Optical receiving apparatus and signal processing method

Abstract

An optical reception device includes a coherent optical reception unit that receives a polarization multiplexed signal generated on the basis of a digital modulation signal generated by phase modulation or quadrature amplitude modulation with coherent detection, a waveform distortion compensation unit that compensates for a transmission line distortion generated in an optical transmission line with respect to the polarization multiplexed signal, a plurality of IQ distortion compensation units that compensate for at least an IQ imbalance or a DC component offset of a signal subjected to transmission line distortion compensation, a plurality of error calculation units that calculate each polarization error obtained from an output signal of each of the IQ distortion compensation units, and a plurality of coefficient updating units that update a filter coefficient used in the waveform distortion compensation unit and filter coefficients used in the plurality of IQ distortion compensation units on the basis of a method of determining a filter coefficient on the basis of a model that minimizes a mean square value of each polarization error calculated by each of the plurality of error calculation units, or a method of searching for a filter coefficient for obtaining a minimum value of a mean square error based on an instantaneous value of an error.

Dependencies are inferred from the claim text.