Iterative decoding of space-time trellis coding under unknown fading channels

Differential space-time block coding provides an efficient decoding technique under unknown fading channels. However, the difficulties regarding blind decoding schemes for space-time trellis coding (STTC) remain unsolved. In this article, we propose to apply noncoherent BCJR algorithm to serial concatenated STTC systems, where an average or integration operation is employed to recover the deterioration caused by channel phase and amplitude. Two types of decoding algorithms are developed, referred to as noncoherent (without knowledge of channel phase) and nonCSI (without knowledge of channel state information (CSI)). The efficiency of our proposed schemes is validated and compared via simulations.