LTE中下行MU-MIMO的物理层技术分析

摘要

In LTE systems, the base station can choose single user MIMO and multi-user MIMO to adapt for user equipment spatial channel. Due to the amount of user increased year by year in LTE network with the commercial progress, operators are taking MU-MIMO techniques as a hot topic. The physical layer of downlink MU-MIMO in LTE is analyzed and the method with code-book feedback is designed. The 2 algorithms regarded as independent codebook precoding and joint zero forcing precoding are studied. The throughput is quantitative evaluated with link level simulation, and the results show that independent codebook precoding outperforms the joint zero forcing precoding algorithm in low SNR, while the joint zero forcing precoding algorithm can get better throughput performance in high SNR.%LTE基站可以针对终端的空间特性采用单用户MIMO（SU-MIMO）和多用户MIMO（MU-MIMO）技术。LTE网络的用户数随着商用化的进程逐年递增， MU-MIMO技术也成为运营商关注的热点。论文分析了LTE中下行MU-MI-MO的物理层技术，侧重设计了基于终端双码本反馈的方法，研究了独立码本预编码和联合迫零（ZF）预编码算法。通过计算机仿真比较了2种算法的吞吐率性能，结果表明低SNR时独立码本预编码优于联合ZF预编码，而高SNR时联合ZF预编码优于独立码本预编码。