Multiple Symbol Detection for Differential Unitary Space-Time Modulation Using a M-BID Algorithm

In order to reduce the computation complexity in flops for multiple symbol differential unitary space-time modulation systems, this paper presents a new algorithm called M-BID algorithm. This algorithm uses the BID to search the best part branches firstly, and then computes their decision metrics to each retained node in the M algorithm that differs from the M algorithm which need compute decision metrics for all paths. So the M-BID algorithm can reduce the computation numbers of Frobenius norm greatly, which can impel the complexity in flops decreased. Simulation results show that the computation numbers of the M algorithm keep unchanging with the signal-noise-ratio increasing, but the M-BID algorithm decreases very quickly, and the average numbers of each block in the M-BID algorithm are lower very much than the M algorithm, this is in the computation complexity aspect. In the performance way, the M-BID algorithm is close to the M algorithm. So the M-BID algorithm has good performance with lower complexity.