On XPM Mitigation in WDM Fiber-Optic Systems

The impact and possible mitigation of interchannel nonlinearity is investigated in single-polarization wavelength-division multiplexing systems by evaluating, both analytically and by simulation, the achievable information rate for a Gaussian-modulated channel surrounded by Gaussian- or constant-envelope-modulated channels. Different number of channels, link configurations, and mitigation strategies are considered. It turns out that a Kalman equalizer can be effective in the ideal case of distributed amplification but fails for practical systems with long spans and lumped amplification.