Analysis of Minimum Decoding Complexity Quasi-Orthogonal Space-Time Block Code for 6 Transmit Antennas

Previous work on quasi-orthogonal space-time block code (QO-STBC) has been designed to achieve full rate and full diversity gain for four antennas. However this conventional QO-STBC scheme decoding is complex. For achieving more diversity gains, an extended QO-STBC scheme is provided to achieve full diversity with one rate for six antennas. Furthermore, by transforming the detection matrix to an orthogonal one, this novel scheme can achieve a simple linear decoding. Therefore it proposes an extended minimum decoding complexity QO-STBC (MDC-QO-STBC) for six antennas. Due to eliminate the interference from different equivalent channels, the novel extended MDC-QO-STBC scheme improves transmission reliability and linear decoding complex compared with the conventional QO-STBC scheme. At last extensive simulation results are presented to prove the theoretical analysis.