Abstract: A transmitting station includes a transmitting antenna whose orientation direction is changeable, and a controller that controls the orientation direction of the transmitting antenna according to an orientation direction of the transmitting antenna determined together with receiving stations to receive data transmitted from the transmitting antenna based on estimate values of received signal quality at receiving stations that are candidates for receiving stations to receive data transmitted from the transmitting antenna. The transmitting station can maintain received signal quality at a plurality of receiving stations at a desired value or more in a data transmission system.

Abstract: A transmitting station includes a transmitting antenna whose orientation direction is changeable, and a controller that controls the orientation direction of the transmitting antenna according to an orientation direction of the transmitting antenna determined together with receiving stations to receive data transmitted from the transmitting antenna based on estimate values of received signal quality at receiving stations that are candidates for receiving stations to receive data transmitted from the transmitting antenna. The transmitting station can maintain received signal quality at a plurality of receiving stations at a desired value or more in a data transmission system.

Abstract: A relay satellite includes reception antennas, reception processing units, transmission processing units, transmission antennas, a reception analog switch matrix unit that outputs a signal received by the reception antenna to one or more of the reception processing units, a digital switch matrix unit that outputs digital reception signals obtained by reception processing performed by the reception processing units to one or more of the transmission processing units, and a transmission analog switch matrix unit that outputs analog signals obtained by transmission processing performed by the transmission processing units to one of the transmission antennas. The reception analog switch matrix unit outputs a broadband reception signal to the reception processing units when a reception signal having a band broader than a band processable by the reception processing unit is inputted, and the reception processing unit performs reception processing on a part of a band when the broadband signal is inputted.