Performance evaluation and parameter optimization of wavelength division multiplexing networks with adaptive importance sampling techniques

In this paper new adaptive importance sampling techniques are applied to the performance evaluation and parameter optimization of wavelength division multiplexing (WDM) network impaired by crosstalk in an optical cross-connect. Worst-case analysis is carried out including all the beat noise terms originated by in-band crosstalk. Both input signal hypotheses are considered. The accurate bit-error-rate estimates, which are obtained in short run-times, indicate that the influence of crosstalk is much lower than that predicted by previous analyses. This finding has a strong impact on the design of WDM networks. Besides, a method is used to optimize the detection threshold, which turns out to improve the system performance significantly. The presented techniques also allow us to determine the power penalty due to the introduction of additional WDM channels.