Nonlinear phase noise in phase-modulated WDM fiber-optic communications

Phase-noise statistics in nonlinear dispersive fiber-optic links are examined. The bit-error rate (BER) in phase-modulated transmission is extracted from the phase-noise probability distribution. For differential phase-shift keying systems, we find that the noise distribution, as well as the overall BER, agree well with the Gaussian approximation for a wide range of system parameters. The analysis is validated using Monte Carlo simulations of wavelength-division-multiplexed systems.