Digital TV tri-state delta modulation system for Space Shuttle ku-band downlink
Abstract
A tri-state delta modulation/demodulation (TSDM) technique which provides for efficient run-length coding of constant-intensity segments of a TV picture is described. Aspects of the hardware implementation of a high-speed TSDM transmitter and receiver for black-and-white TV or field-sequential color or NTSC format color are reviewed. Run-length encoding of the TSDM output can consistently reduce the required channel data rate well below one bit per sample. As compared with a bistate delta modulation system, the present technique eliminates granularity in the reconstructed video without degrading rise or fall times. About 40 chips are used by TSDM when used to handle the luminance information in a color link. A possible overall space and ground functional configuration to accommodate Shuttle digital TV with scrambling for privacy is presented.
- Publication:
-
ITC/USA/'82; Proceedings of the International Telemetering Conference
- Pub Date:
- 1982
- Bibcode:
- 1982isa..conf..803U
- Keywords:
-
- Airborne/Spaceborne Computers;
- Digital Television;
- Downlinking;
- Modulators;
- Space Shuttle Orbiters;
- Spacecraft Electronic Equipment;
- Spacecraft Television;
- Analog To Digital Converters;
- Chips;
- Coders;
- Extremely High Frequencies;
- Space Communications, Spacecraft Communications, Command and Tracking