Polarization Re-alignment for Mobile Satellite Terminals

Abstract

A system for allowing ground terminals, specifically mobile ground terminals, to dynamically and electronically realign signal polarizations to match that of incoming and outgoing signal polarizations from designated space assets, specifically communications from satellites, comprising an adaptive re-orientation technique based on a cost minimization function, and a means of direct calculations of weighting components based on the knowledge of the orientation and bearing of both the satellites and the ground terminals. The embodiment will allow a mobile ground terminal to electronically realign itself to the signals of a satellite, without the need for mechanical processes to physically re-orient the antenna array.

1 - 16 . (canceled) 
     
     
         17 . A method for angle realignment, comprising:
 obtaining a first vertical polarization component and a first horizontal polarization component;   resolving a second vertical polarization component based on information comprising a polarization offset angle and said first vertical and horizontal polarization components;   resolving a second horizontal polarization component based on information comprising said polarization offset angle and said first vertical and horizontal polarization components;   calculating a cost based on information comprising a cross correlation between said second vertical and horizontal polarization components; and   after said calculating said cost, calculating a cost gradient.   
     
     
         18 . The method of  claim 17 , wherein said polarization offset angle has an accuracy between +6 degrees and −6 degrees. 
     
     
         19 . The method of  claim 17  further comprising said calculating said cost gradient in response to finding said calculated cost is greater than a threshold cost. 
     
     
         20 . The method of  claim 17  being performed on a mobile terminal. 
     
     
         21 . The method of  claim 17  further comprising determining said polarization offset angle via a compass. 
     
     
         22 . The method of  claim 17 , wherein said first vertical and horizontal polarization components are converted into ones in a digital mode. 
     
     
         23 . The method of  claim 17  further comprising said resolving said second vertical polarization component based on information comprising a combination of said first vertical polarization component multiplied by cosine of said polarization offset angle minus said first horizontal polarization component multiplied by sine of said polarization offset angle. 
     
     
         24 . The method of  claim 17  further comprising said resolving said second horizontal polarization component based on information comprising a combination of said first vertical polarization component multiplied by sine of said polarization offset angle plus said first horizontal polarization component multiplied by cosine of said polarization offset angle. 
     
     
         25 . A method for angle realignment, comprising:
 obtaining a first vertical polarization component and a first horizontal polarization component;   resolving a second vertical polarization component based on information comprising a polarization offset angle and said first vertical and horizontal polarization components;   resolving a second horizontal polarization component based on information comprising said polarization offset angle and said first vertical and horizontal polarization components;   calculating a cost based on information comprising a cross correlation between said second vertical and horizontal polarization components; and   after said calculating said cost, performing an angle rotation process to output a third vertical polarization component based on information comprising said polarization offset angle and said first vertical and horizontal polarization components and to output a third horizontal polarization component based on information comprising said polarization offset angle and said first vertical and horizontal polarization components.   
     
     
         26 . The method of  claim 25 , after said performing said angle rotation process, further comprising performing a decoding process. 
     
     
         27 . The method of  claim 25  further comprising said performing said angle rotation process in response to finding said calculated cost is less than a threshold cost. 
     
     
         28 . The method of  claim 25  being performed on a movable terminal 
     
     
         29 . The method of  claim 25 , wherein said third vertical polarization component is associated with a combination of said first vertical polarization component multiplied by cosine of said polarization offset angle minus said first horizontal polarization component multiplied by sine of said polarization offset angle. 
     
     
         30 . The method of  claim 25 , wherein said third horizontal polarization component is associated with a combination of said first vertical polarization component multiplied by sine of said polarization offset angle plus said first horizontal polarization component multiplied by cosine of said polarization offset angle. 
     
     
         31 . A method for angle realignment, comprising:
 obtaining a first vertical polarization component and a first horizontal polarization component;   resolving a second vertical polarization component based on information comprising a first polarization offset angle and said first vertical and horizontal polarization components;   resolving a second horizontal polarization component based on information comprising said polarization offset angle and said first vertical and horizontal polarization components;   calculating a first cost based on information comprising a cross correlation between said second vertical and horizontal polarization components; and   after said calculating said first cost, calculating a cost gradient;   obtaining a second polarization offset angle based on information comprising said cost gradient;   resolving a third vertical polarization component based on information comprising said second polarization offset angle and said first vertical and horizontal polarization components;   resolving a third horizontal polarization component based on information comprising said second polarization offset angle and said first vertical and horizontal polarization components;   calculating a second cost based on information comprising a cross correlation between said third vertical and horizontal polarization components; and   after said calculating said cost, performing an angle rotation process to output a fourth vertical polarization component and a fourth horizontal polarization component based on information comprising said second polarization offset angle and said first vertical and horizontal polarization components.   
     
     
         32 . The method of  claim 31  further comprising said calculating said cost gradient in response to finding said first cost is greater than a threshold cost. 
     
     
         33 . The method of  claim 31  further comprising said performing said angle rotation process in response to finding said second cost is less than a threshold cost. 
     
     
         34 . The method of  claim 31  being performed on a mobile terminal. 
     
     
         35 . The method of  claim 31 , wherein said fourth vertical polarization component is associated with a combination of said first vertical polarization component multiplied by cosine of said second polarization offset angle minus said first horizontal polarization component multiplied by sine of said second polarization offset angle. 
     
     
         36 . The method of  claim 31  further comprising said resolving said third vertical polarization component based on information comprising a combination of said first vertical polarization component multiplied by cosine of said second polarization offset angle minus said first horizontal polarization component multiplied by sine of said second polarization offset angle.