Accurate bit-error-ratio computation in nonlinear CRZ-OOK and CRZ-DPSK systems

An efficient, accurate method to compute the bit-error ratio in nonlinear chirped return-to-zero on-off keying (CRZ-OOK) and CRZ differential phase-shift-keying (DPSK) systems is presented. The accumulated optical noise at the receiver is modeled as additive nonwhite Gaussian noise. At high signal powers, phase adjustment is employed to maintain the validity of the Gaussian noise model. Results are presented for 10-Gb/s single-channel CRZ-OOK and CRZ-DPSK systems propagating over 8000 km.