| 摘要 |
<P>PROBLEM TO BE SOLVED: To allow stable phase control at a receiver even if there exists polarization fluctuation. <P>SOLUTION: The digital coherent receiver includes a digital conversion part which samples the signal received from an optical transmission path to generate a digital signal, a phase detecting part which detects a phase of the digital signal, a phase adjusting part which adjusts a sampling phase of the digital signal based on the detected phase, and a demodulation part which demodulates the digital signal having been adjusted for phase. The phase detecting part includes a plurality of filters for equalizing the digital signal in varying equalization characteristics, a plurality of sensitivity monitor phase detectors which are connected to the plurality of filters, to output a phase detection signal representing a phase of the signal outputted from a corresponding filter and a sensitivity monitor signal representing phase detection sensitivity, a plurality of sensitivity correction factor generating parts for generating sensitivity correction factors for correcting the corresponding phase detection signals, and an adder which composites the phase detection signals having been corrected by the sensitivity correction factor together, for outputting a phase signal. <P>COPYRIGHT: (C)2013,JPO&INPIT |
