Iterative near-optimal decoder for STBC from CIOD over time-varying channel

Space-time block code from coordinate interleaved orthogonal design (STBC-CIOD) is considered as an effective transmit diversity scheme for achieving full-rate and full-diversity with low decoding complexity. The simple maximum likelihood (SML) decoder for STBC-CIOD is known to be an optimal decoder in time-invariant channel. However, the performance of the SML decoder is inevitably degraded when the channel becomes time-varying. In this paper, we propose a computationally efficient near-optimal decoding algorithm for STBC-CIOD to mitigate the interference caused by time-selectivity of the channel. The algorithm establishes partial candidate sequences and iteratively finds the best sequence among the sequences through metric comparison. Simulation results show that the proposed decoder outperforms the SML decoder and achieves near-optimal performance with significantly low complexity.