Providing an accurate timing source for locating the geographical position of a mobile
US6493539B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 28, 1999 |
| Grant date | Dec 10, 2002 |
| Priority date | — |
| Expiry date | Jul 28, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04W64/00
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
The synchronization system uses a TDMA or AMPS air interface to provide timing synchronization between previously unsynchronized base stations. The synchronization of base stations is critical between when determining the geographical position of a mobile because the geographical position is determined using a time difference of arrival method. In order to synchronize a remote base station with a serving base station, the remote base station receives a signal from the serving base station and measuring the receiving time of the signal at the remote base station in relation to the clock of the remote base station. The synchronization system determines the transmission time of the signal based on the reception time of the signal and the distance between the base stations, in relation to the clock signal of the second station, and synchronizes the clock of the remote base station to the clock of the serving base station based on the offset in the clock cycles at the time the signal was transmitted.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.