Digital AM/FM positioning system (DAFPS)--an international positioning system
US6219385A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 21, 1999 |
| Grant date | Apr 17, 2001 |
| Priority date | — |
| Expiry date | Dec 21, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/2601
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A digital positioning system using digital AM and FM radio stations for use in the environment of a plurality of digital AM and FM (AM/FM) radio stations which comprises a customer service center and a reference station which regularly and passively receives signals from all local digital AM/FM stations and measures variations in key parameters of frequency and wavelength thereof and provides AM/FM correctional data signals corresponding to each AM/FM station frequency and wavelength variation to the customer service center. The customer service center is adapted to provide the AM/FM correctional data signals to each of the digital AM/FM radio stations for insertion into ancillary digital data broadcast from each digital AM/FM radio station. A plurality of mobile receivers in the environment of AM/FM radio stations, each of the mobile receivers receiving and processing three or more digital AM and/or FM signals and estimating and updating its position at periodic intervals and sending the results thereof to the customer service center via cellular or other network.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.