According to an aspect of the present invention, there is provided an optical receiver in an optical transmission system that transmits an optical signal between an optical transmitter and an optical receiver connected via an optical fiber transmission path, the optical receiver including: a channel distribution estimation unit that estimates channel distribution information in a transmission direction based on the optical signal transmitted from the optical transmitter and a reference signal; and a non-linear compensation unit that performs non-linear compensation based on the channel distribution information estimated by the channel distribution estimation unit.

This application discloses a system, a communication apparatus, an optical module, a method, and an optical network. The system may include a communication apparatus and an optical module. The communication apparatus includes a control module and a service module. The optical module includes a storage unit and an optical transmitter unit. The storage unit may store nonlinear compensation information of a modulator in the optical transmitter unit. After the optical transmitter unit is directly connected to the service module, the control module may read the nonlinear compensation information from the storage unit, and configure a nonlinear compensation coefficient of the service module based on the nonlinear compensation information. The service module sends an electrical signal to the optical transmitter unit based on the configured nonlinear compensation coefficient. The modulator modulates an electrical signal obtained through nonlinear compensation into an optical signal.

A signal processing circuit includes a MIMO filter that performs polarization separation on a reception signal obtained by performing optical sampling reception on optical signals that are polarization multiplexed signals in parallel by using a plurality of local light beams using optical pulses, and a coefficient update unit that updates a coefficient of the MIMO filter based on periodicity based on a parallel number in the optical sampling reception.

An approach to isolate and characterize non-linear distortion attributable, at least in part, to an LPO (Linear Pluggable Optics) module is provided. A method includes receiving, at a linear pluggable optics (LPO) module, a signal from a host, converting, by the LPO module, the signal to an optical signal, isolating nonlinear distortion of the optical signal attributable, at least in part, to the LPO module, determining a portion of the nonlinear distortion that is memoryless, processing the signal to reduce an impact of the portion of the nonlinear distortion that is memoryless and generating a processed signal as a result of the processing, and determining a signal-to-distortion ratio (SDR) level of the processed signal based on a remaining portion of the nonlinear distortion.