Satellite communications system, key station and slave station

摘要

PPROBLEM TO BE SOLVED: To obtain a satellite communications device, a master station, and a slave station for further high accuracy executing of automatic frequency control of communication waves in satellite communication when two-way satellite communication is executed between the master station and the slave station via a nongeosynchronous satellite, such as a quasi-zenith satellite. PSOLUTION: The master station 2 detects a frequency deviation fL in the satellite by receiving a return signal 6 of a pilot signal 5 and calculates the Doppler frequency shift fogr of an outbound signal 7, by using orbital information of the nongeosynchronous satellite 1 and positional information of the master station 2. Compensation is made so that the transmission frequency of the outbound signal 7 becomes (a reference frequency of the outbound signal 7)-(fogr + fL). The slave station 3 calculates the Doppler frequency shift of an outbound signal 8, by using the orbital information of the nongeosynchronous satellite 1 and the positional information of the slave station 3, and executes frequency compensation to the outbound signal 8 to be received. PCOPYRIGHT: (C)2006,JPO&NCIPI