Transmitter-side Volterra Filtering for Increased Dispersion Tolerance in 56 Gbaud PAM-4 Systems

We experimentally demonstrate that a transmitter-side Volterra-based pre-distortion for 56 GBaud, PAM4 signal with receiver FFE outperforms receiver-side Volterra filtering and allows for 70% higher tolerance to chromatic-dispersion. Transmitter coefficients are computed without receiver feedback.