一种格约减辅助的协作多址接入方案

摘要

针对传统协作多址接入(CMA)系统可靠性不高的问题,提出了一种格约减(LR)辅助的协作多址接入方案(LR-CMA).首先将传统CMA系统中源端到目的端的信道等效成虚拟多输入多输出(MIMO)模型,然后在接收端用LR算法改善虚拟MIMO信道矩阵的正交性,减少信号之间的干扰,最后检测并恢复信号.通过计算机仿真将LR-CMA方案与传统CMA方案相比较,结果表明,2种方案的复杂度均随维度呈指数增长,但LR-CMA方案的误码率性能要优于传统CMA方案,接近复杂度很高的最大似然检测的误码率性能,在信噪比为30 dB时,其误码率差距超过14dB,并且LR-CMA方案在衰落信道下可以获得最优的分集增益和复用增益的均衡.%A new cooperative multiple access scheme is proposed to improve the reliability of traditional cooperative multiple access (CMA) system. The new scheme applies lattice reduction to cooperative multiple access (CMA) system. Firstly, the channel between source and destination is equated into a virtual model with multiple inputs and multiple outputs (MIMO). The signal is processed using the LR algorithm at the destination to improve the orthogonality of channel matrix, to reduce interference, and then to be detected. Comparisons with the traditional CMA system show that the complexity of both the algorithms increases as the index is increased, but the bit error rate of LR-CMA system is better than that of the traditional CMA, and that the LR-CMA system achieves the bit error rate (BER) of maximum likelihood detection, and the BER gap outstrips 14 dB at the SNR of 30 dB. It also can get optimal diversity- multiplexing tradeoff.