Postdetection diversity receiver for DAPSK signals on the Rayleigh and Rician-fading channel
Postdetection diversity receiver for DAPSK signals on the Rayleigh and Rician-fading channel
复制标题
瑞利和莱斯衰落信道上 DAPSK 信号的后检测分集接收机
DOI：
10.1109/25.950320
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发表时间：
2001
期刊：
影响因子：
--
通讯作者：
Sang Uk Lee
中科院分区：
文献类型：
--
作者：
Jong Youl Lee;Y. Chung;Sang Uk Lee
本文分析了瑞利衰落信道中（N，M）差分幅度相移键控的最佳判决边界。提出了一种检测后最大比合并（MRC）和加权最大比合并（WMRC）分集接收机。在瑞利衰落信道中，假设高信噪比和小归一化多普勒频率，得到了解析的最优判决边界。此外，它示出了外部最优决策边界是内部最优决策边界的逆。在建议的MRC接收机中，在每个分支的决定是基于最小距离准则。根据误比特概率的联合界，分析了MRC接收机的性能。所提出的WMRC接收机分配加权因子的决策变量在每个分支，基于最佳的决策边界。通过计算机仿真研究了WMRC的性能，并与MRC和等增益合并（EGC）的性能进行了比较。从结果中，MRC和WMRC的性能被发现优于EGC接收机的瑞利和Rician衰落信道上。研究还发现，随着分集分支数的增加，WMRC比MRC的性能改善更为明显。
In this paper, the optimum decision boundaries for (N, M) differential amplitude phase-shift keying on the Rayleigh-fading channel are analyzed. A postdetection maximal ratio combining (MRC) and weighted maximal ratio combining (WMRC) diversity receivers are proposed. In the Rayleigh-fading channel, assuming a high signal-to-noise ratio and a small normalized Doppler frequency, the analytical optimum decision boundaries are obtained. In addition, it is shown that an outer optimum decision boundary is the inverse of the inner optimum decision boundary. In the proposed MRC receiver, the decision at each branch is made based on the minimum distance criterion. The performance of the MRC receiver is analyzed, in terms of the union bound for bit error probability. The proposed WMRC receiver assigns weighting factors to the decision variable at each branch, based on the optimum decision boundaries. The performance of the WMRC is investigated through computer simulation and compared with those of MRC and equal gain combining (EGC). From the results, the performances of MRC and WMRC are found to be better than those of the EGC receiver on both the Rayleigh- and Rician-fading channels. It is also found that the performance improvement of WMRC over MRC is more pronounced as the number of diversity branches increases.