Fundamental limitations of digital back-propagation in coherent transmission systems

Nonlinear compensation techniques using digital back-propagation have been recently proposed. Although a significant effort has been directed towards minimization of the computational load of this method, little work has been reported in terms of the ultimate benefits that can be derived from this approach. Here, we discuss the nonlinear performance bounds imposed by intra-/inter-channel nonlinearities and non-deterministic signal-noise interactions, and investigate their impact on the performance of coherent-detection based optical transmission systems employing high-level modulation formats and digital back-propagation.