Design and implementation of a spread spectrum demodulator for data-relay systems
Abstract
The ESA Data-Relay System is a space-borne communications system which provides communications between ground stations and satellites in LEOs with intersatellite communications giving a data-relay facility. The system requires a ground based demodulator and this paper describes the requirements, design and implementation of such a receiver. The demodulator is a part of a spread spectrum receiver and modem presently under development. The specification requirement for the demodulator is severe, with low signal-to-noise ratios and high Doppler shifts. The demodulator is very flexible in terms of the types of signal it can receive, which include spread spectrum signals. The demodulator is implemented almost completely using digital techniques. Such an approach leads to potentially low implementation losses and allows the use of novel techniques in the receiver's subsystems.
- Publication:
-
Washington, DC International Astronautical Federation Congress
- Pub Date:
- August 1992
- Bibcode:
- 1992wadc.iafcZ....A
- Keywords:
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- Communication Networks;
- Data Links;
- Demodulators;
- Satellite Communication;
- Spread Spectrum Transmission;
- Matched Filters;
- Phase Locked Systems;
- Signal To Noise Ratios;
- Tdr Satellites;
- Space Communications, Spacecraft Communications, Command and Tracking