Demodulator for PSK-modulated signals
US4827488A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 8, 1987 |
| Grant date | May 2, 1989 |
| Priority date | — |
| Expiry date | Sep 8, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/22
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A demodulator is disclosed for a PSK-modulated transmission signal in which the time average value of the frequencies thereof ar equal to the carrier frequency. A mixer receives and mixes the PSK-modulated transmission signal with a signal from a local variable frequency oscillator and the output thereof is converted to a square wave which is used to reconstruct the original digital modulation data. A pulse counter receives and counts the square wave signal for every period of time which is n times a time slot of a digital signal and a subtractor provides a difference between the count value from the pulse counter and a reference count number. The subtractor output is converted to an analog signal which controls the local oscillator frequency.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.