Non-Unitary Precoding Base on Codebook for Multi-user MIMO System with Limited Feedback
基于码本的有限反馈非酉矩阵预编码多用户MIMO系统

A non-unitary precoding system based on codebook for multi-user MIMO downlink transmission with limited feedback is proposed in this paper. The proposed scheme will perform scheduling and precoding just according to the limited feedback channel information SINR of each user to enhance the system capacity. A precoder codebook design method is related to Grassmannian line packing criterion and the vectors from the Grassmannian codebook are grouped into non-unitary matrices according to their correlation coefficient, which aims to enhance the precoding gain and suppress the multi-user co-channel interference. It has the advantages of low feedback as well as low complexity and outperforms the traditional single user MIMO system and the unitary precoding system based on codebook for multi-user MIMO under the same situation.