面向光传输网的Polar-LDGM码方案

针对光传输网（OTN）对纠错码低实现复杂度、逼近香农限性能和无错误平层的要求，提出了一种基于Polar码和低密度生成矩阵（LDGM）码的低复杂度高速级联码方案。首先针对级联模型阐述了Polar-LDGM码的编码设计方案，并分析了编码复杂度。然后基于两种码的结构特点，给出了基于置信传播（BP）算法的级联解码算法。通过合理利用高斯逼近（GA）法推导解码算法中传递消息的均值，能够准确地预测出Polar-LDGM码的理论错误概率。仿真结果表明，Polar-LDGM码满足在OTN中应用的要求。

Design of Polar-LDGM Codes for Optical Transport Network

In order to satisfy the requirements of low complexity, capacity approaching performance and no error floor for the error correcting codes used in the optical transport network (OTN), a high-rate concatenated codes based on polar codes and low density generator matrix (LDGM) is proposed. The polar-LDGM coding scheme for the concatenated model is first described and the encoding complexity of the scheme is analyzed. And then, the concatenated decoding algorithm based on belief propagation (BP) algorithm is detailed according to the decoding structure of both codes. By reasonably using Gaussian approximation (GA) method, we derive the mean of message passed in the decoding structure, which results in the accurate prediction of the error probability for the Polar-LDGM codes. Simulation results show that the proposed scheme achieves the demands of the optical transport network (OTN).