TCXO replacement for GPS
US8373515B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 10, 2011 |
| Grant date | Feb 12, 2013 |
| Priority date | — |
| Expiry date | Feb 10, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/1976
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
To determine the level of frequency drift of a crystal oscillator as a result of a change in the its temperature, the temperature of the crystal oscillator is sensed and used together with previously stored data that includes a multitude of drift values of the frequency of the crystal oscillator each associated with a temperature of the crystal oscillator. Optionally, upon initialization of a GPS receiver in which the crystal oscillator is disposed, an initial temperature of the crystal oscillator is measured and a PLL is set to an initial frequency in association with the initial temperature. When acquisition fails in a region, the ppm region is changed. The temperature of the crystal oscillator is periodically measured and compared with the initial temperature, and the acquisition process is reset if there is a significant change in temperature. The GPS processor enters the tracking phase when acquisition is successful.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.