Low complexity receiver design for MIMO bit-interleaved coded modulation

This paper considers multiple-input multiple-output (MIMO) systems with bit-interleaved coded modulation (BICM). Two receiver structures are considered, one based on zero-forcing, the other on minimum mean square error (MMSE). An approximate log-likelihood (ALL) decoding approach is examined in each case, for PSK and QAM. The resulting receivers are significantly lower complexity compared to the maximum likelihood (ML) receiver. We expand on previous results which showed that for the ZF-ALL receiver the performance gap, compared to ML, reduces when either the number of receive antennas or the modulation order is increased. We demonstrate that the ALL metric with BICM counteracts any noise enhancement from the linear receivers. We also show that the linear BICM schemes outperform the corresponding BLAST approaches.