GNSS receiver using signals of opportunity and assistance information to reduce the time to first fix
US8558738B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 22, 2009 |
| Grant date | Oct 15, 2013 |
| Priority date | — |
| Expiry date | Sep 16, 2030 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S19/27
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A GNSS receiver reduces the time to first fix by utilizing the properties of existing radiated signals of opportunity, such as AM or FM radio signals, television signals and so forth, to reduce the uncertainties associated with oscillator frequency and phase, and further utilizing an Almanac and battery backed-up date and time to determine the satellites in view and reduce the uncertainties associated with Doppler. The receiver may use multiple signals of opportunity to determine the city or local area in which the receiver is located based on the set of frequencies of the signals, and also to reduce search uncertainties for oscillator frequency by estimating an offset based on the differences between the frequencies of the respective signals of opportunity at the receiver and the nominal broadcast frequencies of the signals.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.