Optical receiver, optical receiving method, optical receiving program, and recording medium

Abstract

The optical receiver includes an optical coherent detection unit (210) that receives modulated light optically modulated by a carrier frequency, causes the received modulated light to interfere with interference light, performs coherent detection, and outputs an analog electrical signal, an analog / digital conversion unit (230) that performs analog / digital conversion of the analog electrical signal from the optical coherent detection unit (210) to obtain a digital signal, and a receiving-side digital signal processing unit (240) having a frequency shift unit (241) that performs coarse compensation to shift the center frequency of the digital signal obtained by the analog / digital conversion unit (230) to a frequency that reduces the frequency difference between transmission and reception, and a frequency difference estimation compensation unit (243) that finely compensates the center frequency of the digital signal after the coarse compensation for the frequency difference has been performed by the frequency shift unit (241).

Images