Patent · US Active

Blind carrier frequency offset detection for coherent receivers using quadrature amplitude modulation formats

US8682182B2 · kind B2 · utility

12Cited by
6References
20Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMay 17, 2011
Grant dateMar 25, 2014
Priority date—
Expiry dateJan 17, 2032

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04B10/6164
  • WIPO fieldTelecommunications
  • WIPO sectorElectrical engineering

Abstract

Exemplary embodiments are directed to a blind carrier recovery system for blind detection and/or correction of carrier frequency offset between the signal laser source and local oscillator (i.e., carrier frequency recovery) for optical systems employing quadrature amplitude modulation (QAM). Exemplary embodiments can be implemented using an improved fast Fourier transform (FFT)-based approach. Some embodiments can include a frequency sign detection technique that uses parallel, concurrently implemented FFTs having a modified FFT architecture. Some embodiments can include a frequency sign detection technique that uses time-domain slope detection based on constellation classification.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.