Positioning of mobile wireless terminal

• US 20030197645A1
• Filed: 01/29/2003
• Published: 10/23/2003
• Est. Priority Date: 04/18/2002
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Yamada, Isamu, Ninomiya, Teruhisa
• Granted Patent: US 7,158,078 B2
• Time in Patent Office: Days
• US Class Current: 342/464
• CPC Class Codes: G01S 3/46 using antennas spaced apart and measuring phase or time difference between signals therefrom, i.e. path-difference systems
• CPC Class Codes: G01S 5/02 using radio waves using satellite radio beacon systems for determining position G01S19/00
• CPC Class Codes: G01S 5/08 Position of single direction-finder fixed by determining direction of a plurality of spaced sources of known location

Abstract

An apparatus for determining a position of a mobile wireless station comprises means for determining the position of the mobile wireless station in accordance with a position of a first reference wireless station, a position of a second reference wireless station, a first relative angular direction between the mobile wireless station and the first reference wireless station, and a second relative angular direction between the mobile wireless station and the second reference wireless station.

Claims

1. An apparatus for determining a position of a mobile wireless station, said apparatus comprising:

means for determining the position of said mobile wireless station in accordance with a position of a first reference wireless station, a position of a second reference wireless station, a first relative angular direction between said mobile wireless station and said first reference wireless station, and a second relative angular direction between said mobile wireless station and said second reference wireless station.

2. An apparatus according to claim 1, wherein said first and second relative angular directions are angular directions of said first and second reference wireless stations relative to a reference angular direction of said mobile wireless station.

3. An apparatus according to claim 1, wherein said first relative angular direction is determined in accordance with a first phase difference associated with a first RF signal from said first reference wireless station which is received by said mobile wireless station, and

said second relative angular direction is determined in accordance with a second phase difference associated with a second RF signal from said second reference wireless station which is received by said mobile wireless station.

4. An apparatus according to claim 1, wherein said first relative angular direction is an angular direction of said mobile wireless station relative to a reference angular direction of said first reference wireless station, and said second relative angular direction is an angular direction of said mobile wireless station relative to a reference angular direction of said second reference wireless station.

5. An apparatus according to claim 1, wherein the position of said mobile wireless station is determined further in accordance with a third relative angular direction between said first reference wireless station and said second reference wireless station.

6. An apparatus according to claim 1, wherein said first relative angular direction is determined in accordance with a first phase difference associated with an RF signal from said mobile wireless station which is received by said first reference wireless station, and

said second relative angular direction is determined in accordance with a second phase difference associated with an RF signal from said mobile wireless station which is received by said second reference wireless station.

7. An apparatus according to claim 1, wherein said position determining means determines the position of said mobile wireless station in accordance with the positions of said first and second reference wireless stations, said first and second relative angular directions, a position of a third reference wireless station, and a third relative angular direction between said mobile wireless station and said third reference wireless station.

8. An apparatus according to claim 7, wherein the position of said mobile wireless station is determined in accordance with at least two of three angles between said first, second and third relative angular directions.

9. An apparatus according to claim 1, wherein said apparatus is said mobile wireless station.

10. An apparatus according to claim 1, wherein said apparatus is one of said first and second reference wireless stations.

11. An apparatus according to claim 1, wherein said apparatus is connected to said first reference wireless station via a local area network.

12. An apparatus for determining an angular direction of a wireless station, comprising

means for determining the angular direction of said wireless station relative to a reference angular direction, in accordance with a phase difference associated with a received RF signal.

13. An apparatus according to claim 12, wherein said RF signal is received from said wireless station.

14. An apparatus according to claim 12, wherein said RF signal is received by said wireless station.

15. An apparatus according to claim 12, wherein said phase difference is a phase difference associated with said received RF signal between two antennas.

16. An apparatus according to claim 12, wherein said apparatus is said wireless station.

17. An apparatus according to claim 12, wherein said apparatus receives said RF signal from said wireless station.

18. An apparatus according to claim 12, wherein said apparatus receives said phase difference.

19. An apparatus according to claim 12, wherein said apparatus further comprises means for determining a position of said wireless station from the determined angular direction.

20. A wireless device comprising:

first and second antennas displaced from each other by a predetermined distance for receiving an RF signal; and

means for detecting a phase difference associated with said received RF signal between said first and second antennas.

21. A wireless device according to claim 20, further comprising means for detecting source identification included in said received RF signal.

22. A program stored on a storage medium for an information processing apparatus, said program being operable to effect the steps of:

obtaining a first relative angular direction between a mobile wireless station and a first reference wireless station;

obtaining a second relative angular direction between said mobile wireless station and a second reference wireless station; and

determining a position of said mobile wireless station in accordance with a position of said first reference wireless station, a position of said second reference wireless station, said first relative angular direction, and said second relative angular direction.

23. A program according to claim 22, being operable to further effect the steps of:

determining said first relative angular direction in accordance with a first phase difference associated with a first RF signal from said first reference wireless station which is received by said mobile wireless station, and

determining said second relative angular direction in accordance with a second phase difference associated with a second RF signal from said second reference wireless station which is received by said mobile wireless station.

24. A program according to claim 22, wherein the step of determining a position comprises determining the position of said mobile wireless station further in accordance with a third relative angular direction between said first reference wireless station and said second reference wireless station.

25. A program according to claim 22, being operable to further effect the steps of:

determining said first relative angular direction in accordance with a first phase difference associated with an RF signal from said mobile wireless station which is received by said first reference wireless station, and

determining said second relative angular direction in accordance with a second phase difference associated with an RF signal from said mobile wireless station which is received by said second reference wireless station.

26. A program according to claim 22, wherein the step of determining a position comprises determining the position of said mobile wireless station in accordance with the positions of said first and second reference wireless stations, said first and second relative angular directions, a position of a third reference wireless station, and a third relative angular direction between said mobile wireless station and said third reference wireless station.

27. A program stored on a storage medium for an information processing apparatus, said program being operable to effect the steps of:

obtaining a phase difference associated with a received RF signal; and

determining the angular direction of said wireless station relative to a reference angular direction, in accordance with said phase difference.

28. A program according to claim 27, being operable to further effect the step of determining a position of said wireless station in accordance with the determined angular direction.

29. A method for determining a position of a mobile wireless station, said method comprising:

obtaining a first relative angular direction between said mobile wireless station and a first reference wireless station;

obtaining a second relative angular direction between said mobile wireless station and a second reference wireless station; and

determining a position of said mobile wireless station in accordance with a position of said first reference wireless station, a position of said second reference wireless station, said first relative angular direction, and said second relative angular direction.

30. A method according to claim 29, further comprising the steps of:

determining said first relative angular direction in accordance with a first phase difference associated with a first RF signal from said first reference wireless station which is received by said mobile wireless station, and

determining said second relative angular direction in accordance with a second phase difference associated with a second RF signal from said second reference wireless station which is received by said mobile wireless station.

31. A method according to claim 29, wherein the step of determining a position comprises determining the position of said mobile wireless station further in accordance with a third relative angular direction between said first reference wireless station and said second reference wireless station.

32. A method according to claim 29, further comprising the steps of:

determining said first relative angular direction in accordance with a first phase difference associated with an RF signal from said mobile wireless station which is received by said first reference wireless station, and

determining said second relative angular direction in accordance with a second phase difference associated with an RF signal from said mobile wireless station which is received by said second reference wireless station.

33. A method according to claim 29, wherein the step of determining a position comprises determining the position of said mobile wireless station in accordance with the positions of said first and second reference wireless stations, said first and second relative angular directions, a position of a third reference wireless station, and a third relative angular direction between said mobile wireless station and said third reference wireless station.

34. A method for determining an angular direction of a wireless station, said method comprising the steps of:

obtaining a phase difference associated with a received RF signal; and

determining the angular direction of said wireless station relative to a reference angular direction, in accordance with said phase difference.

35. A method according to claim 34, further comprising the step of determining a position of said wireless station from the determined angular direction