Method for optimal search scheduling in satellite acquisition
US6836241B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 19, 2002 |
| Grant date | Dec 28, 2004 |
| Priority date | — |
| Expiry date | Nov 17, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S19/30
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method in a Global Positioning System (GPS) receiver achieves enhanced performance by scheduling searches in the Doppler search space according to a cost function. The cost function relates to both the cost of building a 3-dimensional correlation grid and the cost of searching satellite, code phase, Doppler and integration time interval spaces for values that provide a maximum in the correlation grid. In one embodiment, after the clock Doppler is determined upon acquiring one satellite, the Doppler search range associated with a cell in the grid is dominated by the receiver's own motion. The scheduler schedules searching of the Doppler search space using search ranges determined empirically by the expected receiver velocity. In one embodiment, the scheduler increases integration times before changing Doppler search ranges, which require a recalculation of the grid.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.