Low-Complexity Precoding Techniquefor Eight Transmit Antenna MIMO system

• Main Authors: Chih-Lun Wu, 吳至倫
• Other Authors: 張進福
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/54932602665989683548

碩士 === 國立臺灣大學 === 電信工程學研究所 === 100 === Spatial Multiplexing for MIMO system uses antenna arrays provide communication link with substantial capacity. Unfortunately, spatial multiplexing is sensitive to multi-antenna Interference. Precoding can improve the resilience of spatial multiplexing at the expense of full channel knowledge at the transmitter—which is often not realistic. Use quantized precoding system where the optimal precoder is chosen from a finite codebook known to both receiver and transmitter. Receiver calculate preferred codeword as precoding matrix in the codebook，and feedback index of codeword to transmiter. In order to minimize computational complexity of search precoding matrix. Assume RI evaluation perfect, PMI evaluating based on mutual information. Mutual information is proportional to its subspace distance. We group codewords based on the subspace distance, then minimize complexity of searching precoding matrix using the grouped codebook. Finally we use characteristics of 8Tx codebook and minimize number of codeword selection.