基于多级编码调制的星座几何成形和重传技术  

Geometric Shaping and Retransmission Method for Multi-level Coded Modulation

作　　者：丁凡[1] 姜明[1] 王易 徐秋实 王强 DING Fan;JIANG Ming;WANG Yi;XU Qiushi;WANG Qiang(Southeast University,Nanjing 210096,China;China Information Consulting&Designing Institute Co.,Ltd.,Nanjing 210018,China)

机构地区：[1]东南大学,江苏南京210096 [2]中通服咨询设计研究院,江苏南京210018

出　　处：《移动通信》2025年第2期26-30,50,共6页Mobile Communications

基　　金：国家自然科学基金资助项目“面向6G的中短码长弹性编码理论与方法”(62331002)。

摘　　要：未来6G通信系统需要达到更高的峰值速率和频谱效率。由于在低密度奇偶校验码的解码算法上很难实现重大突破,相比于5G通信网络若要实现1~2个数量级的吞吐量提升,物理层比特交织编码调制系统的解调和解码的高效硬件实现是亟待解决的问题。多级编码调制是一种能够降低解调和解码实现复杂度的有效方案,其中部分调制比特可以采用分层解调,并只用经典低复杂度的代数码译码或者不进行译码。提出了一种基于高频谱效率多级编码调制的高阶星座几何成形和重传技术。为了优化几何成形的星座点,提出一种基于自编码结构的深度学习方法,通过并联编码器和串联解码器组成的自编码器,学习多级编码调制特性,并优化几何成形。相比于常规方形星座,自编码几何成形星座有约0.2 dB性能增益,同时只需原编码调制方案不到50%的编码长度,有效降低了解码硬件实现复杂度。还研究了基于Chase合并的重传方案,在重传时使用比特旋转的自编码几何成形星座图,能够有效提高传输性能。The future 6G system needs to achieve higher peak rate and spectral efficiency.Due to the difficulty in realizing a major technological breakthrough in the decoding algorithm of low-density parity-check(LDPC)codes,the data throughput improvement of 1~2 orders of magnitude compared to current 5G networks poses significant challenges,where the efficient hardware implementation of demodulation and decoding of the physical layer bit-interleaved coded modulation(BICM)system is an urgent problem to be solved.The multilevel coded(MLC)scheme is a promising approach that effectively reduces the implementation complexity,where partial modulated bits can be processed with hierarchical demodulation and low-complexity hard-decision decoding of classical algebraic codes or even without decoding.To this end,a high-order constellation design of geometric shaping(GS)and retransmission technology is proposed based on the MLC with high spectral efficiency.In order to optimize the GS of constellation,a deep learning based on the autoencoder structure is proposed,where the autoencoder,consisting of the parallel encoders and serial decoders,learns the characteristics of MLC and optimizes the GS.Compared with conventional square constellation,the autoencoder GS constellation has a performance gain of almost 0.2 dB,and only less than 50%of the encoding length for the original coding modulation scheme is required,thereby effectively reducing the complexity of decoding hardware implementation.Furthermore,this paper also investigates the retransmission scheme based on Chase combining(CC),which uses the autoencoder GS constellation with bit rotation during retransmission to effectively improve transmission performance.

关 键 词：几何成形 多级编码调制 自编码器 

分 类 号：TN929.5[电子电信—通信与信息系统]