Methods of ground based beamforming and on-board frequency translation and related systems

• US 20050288011A1
• Filed: 06/24/2005
• Published: 12/29/2005
• Est. Priority Date: 06/25/2004
• Status: Active Grant

• Current Assignee: ATC Technology Corporation (FedEx Corporation)
• Original Assignee: ATC Technology Corporation (FedEx Corporation)
• Inventors: Dutta, Santanu
• Granted Patent: US 7,706,748 B2
• Time in Patent Office: Days
• US Class Current: 455/13.3
• CPC Class Codes: H04B 7/18539 Arrangements for managing radio, resources, i.e. for establishing or releasing a connection
• CPC Class Codes: H04B 7/2041 Spot beam multiple access

Abstract

Methods are provided to operate a communications system including a satellite and a satellite gateway. In particular, a feeder link may be provided between the satellite and the satellite gateway over a feeder link frequency band for communication of information between the satellite gateway and the satellite. A service link may be provided between the satellite and at least one radioterminal in a coverage area of the satellite over a service link frequency band. Moreover, the feeder link and service link frequency bands may be different. In addition, a frequency segment of the feeder link may be linearly translated from the feeder link frequency band to the service link frequency band to provide a frequency segment of the service link. Related satellites are also discussed.

Claims

1. A method of operating a communications system including a satellite and a satellite gateway, the method comprising:

providing a feeder link between the satellite and the satellite gateway, wherein the feeder link is provided over a feeder link frequency band for communication of information between the satellite gateway and the satellite;

providing a service link between the satellite and at least one radioterminal in a coverage area of the satellite, wherein the service link is provided over a service link frequency band and wherein the feeder link and service link frequency bands are different; and

linearly frequency translating a frequency segment of the feeder link from the feeder link frequency band to the service link frequency band to provide a frequency segment of the service link.

2. A method according to claim 1 further comprising:

providing a second service link between the satellite and at least one radioterminal in a second coverage area of the satellite, wherein the second service link is provided over the service link frequency band; and

linearly frequency translating a second frequency segment of the feeder link from the feeder link frequency band to the service link frequency band to provide a second frequency segment of the second service link.

3. A method according to claim 2 wherein the first frequency segment of the first service link provides content for a first plurality of radioterminals in the first coverage area, and wherein the second frequency segment of the second service link provides content for a second plurality of radioterminals in the second coverage area.

4. A method according to claim 2 wherein the first frequency segment of the feeder link is transmitted to the satellite using a first polarization and wherein the second frequency segment of the feeder link is transmitted to the satellite using a second polarization, wherein the first and second polarizations are different.

5. A method according to claim 4 wherein the second polarization is orthogonal with respect to the first polarization.

6. A method according to claim 1 wherein a bandwidth of frequencies spanned by the frequency segment of the feeder link is about the same as a bandwidth of frequencies spanned by the frequency segment of the service link.

7. A method according to claim 1 further comprising:

providing a second feeder link between the satellite and a second satellite gateway, wherein the second feeder link is provided over the feeder link frequency band for communication of information between the second satellite gateway and the satellite;

providing a second service link between the satellite and at least one radioterminal in a second coverage area of the satellite, wherein the second service link is provided over the service link frequency band; and

linearly frequency translating a frequency segment of the second feeder link from the feeder link frequency band to the service link frequency band to provide a second frequency segment of the second service link.

8. A method according to claim 7 wherein the first frequency segment of the first service link provides content for a first plurality of radioterminals in the first coverage area, and wherein the second frequency segment of the second service link provides content for a second plurality of radioterminals in the second coverage area.

9. A method according to claim 7 further comprising:

transmitting first pilot signals from the first satellite gateway to the satellite over the first feeder link;

transmitting second pilot signals from the second satellite gateway to the satellite over the second feeder link wherein the first and second pilot signals are different; and

performing interference cancellation at the satellite based on a priori knowledge of the first and second pilot signals.

10. A method according to claim 1 wherein the frequency segment of the service link provides content for the at least one radioterminal.

11. A method according to claim 1 wherein the frequency segment of the service link provides content for a plurality of radioterminals in the coverage area.

12. A method of operating a communications system including a satellite and a satellite gateway, the method comprising:

providing a feeder link between the satellite and the satellite gateway, wherein the feeder link is provided over a feeder link frequency band for communication of information between the satellite gateway and the satellite;

providing a service link between the satellite and at least one radioterminal in a coverage area of the satellite, wherein the service link is provided over a service link frequency band and wherein the feeder link and service link frequency bands are different; and

linearly frequency translating a frequency segment of the service link from the service link frequency band to the feeder link frequency band to provide a frequency segment of the feeder link.

13. A method according to claim 12 further comprising:

providing a second service link between the satellite and at least one radioterminal in a second coverage area of the satellite, wherein the second service link is provided over the service link frequency band; and

linearly frequency translating a second frequency segment of the second service link from the service link frequency band to the feeder link frequency band to provide a second frequency segment of the feeder link.

14. A method according to claim 13 wherein the first frequency segment of the first service link provides content from a first plurality of radioterminals in the first coverage area, and wherein the second frequency segment of the second service link provides content from a second plurality of radioterminals in the second coverage area.

15. A method according to claim 13 wherein the first frequency segment of the feeder link is transmitted from the satellite using a first polarization and wherein the second frequency segment of the feeder link is transmitted from the satellite using a second polarization, wherein the first and second polarizations are different.

16. A method according to claim 15 wherein the second polarization is orthogonal with respect to the first polarization.

17. A method according to claim 12 wherein a bandwidth of frequencies spanned by the frequency segment of the feeder link is about the same as a bandwidth of frequencies spanned by the frequency segment of the service link.

18. A method according to claim 12 further comprising:

providing a second feeder link between the satellite and a second satellite gateway, wherein the second feeder link is provided over the feeder link frequency band for communication of information between the second satellite gateway and the satellite;

providing a second service link between the satellite and at least one radioterminal in a second coverage area of the satellite, wherein the second service link is provided over the service link frequency band; and

linearly frequency translating a second frequency segment of the second service link from the service link frequency band to the feeder link frequency band to provide a second frequency segment of the second feeder link.

19. A method according to claim 18 wherein the first frequency segment from the first service link provides content from a first plurality of radioterminals in the first coverage area, and wherein the second frequency segment from the second service link provides content from a second plurality of radioterminals in the second coverage area.

20. A method according to claim 18 further comprising:

transmitting first pilot signals from the satellite over the first feeder link to the first satellite gateway;

transmitting second pilot signals from the satellite over the second feeder link to the second satellite gateway wherein the first and second pilot signals are different; and

performing interference cancellation at the first and second satellite gateways based on a priori knowledge of the first and second pilot signals.

21. A method according to claim 12 wherein the frequency segment of the service link provides content from the at least one radioterminal in the coverage area of the service link.

22. A method according to claim 12 wherein the frequency-segment of the service link provides content from a plurality of radioterminals in the coverage area of the service link.

23. A satellite for relaying communications between a satellite gateway and at least one radioterminal in a coverage area of the satellite, the satellite comprising;

a feeder link receiver configured to receive information from the satellite gateway using a feeder link provided over a feeder link frequency band;

a service link transmitter configured to transmit information to the at least one radioterminal in the coverage area using a service link provided over a service link frequency band, wherein the service link frequency band and the feeder link frequency band are different; and

a frequency translator coupled between the feeder link receiver and the service link transmitter, wherein the frequency translator is configured to provide linear frequency translation of a frequency segment of the feeder link from the feeder link frequency band to the service link frequency band to provide a frequency segment of the service link.

24. A satellite according to claim 23 wherein the service link transmitter is further configured to transmit information to at least one radioterminal in a second coverage area using a second service link provided over the service link frequency band, the satellite further comprising:

a second frequency translator coupled between the feeder link receiver and the service link transmitter, wherein the second frequency translator is configured to provide linear frequency translation of a second frequency segment of the feeder link from the feeder link frequency band to the service link frequency band to provide a second frequency segment of the second service link.

25. A satellite according to claim 24 wherein the first frequency segment of the first service link provides content for a first plurality of radioterminals in the first coverage area, and wherein the second frequency segment of the second service link provides content for a second plurality of radioterminals in the second coverage area.

26. A satellite according to claim 24 wherein the feeder link receiver is configured to receive first frequency segment using a first polarization and to receive the second frequency segment using a second polarization, wherein the first and second polarizations are different.

27. A satellite according to claim 26 wherein the second polarization is orthogonal with respect to the first polarization.

28. A satellite according to claim 23 wherein a bandwidth of frequencies spanned by the frequency segment of the feeder link is about the same as a bandwidth of frequencies spanned by the frequency segment of the service link.

29. A satellite according to claim 23 further comprising:

a second feeder link receiver configured to receive information from a second satellite gateway using a second feeder link provided over the feeder link frequency band wherein the service link transmitter is configured to provide a second service link between the satellite and at least one radioterminal in a second coverage area of the satellite, wherein the second service link is provided over the service link frequency band; and

a second frequency translator coupled between the second feeder link receiver and the service link transmitter, wherein the second frequency translator is configured to provide linear frequency translation of a second frequency segment of the second feeder link from the feeder link frequency band to the service link frequency band to provide a second frequency segment of the second service link.

30. A satellite according to claim 29 wherein the first frequency segment of the first service link provides content for a first plurality of radioterminals in the first coverage area, and wherein the second frequency segment of the second service link provides content for a second plurality of radioterminals in the second coverage area.

31. A satellite according to claim 29 wherein the first feeder link receiver is configured to receive first pilot signals from the first satellite gateway over the first feeder link, wherein the second feeder link receiver is configured to receive second pilot signals from the second satellite gateway over the second feeder link, wherein the first and second pilot signals are different, and wherein the first and/or second feeder link receivers are configured to perform interference cancellation based on a priori knowledge of the first and second pilot signals.

32. A satellite according to claim 23 wherein the frequency segment of the service link provides content for the at least one radioterminal in the coverage area.

33. A satellite according to claim 23 wherein the frequency segment of the service link provides content for a plurality of radioterminals in the coverage area.

34. A satellite for relaying communications between a satellite gateway and at least one radioterminal in a coverage area of the satellite, the satellite comprising:

a service link receiver configured to receive information from the at least one radioterminal in the coverage area using a service link provided over a service link frequency band,

a feeder link transmitter configured to transmit information to the satellite gateway using a feeder link provided over a feeder link frequency band, wherein the service link frequency band and the feeder link frequency band are different; and

a frequency translator coupled between the service link receiver and the feeder link transmitter, wherein the frequency translator is configured to provide linear frequency translation of a frequency segment of the service link from the service link frequency band to the feeder link frequency band to provide a frequency segment of the feeder link.

35. A satellite according to claim 34 wherein the service link receiver is further configured to receive information from at least one radioterminal in a second coverage area using a second service link provided over the service link frequency band, the satellite further comprising:

a second frequency translator coupled between the service link receiver and the feeder link transmitter, wherein the second frequency translator is configured to provide linear frequency translation of a second frequency segment of the second service link from the service link frequency band to the feeder link frequency band to provide a second frequency segment of the feeder link.

36. A satellite according to claim 35 wherein the first frequency segment of the first service link provides content from a first plurality of radioterminals in the first coverage area, and wherein the second frequency segment of the second service link provides content from a second plurality of radioterminals in the second coverage area.

37. A satellite according to claim 35 wherein the feeder link transmitter is configured to transmit the first frequency segment using a first polarization and to transmit the second frequency segment using a second polarization, wherein the first and second polarizations are different.

38. A satellite according to claim 37 wherein the second polarization is orthogonal with respect to the first polarization.

39. A satellite according to claim 34 wherein a bandwidth of frequencies spanned by the frequency segment of the feeder link is about the same as a bandwidth of frequencies spanned by the frequency segment of the service link.

40. A satellite according to claim 34 further comprising:

a second feeder link transmitter configured to transmit information to a second satellite gateway using a second feeder link provided over the feeder link frequency band, wherein the service link receiver is configured to provide a second service link between the satellite and at least one radioterminal in a second coverage area of the satellite; and

a second frequency translator coupled between the second feeder link receiver and the service link transmitter, wherein the second frequency translator is configured to provide linear frequency translation of a second frequency segment of the second service link from the service link frequency band to the feeder link frequency band to provide a second frequency segment of the second feeder link.

41. A satellite according to claim 40 wherein the first frequency segment of the first service link provides content from a first plurality of radioterminals in the first coverage area, and wherein the second frequency segment of the second service link provides content from a second plurality of radioterminals in the second coverage area.

42. A satellite according to claim 40 wherein the first feeder link transmitter is configured to transmit first pilot signals to the first satellite gateway over the first feeder link, wherein the second feeder link transmitter is configured to transmit second pilot signals to the second satellite gateway over the second feeder link, wherein the first and second pilot signals are different, and wherein the first and/or second satellite gateways are configured to perform interference cancellation based on a priori knowledge of the first and second pilot signals.

43. A satellite according to claim 34 wherein the frequency segment of the service link provides content from the at least one radioterminal in the coverage area.

44. A satellite according to claim 34 wherein the frequency segment of the service link provides content from a plurality of radioterminals in the coverage area.