Patent ID: 9100126
Filing Date: 2015-08-04
Classification: H04B

Abstract:
1. An optical reception device comprising: an electrical signal converter that converts, into electrical signals, respective polarization components of a polarization multiplexed signal forming an optical signal in which the polarization components are multiplexed; a signal processor that executes A/D conversion processing for the electrical signals output from said electrical signal converter and digital signal processing for digital signals generated by the A/D conversion processing; and a phase difference output unit that detects a phase difference generated between the polarization components of the polarization multiplexed signal based on the digital signals output from said signal processor, and outputs information representing the phase difference, wherein said signal processor compensates for a distortion of the polarization multiplexed signal based on the information representing the phase difference that is output from said phase difference output unit, wherein said signal processor includes: an A/D converter that converts the electrical signals into digital signals at predetermined sampling timings by executing the A/D conversion processing, an FIR filter which receives, as input signals, the digital signals output from said A/D converter and has a predetermined number of taps, and a distortion compensation processor that compensates for a distortion of the polarization multiplexed signal based on the information representing the phase difference that is output from said phase difference output unit, and wherein said phase difference output unit includes a tap coefficient estimation unit that estimates weighting coefficients for weighting tap coefficients of the FIR filter, and a phase difference correction unit that derives the phase difference between the polarization components of the polarization multiplexed signal based on the weighting coefficients, and outputs, to said signal processor, information representing the derived phase difference.