Soft output decoding algorithm for spacetime block codes over unknown time varying channels with intersymbol interference

In this paper we describe and evaluate a soft input soft output (SlSO) decoding algorithm for space time block codes (STBC's) over unknown, time-varying intersymbol interference (ISI) channels. We consider a per-survivor processing (PSP) approach with Kalman filter tracking and forward-backward processing. We also provide a space-time coding example, which employs a serially concatenated recursive systematic code (RSC) and a STBC scheme, with interleaving, and a soft decision iterative (turbo) receiver for unknown time-varying ISI channels.