Feeder link configurations to support layered modulation for digital signals

• US 7,423,987 B2
• Filed: 10/20/2003
• Issued: 09/09/2008
• Est. Priority Date: 04/27/2001
• Status: Expired due to Term

• Current Assignee: The DIRECTV Group, Inc. (AT&T, Inc.), Hughes Electronics Corporation (Rtx Corporation)
• Original Assignee: The DIRECTV Group, Inc. (AT&T, Inc.)
• Inventors: Santoru, Joseph, Chen, Ernest C., Anderson, Paul R.
• Primary Examiner(s): D AGOSTA, STEPHEN M
• Application Number:
  US10/532,631
• Publication Number:
  US 20060056330A1
• Time in Patent Office: 1,786 Days
• Field of Search: 370/316, 370319-321, 370/322, 370/325, 370/327, 370/328, 370/329, 370/336, 370/339, 455/427, 455/428, 455/429, 455/431, 455/422, 375/316, 375/320, 375/327, 375/308, 375/261, 375/298, 332/103, 329/304
• US Class Current: 370/316
• CPC Class Codes: H04B 7/18526 Arrangements for data linking, networking or transporting, or for controlling an end to end session data switching networks H04L12/00
• CPC Class Codes: H04L 27/0008 arrangements for allowing a transmitter or receiver to use more than one type of modulation negotiating modulation type for two-way transmission paths H04L5/1453
• CPC Class Codes: H04N 7/20 Adaptations for transmission via a GHz frequency band, e.g. via satellite

Abstract

Systems and methods are disclosed for feeder link configurations to layered modulation. One feeder link system employs feeder link spot beam to antennas in distinct coverage areas to enable frequency reuse. Another system employs narrow beam width feeder link antenna to illuminate individual satellites also enabling frequency reuse. Yet another system uses layered modulation in the feeder link. Another feeder link system employs a higher order synchronous modulation for the satellite feeder link than is used in the layered modulation downlink signals.

Claims

1. A system for uplinking signals, comprising:

a first receiver for receiving a first feeder link signal using a first feeder link spot beam antenna for a first satellite transponder, the first satellite transponder transmitting an upper layer signal of a layered modulation signal to at least one receiver;

a second receiver for receiving a second feeder link signal using a second feeder link spot beam antenna for a second satellite transponder, the second satellite transponder transmitting a lower layer signal of the layered modulation signal to the at least one receiver;

wherein the first feeder link spot beam antenna transmits from a first coverage area and the second feeder link spot beam antenna transmits from a second coverage area distinct from the first coverage area and the second feeder link signal reuses a frequency spectrum of the first feeder link signal.

2. The system of claim 1, wherein a first frequency bandwidth of the upper layer signal partially overlaps a second frequency bandwidth of the lower layer signal.

3. The system of claim 1, wherein a first frequency bandwidth of the upper layer signal completely overlaps a second frequency bandwidth of the lower layer signal.

4. The system of claim 1, wherein the upper layer signal comprises a legacy signal.

5. The system of claim 1, wherein the first transponder and the second transponder are both on a common satellite.

6. The system of claim 1, wherein the first transponder and the second transponder are each on a different satellite.

7. The system of claim 1, wherein the first transponder and the second transponder include amplifiers operable substantially at saturation.

8. The system of claim 1, wherein the first satellite transponder for the upper layer signal includes a power combiner.

9. The system of claim 1, wherein at least one of the first feeder link signal and the second feeder link signal are power level adjusted to maintain a relative power level between the upper layer signal and the lower layer signal for reception.

10. The system of claim 1, wherein the upper layer signal and the lower layer signal are non-coherent.

11. A method of uplinking signals, comprising:

receiving a first feeder link signal using a first feeder link spot beam antenna for a first satellite transponder, the first satellite transponder transmitting an upper layer signal of a layered modulation signal to at least one receiver;

receiving a second feeder link signal using a second feeder link spot beam antenna for a second satellite transponder, the second satellite transponder transmitting a lower layer signal of the layered modulation signal to the at least one receiver;

wherein the first feeder link spot beam antenna transmits from a first coverage area and the second feeder link spot beam antenna transmits from a second coverage area distinct from the first coverage area and the second feeder link signal reuses a frequency spectrum of the first feeder link signal.

12. The method of claim 11, wherein a first frequency bandwidth of the upper layer signal partially overlaps a second frequency bandwidth of the lower layer signal.

13. The method of claim 11, wherein a first frequency bandwidth of the upper layer signal completely overlaps a second frequency bandwidth of the lower layer signal.

14. The method of claim 11, wherein the upper layer signal comprises a legacy signal.

15. The method of claim 11, wherein the first transponder and the second transponder are both on a common satellite.

16. The method of claim 11, wherein the first transponder and the second transponder are each on a different satellite.

17. The method of claim 11, wherein the first satellite transponder and the second satellite transponder include amplifiers operable substantially at saturation.

18. The method of claim 11, wherein the first satellite transponder for the upper layer signal includes a power combiner.

19. The method of claim 11, wherein at least one of the first feeder lick signal and the second feeder link signal are power level adjusted to maintain a relative power level between the upper layer signal and the lower layer signal for reception.

20. The method of claim 11, wherein the upper layer signal and the lower layer signal are non-coherent.