基于星座成形的高谱效编码调制方案

针对规则正交幅度调制星座在高阶调制系统中产生的成形损失问题，研究比较了概率成形和几何成形方案。通过平均互信息的分析，从理论上表明概率成形可以获得更好的成形增益。在相同谱效、相同误帧率的条件下，概率成形相比几何成形需要的信噪比更低。编码方面，相比二元低密度奇偶校验(low-density parity-check，LDPC)码，多元LDPC码可以获得编码增益。仿真结果表明，基于星座成形的高谱效编码调制方案是有效的，适用于未来移动通信系统超高可靠性的要求。

High spectral efficient coded modulation scheme based on constellation shaping

Aiming at the problem of shaping loss of regular quadrature amplitude modulation constellation in high-order modulation system, probabilistic shaping and geometric shaping schemes are studied and compared. Through the analysis of the average mutual information, it is shown theoretically that probabilistic shaping can obtain better shaping gain. Under the same spectral efficiency and frame error rate, the signal to noise ratio (SNR) of probabilistic shaping is lower than that of geometric shaping. In terms of coding, compared with binary low-density parity-check (LDPC) codes, nonbinary LDPC codes can obtain coding gain. Simulation results show that the high spectral efficient coded modulation scheme based on constellation shaping is effective and suitable for the ultra-high reliability requirements of future mobile communication systems.