Enhanced HARQ Employing Constellation Rearrangement Based on Bit Reliability

To investigate the low density parity check(LDPC) coded Chase combining hybrid ARQ(HARQ)system with 64QAM modulation,a searching algorithm is proposed for searching constellation rearrangement(CoRe) schemes with arbitrary retransmission number.Based on that,the enhanced HARQ strategies employing CoRe can be got by computer searching.Simulation results show that the proposed strategies can not only efficiently reduce the reliability variances of bits after soft combining but also significantly improve the BER performance and information transmission efficiency.