中文摘要：

针对Polar码性能收敛速度慢和低密度生成矩阵（LDGM）码存在高错误平层的问题，在保持这两种码的低编码复杂度和低译码复杂度不变的前提下，提出了一种将Po-1ar码作为外码，LDGM码作为内码的串行级联Polar-LDGM编译码设计方案，使之可以接近二进制输入加性高斯白噪声（BI．AWGN）信道香农容量。通过对Polar-LDGM编译码系统模型的仿真，得到了近优的内外码编码速率组合与近优的内码码重。仿真结果表明，上述方案在保证低复杂度的前提下，可以获得良好的比特错误率（BER）性能，并可以有效地降低LDGM码错误平层。

英文摘要：

Considering the problems of low convergence performance of Polar codes and high error floor of low density generator matrix （LDGM） codes, a serially-concatenated Polar-LDGM Code, which regards polar codes as external codes and LDGM codes as inner codes, was proposed on the premise of keeping the low encoding and decoding complexity of the both codes to approach the Shannon capacity of binary-input additive white Gaussian noise （ BI- AWGN） channels. By the simulations for the proposed encoding and decoding system, the near-optimal combina- tion of the inner coding rate and the outer coding rate and the near-optimal column weight of inner codes were ob- tained. The simulation results showed that the proposed scheme achieved a good bit error rate （BER） performance without the high error problem while keeping the low complexity.