Satellite communication system employing a combination of time slots and orthogonal codes

• US 7,630,682 B2
• Filed: 01/04/2006
• Issued: 12/08/2009
• Est. Priority Date: 01/04/2006
• Status: Active Grant

• Current Assignee: Globalstar Incorporated
• Original Assignee: Globalstar Incorporated
• Inventors: Gallagher, Vijaya, Monte, Paul A.
• Primary Examiner(s): Lee; John
• Application Number:
  US11/325,176
• Publication Number:
  US 20070155316A1
• Time in Patent Office: 1,434 Days
• Field of Search: 455/12.1, 455/13.2, 455/3.02, 455/3.03, 455/427, 455/430, 455/428, 455/456.1, 455/429, 455/437, 455/436, 455/446, 455/13.4, 455/69, 370/252, 370/321, 370/329, 370/401, 370/259
• US Class Current: 455/12.1
• CPC Class Codes: H04B 7/195 Non-synchronous stations

Abstract

A satellite communication system is disclosed which provides multiple beams and employs a plurality of user terminals (UT) and at least one gateway connected to a PSTN which communicates with at least one UT over the constellation wherein each of the UTs within a given frequency band is distinguished one from the other employing a combination of time slots and orthogonal codes.

Claims

1. A satellite communication system for communicating between a plurality of user terminals comprising:

a satellite constellation wherein each satellite of said constellation provides multiple beams;

a plurality of user terminals that communicate with each other via satellites of said constellation;

at least one gateway connected to a PSTN and communicating with at least one user terminal over the constellation wherein each of said user terminals within a given frequency band is distinguished from another of said user terminals employing a combination of time slots and orthogonal codes;

wherein each of said user terminals is equipped to initiate or receive or terminate packet data messages;

wherein each of said user terminals is handed off from one beam of a satellite to another beam of said satellite; and

wherein said hand off is predicated on signal strength determined at said plurality of user terminals.

2. A satellite communication system as defined in claim 1 wherein said combination of time slots and orthogonal codes is implemented in a forward and return link.

3. A satellite communication system as defined in claim 2 wherein said forward link comprises orthogonal codes and said return link comprises a combination of time slots and phase shift of one or more pseudo-random codes.

4. A satellite communication system as defined in claim 1 wherein said satellite constellation comprises a LEO satellite constellation.

5. A satellite communication system as defined in claim 4 wherein said combination of time slots and orthogonal codes is implemented in a forward and return link.

6. The constellation as defined in claim 5 wherein said forward link comprises orthogonal codes and said return link comprises a combination of time slots and phase shift of one or more pseudo-random codes.

7. A satellite communication system as defined in claim 1 wherein said satellite constellation comprises a MEO satellite constellation.

8. The constellation as defined in claim 7 wherein said combination of time slots and orthogonal codes is implemented in a forward and return link.

9. A satellite communication system as defined in claim 1 wherein said satellite constellation comprises a GEO satellite constellation.

10. The constellation as defined in claim 8 wherein said forward link comprises orthogonal codes and said return link comprises a combination of time slots and phase shift of one or more pseudo-random codes.

11. The constellation as defined in claim 9 wherein said combination of time slots and orthogonal codes is implemented in a forward and return link.

12. A satellite communication system as defined in claim 11 wherein said forward link comprises orthogonal codes and said return link comprises a combination of time slots and phase shift of one or more pseudo-random codes.

13. A satellite communication system for communicating with a plurality of user terminals comprising:

a satellite constellation wherein each satellite of said constellation provides multiple beams;

a plurality of user terminals that communicate with each other, a PSTN, or a data network, via satellites of said constellation;

at least one gateway connected to a PSTN and/or a data network and communicating with at least one user terminal over the constellation wherein each of said user terminals within a given frequency band is distinguished from another of said user terminals employing a combination of time slots and orthogonal codes;

wherein each of said user terminals is equipped to initiate or receive or terminate packet data messages; and

wherein each of said user terminals is handed off from one beam of a satellite to another beam of said satellite.

14. A satellite communication system as defined in claim 13 wherein said combination of time slots and orthogonal codes is implemented in a forward and return link.

15. A satellite communication system as defined in claim 14 wherein said forward link comprises orthogonal codes and said return link comprises a combination of time slots and phase shift of one or more pseudo-random codes.

16. A satellite communication system as defined in claim 13 wherein said satellite constellation comprises a LEO satellite constellation, wherein said combination of lime slots and orthogonal codes is implemented in a forward and return link, and wherein said forward link comprises orthogonal codes and said return link comprises a combination of time slots and phase shift of one or more pseudo-random codes.

17. A satellite communication system as defined in claim 13 wherein said satellite constellation comprises a MIEO satellite constellation, wherein said combination of time slots and orthogonal codes is implemented in a forward and return link, and wherein said forward link comprises orthogonal codes and said return link comprises a combination of time slots and phase shift of one or more pseudo-random codes.

18. A satellite communication system as defined in claim 13 wherein said satellite constellation comprises a GEO satellite constellation, wherein said combination of time slots and orthogonal codes is implemented in a forward and return link, and wherein said forward link comprises orthogonal codes and said return link comprises a combination of time slots and phase shift of one or more pseudo-random codes.