Soft-Input Soft-Output Non-Coherent Detection for Differential Space-Time Block Code Systems

A soft-input soft-output non-coherent detection algorithm is proposed for multi-antenna systems, where differential space-time block code is employed. The proposed algorithm aims to calculate a posteriori probabilities of the information bits by means of forward and backward message passing of the BCJR approach. The proposed algorithm can exploit the soft information effectively with the aid of the bidirectional message passing mechanism. In addition, the proposed algorithm can be exploited in conjunction with channel decoding to obtain an effective iterative detection and decoding approach. In view of low implementation complexity, the application of the proposed scheme is instantiated with the ultra-wideband impulse radio (UWB-IR) systems. Simulations show that the proposed approaches improve detection performance for UWB-IR systems.