Method and system for transmitting and receiving PCM audio signals in combination with a video signal
US5072297A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 27, 1990 |
| Grant date | Dec 10, 1991 |
| Priority date | — |
| Expiry date | Mar 27, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N7/088
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method and system for multiplexing additional audio information in the form of pulse code modulation (PCM) audio signals onto a television signal. The PCM audio signal is time multiplexed into scanning retrace intervals of the video signal. At a receiver, the bit error rate of the decoded PCM audio signal is compared with a threshold so as to switch the audio output from the PCM audio signal to a conventional FM demodulated audio signal when the bit error rate exceeds the predetermined threshold. In this way, the benefits of both PCM audio and FM audio can be obtained by utilizing the higher immunity of FM signals in low signal-to-noise ratio environments, while the high fidelity PCM audio signal is utilized when the signal-to-noise ratio environment is relatively high.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.