Optimization of the control of dispersion and nonlinear effects in WDM communication systems

A method to compensate linear and nonlinear effects in a high capacity fiber-optic (FO) communication systems, called Distance Folded Digital Backward Propagation (DF or DF-DBP), is implemented. It is a variant of the Digital Backward Propagation method (DBP) and it has the advantage of reducing the computational cost with respect to DBP. The DF consists in applying the Split Step Fourier Method (SSFM) to solve the nonlinear Schrödinger equation (NLSE) conversely, but using fewer steps than in the DBP. It is evaluated a DF implementation for an 8-channel division multiplexed wavelength (WDM) system, with a transmission rate of 128 Gb/s per channel, a 16-QAM modulation format, and a link of 1200 km length. The system performance is compared in three cases: when electronic compensation is used by DF and by DBP, and when optical dispersion compensation is employed through DCF fiber.