A new soft-decision adaptive decoder for space-time trellis code

Soft-decision adaptive decoding of space-time trellis code (STTC) used in TDMA communication links is considered. To fully utilize preambles of successive downlink slots, bi-directional processing (BD-P) is proposed, which performs forward and backward adaptive decoding with two-step LMS (TSLMS) based channel tracking. Computer simulation shows that the proposed decoder can improve system performance distinctly on slowly or moderately fast time-varying channels. Besides, the computational complexity of the proposed BD-TSLMS decoder is modest.