There is a trend for mobile satellite system architectures aimed at the deployment of multi-satellite constellations in Non-Geostationary Earth Orbits (NGEOs). This allows the user terminals to be small size, low cost and having low power demand. In present and next generation satellite systems, CDMA has been proposed as the multiple access technique for a number of mobile satellite communicati...

A control system in satellite communication terminal of low information rate is designed via program based on ATmega128 system controller, which has realized the function of operation control in the satellite communication terminal of low information rate. The synchronization signal of clock is simulated via Mcu I/O interface to voice-coder. Mcu controls the input and output of analog signal an...

This paper presents a realization of a simple antenna system for land vehicle satellite communication that is tested in experiments conducted on the Engineering Test Satellite-VIII (ETS-VIII). The developed antenna system which was mounted onto a vehicle roof is compact, light weight with simple satellite-tracking operation. In order to realize compact antennas, an onboard-power divider and swi...

The R&D in satellite communications in Korea has been driven mainly by KCC (Korea Communications Commission) but in a small scale compared to Korea space development program organized by MEST (Ministry of Education, Science and Technology). Public and civilian satcom sector R&D has been led mainly by ETRI with small/medium companies contrary to rare investment in private sector while military s...

Communication via satellite begins when the satellite is positioned in the desired orbital position. Ground stations can communicate with LEO (Low Earth Orbiting) satellites only when the satellite is in their visibility region. The duration of the visibility and so the communication duration varies for each satellite pass at the ground station, specifically for LEO satellites which do move too...

Considering the advantage of interleave division multiple access (IDMA) technique and the existing technical bottlenecks in satellite systems, IDMA is introduced into satellite communication networks. In multi-beam IDMA satellite systems, combined with unique SINR evolution technology, the system interference value can be accurately estimated, and system capacity can be accurately calculated co...

Redundancy is a major concern to satellite communication amplifier systems. This paper examines the various types of redundant systems used in satellite communication systems from a system reliability viewpoint. To overcome the ambiguities involved with comparing MTBFs, the paper discusses amplifier reliability based on static reliability concepts. Both traditional switched redundant systems an...