Timing recovery for optical coherent receivers in the presence of polarization mode dispersion
US9178625B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 3, 2013 |
| Grant date | Nov 3, 2015 |
| Priority date | — |
| Expiry date | Apr 7, 2034 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L7/0079
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A timing recovery system generates a sampling clock to synchronize sampling of a receiver to a symbol rate of an incoming signal. The input signal is received over an optical communication channel. The receiver generates a timing matrix representing coefficients of a timing tone detected in the input signal. The timing tone representing frequency and phase of a symbol clock of the input signal and has a non-zero timing tone energy. The receiver computes a rotation control signal based on the timing matrix that represents an amount of accumulated phase shift in the input signal relative to the sampling clock. A numerically controlled oscillator is controlled to adjust at least one of the phase and frequency of the sampling clock based on the rotation control signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.