Space-based communication system and method with continuous channel reuse maintenance

• US 5,862,479 A
• Filed: 12/27/1996
• Issued: 01/19/1999
• Est. Priority Date: 12/27/1996
• Status: Expired due to Term

• Current Assignee: CDC Propriete Intellectuelle
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Olds, Keith Andrew, Davieau, Gerald Joseph, Cutler, Jr., Victor Hawes
• Primary Examiner(s): LE, THANH C
• Application Number:
  US08/775,073
• Time in Patent Office: 753 Days
• Field of Search: 455/446, 455/447, 455/448, 455/450, 455/451, 455/452, 455/427, 455/428, 455/429, 455/430, 455/62, 455/63, 455/67.1, 455/67.3, 455/12.1, 455/13.1, 455/507, 455/509
• US Class Current: 455/428
• CPC Class Codes: H04B 7/195 Non-synchronous stations

Abstract

The system (10) and method (100) adjust reuse units when nodes (e.g., satellites (20, 22)) move in a communication system (10), such as satellites (20,22) moving in their orbits around the earth in a space-based communication system (10). The method (100) and system (10) computes interference potentials between a reference reuse unit in a first reuse unit table of a first satellite (20) and reuse units being used in second reuse unit tables in second satellites (20) that are adjacent to the first satellite (20); and when the interference potentials is less than a predetermined threshold, then assigns the satellite a non-interfering reuse unit for the specific time interval.

Claims

1. A method of reuse channel management, the method comprising the steps of:

(a) computing interference potentials between a reference reuse unit being used by a first satellite and reuse units being used by second satellites by determining each of the interference potentials based on a physical distance between a center of a first beam that uses the reference reuse unit and each of a center of second beams that use the reuse units and a correlation factor; and

(b) assigning a non-interfering reuse unit to the first satellite when each of the interference potentials are less than a threshold interference potential.

2. A method as recited in claim 1, further comprising the step of initiating the method during a planning process.

3. A method as recited in claim 1, further comprising the step of initiating the method when one of the first and the second satellites goes down or malfunctions.

4. A method as recited in claim 1, further comprising the steps of:

using a first reuse unit table to store the reference reuse unit; and

using second reuse unit tables, each storing reuse units being used by one of the second satellites.

5. A method as recited in claim 1, wherein the reference reuse unit and each of the reuse units includes eight contiguous communication channels.

6. A method as recited in claim 1, wherein the reference reuse unit and each of the reuse units has a particular time slot and frequency.

7. A method as recited in claim 1, wherein the reference reuse unit and each of the reuse units has a combination of a time slot, frequency or code.

8. A method as recited in claim 1, further comprising the step of:

(c) repeating steps (a) and (b) for each reference reuse unit being used by the first satellite.

9. A method as recited in claim 8, further comprising the step of:

(d) repeating steps (a), (b), and (c) for each time interval.

10. A method as recited in claim 1, further comprising the step of:

(c) repeating steps (a) and (b) for each reuse unit of each of the second satellites.

11. A method as recited in claim 10, further comprising the step of:

(d) repeating steps (a), (b), and (c) for each time interval.

12. A method as recited in claim 1, further comprising the steps of:

(c) repeating steps (a) and (b) for each reference reuse unit being used by the first satellite and for each reuse unit of each of the second satellites; and

(d) repeating steps (a), (b), and (c) for each time interval.

13. A method as recited in claim 1, wherein the determining step includes the step of measuring the physical distance as a linear distance between the centers of the first and second beams.

14. A method as recited in claim 1, wherein the determining step includes the step of measuring the physical distance along a surface of earth where the center of the first and second beams are located.

15. A method as recited in claim 1, wherein step (b) comprises the step of determining whether the interference potentials are less than a predetermined threshold distance and correlation.

16. A method as recited in claim 1, wherein step (b) comprises the step of determining whether the interference potentials of the reference reuse unit and each of the reuse units will not interfere with each other.

17. A system comprising:

a plurality of satellites; and

a base station that is capable of communicating with the satellites and includes means for performing a reuse maintenance method that computes interference potentials between a reference reuse unit being used by a first satellite and reuse units being used by the other satellites, for determining each of the interference potentials based on a physical distance between a center of a first beam that uses the reference reuse unit and each of a center of second beams that uses one of the reuse units and a correlation factor and for assigning a non-interfering reuse unit to the first satellite when each of the interference potentials are less than a threshold interference potential.

18. A system as recited in claim 17, wherein the base station includes means for initiating the reuse maintenance method during a planning process.

19. A system as recited in claim 17, wherein the base station includes means for initiating the reuse maintenance method when one of the satellites goes down or malfunctions.

20. A system as recited in claim 17, wherein the base station includes means for repeating the computation and assignment for each reference reuse unit being used by each of the satellite.

21. A system as recited in claim 17, wherein the base station includes means for repeating the computation and assignment for each reference reuse unit being used by each of the satellite for each time interval.

22. A system as recited in claim 17, wherein the base station includes means for determining whether each of the interference potentials are less than a predetermined threshold distance and correlation.

23. A system as recited in claim 17, wherein the base station includes means for determining whether each of the interference potentials of the reference reuse unit and each of the reuse units will not interfere with each other.

24. A system as recited in claim 17, wherein the base station is a satellite.

25. A system as recited in claim 17, wherein the base station is located on earth.

26. A system comprising:

a plurality of satellites; and

a base station that is capable of communicating with the satellites and includes means for performing a reuse maintenance method that computes interference potentials between a reference reuse unit being used by a first satellite and reuse units being used by the other satellites, for determining each of the interference potentials based on a linear distance between a center of a first beam that uses the reference reuse unit and each of a center of second beams that uses one of the reuse unit and a correlation factor and for assigning a non-interfering reuse unit to the first satellite when each of the interference potentials are less than a threshold interference potential.

27. A system comprising:

a plurality of satellites; and

a base station that is capable of communicating with the satellites and includes means for performing a reuse maintenance method that computes interference potentials between a reference reuse unit being used by a first satellite and reuse units being used by the other satellites, for determining each of the interference potential based on a distance along a surface of earth between a center of a first beam that uses the reference reuse unit and each of a center of second beams that uses one of the reuse units and a correlation factor and for assigning a non-interfering reuse unit to the first satellite when each of the interference potentials are less than a threshold interference potential.

28. A method of reuse channel management comprising the steps of:

(a) computing interference potentials between a reference reuse unit being used by a first satellite and reuse units being used by second satellites by determining each of the interference potentials based on a linear distance between a center of a first beam that uses the reference reuse unit and each of a center of second beams that use the reuse units and a correlation factor; and

(b) assigning a non-interfering reuse unit to the first satellite when each of the interference potentials are less than a threshold interference potential.

29. A method of reuse channel management comprising the steps of:

(a) computing interference potentials between a reference reuse unit being used by a first satellite and reuse units being used by second satellites by determining each of the interference potentials based on a distance along a surface of earth between a center of a first beam that uses the reference reuse unit and each of a center of second beams that use the reuse units and a correlation factor; and

(b) assigning a non-interfering reuse unit to the first satellite when each of the interference potentials are less than a threshold interference potential.