Terminal position location using multiple beams

• US 6,684,071 B1
• Filed: 02/05/1996
• Issued: 01/27/2004
• Est. Priority Date: 01/11/1994
• Status: Expired due to Term

• Current Assignee: Ericsson, Inc. (Telefonaktiebolaget LM Ericsson)
• Original Assignee: Ericsson, Inc. (Telefonaktiebolaget LM Ericsson)
• Inventors: Molnar, Karl J., Dent, Paul W.
• Primary Examiner(s): CUMMING, WILLIAM D
• Application Number:
  US08/597,073
• Time in Patent Office: 2,913 Days
• Field of Search: 455/429, 455/456, 340/825.21, 340/825.49, 342/357
• US Class Current: 455/429
• CPC Class Codes: G01S 5/14 Determining absolute distances from a plurality of spaced points of known location
• CPC Class Codes: H01Q 1/246 specially adapted for base stations
• CPC Class Codes: H01Q 21/08 the units being spaced along or adjacent to a rectilinear path waveguide fed H01Q21/0037
• CPC Class Codes: H01Q 21/28 Combinations of substantially independent non-interacting antenna units or systems multiple beam H01Q25/00
• CPC Class Codes: H04B 7/0837 using pre-detection combining H04B7/0868 takes precedence
• CPC Class Codes: H04B 7/0851 using training sequences or error signal minimizing error signal H04B7/0854
• CPC Class Codes: H04B 7/10 Polarisation diversity; Directional diversity
• CPC Class Codes: H04B 7/18515 Transmission equipment in satellites or space-based relays
• CPC Class Codes: H04B 7/18532 Arrangements for managing transmission, i.e. for transporting data or a signalling message
• CPC Class Codes: H04B 7/18545 Arrangements for managing station mobility, i.e. for station registration or localisation
• CPC Class Codes: H04B 7/1855 using a telephonic control signal, e.g. propagation delay variation, Doppler frequency variation, power variation, beam identification
• CPC Class Codes: H04B 7/18567 Arrangements for providing additional services to the basic mobile satellite telephony service
• CPC Class Codes: H04L 25/03331 Arrangements for the joint estimation of multiple sequences
• CPC Class Codes: H04W 16/28 using beam steering
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management
• CPC Class Codes: H04W 84/06 Airborne or Satellite Networks space-based or airborne stations H04B7/185
• CPC Class Codes: H04W 88/02 Terminal devices

Abstract

Exemplary embodiments of the present invention describe terminal position location methods and systems. Relative powers of nearby spot beams which are generated by array antennas are determined. For example, powers from six neighboring spot beams relative to a center spot beam within which a mobile station is currently operating, can be measured relative to the power of the center spot beam. Using information from these measurements, the mobile stations position can be determined using, for example, an exponential model of the spot beam pattern.

Claims

1. A method for estimating a position of a terminal in a radiocommunication system using an array to illuminate areas with spot beams, comprising the steps of:

measuring a received power associated with each of a plurality of said spot beams;

determining relative powers associated with said received power by comparing said measured received powers with a reference power; and

estimating said position of said terminal using said relative powers and a model of spot beam shape.

2. The method of claim 1, wherein said step of measuring is performed at said terminal.

3. The method of claim 1, wherein said step of measuring is performed at one of a base station and a satellite.

4. The method of claim 2, wherein said reference power is a power received by said terminal of a spot beam which illuminates a geographical region in which said terminal is currently located.

5. The method of claim 1, wherein said steps of determining and estimating are performed in said terminal.

6. The method of claim 1, wherein said steps of determining and estimating are performed in one of a base station and a satellite.

7. The method of claim 1, wherein said model is an exponential model.

8. The method of claim 1, wherein said step of locating further comprises the step of:

repeatedly evaluating the following equation;

20. The method of claim 1, wherein said step of measuring further comprises the step of:

measuring each received power simultaneously.

21. The method of claim 1, wherein said step of measuring further comprises the step of:

measuring each received power in each of said plurality of spot beams on a different frequency.

22. The method of claim 1, wherein said step of measuring further comprises the step of:

measuring each received power at different times and adjusting the measured power taking into account movement of a satellite including said array.

9. A method for accessing a radiocommunication system comprising the steps of:

measuring a received power associated with each of a plurality of said spot beams;

determining relative powers associated with said received power by comparing said measured received powers with a reference power;

locating said terminal using said relative powers and a model of spot beam shape;

using said location of said terminal to determine a Doppler compensation; and

accessing said radiocommunication system using said Doppler compensation.

10. The method of claim 9, wherein said step of measuring is performed at said terminal.

11. The method of claim 9, wherein said step of measuring is performed at one of a base station and a satellite.

12. The method of claim 9, wherein said reference power is a power received by said terminal of a spot beam which illuminates a geographical region in which said terminal is currently located.

13. The method of claim 9, wherein said model is an exponential model.

14. The method of claim 9, wherein said step of locating further comprises the step of:

repeatedly evaluating the following equation;

23. The method of claim 9, wherein said step of measuring further comprises the step of:

measuring each received power simultaneously.

24. The method of claim 9, wherein said step of measuring further comprises the step of:

measuring each received power in each of said plurality of spot beams on a different frequency.

25. The method of claim 10, wherein said step of measuring further comprises the step of:

measuring each received power at different times and adjusting the measured power taking into account movement of a satellite including said array.

15. A method for handing over a connection in a system using an array to provide radiocommunication coverage to areas using spot beams, comprising the steps of:

measuring a received power associated with each of a plurality of said spot beams;

determining relative powers associated with said received power by comparing said measured, received powers with a reference power;

locating said terminal'"'"'s position using said relative powers and a model of spot beam shape; and

handing over said connection from a first spot beam to a second spot beam based on said terminal'"'"'s position.

16. The method of claim 15, wherein said reference power is a power received by said terminal of said first spot beam which illuminates a geographical region in which said terminal is currently located.

17. The method of claim 15, wherein said reference power is a power transmitted by said terminal of and received in a first spot beam of an array antenna which illuminates a geographical region in which said terminal is currently located when said array antenna is being used to transmit.

18. The method of claim 17, wherein said model is an exponential model.

19. The method of claim 15, wherein said step of locating further comprises the step of:

repeatedly evaluating the following equation;

26. The method of claim 15, wherein said step of measuring further comprises the step of:

measuring each received power simultaneously.

27. The method of claim 15, wherein said step of measuring further comprises the step of:

measuring each received power in each of said plurality of spot beams on a different frequency.

28. The method of claim 16, wherein said step of measuring further comprises the step of:

measuring each received power at different times and adjusting the measured power taking into account movement of a satellite including said array.