Service detection circuit and method
US5974042A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 28, 1997 |
| Grant date | Oct 26, 1999 |
| Priority date | — |
| Expiry date | Feb 28, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B7/2628
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A radiotelephone (121) employs a service detection circuit (125) comprising at least one chip-rate detector (109) that measures the energy of the autocorrelation of a received composite CDMA signal and employs a different time delay for each measurement of the energy. A threshold detection circuit (127) combines the measured energies and determines that service is available if the combined energies exceeds a threshold, and determines service is unavailable otherwise. The chip-rate detectors (109) can be coupled in parallel to provide simultaneous measurements of the energy of the autocorrelation of the received composite CDMA signal, or a single chip-rate detector (109) can serially measure the energy of the autocorrelation of the received composite CDMA signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.