STRATOSPHERIC-BASED COMMUNICATION SYSTEM FOR MOBILE USERS USING ADDITIONAL PHASED ARRAY ELEMENTS FOR INTERFERENCE REJECTION

• US 20080233884A1
• Filed: 10/30/2007
• Published: 09/25/2008
• Est. Priority Date: 09/14/2000
• Status: Active Grant

• Current Assignee: DIRECTV, LLC (AT&T, Inc.)
• Original Assignee: The DIRECTV Group, Inc. (AT&T, Inc.)
• Inventors: Chang, Donald C. D., Cha, Alan, Chen, Jacqueline C., Hagen, Frank A.
• Granted Patent: US 7,890,052 B2
• Time in Patent Office: Days
• US Class Current: 455/63.1
• CPC Class Codes: H04B 7/18506 Communications with or from aircraft, i.e. aeronautical mobile service

Abstract

A communication system has a stratospheric platform with a payload controller and a phased array antenna having a plurality of main array elements for generating a plurality of communication beams and a plurality of auxiliary elements for canceling interference between the communication beams. A gateway station communicates with the stratospheric platform. The gateway station scales the plurality of elements to form a reconfigurable plurality of beams. The gateway station communicates an embedded control signal to the stratospheric platform to communicate a scaling of elements to form the communication beams and the auxiliary element output. The auxiliary element output is used to provide interference canceling.

Claims

1. A communications system comprising:

stratospheric platform having a payload controller and a phased array antenna having a plurality of main array antenna elements for generating a plurality of communication beams and a plurality of auxiliary elements for canceling interference from side lobes of the plurality of the communication beams;

a gateway station in communication with said stratospheric platform, said gateway station scaling user signals to form a plurality of main array element control signals and auxiliary element control signals, said gateway station communicating the main array element control signals and the auxiliary element control signals to the stratospheric platform;

said stratospheric platform forming the communication beams and the auxiliary element output to reduce interference from side lobes of the communication beams from the main array element control signals and the auxiliary element control signals.

2. A communications system as recited in claim 1, wherein the payload controller comprises a demultiplexer for receiving the main element and auxiliary element control signals.

3. A communications system as recited in claim 2, wherein the demultiplexer generates a plurality of regenerated element control signals.

4. A system as recited in claim 3, wherein the regenerated element control signals are coupled to an RF feed, the RF feed is coupled to elements of said phased array antenna.

5. A system as recited in claim 1, wherein said auxiliary element output is a function of a direction of the plurality of the communication beams.

6. A system as recited in claim 1, wherein the gateway station comprises a plurality of multiplication gates each having a respective weight, said auxiliary element output being a function of said weight.

7. A system as recited in claim 1, wherein the gateway station scales the user signals by:

dividing each of the user signals into a number of paths corresponding to one of the plurality of main array elements to form user signal components, multiplying each user signal components by an amplitude and phase weighting and adding the user components together element by element to form component sums and placing the component sums into corresponding element bins to form the main array element control signals.

8. A system as recited in claim 1, wherein said gateway station further comprises a multiplexer multiplexing the element signals.

9. A system as recited in claim 8, wherein said multiplexer comprises a code division multiplexer.

10. A system as recited in claim 1, wherein said ground station is coupled to a terrestrial network.

11. A system as recited in claim 10, wherein said terrestrial network comprises the Internet.

12. A system as recited in claim 10, wherein the terrestrial network comprises the public service telephone network.

13. A system as recited in claim 1, wherein phased array antenna does not include phase shifters.

14. A system as recited in claim 1, wherein phasings for each of the communication beams are embedded in the main array element control signals.

15. A system as recited in claim 1, wherein the main array element control signals are added together to form the communication beams.

16. A method of controlling a communications system having a stratospheric platform with a phased array antenna having a plurality of main array elements and a plurality of auxiliary elements, said method comprising:

scaling a plurality of user signals to form a plurality of main array element control signals and a plurality of auxiliary element control signals in a gateway station;

communicating the main array element control signals and the plurality of auxiliary element control signals to a stratospheric platform;

generating communication beams in response to scaling the plurality of user signals;

generating auxiliary element outputs in response to the auxiliary element control signals at stratospheric platform; and

reducing side lobe interference from side lobes communication beams in response to the auxiliary element outputs.

17. A method as recited in claim 16, wherein said step of generating the auxiliary element outputs comprises weighting the auxiliary element control signals.

18. A method as recited in claim 16, wherein the stratospheric platform comprises a payload controller having a demultiplexer, said method further comprising receiving the main element and auxiliary element control signals at the demultiplexer of the stratospheric platform and generating a plurality of regenerated element control signals at the demultiplexer and coupling the regenerated signals to an RF feed in communication with said phased array antenna.

19. A method as recited in claim 16, wherein generating the auxiliary element outputs comprises generating the auxiliary element output as a function of a direction of the plurality of the communication beams.

20. A method as recited in claim 16, wherein generating the auxiliary element outputs comprises generating the auxiliary element output as a function of a respective weight of a multiplication gate of the gateway station.

21. A method as recited in claim 16, scaling a plurality of user signals comprises dividing each of the user signals into a number of paths corresponding to one of the plurality of main array elements to form user signal components, multiplying each user signal components by an amplitude and phase weighting and adding the user components together element by element to form component sums and placing the component sums into corresponding element bins to form the main array element control signals.

22. A method as recited in claim 16, wherein phased array antenna does not include phase shifters.

23. A method as recited in claim 16, further comprising embedding phasings for each of the communication beams in the main array element control signals.

24. A method as recited in claim 16, further comprising adding the main array element control signals together to form the communication beams.