Electronics and Telecommunications Research Institute

Samsung Electronics Co., Ltd.

Kt Corporation

Sk Telecom Company, Ltd.

Hanaro Telecom., Inc.

Ktfreetel Co., Ltd

Korea Advanced Institute of Science and Technology

Yonsei University

In-Kyeong Choi

Dong-Seung Kwon

Seong-Rag Kim

Yu-Ro Lee

Jong-Ee Oh

Chung-Yong Lee

Seung-Joon Lee

Choong-Il Yeh

Young-Seog Song

Sok-Kyu Lee

Dong Seung Kwon

Seong Rag Kim

Ji Won Kang

Seung-Ku Hwang

Chung Yong Lee

Kwang-Jae Lim

Hyoung-Soo Lim

Myeong-Cheol Shin

Ji-Won Kang

Young-Gyun Jeong

Young-Ho Jung

Il-Gu Lee

Ji Hyung Kim

Yong-Hoon Lee

Byung-Jae Kwak

Eun-Young Choi

Yong Hoon Lee

Hee-Jung Yu

Seung Joon Lee

Young Seog Song

Choong Il Yeh

Seong-Keun Oh

Jin-Kyu Choi

Seo-Young Lee

Young Wha Kim

Nam-Jin Park

Joon Doo Kim

Hyong-Woo Ku

Moon-Il Lee

Jin-Ho Choi

Myoung-Seog Kim

Young Ho Jung

Seung-Chul Hong

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.

Apparatus and method for receiving data in communication system

Disclosed is an apparatus for transmitting data in a communication system, including: a receiving unit configured to receive signals from multi-users by a multi-user-multi input multi output (MIMO) scheme and acquire channel information from the users; a calculation unit configured to calculate precoding vectors for the users using the channel information; a precoding unit configured to precode data of the users using the precoding vectors; and a transmitting unit configured to transmit the precoded data to users by the multi user-MIMO scheme.

Apparatus and method for transmitting/receiving data in communication system

A method for transmitting, by a transmitting terminal, data to a receiving terminal in a wireless communication system includes: generating a first detection field including symbols modulated by using a BPSK data tone; generating a second detection field including symbols modulated such that an even numbered subcarrier and an odd numbered subcarrier have a phase difference of 90 degrees; generating a data packet including the first detection field, the second detection field, and the data; and transmitting the data packet.

Method and apparatus for transmitting/receiving data in wireless communication system

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.

Method for beamforming

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.

Transmitting/receiving method for multi-user multiple-input multiple-output system

A MU-MIMO method of an access point in a WLAN using multi-channels and having at least one station includes: receiving index information indicating a precoding vector for a beam selected by the station and channel quality information thereof for each one of the multi-channels; generating first channel capacity information of channel combination groups using the channel quality information wherein the channel combination groups are grouped according to a predetermined channel bandwidth of the multi-channels; and allocating resources to the station from a channel combination selected from the channel combination groups according to the first channel capacity information using the index information and the channel quality information, wherein the access point and the station previously store precoding vector information for a plurality of beams for the MU-MIMO.

MU-MIMO method in WLAN system, and access point and station for MU-MIMO

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.

Multiple beamforming 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.

Beam forming method and apparatus

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.

Precoding device and method in wireless communication system

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 () and a receiver (). The transmitter () includes N transmit antennas (--) that are more than M transmit antennas (--) used for transmitting a signal to space channel, selects the M transmit antennas (--) among the N transmit antennas (--), and transmits symbol by space-time encoding the symbol. The receiver () includes M receive antenna (--) for receiving a signal from the space channel, detects an information symbol by using the signal received through the receive antenna (--), generates transmit antenna selection information for selecting M transmit antennas (--) among transmit antennas (i--) with reference to a channel estimate, and returns the information to the transmitter.

Multi-input multi-output system for enhancing transmission performance

A receiver according to an exemplary embodiment of the present invention receives a transmitted signal, converts the signal to a predetermined symbol, and estimates channel information including a channel gain of a channel of the transmitted signal. In addition, the receiver generates an intermediate processing value for decoding the signal based on the estimated channel information and the symbol, and normalizes the intermediate processing value to the channel gain to generate a reference value. The generated reference value is used for a soft-decision value for decoding the signal. In addition, when the signal is decoded by using a hard-decision value, a constellation point value that is closest to the reference values is generated and set as the hard-decision value.

Decoding method for space-time encoding transmission scheme in with multiple input multiple output system and receiving apparatus for using the method

In a method for allocating transmission power in a communication system including multiple antennas, a plurality of subcarriers are grouped by a plurality of groups, and each group includes at least one subcarrier. A transmission power weight and an antenna transmission vector are calculated for each group by using channel information, a transmission power for each group of each antenna is calculated by using the transmission power weight and the antenna transmission vector for each group, and transmission signals are transmitted through the multiple antennas after determining which signals need to be transmitted from the multiple antennas by using the transmission power.

Method and apparatus for allocating transmission power in communication system with multiple antennas

The present invention relates to a system for selecting a switched beam for supplying a maximum received power to a subscriber station, and a method thereof. The number of switched beams used by a base station is limited, and a weight value vector for forming the switched beam is predefined. The subscriber station uses a pilot signal for discerning transmitting antennas to estimate channel values for the respective transmitting antennas, and uses the channel values and the predefined weight value vectors to determine a switched beam for supplying a maximum signal-to-noise ratio (SNR). The subscriber station notifies the base station of an identifier of a selected beam by using a feedback channel, and the base station uses the switched beam to transmit traffic data.

Method for selecting switched beam using pilot signal and system thereof

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.

Structured space-time code achieving the full diversity and full rate and generating method thereof, and multi-input multi-output system

A mobile station transmitting and receiving method and a corresponding mobile station transmitter and receiver of a smart antenna system for forming uplink eigenbeams of the OFDM/TDD (orthogonal frequency division multiplex/time division duplex), wherein OFDM symbols are received from a base station through a downlink via multiple antennas () and an FFT (fast Fourier transform) is performed on the received OFDM symbols by the FFT units (). By means of a channel estimator () the channels are estimated and a beam weight generator () generates respective beam weights from the channels of the respective pilot tones of the respective subcarriers according to the channel estimation result. A beam weight multiplier () forms the uplink beam by multiplying the respective beam weights with the output of the signal repeater () and IFFT units () generate respective OFDM symbols which are transmitted via multiple antennas () through an uplink.

Smart antenna system and method thereof for forming uplink eigenbeam of OFDM/TDD

Growing community of inventors

Daejeon, South Korea

In-Kyeong Choi