Abstract:
A wireless network access point can operate as a closed loop MIMO device when communicating with a station that is operating as an open loop MIMO device. Transmit/receive chains in the access point are calibrated to support aggregate channel reciprocity.
Abstract:
A method for performing hierarchical feedback with space information assisted in a mobile communication system is provided. At the user terminal, the method comprises: measuring a space correlated matrix of multiple transmit antennas of a base station; converting a hierarchical code book in the mode of hierarchical feedback by using the spatial correlation matrix; selecting the code word from the converted hierarchical code book; and feedbacking a pre-coding matrix index corresponding to the index of the selected code word and the space correlated correlation matrix from the user terminal to the base station by using the mode of hierarchical feedback.
Abstract:
To feedback MIMO channel conditions, a codeword from a codebook is selected. To reduce signalling, the codewords are organized into codeword subsets. The receiver signals an index of a codeword into a current 5 codeword subset previously made known to the transmitter. The current codeword subset is adaptively selected based on a threshold criterion. For example, if the best codeword from the current codeword subset is not sufficiently similar to the best codeword in the full codebook, a switch in the codeword subset is made.
Abstract:
A wireless network access point can operate as a closed loop MIMO device when communicating with a station that is operating as an open loop MIMO device. Transmit/receive chains in the access point are calibrated to support aggregate channel reciprocity.
Abstract:
PLCP 헤더 전송 모드 지시 방법 및 장치가 개시되어 있다. 데이터 프레임의 physical layer convergence protocol(PLCP) 헤더 생성 방법은 수신된 프레임의 스크램블링 시퀀스(scrambling sequence) 또는 수신된 프레임에 포함된 information element를 기초로 PLCP 헤더 모드 정보를 복조하는 단계와 PCLP 헤더 모드 정보를 기초로 생성된 PLCP 헤더를 포함하는 데이터 프레임을 생성하는 단계를 포함할 수 있다. PLCP 헤더 모드 정보는 STBC 모드 지시자(space time block coding mode indication), GI 모드 지시자(guard interval mode indication), repetition mode 지시자(repetition mode indication) 중 적어도 하나의 지시자를 포함할 수 있다. 채널 상황에 적응적으로 PCLP 헤더의 전송 모드를 결정하여 데이터 전송 효율을 높일 수 있다.
Abstract:
A space-time-frequency block coding apparatus and method in a transmitter with three transmit (Tx) antennas are provided. An input symbol sequence is transmitted through three Tx antennas according to a permutation method using a selected transmission matrix in order to improve the performance of an STFBC.