Multipath link and modem design for satellite mobile communications
Abstract
Modems for digital L-band communication between satellites and aircraft, ships, and land vehicles are discussed. Low-rate, low-cost communications for small users is desired, so antennas are nonsteerable. Received signal-to-noise ratios are small so power conservation is critically important. Reflections from the Earth's surface have significant amplitude and cause multipath interference to the desired signal. Data rates of 100, 1200, and 4800 bps were considered. Modulation types examined include BPSK/DPSK, FSK, and GMSK. Digital implementation of the modems is proposed wherever feasible.
- Publication:
-
NASA STI/Recon Technical Report N
- Pub Date:
- August 1983
- Bibcode:
- 1983STIN...8421793G
- Keywords:
-
- Data Links;
- Digital Techniques;
- Modems;
- Multipath Transmission;
- Satellite Networks;
- Antenna Design;
- Carrier Frequencies;
- Cost Reduction;
- Phase Modulation;
- Receivers;
- Ultrahigh Frequencies;
- Communications and Radar