Circuit for demodulating PSK modulation signals
US5241567A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 1, 1991 |
| Grant date | Aug 31, 1993 |
| Priority date | — |
| Expiry date | Jul 1, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2027/0053
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
In a differential-detection demodulator circuit, a PSK modulated signal is compared with a locally oscillated signal to obtain a phase difference between the two signals, whereupon the phase difference is demodulated. A phase detector circuit of the digital type outputs the phase difference signal. The digital phase comparator circuit compares plural reference signals, which give predetermined delays to the locally oscillated signals having carrier frequencies, with the inputted modulated signals. Preferably, a pulse signal having a phase difference between the inputted modulated signal and the locally oscillated signal is produced, and the pulse width of this pulse signal is measured by a counter. By digitalizing the entire phase comparator, it is possible to realize demodulation with low electrical power consumption and simple circuit construction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.