Multiple-symbol differential detection of double differential MPSK by using the Viterbi algorithm

In this paper, a Multiple-symbol differential detection (MSDD) receiver by using the Viterbi algorithm for double differential phase-shift keying (DDPSK) signals is presented. The structure of branch metric is also derived. It is shown that the proposed receiver has lower computational complexity, since it reduces the number of trellis paths searched in performing maximum likelihood sequence estimation (MLSE). Computer simulations demonstrate that the performance of the proposed receiver can reach the lower bound on the error probability of MSDD with very lower complexity.