基于低密度奇偶校验码的超强前向纠错码设计

光纤中的传输效应(如色散、偏振模色散(PMD)和非线性效应等)会严重影响传输速率和传输距离的进一步提高。因而有必要研究性能更好的新超强前向纠错(Super-FEC) 码型,使其在光通信系统中获得更高的编码增益和更好的纠错性能。简单介绍了低密度奇偶校验(LDPC)码, 然后提出光通信系统中一种基于LDPC码的超强前向纠错(Super-FEC)码型,构造了冗余度为6.68%的新颖LDPC(3969,3720)码, 并给出超强FEC码型的仿真结果。通过与RS(255,239)及BCH(3860,3824)+BCH(2040,1930)进行对比分析, 还分析与探讨了新LDPC码型的编译码电路的设计实现问题。通过理论分析与仿真结果表明这种超强 FEC 码型具有良好的性能, 可以节省硬件开销, 比较适用于光通信系统中, 可作为超强 FEC 码型的候选码。

Design of a Super-FEC Code Based on Low Density Parity Check Code in Optical Communication System

The effect of optical fiber transmission (dispersion, PMD and nonlinear effects, etc.) will seriously affect the transmission speed and further improvement of the distance. Consequently, it is essential to work out new super forward error correction (Super-FEC) codes with better performance so that higher coding gain and better error correction performance will be received. This paper briefly introduced the low density parity check (LDPC) codes, and then proposed a SFEC code based on LDPC code in optical communication system. The novel LDPC(3969,3720) code with 6.68% redundanc was constructed., and the simulation result of the FEC code was showed up. It not only compared with those of the RS(255,239)code and BCH(3860,3824)+BCH(2040,1930) code, but also analyzed and discussed the problem that the encoding and decoding of LDPC circuit design and implementation. Through the theoretical analysis and simulation results show that this super-FEC code has a good performance,and can save hardware costs so that it is suitable in optical communication system and can be used as a super-FEC candidate code.