Location and tracking system
US6275705A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 27, 1998 |
| Grant date | Aug 14, 2001 |
| Priority date | — |
| Expiry date | Nov 27, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S5/10
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The invention concerns a method of finding the position of a mobile radio-frequency transceiver in a communications system. A network of at least two unsynchronized base stations arranged to transmit/receive signals to at least one mobile-radio frequency transceiver; a reference receiver located at a known distance from the base stations and including measuring means to measure the times of arrival of signals transmitted from the base stations; determination means to use the known distances and measured times to determine the relative time offsets of transmissions from each base station; and location means to use the determined relative time offsets to calculate the position of a mobile transceiver in the network area using hyperbolic positioning techniques. A number of other enhancements to positioning systems relating to the usage of Doppler, carrier information, direction of arrival to improve the performance of mobile telephone-based positioning systems are also described.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.