Coherent optical receiver, apparatus and method for detecting inter-channel skew in coherent optical receiver
US8626000B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 2, 2011 |
| Grant date | Jan 7, 2014 |
| Priority date | — |
| Expiry date | Sep 2, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B10/6165
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
In a coherent optical receiver, sufficient demodulation becomes impossible and consequently receiving performance deteriorates if an inter-channel skew arises, therefore, a coherent optical receiver according to an exemplary aspect of the invention includes a local light source, a 90° hybrid circuit, an optoelectronic converter, an analog to digital converter, and a digital signal processing unit; wherein the 90° hybrid circuit makes multiplexed signal light interfere with local light from the local light source, and outputs a plurality of optical signals separated into a plurality of signal components; the optoelectronic converter detects the optical signals and outputs detected electrical signals; the analog to digital converter quantizes the detected electrical signals and outputs quantized signals; the digital signal processing unit includes a skew compensation unit for compensating a difference in propagation delay between the plurality of signal components, and an FFT operation unit for performing a fast Fourier transform process on the quantized signals; and wherein the difference in propagation delay is calculated on the basis of a plurality of peak values with a central fo…
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