Estimating frequency offset
US7330523B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Feb 15, 2002 |
| Grant date | Feb 12, 2008 |
| Priority date | — |
| Expiry date | May 27, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2027/0081
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
Frequency offset estimation apparatus for estimating the offset from a predetermined centre frequency of an input signal carrying a plurality of frequency shifted symbols, the apparatus comprising: a demodulator for demodulating the input signal to estimate the symbols; a first filter for forming a first estimate of the offset by determining the average of a first predetermined number of the last maxima and minima of the instantaneous frequency difference between the input signal and a signal at the centre frequency; a second filter for forming a second estimate of the offset by determining the average of the values of the instantaneous frequency difference between the input signal at the centre frequency associated with the estimation by the demodulator of those of the symbols having the greatest positive and negative frequency shifts; and selector for selecting the first estimate or the second estimate as an output estimate of the frequency error.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.