Third-order Sparse Volterra Equalizer based Nonlinear Suppression Method for High-Capacity 64/256QAM WDM PDM CO-GFDM system

We proposed a 3rd-order sparse Volterra equalizer (SVE) based nonlinear suppressing method for WDM PDM CO-GFDM system. Compared with the traditional Volterra equalizer, SVE significantly reduces complexity while achieving almost the same optimization performance. Simulation results demonstrate that this method can effectively suppress the nonlinear effects in 64/256-QAM WDM PDM CO-GFDM system, thereby enabling a medium-distance high-capacity coherent optical transmission system with a Terabit-level net bit rate at the BER of HD-FEC.