Single channel per carrier transmission for satellite communications
Abstract
Single channel per carrier FM (SCPC/FM) is compared to single channel per carrier phase-shift keying (SCPC/PSK) as transmission mode for voice and data communications via satellite. Syllabic companding, voice activation of the carrier, pre-emphasis and de-emphasis, and threshold extension receivers are employed as signal processing techniques for FM, and variable slope delta modulation, phase-shift-keyed modulation, and voice activation of the carrier are employed in digital modulation. Output SNR versus carrier/noise density ratio is used in objective comparison of the two methods, along with subjective comparisons. Availability of a delta channel as a highly intelligible link allows optimization of satellite network capacity by allocating minimum link margins in link design budgets. Echo suppression was applied in both SCPC/FM and SCPC/PSK. Both modes are satisfactory, while the digital mode offers greater security and channel capacity.
- Publication:
-
National Telecommunications Conference, Volume 2
- Pub Date:
- 1975
- Bibcode:
- 1975ntc.....2...25G
- Keywords:
-
- Communication Satellites;
- Data Transmission;
- Frequency Modulation;
- Phase Shift Keying;
- Satellite Transmission;
- Voice Communication;
- Carrier Frequencies;
- Digital Techniques;
- Network Synthesis;
- Noise Reduction;
- Phase Modulation;
- Satellite Networks;
- Signal Processing;
- Signal To Noise Ratios;
- Space Communications, Spacecraft Communications, Command and Tracking