莱斯衰落信道下协作通信的分集接收算法

Diversity Reception Algorithm for Cooperative Communications in Ricean Fading Channels

针对协作通信系统提出一种新型分集接收算法.首先在中继节点对发送信号做空时分组编码处理,当接收机接收到信号后进行快速傅里叶变换,再进行空时与频域的联合均衡运算,最后变换到时域硬判决,从而得到发送信号的估计结果.通过采用判决反馈与干扰抵消等联合处理方法,可获得中继的协作分集增益,降低了均衡过程的信噪比损失,提高了协作通信的传输质量.仿真结果表明,当信噪比为12 d B时,所提接收算法可将传统算法的误码率数量级从10-2降低到10-3.

Proposed in this paper is a new diversity receiving algorithm for cooperative communication systems.Firstly,space-time block coding is carried out by relay nodes to acquire a transmission signal. Secondly,spatial and frequency domain equalization is executed to the received signal by means of fast Fourier transform（ FFT） at the receiver. Then,the transmitted signal is estimated by hard decisions after inverse FFT operations. In this algorithm,a new scheme combining decision feedback and interference cancellation is adopted to acquire cooperative diversity gain of the relay and to reduce the signal-to-noise ratio（ SNR） loss in the process of equalization. Thus,transmission quality of cooperative communications is improved. Simulated results show that the proposed algorithm decreases the magnitude of bit error rate from original 10-2to 10-3when SNR is 12 d B.