Electronics and Telecommunications Research Institute

Yonsei University

Samsung Electronics Co., Ltd.

Young-Seog Song

Dong-Seung Kwon

In-Kyeong Choi

Seung-Joon Lee

Jong-Ee Oh

Myeong-Cheol Shin

Choong-Il Yeh

Yu-Ro Lee

Kwang-Jae Lim

Hyoung-Soo Lim

Chung-Yong Lee

Seung-Ku Hwang

Seong-Rag Kim

Chungyong Lee

Seong-Keun Oh

Myoung-Seog Kim

Moon-Il Lee

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

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.

Transmitting apparatus and method, and receiving apparatus and method in multple antenna system

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

In a method for optimizing a codebook including a quantized channel between a base station transmitter and a portable terminal: a) select the codebook to be optimized; b) a steepest descent algorithm is applied to respective codewords of the codebook selected in a), wherein the codewords are transformed so that a correlation between the codewords is minimized, and a function indicating the correlation between the codewords is differentiated and is multiplied by a predetermined step size and is used for a parameter for generating a new codeword in the steepest descent algorithm; c) it is determined whether the codebook including the codewords transformed in b) is optimized; and d) the codebook is stored when it is determined in c) that the codebook is optimized.

Method and device for optimizing codebook for quantized precoder by using steepest descent algorithm

Growing community of inventors

Daejeon, South Korea

Young-Seog Song