Demodulation of a digitally frequency-modulated analog received signal by evaluation of the time intervals between the zero crossings
US7646827B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 1, 2004 |
| Grant date | Jan 12, 2010 |
| Priority date | — |
| Expiry date | Jan 13, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/2017
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A detector (1) for zero crossings and a counter (2) which is connected to it are used to determine the time intervals between the zero crossings of the received signal or of an intermediate-frequency signal which is produced from the received signal, and for detection of the digital signal data. In this case, a sequence of determined zero crossing intervals can be stored in digital form in a shift register chain (3), and can be compared in a classification device (4) with previously stored interval sequences. Furthermore, a frequency offset can be determined by averaging the zero crossing intervals and can be compensated for by suitable selection or modification of the previously stored interval sequences, in which case the latter can also be used during the synchronization phase. The synchronization process may, furthermore, be assisted by payload data identification.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.