IRA码在远程光纤通信系统中的应用

Irregular repeat accumulate codes for long-haul optical fiber communication

前向纠错码 (FEC)是光纤通信系统提高系统容量的一项关键技术。在远程光纤信道中 ,放大器自发辐射 (ASE)噪声是主要噪声源。FEC在光纤通信系统应用时 ,通常用高斯分布估计ASE噪声。本文提出用x平方律分布模型代替高斯信道模型 ,并将高性能的不规则重复累积 (IRA)码应用于远程光纤通信系统。仿真结果表明 :IRA码的性能优于RS码、Turbo码等 ,而且x平方律信道的性能优于高斯信道。

Forward error correction(FEC)codes have become a practical solution in improving system capacity of fiber communication.In the optical-fiber channel,amplified spontaneous emission(ASE) noise in the optical amplifier is the major source of noise.Gaussian approximation of ASE noise is widely used in the study of optical-fiber communication systems.In this paper,we use Chi-square distribution instead of Gaussian distribution as the model of ASE noise.Irregular repeat accumulate(IRA)codes have high performance very closed to Shannon limit.We apply IRA codes to the long haul fiber communication system.Simulation results show the performance of IRA outperforms that of RS codes and Turbo codes in fiber communication system.The decoder based on Chi-square also has better performance than that of the decoder based on Gaussian noise assumptions.