双路径MIMO中继网络预编码盲干扰抑制

针对放大转发的双路径多进多出中继网络由于信道估计误差带来严重的剩余中继间干扰问题,提出了一种未知信道状态下基于行空间预编码的盲干扰抑制方案。新方案通过对发送信号进行交替行空间预编码,将期望接收信号和中继间干扰信号映射到不依赖信道状态信息的正交子空间,从而实现在未知信道状态信息下中继间干扰信号和中继噪声的盲干扰抑制,并从最大化信噪比角度给出最佳预编码设计。仿真结果表明,该方案可以有效地避免链路信道估计误差对中继间干扰抑制算法的影响,在系统性能和容量上优于传统基于信道状态信息的干扰抑制方案。

Blind interference suppression based on precoding in two-path MIMO relay networks

Aiming at the problem of residual inter-relay interference (IRI) caused by the channel estimation error in amplify-and-forward two-path MIMO relay networks, a blind interference suppression scheme based on row space precoding under unknown channel state information (CSI) is proposed. In the new scheme, the desired received signal and IRI signal are mapped to an orthogonal subspace independent of CSI by alternating the row space precoding of the transmitted signal, so that the blind interference suppression of the IRI signal and relay noise under unknown channel state information is realized, and the optimal precoding design is given from the angle of the maximizing signal-to-noise ratio. Simulation results show that the proposed scheme can effectively avoid the impact of the link channel estimation error on the IRI suppression algorithm, and is superior to the traditional CSI-based interference suppression scheme in system performance and capacity.