SATELLITE COMMUNICATION SYSTEM

• Main Authors: MURATANI TAKUO, KOGA KEIICHIRO, OKAWA NORIHISA, WATANABE TATSUO
• Format: Patent
• Language: English
• Published: 03.03.1987
• Subjects: ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; MULTIPLEX COMMUNICATION; TRANSMISSION

PURPOSE:To attain communication between small sized earth stations and to simplify modulation/demodulation of the small sized earth station by using a digital modulation wave and inserting the earth station having an antenna larger in size than that of the small earth station as a relay station. CONSTITUTION:When a station (a) in a small sized earth station group 1 constitutes a voice communication line with a specific station of a small sized earth station group 2, the station (a) digitizes a voice signal, uses it to modulate a prescribed frequency and sends the result to a satellite 4. The satellite 4 converts the signal into a frequency for outgoing line, amplifies it and sends the result to a relay earth station 3. The station 3 demodulates the signal together with signals from other small sized earth stations and recovers them into digital signals. Then the signals are subject to multiplex, sent to a satellite 5 and the result is received by a specific small sized earth station of the group 2. A digital modulation wave is used in this way and the earth station having an antenna larger in size than that of the small sized earth station is inserted as the relay station so as to attain the communication between the small sized earth stations, the modulation/demodulation is simplified so as to improve the reliability and economy.