Method and apparatus for improving the quality of AM compatible digital broadcast system signals in the presence of distortion
US5809065A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 20, 1996 |
| Grant date | Sep 15, 1998 |
| Priority date | — |
| Expiry date | Feb 20, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04H2201/186
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A system and method are provided for reducing perceived distortion in an output audio signal derived from an amplitude modulated compatible digital broadcast signal having an analog portion and a digital portion. The digital portion of this signal is demodulated to produce a demodulated digital signal and the analog portion of the signal is demodulated to produce a demodulated analog signal. The noise in the demodulated digital signal is measured and an estimate of the signal-to-noise ratio is derived. This estimated signal-to-noise ratio is compared with a threshold level which is set at the minimum acceptable signal quality for the digital signal. Based upon the estimated signal-to-noise ratio, a switch directs either the analog derived audio output or the digitally derived audio output as the system output signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.