SATELLITE COMMUNICATIONS SYSTEMS AND METHODS USING RADIOTELEPHONE LOCATION-BASED BEAMFORMING

• US 20090137203A1
• Filed: 12/22/2008
• Published: 05/28/2009
• Est. Priority Date: 05/18/2004
• Status: Active Grant

• Current Assignee: ATC Technology Corporation (FedEx Corporation)
• Original Assignee: ATC Technology Corporation (FedEx Corporation)
• Inventors: Karabinis, Peter D., Dutta, Santanu, Churan, Gary G.
• Granted Patent: US 8,238,818 B2
• Time in Patent Office: Days
• US Class Current: 455/12.100
• CPC Class Codes: H04B 7/0408 using two or more beams, i.e. beam diversity
• CPC Class Codes: H04B 7/10 Polarisation diversity; Directional diversity
• CPC Class Codes: H04B 7/18515 Transmission equipment in satellites or space-based relays
• CPC Class Codes: H04B 7/2041 Spot beam multiple access

Abstract

A processor for use in a satellite communications system includes a selector that is configured to select a subset of a plurality of spatially diverse satellite signals based upon a location of a radioterminal. The processor further includes a signal processor that is configured to detect a return-link transmission from the radioterminal responsive to the selected subset of the spatially diverse satellite signals. The respective spatially diverse satellite signals may include respective signals corresponding to respective antenna elements of a satellite. The selector and the signal processor may be ground based.

Claims

1. A system for a communications satellite, the system comprising:

a processor that is configured to form an antenna pattern of the communications satellite responsive to a plurality of signals that are provided to the processor by a respective plurality of antenna elements of the communications satellite and to maintain the antenna pattern substantially invariant to a relative phase change between any two signals of the plurality of signals;

wherein the processor is positioned at a distance from the communications satellite and the plurality of signals are transported from the plurality of antenna elements to the processor using a wireless link.

2. A system according to claim 1 wherein the antenna pattern is a return service link antenna pattern and wherein the plurality of signals are transported from the plurality of antenna elements to the processor using frequency division multiplexing.

3. A system according to claim 1 wherein the processor is positioned at a gateway of the communications satellite.

4. A system according to claim 1 wherein the processor forms the antenna pattern by altering at least one signal of the plurality of signals and combining the plurality of signals, and wherein the processor maintains the antenna pattern substantially invariant to a relative phase change between any two signals of the plurality of signals by further altering at least one signal of the plurality of signals responsive to the relative phase change.

5. A system for a communications satellite, the system comprising:

a processor that is configured to provide an antenna pattern of the communications satellite by forming and providing a plurality of signals to a respective plurality of antenna elements of the communications satellite, and to maintain the antenna pattern substantially invariant to a relative phase change between any two signals of the plurality of signals;

wherein the processor is positioned at a distance from the communications satellite and the plurality of signals are transported from the processor to the plurality of antenna elements using a wireless link.

6. A system according to claim 5 wherein the antenna pattern is a forward service link antenna pattern and wherein the plurality of signals are transported from the processor to the plurality of antenna elements using frequency division multiplexing.

7. A system according to claim 5 wherein the processor is positioned at a gateway of the communications satellite.

8. A system according to claim 5 wherein the processor maintains the antenna pattern substantially invariant to a relative phase change between any two signals of the plurality of signals by altering at least one signal of the plurality of signals responsive to the relative phase change.

9. A method of providing an antenna pattern for a communications satellite, the method comprising:

transporting a plurality of signals of a respective plurality of antenna elements of the communications satellite from the respective plurality of antenna elements to a processor; and

forming the antenna pattern at the processor responsive to the plurality of signals that are transported to the processor, including maintaining the antenna pattern substantially invariant to a relative phase change between any two signals of the plurality of signals;

wherein the processor is positioned at a distance from the communications satellite and wherein transporting comprises wirelessly transporting.

10. A method according to claim 9 wherein the antenna pattern is a return service link antenna pattern and wherein wirelessly transporting comprises using frequency division multiplexing.

11. A method according to claim 9 wherein the processor is positioned at a gateway of the communications satellite.

12. A method according to claim 9 wherein forming the antenna pattern at the processor comprises:

altering at least one signal of the plurality of signals; and

combining the plurality of signals, and wherein maintaining the antenna pattern substantially invariant to a relative phase change between any two signals of the plurality of signals comprises altering at least one signal of the plurality of signals responsive to the relative phase change.

13. A method of providing an antenna pattern for a communications satellite, the method comprising:

forming a plurality of signals by a processor;

transporting the plurality of signals from the processor to a respective plurality of antenna elements of an antenna of the communications satellite; and

forming the antenna pattern by the antenna of the communications satellite responsive to the plurality of signals that are transported to the respective plurality of antenna elements, including maintaining the antenna pattern substantially invariant to a relative phase change between any two signals of the plurality of signals;

wherein the processor is positioned at a distance from the communications satellite and wherein transporting comprises wirelessly transporting.

14. A method according to claim 13 wherein the antenna pattern is a forward service link antenna pattern and wherein wirelessly transporting comprises using frequency division multiplexing.

15. A method according to claim 13 wherein the processor is positioned at a gateway of the communications satellite.

16. A method according to claim 13 wherein maintaining the antenna pattern substantially invariant to a relative phase change between any two signals of the plurality of signals comprises altering by the processor prior to the transporting at least one signal of the plurality of signals responsive to the relative phase change.