Demodulating frequency shift keying modulated input signal
US9660849B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 28, 2015 |
| Grant date | May 23, 2017 |
| Priority date | — |
| Expiry date | Sep 28, 2035 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04W56/0045
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A method of demodulating an FSK modulated input signal whose frequency varies between first and second frequencies. The input signal is delayed by a plurality of cycles, providing a second signal. A succession of phase reference signals having respective incrementally greater phase delays relative to the input signal are provided. Samples of the phase reference signals are taken at intervals determined by the second signal. A transition between the first and second frequencies is detected when the relative values of the samples of the phase reference signals remain constant during a plurality of intervals after varying. A high speed clock is not required to perform the demodulation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.