光传输系统中一种新颖的SCG-LDPC码译码算法分析

Analysis on a Novel Decoding Algorithm of SCG-LDPC Codes for Optical Transmission Systems

摘要:

依据SCG-LDPC码的结构特点提出了一种高效的分层可靠置信传播(HRBP)译码算法, 该算法结合分层迭代与可靠度判决测量有效降低后续迭代过程中的变量节点数, 同时加快了收敛速度。针对适用于光传输系统的SCG-LDPC(3969, 3720)码进行仿真, 仿真结果表明HRBP算法与传统的BP算法相比, 在保证性能的同时大大降低了运算量, 在阈值为15时, HRBP译码算法误码率性能与BP译码算法相当, 但是后续迭代的变量节点数在高信噪比下相比BP译码算法减少约69%, 当阈值进一步增大时, HRBP算法将逐步退化为分层置信传播(Layered-BP)译码算法。

Abstract:

According to the structural characteristics of SCG-LDPC codes, an effective Hierarchical Reliable Belief Propagation (HRBP) decoding algorithm is proposed. The novel decoding algorithm combines the layered iteration with the reliability judgment and can greatly reduce the number of the variable node involved in the subsequent iteration process and accelerate the convergence rate. The simulation result of SCG-LDPC (3969, 3720) code for optical transmission systems shows that the novel HRBP decoding algorithm, compared with the traditional BP algorithm, can highly reduce the computing amount at the condition of ensuring the performance. The bit error rate (BER) performance of the HRBP algorithm is similar to that of the BP algorithm at the threshold value of 15, but in the subsequent iteration process, the number of the variable nodes for the HRBP algorithm, compared with the BP algorithm, can reduce about 69% at the high signal noise ratio (SNR). When the threshold value is further increased, the HRBP algorithm will gradually degenerate into the Layered-BP algorithm.