Signal processing circuit, optical signal receiving device, and signal processing method

An optical signal receiving device comprising:

• a signal processing circuit comprising:
• a multi input multi output (MIMO) filter that performs polarization separation on a reception signal obtained by performing optical sampling reception on optical signals that are polarization multiplexed signals in parallel by using a plurality of local light beams using optical pulses;
• a memory storing instructions;
• and
• a processor configured to execute the instructions to update a coefficient of the MIMO filter based on periodicity based on a parallel number in the optical sampling reception;
• an optical receiver that performs optical sampling reception on the optical signals in parallel by using a plurality of local light beams using the optical pulse;
• and
• a combiner that combines a plurality of signals obtained by the optical receiver performing optical sampling reception on the optical signals in parallel, and inputs the combined plurality of signals to the signal processing circuit as the reception signal.