Apparatus and method for locating cellular telephones
US5512908A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 8, 1994 |
| Grant date | Apr 30, 1996 |
| Priority date | — |
| Expiry date | Jul 8, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S5/04
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method for determining the time difference of arrival, tdoa, of signals from a cellular telephone, includes determining tdoas for a plurality of channels, averaging the tdoas from the channels, subtracting the average tdoa from the individual channel tdoas to determine residual channel tdoas and determining an overall residual tdoa from the residual channel tdoas. An apparatus and method for collecting cell phone transmission signals for performing tdoa calculations, includes receiving, digitizing and temporarily storing wideband transmission signals while monitoring a known reverse control channel for a predetermined cell phone number to be located, and permanently storing the delayed reverse control channel signal once the predetermined number is identified.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.