Automatic frequency control system using multiple threshold levels and method of using same
US5963851A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 7, 1997 |
| Grant date | Oct 5, 1999 |
| Priority date | — |
| Expiry date | Apr 7, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03J7/04
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A radio device requires a tunable transceiver such that the transceiver can be accurately set to a desired frequency. When a signal with known frequency accuracy is being received, an offset detector can determine the frequency offset generated by the transceiver due to improper tuning. An automatic frequency control (AFC) system (100) is comprised of a tunable transceiver, an offset detector (103) and an AFC control processor (105) for utilizing information from the offset detector to reduce the inaccuracy in frequency by tuning the transceiver towards the received signal frequency. The AFC control processor (105) utilizes one of more threshold levels for defining a maximum correction threshold (311) based upon the desired maximum offset correction. These thresholds are used by the AFC control processor (105) to efficiently control the predetermined frequency range of the tunable transceiver (101) for most efficient operation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.