FREQUENCY OFFSET ESTIMATION DEVICE, FREQUENCY OFFSET ESTIMATION METHOD AND DIGITAL COHERENT RECEIVER

摘要

PROBLEM TO BE SOLVED: To extend the range capable of estimating the frequency offset between transmission/reception light sources.;SOLUTION: A frequency offset estimation device 20 comprises a first frequency offset estimation unit 23 which estimates a first frequency offset estimation value (a), i.e. the phase variation amount in the symbol period T_sym of a multilevel PSK demodulation signal sampled at a predetermined timing, a second frequency offset estimation unit 24 which estimates a second frequency offset estimation value (b), i.e. the phase variation amount in the symbol period T_sym/N(N is an integer of 2 or more) of a multilevel PSK demodulation signal sampled at a predetermined timing, and an estimation value correction unit 25 which estimates the frequency offset between transmission/reception light sources on the basis of the first frequency offset estimation value (a) and the second frequency offset estimation value (b).;COPYRIGHT: (C)2013,JPO&INPIT