光通信系统中基于BIBD对QC-LDPC码的研究

Study on QC-LDPC Codes Based on BIBD for Optical Communication Systems

摘要:

基于平衡不完全区组设计（BIBD），深入分析与研究了准循环低密度奇偶校验（QC-LDPC）码的一种新颖构造方法，并通过该构造方法构造了3种同码率不同码长的QC-LDPC码，通过对这3种QC-LDPC码的仿真分析表明，同码率下，码长越长性能越好。同时在BER＝10^-6时码率均为93.7% 的情况下，所构造的BIBD-QC-LDPC（53925056）码的净编码增益（NCG）比已广泛应用于光通信系统中的经典RS（255,239）码和ITU-T G．975．1中的LDPC（32640,30592）码分别提高了约213dB和141dB。因而其纠错性能更强，更适用于高速长距离光通信系统。该新颖构造方法简单灵活且编译码更容易实现。

Abstract:

Based on the Balanced Incomplete Block Design (BIBD), a novel construction method of Quasi-Cyclic Low-Density Parity-Check(QC-LDPC) codes is further analyzed and researched. And the three QC-LDPC codes with the same code rate and different code length are constructed by applying the proposed method. The simulation analysis shows that under the condition of the same code rate, the QC-LDPC code with the longer code length has better error correction performance. Simultaneously, at the condition of the bit error rate (BER) of 10^-6 and the same code rate of 93.7%, the net coding gain (NCG) of the constructed BIBD-QC-LDPC(5392,5056) code is respectively 2.13dB and 1.41dB higher than that of the classic RS(255,239) code widely used in optical communication systems and that of the LDPC(32640,30592) code in ITU-T G.975.1. Therefore, the BIBD-QC-LDPC(5392,5056) code has much superior error correction performance and is better suitable for high speed long haul optical communication systems.