. The mobile station detects only an address of a broadcast channel for a physical channel allocated thereto from the first broadcast channel among broadcast channels belonging to the frame.

Method for transmitting broadcast channel in a cellular wireless communication system

An apparatus and method for determining a beamforming vector in a codebook-based transmission beamforming system are provided. In a feedback method for a receiver in a codebook-based transmission beamforming system, forthcoming channel values for a forthcoming period are generated using M present and previous channel estimates. Effective channel gains for all transmission beamforming vectors included in a codebook are calculated using the forthcoming channel values. A codebook index corresponding to the maximum effective channel gains is fed back to a transmitter.

Apparatus and method for determining beamforming vector in a codebook-based beamforming system

Provided are an apparatus and method for eliminating multi-user interference in a codebook-based beamforming system. A transmitter for providing a service to multi-users in the codebook-based beamforming system includes a beamformer for generating beamformed user signals by multiplying transmit data of users, to whom the service is to be provided, by corresponding weighting factor vectors using feedback information; a null space generator for generating a null space matrix orthogonal to weighting factor vectors of other users; and a projector for projecting the beamformed user signals on the corresponding null space matrix and transmitting the resulting signals through a plurality of antennas. Because the multi-user signals can maintain orthogonality, the performance degradation caused by the multi-user interference can be prevented.

Apparatus and method for eliminating multi-user interference

A transmitter and a receiver are disclosed herein that support transmit antenna diversity using space-time block coding in a wireless communication system. The transmitter produces symbol combinations containing, as their elements, input symbols, the inversions and conjugates of the symbols, and symbols obtained by rotating the phases of the symbols once, forms a matrix having symbols in at least two columns orthogonal to each other with the symbol combinations, and transmits the matrix. The receiver detects symbols that minimize maximum likelihood (ML) decoding metrics over all possible symbols using channel gains from transmit antennas to a receive antenna. Also, the receiver selects candidate symbols among all possible symbols according to the characteristics of transmitted modulation symbols and detects symbols that minimize the ML decoding metrics.

Transmitting and receiving apparatus for supporting transmit antenna diversity using space-time block code

A differential STBC transmitting/receiving apparatus in a multiple antenna system using eight or less transmit antennas is provided. In the differential STBC transmitting apparatus, a symbol mapper receives binary data and generates a number of symbols from the binary data, each symbol having a number of bits. A space-time block encoder generates an STBC by encoding the symbols. A differential processor differentially encodes the STBC through feedback and delay. A distribution matrix processor substitutes the differentially coded STBC into a distribution matrix preset according to the number of transmit antennas, and outputs the differential STBC code of the distribution matrix to the transmit antennas.

Differential space-time block coding apparatus using eight or less transmit antennas

A system and method are provided for controlling a data rate in a communication system. A transmitter sets threshold values for classifying Modulation and Coding Scheme (MCS) levels. When receiving information about an MCS level desired to be used in the receiver, the transmitter sets an MCS level to be actually used in the receiver and transmits information about the set MCS level to the receiver. When detecting that the information is to be transmitted to the transmitter, the receiver computes instantaneous link capacity using a channel estimation result, sets an MCS level mapped to the instantaneous link capacity, and transmits information about the set MCS level to the transmitter. The receiver receives the information about the MCS level to be actually used from the transmitter.

Method and system for controlling data rate in a communication system

The present invention relates to a transmitter and a transmission method in communication system using three Tx antennas in order to maximize STFBC coding gain. An input symbol sequence is transmitted through a plurality of Tx antennas in a predetermined method.

Apparatus and method of space time frequency block code

Disclosed is a method and apparatus for transmitting data in a cellular communication system including at least one base station that communicates with a plurality of mobile stations through a given frequency band. The method and apparatus divides the frequency band into at least two subcarrier groups each including a plurality of subcarriers; allocates at least one subcarrier group to each mobile station, and changes the subcarrier group allocated to each mobile station according to a predetermined period; and codes data to be transmitted to each mobile station with a plurality of codes, and transmits modulation symbols obtained by performing inverse fast Fourier transform (IFFT) on a plurality of subcarriers of the allocated subcarrier group.

Method and apparatus for transmitting/receiving data in a cellular communication system

An apparatus and method for simultaneously providing service to users each having a different number of antennas in a multiple-antenna wireless communication system are provided. The communication method discloses a BS in a wireless communication system that services a first multiple antenna mode using X transmit antennas and a second multiple antenna mode using Y transmit antennas such that (Y&#x3e;X), the BS determines an MS to be serviced in the second multiple antenna mode and receives a sounding signal from the MS. The BS estimates an uplink channel using the received sounding signal and acquires downlink channel values using estimated uplink channel values. Then the BS services the MS in the second multiple antenna mode using the downlink channel values.

Apparatus and method for extending number of antennas in a wireless communication system using multiple antennas

Disclosed is a signal detection method for a receiver of a Multiple-Input Multiple-Output (MIMO) communication system having nand n(where nis greater than or equal to n) transmission and reception antennas, respectively, and an n&#xd7;nchannel matrix. The signal detection method includes selecting a plurality of sub-channel matrices having smaller dimensions than the n&#xd7;nchannel matrix, estimating transmission symbols received from corresponding transmission antennas using a maximum likelihood decoding method with respect to a received signal corresponding to each of the sub-channel matrices, estimating transmission symbols received from the remaining transmission antenna(s) using the estimated transmission symbols, temporarily storing a candidate symbol set composed of the estimated transmission symbols, and comparing candidate symbol sets corresponding to all the sub-channel matrices and determining the smallest candidate symbol set as a transmission symbol set.

Signal detection method for MIMO communication system employing spatial multiplexing

A pilot designing method in an uplink OFDMA system is provided. In the uplink OFDMA system, communications are carried out in a frame divided into time-frequency lattices, and each time-frequency lattice includes a plurality of data symbol periods and a plurality of pilot symbol periods intermittently arranged with respect to the data symbol periods. The frame is divided into a plurality of blocks. The blocks are allocated to the terminals. A predetermined allocated pilot time-frequency lattice is shared between adjacent terminals.

Pilot designing method in an uplink OFDMA system

An apparatus and method for transmitting/receiving a signal in a communication system with a plurality of antennas are provided. Received modulation symbols of channel coded transmission information data are generated using a space-time mapping scheme and processed to RF symbols. The RF symbols are transmitted through antennas among the plurality of antennas.

Apparatus and method for transmitting/receiving signal in a communication system using a plurality of transmit antennas

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Seoul, South Korea

Seung-Hoon Nam