Bit error rate estimation of DPSK modulated fiber-optic systems using multicanonical Monte-Carlo simulations

We report the first implementation of the multicanonical Monte-Carlo simulation method to phase modulated optical communications systems. The method is used to validate a theoretical approach for estimating bit error rates in DPSK systems. The simulations validate the closed form model predictions that for a wide range of parameters of interest, the phase noise, which determines the BER, can be approximated as Gaussian.