Cellular positioning system (CPS)
US6111538A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 23, 1995 |
| Grant date | Aug 29, 2000 |
| Priority date | — |
| Expiry date | Feb 23, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L5/1469
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Positioning system for locating a mobile body comprising a plurality of earth based spread spectrum (SS) broadcasting stations arranged geographically in a cellular pattern. Each SS broadcasting station include a modulator providing a channel signal structure which is substantially orthogonal with respect to adjacent stations in the cellular pattern, each channel signal including navigation beacon data including a unique beacon identification, station latitude and longitude, time.sub.-- slot and phase characterizations and selected parameters of adjacent stations. In one embodiment, each modulator provides a chirped SS signal in which the navigation beacon is a frequency tone that is repeatedly swept over a selected frequency band for each station. In a further embodiment, each modulator provides a GPS like direct sequence SS signal in which the navigation beacon is a PN coded broadcast. A receiver on the mobile body receives the SS signals from at least three of the SS broadcasting stations and determines the location thereof. A fourth SS broadcasting station provides altitude. CPS satellite signals can be used for timing control.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.