协作通信中一种高性能空时二维RAKE接收算法

A Space-Time Two Dimensional RAKE Receiving Algorithm in Asynchronous Cooperative Communications System with High Performance

将空时二维RAKE接收机理引入异步协作通信系统,提出了一种高性能RAKE接收算法.首先利用该接收机对发送信息进行粗估计,并判决获得估计结果,给出发射信号的各条多径分量;然后将多径分量依次从接收信号中抵消,以消除所接收信号中由多径衰落产生的符号间干扰,从而获得所期望的直达路径分量.对直达路径分量按照空时分组码的合并译码准则进行空时合并,获得空间分集增益.在此基础上通过判决反馈、循环迭代进一步降低误码率.仿真结果表明,当信噪比高于5,dB后,新算法可显著提高传统空时RAKE接收机的性能.

Space-time two dimensional RAKE receiver was introduced into the asynchronous and cooperative com-munication system,and a high-performance RAKE receiving algorithm was proposed. In this algorithm,the trans-mitting signals were estimated roughly by traditional space-time RAKE receiver,and each multipath component of transmitted signal was also estimated with decision feedback technology. Then,the multipath components were elimi-nated from the received signal,so the inter symbol interference of received signal was removed and the strongest path component was obtained correspondingly. Furthermore,the stronger paths were combined according to the decoding standards of space-time block code in order to obtain space diversity gain. The decision feedback architecture was investigated in which a new algorithm was performed iteratively in order to reduce the bit error rate. Simulation results show that performance of traditional RAKE receiver can be improved greatly when SNR is higher than 5dB.