中文摘要：

研究采用低密度奇偶校验（LDPC）码和64QAM调制的Chase合并型混合ARQ（HARQ）系统.提出一种适用于任意重传次数的星座图重排（CoRe）搜索算法,根据该算法搜索得到采用星座图重排的HARQ优化方案.仿真结果表明,所得优化方案能够有效地降低多次重传合并后比特间的可靠性差异,显著提高系统的误比特率（BER）性能和信息传输效率.

英文摘要：

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.