结合波束成形MMSE-THP算法研究

摘要

For multiple input multiple output(MIMO) downlink systems, Tomlinson-Harashima preceding (THP) algorithm is a pre-equalization technique that is used to eliminate the multi-user interferences(MUI). However, THP suffers several sum-capacity losses. This paper proposed a method of THP based minimum mean square error ( MMSE) criterion ( MMSE-THP) combined with receive beamforming to maximize the system sum-capacity. It designed the system scheme under perfect channel state information(CSI) and imperfect channel state information. Both theoretical analysis and simulation results show that the scheme has higher sum-capacity than the traditional MMSE-THP at lower SNR, and improves the bit error ratio performance obviously at higher SNR.%Tomlinson-Harashima预编码(THP)算法是一种多输入多输出下行链路系统中有效去除用户间干扰(MUI)的预均衡技术,但存在系统容量损失的问题.为此,提出通过在接收端进行波束成形使得MMSE-THP系统和容量最大化,设计了信道状态信息完美和不完美两种情况下结合波束成形的系统方案.理论分析与仿真结果均表明,与传统MMSE-THP算法相比较,该方案在低信噪比时能提高系统和容量,并对高信噪比时系统的误码性能有明显改善.