Method and apparatus for symbol independent discriminator correlator automatic frequency control
US6493406B1 · kind B1 · utility
Inventors
Key dates
| Filing date | Jul 22, 1999 |
| Grant date | Dec 10, 2002 |
| Priority date | — |
| Expiry date | Jul 22, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2027/0057
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A symbol independent automatic frequency controller (100) includes a symbol correlator (110) for receiving a complex digital signal generated within a selective call receiver wherein the symbol correlator provides a real signal (114), an imaginary signal (116), and a magnitude signal (112), a discriminator (140) coupled to the symbol correlator for receiving and processing the real signal and the imaginary signal to provide a frequency error signal, a low pass filter (120) and comparison element (130) for filtering the magnitude signal and comparing the magnitude signal to a predetermined lock threshold signal that controls the bandwidth of the symbol correlator in the event the magnitude signal exceeds the lock threshold signal, and a feedback loop providing the imaginary signal (116) to an accumulator (170) and back to the symbol correlator wherein the accumulator provides the symbol correlator with an apriori-symbol phase feedback (172).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.