Forward link repeater frequency watermarking scheme
US6961367B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 17, 2003 |
| Grant date | Nov 1, 2005 |
| Priority date | — |
| Expiry date | Dec 23, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S19/258
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A forward link repeater frequency watermarking (FLRFWM) system and method that enable accurate position location of mobile stations in areas where repeaters are present by watermarking repeated signals with repeater information. A repeater watermarks a forward link signal with a (unique or non-unique) fast frequency modulation waveform watermark every time a signal passes through the repeater. A mobile station detects and/or identifies the fast frequency watermark on the forward link signal to determine repeater information that aids the network position determination entity or mobile station position location system in determining position location using AFLT and/or A-GPS systems. A forward link fast frequency watermarking system described herein achieves minimal impact on FL, AFLT, and GPS performance, good detection, identification and false alarm probabilities, short time-to-detect/identify, and good detection/identification sensitivity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.