Wireless geolocation system
US5999131A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 1, 1997 |
| Grant date | Dec 7, 1999 |
| Priority date | — |
| Expiry date | Jul 1, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01Q3/26
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A wireless system for locating a signal emitter includes at least three base stations for receiving the emitter signal, and a central processing site for converting information from the received signals into range estimates. Specifically, an antenna array at each base station for receives the emitter signal, and a beamformer isolates the direct path component of this received signal from interference and multi-path signals using cyclic phase minimizer techniques. In operation, an extractor is used to separate a cyclostationary feature from the direct path component of the emitter signal, and the cyclostationary feature is identified in an absolute time reference. The identified cyclostationary feature is then passed to the central processing site. At the central processing site, phase delay characteristics of the cyclostationary features from all participating base stations are compared with each other to obtain phase difference measurements. These phase difference measurements are then converted into differential range estimates for locating the emitter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.