Method and apparatus for frequency offset compensation
US6590945B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 13, 1999 |
| Grant date | Jul 8, 2003 |
| Priority date | — |
| Expiry date | Jul 13, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2027/0046
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A simplified method for frequency offset estimation in a TDMA cellular PCS environment using &pgr;/4-shifted DQPSK comprises the steps of multiplying a complex conjugate of a received complex-valued symbol and a succeeding symbol to produce a comparison vector having an angle equal to the phase angle between the received complex-valued symbol and the succeeding symbol, rotating the comparison vector so that the angle thereof is between 0° and 90°, and estimating the frequency offset by determining a constant deviation of the phase angle from an ideal phase angle value of 45° by calculating an average phase angle for a plurality of successive comparison vectors or correlating the rotated comparision vector against a bank of unit vectors to determine a maximum correlation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.