SIMULATION RESULTS AND DISCUSSION
Simulation results of various configurations over a sweep of signal
launch power have been given. Generally, the DBP algorithms are more
efficient for mitigating the effects of dispersion and nonlinearities
and thus demonstrate improved system performance compared to linear
dispersion compensation (LDC) methods. At high launch powers, the system
performance is critically limited by amplified spontaneous emission
(ASE) noise introduced by optical amplifiers. The peak performance is
observed at an optimum launch power, called the nonlinear threshold
point (NLT). The Q-factor curves in this work follow the NLT phenomenon
and align with the literature on the limitation of the DBP algorithm for
impairments mitigation. That is, the inability of DBP to account for
non-deterministic distortions such as ASE noise. As a result, it is
observed that at launch powers higher than the NLT, accumulated ASE
nonlinearities degrade the performance of DBP mitigation.