The design high-speed phase modems for systems based on multistation access and time division multiplexing
Abstract
The parameters of the modem determine the carrying capacity of a communications link and, as a consequence, the efficiency of an entire communications system. The basic principles in the design of high-speed modems, used in the transmission of digital data over a satellite communications system with multistation access and time division multiplexing, are discussed. Particular emphasis is given to the parallel operation of the carrier restoration (CR) and clock frequency restoration (CFR) systems, the independent operation of the CR system and the phase modulation detector, passive filtering in the CR and CFR circuits, and automatic tracking of the average frequency of the received signals in the CR circuit. Recommendations for selecting a functional schematic for the modems are made, and the results of experimental investigations of a modem at a speed of 40 megabits/sec are presented.
- Publication:
-
Elektrosviaz
- Pub Date:
- October 1980
- Bibcode:
- 1980Elekt..34...44B
- Keywords:
-
- Channel Capacity;
- Communication Satellites;
- Digital Television;
- Modems;
- Phase Modulation;
- Time Division Multiple Access;
- Data Transmission;
- Digital Systems;
- Ground Stations;
- High Speed;
- Pulse Communication;
- Satellite Television;
- Signal To Noise Ratios;
- Systems Engineering;
- Time Division Multiplexing;
- Transmission Efficiency;
- Communications and Radar