快衰落瑞利信道下分布式线性卷积空时码的分集增益

Diversity Gain of Distributed Linear Convolutive Space-time Code on Fast Fading Rayleigh Channels

在无线中继网络中,中继节点间的随机传输延迟将导致显著的性能下降。因此,针对慢衰落瑞利信道提出可容忍随机时延的分布式线性卷积空时码(DLC-STC),但该类空时码在快衰落信道下的分集性能尚未明确。该文从理论上证明了DLC-STC在快衰落瑞利信道下的分集增益。分析表明,DLC-STC虽然最初是在慢衰落信道下被提出的,但它在快衰落瑞利信道下通过利用最大似然(ML)接收机,仍可获得满异步协作分集增益,仿真结果验证了该理论分析,仿真结果同时表明:在快衰落瑞利信道下,DLC-STC采用MMSE-DFE接收机能够获得与ML接收机相同的分集增益。

In wireless relay networks,random transmission delays among relay nodes will lead to substantial performance degradation,for which delay-tolerant Distributed Linear Convolutive Space-Time Code(DLCSTC)is proposed.However,its diversity gain on fast fading Rayleigh channels is not clear.This paper analyzes the diversity gain of the DLC-STC on fast fading Rayleigh channels.It is shown that the DLC-STC can achieve full asynchronous cooperative diversity order with Maximum Likelihood(ML)receivers on fast fading Rayleigh channels,although it is originally proposed for slow fading channels.The numerical results verify the theoretical analysis and show that MMSE-DFE receivers,can collect the same diversity order as ML receivers on fast fading Rayleigh channels.