Improving Transmission Performance In Differential Phase Shift Keyed Systems By Use Of Lumped Nonlinear Phase Shift Compensation

We show both analytically and numerically that significant improvement in transmission performance can be achieved in phase-shift-keying (PSK) systems by using lumped nonlinear phase shift compensation (NPSC). In a single-channel 10 Gbit/s dispersion-managed soliton based PSK transmission system, Q improvement of over 3 dB is realized by a single-stage NPSC at 6,000 km, and the improvement can be nearly doubled when a two-stage NPSC is used. We also show that inter-channel cross-phase-modulation (XPM) among dense wavelength-division-multiplexed (DWDM) channels slightly degrades the effectiveness of NPSC. A simple device that provides the NPSC in a 10-Gbit/s system is also presented.