大规模MIMO中继系统基于LoS的等增益传输方案

LoS-based equal gain transmission scheme for massive MIMO relaying systems

在中继分布大规模多输入多输出天线阵列情况下,对莱斯衰落环境中的双向放大转发多对中继系统进行了探讨。为了能有效减轻信道估计负担、提高频谱利用率,首先提出了一个只基于视距(line-of-sight,LoS)分量的线性传输方案。该方案采用实现复杂度低的等增益合并与等增益传输相结合的中继处理。然后分别推导了该方案无功率缩放和有功率缩放情况下的渐近可达速率闭式表达式。与传统的基于全部信道状态信息的线性传输方案比较,该方案更宜在LoS分量较强的情况下得到应用。

A multi-pair and two-way relaying system with amplify-and-forward in Ricean fading environments is considered,where the relay station is equipped with a large-scale multiple input multiple output(MIMO)antenna array.In order to efficiently reduce overhead for channel estimation and improve the spectral efficiency,firstly a linear transmission scheme only based on the line-of-sight(LoS)component is proposed.This scheme employs such a relaying process with low implement complexity that combines equal gain combining with equal gain transmission.For the proposed scheme,closed-form expressions of asymptotically achievable rate with and without power scaling are derived.By comparing with the corresponding traditional linear transmission scheme based on perfect channel state information,this scheme is more suitable for application when the LOS component is relatively strong.