Optical communication systems (OCSs) mainly represent the backbone of modern long-haul communication networks because of low loss transmission over long distances and ultra-high capacity. However high data-rate transmission through optical fiber suffers from deterioration due to nonlinear impairments, such as four-wave mixing (FWM) in particular. At high launch power levels, which are required for the long-haul transmission over hundreds of km, these nonlinear effects become more severe which imposes a challenge to achieve satisfactory transmission performance. In this paper, a theoretical model for the FWM effects and its mitigation is presented and validated through simulation results. Moreover, two other nonlinear effects, polarization mode dispersion and nonlinear dispersion variations are also investigated for various values of launch power level. The transmission performance of the proposed OCS model is evaluated on the basis of bit error rate, optical signal-to-noise ratio and quality factor using different transmission channel parameters such as effective area, nonlinear refractive index, nonlinear dispersion, and linear dispersion.

由于长距离的低损耗传输和超高容量，光通信系统（OCS）主要代表了现代远程通信网络的骨干。但是，通过光纤的高数据速率传输会由于非线性缺陷（例如四波混频（FWM））而恶化。在数百公里的远距离传输所需要的高发射功率水平下，这些非线性效应变得更加严重，这对实现令人满意的传输性能提出了挑战。本文提出了FWM效应及其缓解的理论模型，并通过仿真结果进行了验证。此外，还有另外两个非线性效应 还针对发射功率电平的各种值研究了偏振模色散和非线性色散变化。使用不同的传输通道参数（例如有效面积，非线性折射率，非线性色散和线性色散），基于误码率，光信噪比和品质因数来评估所提出的OCS模型的传输性能。