GPS receiver and terminal device having search frequency band switching function
US6384774B1 · kind B1 · utility
Assignees
Inventors
Key dates
| Filing date | Nov 27, 2000 |
| Grant date | May 7, 2002 |
| Priority date | — |
| Expiry date | Nov 27, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03J1/0091
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A terminal device has a GPS receiver which receives GPS signals from a GPS satellite. The terminal device has an operation unit for instructing operation modes of the GPS receiver, and the GPS receiver has a clock unit, a radio frequency unit and a data extraction unit. The data extraction unit extracts GPS data by scanning signal-to-noise ratios of each frequency over a search frequency band. When a band correction mode is instructed by the operation unit, the data extraction unit switches its search frequency band from a first frequency band determined based on a maximum temperature-dependent change in the frequency of a clock signal to a second frequency band determined based on a maximum aging-dependent change in the frequency of the clock signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.