Digital coherent receiver and receiving method
AssigneeFujitsu Limited
InventorsHisao NAKASHIMA, Takeshi HOSHIDA, Kosuke KOMAKI
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Abstract
A digital coherent receiver includes a front end, an A/D convertor, and a processor. The front end converts a light signal into an electric signal by using a signal light and a local oscillator light. The A/D convertor converts the electric signal of the front end into a digital signal. The processor calculates a spectrum gravity center of the digital signal converted by the A/D convertor, estimates a frequency offset of the digital signal based on the calculated spectrum gravity center, and reduces the frequency offset of the digital signal based on the estimated frequency offset.
Claims10
A digital coherent receiver comprising:
- a front end that converts a light signal into an electric signal by using a signal light and a local oscillator light;
- an A/D convertor that converts the electric signal of the front end into a digital signal;
- and
- a processor that calculates a spectrum gravity center of the digital signal converted by the A/D convertor, estimates a frequency offset of the digital signal based on the calculated spectrum gravity center, and reduces the frequency offset of the digital signal based on the estimated frequency offset.
A method of receiving a light by a digital coherent receiver which includes a front end that converts a light signal into an electric signal by using a signal light and a local oscillator light and an A/D convertor that converts the electric signal of the front end into a digital signal, the method comprising:
- calculating a spectrum gravity center of the digital signal;
- estimating a frequency offset of the digital signal based on the calculated spectrum gravity center;
- and
- reducing the frequency offset of the digital signal based on the estimated frequency offset.
Dependencies are inferred from the claim text.