Satellite uplink power control
First Claim
1. 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.
3 Assignments
0 Petitions
Accused Products
Abstract
A method and system for Uplink Power Control in a satellite communication system comprising a geostationary satellite (2) communicating with a gateway station (3) applying the invention and at least two other gateway station (4) is described. The invention utilizes the existing communication signals in the satellite communication system to compensate for atmospheric distortion as scintillation and rain fading effects. The method is symmetric with regard to which gateway that utilizes the invention in a communication system thereby increasing the regulation of all communication signals in the system.
15 Citations
16 Claims
-
1. 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. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. Device 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:
-
means for transmitting a first outbound signal (11) to said satellite from a first gateway (3);
means for 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;
comprising;
means for 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);
means for 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. means for 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);
means for 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);
the said nominal value is determined on a day with a clear sky;
means for 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);
the nominal value is determined on a day with a clear sky;
means for computing an error signal formed by the difference of the first said difference and the second said difference;
means for 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. - View Dependent Claims (9, 10, 11, 12, 13, 14)
-
-
15. 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), filtering any received signal in an individual high pass filter of the form of subtracting a low pass filtered version of the signal from the signal itself producing an instantaneous change level signal;
compute an absolute change level signal by subtracting the said instantaneous change level signal from a mean of changes from other signals thereby producing a low pass filtered current variance signal;
compute a weight for each signal by taking the inverse of said variance such that when multiplied by the weight, each signal contributes the same variance;
compute a normalized weight for each said signals such that the sum of said normalized weights equal 1;
compute a downlink estimate by first multiplying said instantaneous change level signal with the associated normalized weight and sum all said products to form an instantaneous downlink estimate;
compute an error signal formed as a difference between said instantaneous downlink estimate and a received beacon signal and a RF reference signal;
adjusting the power level of sa first gateway stations (3) outbound signals an amount based on said error signal within the permissible range of said power level.
-
-
16. Device 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:
-
mans for transmitting a first outbound signal (11) to said satellite from a first gateway (3);
means for 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;
comprising;
means for 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), filtering any received signal in an individual high pass filter of the form of subtracting a low pass filtered version of the signal from the signal itself producing an instantaneous change level signal;
means for computing a change level signal by subtracting the said instantaneous change level signal from a mean of changes from other signals thereby producing a low pass filtered current variance signal;
means for computing a weight for each signal by taking the inverse of said variance such that when multiplied by the weight, each signal contribute the same variance;
means for computing a normalized weight for each said signals such that the sum of said normalized weights equal 1;
means for computing a downlink estimate by first multiplying said instantaneous change level signal with the associated normalized weight and sum all said products to form an instantaneous downlink estimate;
means for computing an error signal formed as a difference between said instantaneous downlink estimate and a received beacon signal and a RF reference signal;
means for 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.
-
Specification