Methods and systems for modifying satellite antenna cell patterns in response to terrestrial reuse of satellite frequencies

• US 7,062,267 B2
• Filed: 08/22/2002
• Issued: 06/13/2006
• Est. Priority Date: 09/14/2001
• Status: Expired due to Term

• Current Assignee: ATC Technology Corporation (FedEx Corporation)
• Original Assignee: ATC Technology Corporation (FedEx Corporation)
• Inventors: Karabinis, Peter D.
• Primary Examiner(s): Feild, Joseph
• Assistant Examiner(s): Nguyen, David Q.
• Application Number:
  US10/225,615
• Publication Number:
  US 20030054815A1
• Time in Patent Office: 1,391 Days
• Field of Search: 455/427, 455/12.1, 455/63, 455/524, 455/429, 455/428, 225/63, 225/67, 375/240, 320/300
• US Class Current: 455/427
• CPC Class Codes: H04B 7/18513 Transmission in a satellite or space-based system
• CPC Class Codes: H04B 7/18543 for adaptation of transmission parameters, e.g. power control for detecting or preventing errors in the information received H04L1/00
• CPC Class Codes: H04B 7/18563 Arrangements for interconnecting multiple systems data switching networks H04L12/00
• CPC Class Codes: H04B 7/216 Code division or spread-spectrum multiple access [CDMA, SSMA]
• CPC Class Codes: H04W 16/02 Resource partitioning among network components, e.g. reuse partitioning

Abstract

Space-based wireless radiotelephone communications are provided in a satellite footprint over a satellite radiotelephone frequency band. The satellite footprint is divided into satellite cells in which satellite radiotelephone frequencies of the satellite radiotelephone frequency band are spatially reused. At least one of the satellite radiotelephone frequencies that is assigned to a given satellite cell in the satellite footprint is terrestrially reused outside the given satellite cell. A radiation pattern of at least the given satellite cell is modified to reduce interference with the at least one of the satellite radiotelephone frequencies that is terrestrially reused outside the given satellite cell.

Claims

1. A satellite radiotelephone communications method comprising:

providing space-based wireless radiotelephone communications in a satellite footprint over a satellite radiotelephone frequency band, the satellite footprint being divided into a plurality of satellite cells in which satellite radiotelephone frequencies of the satellite radiotelephone frequency band are spatially reused;

terrestrially reusing at least one of the satellite radiotelephone frequencies that is assigned to a predetermined satellite cell in the satellite footprint, outside the predetermined satellite cell; and

modifying a radiation pattern of at least the predetermined satellite cell to reduce interference with the at least one of the satellite radiotelephone frequencies that is terrestrially reused outside the predetermined satellite cell.

2. A satellite radiotelephone communications method according to claim 1 wherein the modifying comprises:

obtaining at least one location outside the predetermined satellite cell where the at least one of the satellite radiotelephone frequencies that is terrestrially reused is subject to and/or can produce interference; and

modifying the radiation pattern of the predetermined satellite cell to reduce interference at the at least one location outside the predetermined satellite cell, with the at least one of the satellite radiotelephone frequencies that is terrestrially reused at the at least one location outside the predetermined satellite cell.

3. A satellite radiotelephone communications method according to claim 1 wherein the modifying is preceded by:

monitoring signal levels and/or content of at least one satellite Broadcast Control CHannel (BCCH) at at least one location outside the predetermined satellite cell to determine where the at least one of the satellite radiotelephone frequencies that is terrestrially reused is subject to and/or can produce interference.

4. A satellite radiotelephone communications method according to claim 1:

wherein the modifying comprises increasing attenuation of the radiation pattern of the predetermined satellite cell as a boundary of the predetermined satellite cell is approached.

5. A satellite radiotelephone communications method according to claim 1 wherein the modifying is performed repeatedly.

6. A satellite radiotelephone communications method according to claim 1:

wherein the terrestrially reusing comprises terrestrially reusing at least one of the satellite radiotelephone frequencies that is assigned to a predetermined satellite cell in the satellite footprint, outside the predetermined satellite cell, in a network of ancillary terrestrial components; and

wherein the modifying comprises modifying a radiation pattern of at least the predetermined satellite cell to reduce interference with the at least one of the satellite radiotelephone frequencies that is terrestrially reused in at least one of the ancillary terrestrial components outside the predetermined satellite cell.

7. A satellite radiotelephone communications method according to claim 6 wherein the modifying comprises:

determining a location of the at least one of the ancillary terrestrial components outside the predetermined satellite cell where the at least one of the satellite radiotelephone frequencies that is terrestrially reused is subject to and/or can produce interference; and

modifying the radiation pattern of the predetermined satellite cell to reduce interference at the at least one of the ancillary terrestrial components.

8. A satellite radiotelephone communications method according to claim 6 wherein the modifying is preceded by:

monitoring signal levels and/or content of at least one satellite Broadcast Control CHannel (BCCH) at at least one of the ancillary terrestrial components.

9. A satellite radiotelephone communications method according to claim 6:

wherein the modifying comprises increasing attenuation of the radiation pattern of the predetermined satellite cell as the at least one of the ancillary terrestrial components is approached.

10. A satellite radiotelephone communications method according to claim 1 wherein the terrestrially reusing comprises terrestrially reusing at least one of the satellite radiotelephone frequencies that is assigned to a predetermined satellite cell in the satellite footprint, outside the predetermined satellite cell and separated therefrom by a spatial guardband.

11. A satellite radiotelephone communications method according to claim 1:

wherein the modifying comprises calculating new antenna feed network weights for the radiation pattern of the predetermined satellite cell.

12. A satellite radiotelephone communications method according to claim 1 further comprising:

reducing interference by the terrestrially reused at least one of the satellite radiotelephone frequencies with the space-based wireless radiotelephone communications, using the terrestrially reused at least one of the satellite radiotelephone frequencies to cancel at least some of the interference.

13. A satellite radiotelephone system comprising:

a space-based component that is configured to provide wireless radiotelephone communications in a satellite footprint over a satellite radiotelephone frequency band, the satellite footprint being divided into a plurality of satellite cells in which satellite radiotelephone frequencies of the satellite radiotelephone frequency band are spatially reused;

an ancillary terrestrial network comprising a plurality of ancillary terrestrial components that are configured to terrestrially reuse at least one of the satellite radiotelephone frequencies that is assigned to a predetermined satellite cell in the satellite footprint, outside the predetermined satellite cell;

a monitor that is configured to monitor interference in at least one of the ancillary terrestrial components that is configured to terrestrially reuse the at least one of the satellite radiotelephone frequencies, by the at least one of the satellite radiotelephone frequencies that is used in the predetermined satellite cell; and

a controller that is configured to modify a radiation pattern by the space-based component of the at least one of the satellite radiotelephone frequencies in at least the predetermined satellite cell to reduce interference at the at least one of the ancillary terrestrial components, with the at least one of the satellite radiotelephone frequencies that is terrestrially reused by the at least one of the ancillary terrestrial components.

14. A satellite radiotelephone system according to claim 13:

wherein the monitor is further configured to identify the at least one of the ancillary terrestrial components that is configured to terrestrially reuse the at least one of the satellite radiotelephone frequencies.

15. A satellite radiotelephone system according to claim 13:

wherein the monitor is further configured to monitor signal levels and/or content of at least one Broadcast Control CHannel (BCCH) at at least one of the ancillary terrestrial components that is configured to terrestrially reuse the at least one of the satellite radiotelephone frequencies.

16. A satellite radiotelephone system according to claim 13:

wherein the controller is configured to increase attenuation of the radiation pattern by the space-based component as a boundary of the predetermined satellite cell is approached.

17. A satellite radiotelephone system according to claim 13 wherein the controller is configured to repeatedly modify the radiation pattern by the space-based component.

18. A satellite radiotelephone system according to claim 13 wherein the ancillary terrestrial network is configured to terrestrially reuse at least one of the satellite radiotelephone frequencies that is assigned to a predetermined satellite cell in the satellite footprint, outside the predetermined satellite cell and separated therefrom by a spatial guardband.

19. A satellite radiotelephone system according to claim 13:

wherein the controller is further configured to calculate new antenna feed network weights for the space-based component for the predetermined satellite cell.

20. A satellite radiotelephone system according to claim 13 further comprising:

an interference reducer that is configured to reduce interference by the terrestrially reused at least one of the satellite radiotelephone frequencies with the space-based wireless radiotelephone communications, using the terrestrially reused at least one of the satellite radiotelephone frequency to cancel at least some of the interference.

21. A system for reducing interference in a satellite radiotelephone system comprising a space-based component that is configured to provide wireless radiotelephone communications in a satellite footprint over a satellite radiotelephone frequency band, the satellite footprint being divided into a plurality of satellite cells in which satellite radiotelephone frequencies of the satellite radiotelephone frequency band are spatially reused, and an ancillary terrestrial network comprising a plurality of ancillary terrestrial components that are configured to terrestrially reuse at least one of the satellite radiotelephone frequencies that is assigned to a predetermined satellite cell in the satellite footprint, outside the predetermined satellite cell, the interference reducing system comprising:

a monitor that that is configured to monitor interference in at least one of the ancillary terrestrial components that is configured to terrestrially reuse the at least one of the satellite radiotelephone frequencies, by the at least one of the satellite radiotelephone frequencies that is used in the predetermined satellite cell; and

a controller that is configured to modify a radiation pattern by the space-based component of the at least one of the satellite radiotelephone frequencies in at least the predetermined satellite cell to reduce interference at the at least one of the ancillary terrestrial components, with the at least one of the satellite radiotelephone frequencies that is terrestrially reused by the at least one of the ancillary terrestrial components.

22. A system according to claim 21:

wherein the monitor is further configured to identify the at least one of the ancillary terrestrial components that is configured to terrestrially reuse the at least one of the satellite radiotelephone frequencies.

23. A system according to claim 21:

wherein the monitor is further configured to monitor signal levels and/or content of at least one Broadcast Control CHannel (BCCH) at at least one of the ancillary terrestrial components that is configured to terrestrially reuse the at least one of the satellite radiotelephone frequencies.

24. A system according to claim 21:

wherein the controller is configured to increase attenuation of the radiation pattern by the space-based component as a boundary of the predetermined satellite cell is approached.

25. A system according to claim 21 wherein the controller is configured to repeatedly modify the radiation pattern by the space-based component.

26. A system according to claim 21 wherein the ancillary terrestrial network is configured to terrestrially reuse at least one of the satellite radiotelephone frequencies that is assigned to a predetermined satellite cell in the satellite footprint, outside the predetermined satellite cell and separated therefrom by a spatial guardband.

27. A system according to claim 21:

wherein the controller is further configured to calculate new antenna feed network weights for the space-based component for the predetermined satellite cell.

28. A system according to claim 21 further comprising:

an interference reducer that is configured to reduce interference by the terrestrially reused at least one of the satellite radiotelephone frequencies with the space-based wireless radiotelephone communications, using the terrestrially reused at least one of the satellite radiotelephone frequency to cancel at least some of the interference.

29. A system for reducing interference in a satellite radiotelephone system comprising a space-based component that is configured to provide wireless radiotelephone communications in a satellite footprint over a satellite radiotelephone frequency band, the satellite footprint being divided into a plurality of satellite cells in which satellite radiotelephone frequencies of the satellite radiotelephone frequency band are spatially reused, and an ancillary terrestrial network comprising a plurality of ancillary terrestrial components that are configured to terrestrially reuse at least one of the satellite radiotelephone frequencies that is assigned to a predetermined satellite cell in the satellite footprint, outside the predetermined satellite cell, the interference reducing system comprising:

means for monitoring interference in at least one of the ancillary terrestrial components that is configured to terrestrially reuse the at least one of the satellite radiotelephone frequencies, by the at least one of the satellite radiotelephone frequencies that is used in the predetermined satellite cell; and

means for modifying a radiation pattern by the space-based component of the at least one of the satellite radiotelephone frequencies in at least the predetermined satellite cell to reduce interference at the at least one of the ancillary terrestrial components, with the at least one of the satellite radiotelephone frequencies that is terrestrially reused by the at least one of the ancillary terrestrial components.

30. A system according to claim 29:

wherein the means for monitoring comprises means for identifying the at least one of the ancillary terrestrial components that is configured to terrestrially reuse the at least one of the satellite radiotelephone frequencies.

31. A system according to claim 29:

wherein the means for monitoring further comprises means for monitoring signal levels and/or content of at least one satellite Broadcast Control CHannel (BCCH) at the at least one of the ancillary terrestrial components that is configured to terrestrially reuse the at least one of the satellite radiotelephone frequencies.

32. A system according to claim 29:

wherein the means for modifying comprises means for increasing attenuation of the radiation pattern by the space-based component as a boundary of the predetermined satellite cell is approached.

33. A system according to claim 29 wherein the means for modifying comprises means for repeatedly modifying the radiation pattern by the space-based component.

34. A system according to claim 29 wherein the ancillary terrestrial network is configured to terrestrially reuse at least one of the satellite radiotelephone frequencies that is assigned to a predetermined satellite cell in the satellite footprint, outside the predetermined satellite cell and separated therefrom by a spatial guardband.

35. A system according to claim 29:

wherein the means for modifying comprises means for calculating new antenna feed network weights for the space-based component for the predetermined satellite cell.

36. A system according to claim 29 further comprising:

an interference reducer that is configured to reduce interference by the terrestrially reused at least one of the satellite radiotelephone frequencies with the space-based wireless radiotelephone communications, using the terrestrially reused at least one of the satellite radiotelephone frequency to cancel at least some of the interference.

37. A satellite radiotelephone communications method comprising:

providing space-based wireless radiotelephone communications in a satellite footprint over a satellite radiotelephone frequency band, the satellite footprint being divided into a plurality of satellite cells in which satellite radiotelephone frequencies of the satellite radiotelephone frequency band are spatially reused; and

modifying a radiation pattern of a predetermined satellite cell to reduce interference with at least one of the satellite radiotelephone frequencies that is terrestrially reused outside the predetermined satellite cell.

38. A satellite radiotelephone communications method according to claim 37 wherein the modifying comprises:

obtaining at least one location outside the predetermined satellite cell where the at least one of the satellite radiotelephone frequencies that is terrestrially reused is subject to and/or can produce interference; and

modifying the radiation pattern of the predetermined satellite cell to reduce interference at the at least one location outside the predetermined satellite cell, with the at least one of the satellite radiotelephone frequencies that is terrestrially reused at the at least one location outside the predetermined satellite cell.

39. A satellite radiotelephone communications method according to claim 37:

wherein the obtaining at least one location comprises monitoring signal levels and/or content of at least one Broadcast Control CHannel (BCCH) at at least one location outside the predetermined satellite cell to determine where the at least one of the satellite radiotelephone frequencies that is terrestrially reused is subject to and/or can produce interference.

40. A satellite radiotelephone communications method according to claim 37:

wherein the modifying comprises increasing attenuation of the radiation pattern of the predetermined satellite cell as a boundary of the predetermined satellite cell is approached.

41. A satellite radiotelephone communications method according to claim 37 wherein the modifying is performed repeatedly.

42. A satellite radiotelephone communications method according to claim 37:

wherein the modifying comprises calculating new antenna feed network weights for the radiation pattern of the predetermined satellite cell.

43. A satellite radiotelephone communications method according to claim 37 further comprising:

reducing interference by the terrestrially reused at least one of the satellite radiotelephone frequencies with the space-based wireless radiotelephone communications, using the terrestrially reused at least one of the satellite radiotelephone frequencies to cancel at least some of the interference.