Polarization re-alignment for mobile terminals via electronic process
View Patent ↗A system for allowing ground terminals, mobile or stationary, to dynamically and electronically re-align signal polarizations to match that of incoming signal polarizations from transmitting sources. An adaptive re-orientation technique utilizes a cost minimization function to determine the difference between actual orientation values and desired orientation values. Calculations of satellite and ground terminal orientations and bearings to create weighting components allow a mobile ground terminal to electronically realign itself to the signals of a transmitting source, thereby eliminating the need for physically re-orienting the antenna array through mechanical processes.
1. A method for angle realignment comprising:
determining a first polarization offset angle between a first axis of a first coordinate for a terminal and a second axis of a second coordinate for a signal radiated by a satellite;
obtaining a first vertical polarization component of said signal and a first horizontal polarization component of said signal based on information comprising said first polarization offset angle;
calculating a cost based on information comprising a cross correlation between said first vertical polarization component of said signal and said first horizontal polarization component of said signal;
comparing said calculated cost with a threshold cost;
after said comparing said calculated cost with said threshold cost, calculating a cost gradient; and
obtaining a second polarization offset angle based on said cost gradient.
2. The method of claim 1 , wherein said first polarization offset angle has an accuracy between +6 degrees and −6 degrees.
3. The method of claim 1 , further comprising said calculating said cost gradient in response to finding said calculated cost is greater than said threshold cost.
4. The method of claim 1 , wherein said terminal comprises a mobile terminal.
5. The method of claim 1 , further comprising said determining said first polarization offset angle via a compass.
6. The method of claim 1 , wherein said signal comes from a signal path comprising an analog-to-digital converter.
7. The method of claim 1 , further comprising obtaining information comprising a location and an orientation of said terminal.
8. The method of claim 1 , further comprising obtaining information comprising an orbital slot and an orientation of said satellite.
9. The method of claim 1 , further comprising obtaining a second vertical polarization component of said signal and a second horizontal polarization component of said signal based on information comprising said second polarization offset angle.
10. A method for angle realignment comprising:
determining a first polarization offset angle between a first axis of a first coordinate for a terminal and a second axis of a second coordinate for a signal radiated by a satellite;
obtaining a first vertical polarization component of said signal and a first horizontal polarization component of said signal based on information comprising said first polarization offset angle;
calculating a cost based on information comprising a cross correlation between said first vertical polarization component of said signal and said first horizontal polarization component of said signal;
comparing said calculated cost with a threshold cost;
after said comparing said calculated cost with said threshold cost, obtaining a second polarization offset angle; and
performing an angle rotation process to output a second vertical polarization component of said signal and a second horizontal polarization component of said signal based on information comprising said second polarization offset angle.
11. The method of claim 10 , after said performing said angle rotation process, further comprising performing a decoding process.
12. The method of claim 10 , further comprising said performing said angle rotation process in response to finding said calculated cost is less than said threshold cost.
13. The method of claim 10 , wherein said terminal comprises a movable terminal.
14. The method of claim 10 , further comprising obtaining information comprising a location and an orientation of said terminal.
15. The method of claim 10 , further comprising obtaining information comprising an orbital slot and an orientation of said satellite.
16. A method for angle realignment comprising:
determining a first polarization offset angle between a first axis of a first coordinate for a terminal and a second axis of a second coordinate for a signal radiated by a satellite;
obtaining a first vertical polarization component of said signal and a first horizontal polarization component of said signal based on information comprising said first polarization offset angle;
calculating a first cost based on information comprising a cross correlation between said first vertical polarization component of said signal and said first horizontal polarization component of said signal;
comparing said first cost with a threshold cost;
after said comparing said first cost with said threshold cost, calculating a cost gradient;
obtaining a second polarization offset angle based on information comprising said cost gradient;
obtaining a second vertical polarization component of said signal and a second horizontal polarization component of said signal based on information comprising said second polarization offset angle;
calculating a second cost based on information comprising a cross correlation between said second vertical polarization component of said signal and said second horizontal polarization component of said signal;
comparing said second cost with said threshold cost; and
performing an angle rotation process to output a third vertical polarization component of said signal and a third horizontal polarization component of said signal based on information comprising said second polarization offset angle.
17. The method of claim 16 , further comprising said calculating said cost gradient in response to finding said first cost is greater than said threshold cost.
18. The method of claim 16 , further comprising said performing said angle rotation process in response to finding said second cost is less than said threshold cost.
19. The method of claim 16 , wherein said terminal comprises a mobile terminal.
20. The method of claim 16 , after said performing said angle rotation process, further comprising performing a decoding process.