MIMO系统在慢衰落信道中的实用反馈方案

A Utility Feedback Approach Applied in Slow Fading Channels for MIMO Systems

提出了一种可变码长编码方式,其应用于慢衰落信道中的基于有限反馈迫零预编码的多用户MIMO系统。该方案利用了慢衰落信道中每个配置单天线的用户连续两次从码本中选择的量化信道矢量的相关性来对码本进行有效编码,从而减少了需反馈的统计平均比特数,节省了信道带宽。在满足一定条件的慢衰落信道中,在需要反馈的比特数相同的情况下,新方案比应用基于量化的天线合并算法每用户多天线的多用户MIMO系统在信道总容量方面具有更好的性能,且该编码对应于二叉树形结构的叶子,故基站可自动识别其编码,可用于实际的通信系统之中。

A method of variable length coding is proposed in this paper, which is employed in multiuser limited feedback MIMO system using zero- forcing preeoding in slow fading channels. Utilizing the correlation of the quantized channel vectors chosen from the codebook successively twice by each user equipped with one antenna, this method encodes all the quantized channel vectors from the codebook. Thus, it considerably reduces the average feedback bits needed and saves the bandwidth of the feedback channel. In certain slow fading channels,this scheme outperforms multi- user MIMO system with quantization- based antenna combining algorithm in terms of sum capacity, as long as the same average feedback bits are needed. Moreover, corresponding to the leaves of the binary trees the codes can be identified by the base station and used in practical communication systems.