Method and apparatus for automatic frequency correction
US7791408B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 22, 2008 |
| Grant date | Sep 7, 2010 |
| Priority date | — |
| Expiry date | Mar 4, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/0014
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for automatic frequency correction in a demodulation circuit. The apparatus includes a demodulator, a frequency offset estimator, a frequency controller, and an oscillator. The oscillator provides a receiver clock signal which the demodulator employs to demodulate a modulated signal. The frequency offset estimator estimates an offset between a carrier wave frequency of the modulated signal and a frequency of the receiver clock signal. The frequency controller provides a frequency control signal to the oscillator for adjusting the frequency of the receiver clock. While the estimated offset is outside of an adjustment range, the frequency controller maintains the frequency control signal at its previous value. The frequency controller also adjusts the adjustment range based on past error signal values.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.