A novel full-rate full-diversity STBC with application to WiMAX
We 1 present a novel full-rate full-diversity orthogonal space-time block code for QPSK modulation and 4 transmit antennas based on quaternionic algebra. The code does not result in constellation expansion unlike other fullrate full-diversity codes in the literature. The quaternionic structure of the code is exploited to reduce the complexity of maximum likelihood (ML) coherent decoding from a size- 256 search to a size-16 search. Furthermore, we show how to modify this low-complexity coherent ML decoding rule to derive a non-coherent differential ML decoding rule. Finally, extensive simulation results in a WiMAX 802.16 broadband wireless access environment demonstrate that the proposed code increases the cell coverage area by 1.5 and 2.6 folds compared to single-antenna transmission at 10 -3 bit error rate when combined with 1 and 2 receive antenna(s), respectively.
