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.