Unassisted indoor GPS receiver
US7570208B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 29, 2005 |
| Grant date | Aug 4, 2009 |
| Priority date | — |
| Expiry date | Jan 3, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S19/34
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The present invention provides GPS receivers capable of tracking very weak GPS signals particularly in an indoor environment without assistance from an external server or a network. In a preferred embodiment, a GPS receiver initially acquires and locks onto GPS satellite signals to compute receiver position outdoors. The GPS receiver then tracks at least one satellite signal indoors to maintain acquisition parameters for quick acquisition of GPS signals. To save power, the receiver automatically goes to the sleep state and periodically wakes up, i.e., powers up, to maintain the at least one satellite signal tracking. During the wakeup state, the receiver collects ephemeris data from the at least one satellite signal when the ephemeris data needs to be updated for quick acquisition of GPS signals.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.