公开(公告)号：US20170264372A1

公开(公告)日：2017-09-14

申请号：US15606698

申请日：2017-05-26

Applicant: NEC Corporation

Inventor： Kiyoshi FUKUCHI ,  Junichi ABE ,  Wakako YASUDA

IPC: H04B10/61

CPC classification number: H04B10/616

Abstract: The disclosed coherent optical receiver includes a local light source; a 90-degree hybrid circuit; an optoelectronic converter; an analog-to-digital converter; a skew addition unit; and a FFT operation unit. The 90-degree hybrid circuit makes multiplexed signal light interfere with local light from the local light source, and outputs multiple optical signals separated into a plurality of signal components. The optoelectronic converter detects the optical signal and outputs a detected electrical signal. The analog-to-digital converter digitizes the detected electrical signal and outputs a detected digital signal. The skew addition unit adds to the detected digital signal an additional skew amount whose absolute value is equal to, whose sign is opposite to a skew amount of a difference in propagation delay in each lane connected to each output channel of the 90-degree hybrid circuit. The FFT operation unit performs a fast Fourier transform on the output from the skew addition unit.