Television signal transmission system with temporal processing
US5144431A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 15, 1989 |
| Grant date | Sep 1, 1992 |
| Priority date | — |
| Expiry date | Sep 15, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/186
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A hybrid television signal of less transmission power (or better signal to noise performance) is made up by removing low frequency analog components from the video signal, digitizing them and sending them as data in non-active video portions of the transmitted signal. A two step hybridization process, with the first step removing the line averaged value of the video components of the video signal and the second step removing the remainder of the video components under 200 KHz, is described. Temporal filtering, signal pre-emphasis, compression, time dispersal and double sideband suppressed carrier modulation about a centered carrier are disclosed for reducing peak signal amplitudes and for minimizing co-channel interference to and from NTSC signals. Temporal filtering is performed with a feed forward filter in the transmission and a complementary feedback recursive filter in the receiver or with a recursive filter in the transmitter and a complementary feed forward filter in the receiver. The hybrid signal system is uniquely adapted to a high definition television signal in a limited frequency channel with an NTSC signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.