Patent ID: 7043200

Claim:
Method for up-link power control in a first gateway earth station ( 3 ) in a satellite communication system comprising a geostationary satellite ( 2 ), a least two other geographically dispersed earth gateway stations ( 4 ) communicating signal carriers ( 30 ) via said satellite ( 2 ) and a plurality of user stations ( 5 ), comprising the steps of: transmitting a first outbound signal ( 11 ) to said satellite from a first gateway ( 3 ); receiving said first outbound signal ( 11 ) looped back from said satellite ( 2 ) in first said gateway ( 3 ) determining the said first outbound signal ( 11 ) power level; wherein: receiving signal carriers ( 30 ) from at least a second gateway station ( 4 ) and at least a third gateway station ( 4 ) in the same said communication system from said satellite ( 2 ) in the first said gateway station ( 3 ), determining the signal power level of a signal ( 30 ) from said second gateway ( 4 ) and the signal power level from a signal ( 30 ) from said third gateway ( 4 ); replacing the signal power level of any received signal ( 30 ) from said second gateway ( 4 ) or from said third gateway ( 4 ) in said first gateway ( 3 ) with a predefined nominal power value level if one of said signals ( 30 ) are below a first predefined threshold value for that said signal power level; computing a mean value of the signal power level of the outbound signals ( 30 ) from said second gateway station ( 4 ) and said third gateway station ( 4 ) in said first gateway station ( 3 ); computing a first difference between said first signal ( 11 ) power level of said first outbound signal ( 11 ) from first said gateway ( 3 ) and a nominal signal power level of an outbound signal looped back from said satellite ( 2 ) to first said gateway ( 3 ); computing a second difference between said mean signal power level of said second signal ( 30 ) from said second gateway ( 4 ) and said third signal ( 30 ) from said third gateway ( 4 ) and a nominal mean power level of a signal from said second gateway ( 4 ) and a signal from said third gateway ( 4 ); computing an error signal formed by the difference of the first said difference and the second said difference; adjusting the power level of said first gateway stations ( 3 ) outbound signals an amount based on said error signal within the permissible range of said power level.