Digital coherent phase demodulator
US4246654A · kind A · utility
23Cited by
5References
4Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jan 9, 1979 |
| Grant date | Jan 20, 1981 |
| Priority date | — |
| Expiry date | Jan 9, 1999 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/2334
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A digital system for demodulating coherent phase shift keyed signals. Maximum likelihood estimates of the unmodulated phase and rate of change of the unmodulated phase of the received signal relative to a local oscillator signal are used to improve the demodulation process. The maximum likelihood estimates are obtained from measurements of the phase of the received signal relative to the local oscillator signal over a predetermined set of keying intervals. The digital demodulation process permits rapid "lock-on" at low signal-to-noise ratios.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.