Multiple access equipment design for satellite communication systems in the USSR
Abstract
The fundamental concepts of the equipment and the basic trend of the development of satellite communication systems in the USSR using FDMA (Gradient-N and Gruppa) and TDMA (MDVR-40) equipment are examined. In the Gradient-N system, every telephone signal is transmitted at an individual carrier in a common baseband and is frequency modulated by this carrier. The whole transponder bandwidth is separated into frequency blocks, with each block having ten individual frequencies. The Gruppa equipment transmits a group of channels rather than a single telephone channel at one carrier frequency as does the Gradient-N system. A group of channels can be transmitted using ths system either by carrier frequency modulation by a conventional 12 channel group or by carrier phase modulation by a 512 kbit/s digital signal obtained as a result of analog to digital conversion of eight standard PCM voice channels. The Gruppa equipment is employed at low-capacity earth stations (12-24), while TDMA-40 is used by stations with the capacity of no less than 60 channels.
- Publication:
-
Budapest International Astronautical Federation Congress
- Pub Date:
- October 1983
- Bibcode:
- 1983buda.iafcQ....D
- Keywords:
-
- Communication Networks;
- Communication Satellites;
- Data Processing Equipment;
- Multiple Access;
- Onboard Equipment;
- Satellite Communication;
- U.S.S.R. Space Program;
- False Alarms;
- Frequency Division Multiple Access;
- Systems Engineering;
- Time Division Multiple Access;
- Communications and Radar