A New Irregular Modulation Technique for Turbo-BLAST Systems

A new adaptive irregular modulation technique is proposed for Turbo iterative detected multi-antenna system with different bit mapping schemes or (and) modulation schemes used in different transmit antennas. The modulation scheme and the bit mapping scheme can be adaptively chosen according to the time varying channel quality to improve the channel throughput. When combining the proposed approach and the irregular modulation scheme, it can provide more flexible adaptation to the current channel quality. Simulation results show that using this adaptive technique, the system can converge earlier without changing the system throughput; meanwhile, system using this adaptive method can have higher system throughput compared with conventional adaptive method.