OPTICAL COMMUNICATION RECEIVER AND FREQUENCY OFFSET-COMPENSATION METHOD

摘要

PROBLEM TO BE SOLVED: To provide an optical communication receiver for reducing a residual frequency offset.SOLUTION: An optical communication receiver for performing digital signal processing by converting a signal obtained by mixing signal light from an optical transmission line and local oscillation light to a digital signal comprises: a frequency offset-compensation unit which calculates a frequency offset of the digital signal and compensates a phase of the digital signal on the basis of the frequency offset; a carrier wave phase restoration unit for calculating a carrier wave phase of the digital signal whose phase is compensated by the frequency offset-compensation unit; and a residual frequency offset detection unit which calculates the average of differential values of the carrier wave phase and outputs it as a residual frequency offset. The frequency offset-compensation unit corrects the frequency offset by using the residual frequency offset output by the residual frequency offset detection unit.