K-BAND SS/TDMA IN JAPANESE SATELLITE COMMUNICATION SYSTEM

should be chosen in consideration of the realizable satellite scale and link budget including satellite EIRP, rain-fall attenuation and antenna pointing This paper describes the K-band (30/20 GHz band) satellite-switched time-division multipleaccess (SS/TDMA) satellite communication system, which will be built in the terrestrial digital toll network of Japan. A four-beam antenna and 4X 4 microwave-switch-matrix are provided in the satellite, and a 2OOMbps four-phase CPSK modem system is employed in the TDMA terminal. The system can be realized by employing a 550 kg satellite. The main techniques in the SS/TDMA system, acquisition and synchronization technique and techniques for interfacing with the terrestrial network, are described, and the functional equipment structure is presented. loss. This paper proposes a four-beam SS/TDMA system, which will be built in the terrestrial digital toll network of Japan. As the number of beams is not great, and the sizes of the multi-beam antenna, transponders and microwave-switch-matrix (MSM) are not large, this plan can be realized by using a 550 kg satellite. This paper first describes the system in the