Timing recovery in presence of optical impairments and optimization of equalization based on timing recovery moment strengths
US8401403B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 3, 2010 |
| Grant date | Mar 19, 2013 |
| Priority date | — |
| Expiry date | Apr 29, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L7/0029
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
The present disclosure provides timing recovery in optical systems in the presence of chromatic dispersion (CD), polarization mode dispersion (PMD), and polarization dependent loss (PDL) and to optimization of equalization settings based upon timing recovery moment strengths. A stable timing point may be determined in the presence of PMD and PDL impairments, even when the direct estimate of timing becomes unreliable. This determination may be performed entirely in the digital domain providing precise, predictable performance. Also, the present invention utilizes a monotonic relationship between the timing metric and CD setting error to provide directed search in setting the CD equalizer thereby reducing significantly the overall search effort in optimizing CD equalizer settings. This utilizes computations already performed by the transceiver for timing recovery function yielding a computational advantage over competing methods.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.