Method for Compensating for Nonlinear Distortions in Long-Haul Soliton Fiber-Optic Communication Lines

The paper addresses the problem of increasing the soliton fiber-optic line throughput limited by nonlinear effects in optical fiber. An approximate analytical description of the pulse dynamics in a passive communication line medium is developed, and a combined quasi-analytical method for compensating for nonlinear distortions at the receiver is proposed based on this description. The proposed approach enables a transition from a phase modulation format to an amplitude‒phase modulation format for a soliton signal, leading to an increase in the throughput of the systems in question due to constellation compression.