Method and apparatus for performing power control using the wide-band synchronization

A communication system, comprising:

• a spacecraft repeater for receiving signals within a first frequency range, for converting said signals to a second frequency range, and for retransmitting signals at a second frequency;
• a plurality of ground stations for transmitting signals to said spacecraft repeater, and for receiving signals from said spacecraft repeater, a first ground station of said plurality of ground stations transmitting a first signal with a calibrated characteristic, and a second ground station of said plurality of ground stations transmitting a second signal, also with a calibrated characteristic;
• receiving means associated with said first ground station, for receiving said first signal retransmitted at said second frequency by said spacecraft repeater, and for receiving said second signal at said second frequency retransmitted by said spacecraft repeater;
• receiving means associated with said second ground station, for receiving said first signal retransmitted at said second frequency by said spacecraft repeater;
• first carrier-to-noise ratio determining means coupled to said first ground station for determining the total carrier-to-noise ratio of said first signal, to thereby determine a first-to-first signal carrier-to-noise ratio;
• second carrier-to-noise ratio determining means coupled to said second ground station for determining the total carrier-to-noise ratio of said first signal, to thereby determine a first-to-second signal carrier-to-noise ratio;
• third carrier-to-noise ratio determining means coupled to said first ground station for determining the total carrier-to-noise ratio of said second signal, to thereby determine a second-to-first signal carrier-to-noise ratio;
• processing means coupled to said first ground station for receiving said first-to-first signal carrier-to-noise ratio, said first-to-second signal carrier-to-noise ratio, and said second-to-first signal carrier-to-noise ratio, and for determining downlink rain attenuation on first and second downlinks and the number of active signals repeated by said spacecraft repeater;
• and
• control means coupled to said first and second ground stations, for controlling the transmitted power of data signals transmitted to said spacecraft repeater.