Automatic frequency tracking apparatus and method for a television signal receiving system
US6421099B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 19, 1999 |
| Grant date | Jul 16, 2002 |
| Priority date | — |
| Expiry date | Nov 19, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N21/4383
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An automatic frequency tracking apparatus and method for a receiver for receiving a television signal including a pilot signal which can automatically track and compensate for the frequency offset of the received television signal even in a case where the frequency offset deviates from a determined range in which carrier restoration is possible. According to the method, a maximum frequency offset range which can occur in receiving a television signal is divided into a plurality of window regions, and each window region is searched to determine if a lock signal of a frequency phase-locked loop is detected at representative frequencies of the respective divided window regions in a wide-range tracking adjustment mode performing step. Thereafter, a fine-tuning adjustment mode is performed so that the respective frequencies existing in the window regions in which the lock signal is detected are determined as tuned frequencies, and if a frequency offset detected from the determined tuned frequencies has a value in a predetermined range, the corresponding tuned frequency is determined as an optimum tuned frequency.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.