System and method for SAP FM demodulation
US7006806B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 26, 2002 |
| Grant date | Feb 28, 2006 |
| Priority date | — |
| Expiry date | Sep 10, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04H20/48
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Certain embodiments of the present invention provides a system and method for SAP FM demodulation. The system includes a bandpass filter for isolating the SAP signal, a Hilbert filter to produce a copy of the SAP signal phase shifted by 90 degrees, an FM demodulator for demodulating the SAP signal using the phase shifted SAP signal and a delayed SAP signal, and a lowpass filter to eliminate noise from the FM demodulated SAP signal. The system may also include an automatic gain control for normalizing amplitude of FM demodulator input signals. The digital FM demodulator uses a simplified approximation using non-unity delay for simplified demodulation of frequency modulated signals.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.