The Benefit of Split Nonlinearity Compensation for Single-Channel Optical Fiber Communications

In this letter, we analyze the benefit of digital compensation of fiber nonlinearity, where the digital signal processing is divided between the transmitter and the receiver. The application of the Gaussian noise model indicates that, where there are two or more spans, it is always beneficial to split the nonlinearity compensation. The theory is verified via numerical simulations, investigating the transmission of a single-channel 50-GBd polarization division multiplexed 4- and 256-
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quadrature amplitude modulation signals over 100-km standard single-mode fiber spans, using lumped amplification. It is shown, theoretically, that the signal-to-noise ratio gain for long distances and high bandwidth transmission is 1.5 dB versus transmitter-or receiver-based nonlinearity compensation.