PURPOSE: To reduce earth station transmission power and to simplify the device, by using an FDMA system for an incoming line from an earth station for a communication sattellite and a TDMA system for an outgoing line from the communication satellite to the earth station.
CONSTITUTION: Earth stations 2∼5 transmit signals in the FDMA system by using a carrier frequency assigned to a station itself. The satellite 1 receives a signal from the stations 2∼5 in the FDMA system, demodulates a received FDMA signal, converts it into a TDMA signal and transmits the signal to the earth station. In case of the communication from the earth station placed in the same antenna irradiating area, e.g., earth stations 2, 3, the switching of the beam for incoming and outgoing lines is not done. In the communication of the earth station placed in a different antenna irradiating area, e.g., earth stations 2 and 5, the signal system is converted, and the beam is switched from the beam 6 to 7 and from 7 to 6 in the incoming and outgoing lines.
INOUE TAKEO
KUBOTA SHIYUUJI
TAMAI TOSHIHIKO
