Communication device
US5073898A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 30, 1990 |
| Grant date | Dec 17, 1991 |
| Priority date | — |
| Expiry date | Jan 30, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B1/70712
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A signal processing circuit utilizes a convolver correlating a reference carrier signal with a received signal. The correlator output is detected and then demodulated to output the signal information originally present on the carrier. For a conventional AM signal the reference carrier signal is applied at a frequency offset from the AM center frequency. When the carrier is an FM signal, the reference signal is applied at a frequency equal to the center frequency of the FM signal. Similar procedures are followed for a spread-modulated AM signal, and the reference signal is modulated with a suitably timed-reverse replica of the pseudo-noise code. A similar procedure is used to process spread-spectrum frequency shift keyed FM signals.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.