Coherent optical reception device and coherent optical reception method

A coherent optical reception device comprising:

• a coherent receiver that receives signal light in which an auxiliary management and control channel (AMCC) signal is superimposed on a main signal, converts the signal light into an analog electric signal, and outputs in-phase components and quadrature-phase components of a reception signal for each polarization state;
• a polarization combiner that performs a first polarization combining on the in-phase components and performs a second polarization combining the quadrature-phase components of the reception signal output from the coherent receiver for each polarization state and outputs the reception signal as an AMCC signal identification reception signal that is the reception signal used for identification of the AMCC signal and a main signal identification reception signal that is the reception signal used for identification of the main signal;
• and
• a digital signal processor that decodes a code sequence corresponding to the AMCC signal and a code sequence corresponding to the main signal from the reception signal by performing digital signal processing on the reception signal, wherein
• the digital signal processor includes an AMCC signal identificator that identifies the AMCC signal and a main signal identificator that identifies the main signal,
• the AMCC signal identificator includes an intensity calculator that calculates an absolute value of a complex amplitude as an intensity component of the AMCC signal identification reception signal output from the polarization combiner, and a high frequency component remover that removes a high frequency component included in the intensity component of the AMCC signal identification reception signal calculated by the intensity calculator, and
• the main signal identificator includes a complex amplitude calculator that calculates a complex amplitude of the main signal identification reception signal output from the polarization combiner, and an equalization processor that performs equalization processing on the main signal identification reception signal.