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US 8,805,207 B2Granted
Distortion compensator, optical receiver, distortion compensator and optical receiver controlling methods, and optical transmission system
AssigneeFujitsu Limited
InventorsTakahito Tanimura, Takeshi Hoshida, Hisao Nakashima, Shoichiro Oda
Life of this patent
Estimating the term…
Abstract
A distortion compensator, an optical receiver and a transmission system including an operation selectively compensating for linear waveform distortion exerted on an optical signal via a plurality of distortion compensators and compensating for nonlinear waveform distortion exerted on the optical signal using nonlinear distortion compensators.
Claims6
An apparatus, comprising:
- linear distortion digital compensators that each compensate linear distortion of an input channel signal, compensated channel signals being output from the linear distortion digital compensators;
- and
- nonlinear digital distortion compensators that each input the compensated channel signals output from different one of the linear distortion digital compensators, and compensate nonlinear distortion, based on the compensated channel signals.
An optical receiver, comprising:
- a polarization beam splitter that separates an input optical signal into a first polarized optical signal and a second polarized optical signal;
- an oscillator configured to output a local oscillator light;
- two optical hybrids that mix the first polarized optical signal and the second polarized optical signal with the local oscillator light output from the oscillator;
- photoelectrical converters that each convert different one of the mixed optical signals related to the first polarized optical signal and the second polarized optical signal into analog electrical signals;
- analog-digital-converters that each convert different one of the analog electrical signals into digital channel signals;
- linear distortion digital compensators that each compensate linear distortion of different one of the digital channel signals and output compensated digital channel signals;
- and
- nonlinear digital distortion compensators that each input compensated digital channel signals output from different one of the linear distortion digital compensators, and compensate nonlinear distortion, based on the compensated channel signals.
5 more elements
A method of an optical receiver, comprising:
- compensating linear distortion of input signals from respective channels, and outputting compensated signals of the respective channels;
- and
- performing nonlinear distortion compensation on both of the compensated signals output, using each of nonlinear digital distortion compensators, and providing output channel signals to different output channels.
Dependencies are inferred from the claim text.