Digital modem techniques for low cost domestic SCPC earth stations
Abstract
A new modulation technique, the intersymbol interference jitter-free offset keyed QPSK, which has been implemented in the design of low-cost SCPC earth stations is discussed, and the principal subsystems are characterized. In particular, attention is given to the modulator, downconverter, demodulator, carrier recovery, symbol timing recovery, and the pilot receiver. It is shown that the new modulation technique combined with innovative circuit design contributes to lower earth station cost by allowing fully saturated operation of the high-power amplifier. The tradeoffs between low cost and high performance are outlined for the main subsystems.
- Publication:
-
Canadian Domestic and International Satellite Communications Conference
- Pub Date:
- 1984
- Bibcode:
- 1984cdsc.conf...14G
- Keywords:
-
- Digital Data;
- Ground Stations;
- Low Cost;
- Modems;
- Single Channel Per Carrier Transmission;
- Telephony;
- Block Diagrams;
- Circuits;
- Down-Converters;
- Modulation;
- Performance Prediction;
- Systems Engineering;
- Tradeoffs;
- Communications and Radar