Analytical Performance Evaluation of Optical DQPSK Systems With Postdetection Filtering

A novel analytical method for evaluating the performance of optical transmission systems using differential quadrature phase-shift keying is presented. It is shown that the bit-error probability (BEP) can be evaluated through the statistics of the received signal phase difference directly filtered by the postdetection filter. The accuracy of the method is checked against the results obtained through a simulator based on the multicanonical Monte Carlo algorithm. Some results in terms of BEP evaluation and nonlinear phase noise issues are also provided.