信道串扰对WDM光网络节点性能的影响

Influence of channel crosstalk on optical WDM networks

分别采用高斯法和自适应重要性采样 (IS)方法 ,建立了WDM网络节点的串扰分析模型 ,计算得出该节点误码率 (BER)随串扰变化曲线 .IS方法的关键在于选取合适的概率分布函数及参数 ,本文选取带参量的高斯分布模拟干扰信道的相位噪声 ,并用牛顿迭代法求取参量的值 .与高斯法相比 ,IS方法在串扰较大且串扰源不是很多的情况下 ,准确度更高 .采用此模型分析判决门限和消光比等因素对系统性能的影响 。

A model of optical cross connect nodes (OXC's) in WDM optical networks is made to analyze the impact of the channel crosstalk on the network transmission performance through Gaussian approximation (GA) and importance sampling (IS) method respectively, and the Bit error rate (BER) is calculated as a function of the crosstalk. Compared with GA, IS method is more accurate when the crosstalk level is high or the number of interferers is not very large. Finally the influence of the threshold and the extinction ratios on the system performance through IS method are studied, and the results coincide with the actual situation.