Postdetection diversity receiver for DAPSK signal over the Rayleigh and Rician fading channel

A new postdetection maximal ratio combining (MRC) and weighted maximal ratio combining (WMRC) diversity receivers for (N, M) differential amplitude phase shift keying (DAPSK) signal are proposed. In the MRC receiver, decision at each branch is made by the minimum distance criterion. The performance of the MRC receiver is analyzed in terms of the union bound for the bit error probability. The WMRC receiver assigns weighting factors to the decision variable at each diversity branch according to the relative distance from the optimum decision boundary. From the results, performance of the WMRC is found to be better than that of the MRC and equal gain combining (EGC) receiver on both the Rayleigh and Rician fading channel. It is also found that the performance improvement of the WMRC over the MRC increases as the number of the diversity branches increases.