Electronic compensation of cross-phase modulation

摘要

An optical signal (116) is modulated with a transmitted electrical signal comprising an information-bearing component (122) and a pilot tone (120) having a predetermined frequency. Transmission of the signal results in distortion, including nonlinear optical transmission impairments. A method of receiving the signal includes detecting the optical signal to produce a received electrical signal (X) comprising a distorted variant of the transmitted electrical signal. The pilot tone is extracted from the received electrical signal using a filtering operation (308) having a predetermined characteristic, and a compensation signal determined based upon the extracted pilot tone. The compensation signal is applied to the received electrical signal (X) to produce a compensated signal (Y) having reduced distortion. The predetermined characteristic of the filtering operation (308) is represented by one or more parameters having values selected so as to substantially maximize a measure of quality of the compensated signal.

主权项

1. A method of receiving an optical signal modulated with a transmitted electrical signal which comprises an information-bearing component and a pilot tone having a predetermined frequency, the method comprising steps of:
detecting the optical signal to produce a received electrical signal comprising a distorted variant of the transmitted electrical signal, wherein sources of distortion of the received signal include nonlinear optical transmission impairments; extracting the pilot tone from the received electrical signal using an adaptive filter having at least an adaptive bandwidth parameter; determining a compensation signal which comprises a complex conjugate of the extracted pilot tone; and processing the received electrical signal using the compensation signal to produce a compensated signal having reduced distortion resulting from said nonlinear optical transmission impairments, wherein the processing comprises multiplying the received electrical signal by the compensation signal, wherein the adaptive bandwidth parameter is predetermined so as to substantially maximise a measure of quality of the compensated signal.