Methods and apparatus for calibrating oscillators in a receiver
US7720451B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 3, 2004 |
| Grant date | May 18, 2010 |
| Priority date | — |
| Expiry date | Jun 10, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2027/0053
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A receiver includes a first oscillator supplying a reference frequency signal; a reference signal generator producing a first frequency conversion signal and a local calibration signal from the reference frequency signal; a first frequency converter responsive to the first frequency conversion signal to down-convert the received signal during normal receive operation and to down-convert the local calibration signal during calibration processing; a second frequency converter responsive to a second frequency conversion signal from a second oscillator to further down-convert the received signal and the local calibration signal; a demodulator that demodulates the received signal at a demodulation frequency; and a frequency error processor that determines a frequency error from the local calibration signal at the demodulation frequency, wherein the reference signal generator adjusts a frequency of the first frequency conversion signal used during normal receive operation in response to the frequency error to compensate for the frequency error.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.