偏振模色散对NRZ码和RZ码的40Gbit/s系统性能影响的仿真分析

偏振模色散(PMD)是进一步提高现有光纤通信系统单信道速率必须克服的障碍之一。本文基于已铺设光纤的典型值，针对偏振模色散对采用NRZ码和RZ码的40Gbit／s光纤通信系统的性能影响进行了分析与仿真。结果表明，考虑PMD的影响时，采用RZ码的系统并不一定比采用NRZ码的系统的传输性能好，而在占空比[0，1]之间存在一个最佳值，此时，高速系统受偏振模色散的影响最小。这对于研究、设计高速光纤通信系统时选择合适的码型和RZ码的占空比，具有重要的参考意义。

The Simulation Analysis of Impact of Polarization Mode Dispersion on Performance of 40Gbit/s System with NRZ and RZ Optical Signals

In order to further increase single channel rate, polarization mode dispersion (PMD) is one of obstacles that must be overcome in existing optical communication systems. In this paper, the analysis and simulation of the impact of PMD on performance of 40Gbit/s system with NRZ and RZ optical signals are carried out, based on the typical parameters of optical fiber systems which are laid. The results show that the transmission performance of the system using RZ optical signals is not always better than that of the system using NRZ optical signals when the effect of PMD on the system performance is considered, and the pulse length ratio has an optimum value between [0, 1], and here the effect of PMD on the performance of high-speed system is minimum. This is very important and provides referrence for choosing suitable code type and pulse length ratio when a high-speed optical fiber communication system is studied and designed.