A hybrid ARQ scheme with constellation rearrangement and power adjustment

There are many parameters to be selected in the hybrid-ARQ (automatic repeat request) systems, e.g., transmission power, modulation format, bit-to-symbol mapping in the constellation and so on. In the retransmissions, different parameters or the combination of them could be selected to improve the performance. This paper proposes a new HARQ scheme, where the constellation mapping and the transmission power in the retransmissions differ with the new transmission. Compared to the conventional HARQ schemes, the proposed scheme can increase the throughput and decrease the average number of retransmissions and the power consumption.