Position estimation of transceivers in communication networks

• US 20050255864A1
• Filed: 04/28/2004
• Published: 11/17/2005
• Est. Priority Date: 04/28/2004
• Status: Active Grant

• Current Assignee: Lawrence Livermore National Security LLC (Government of the United States of America)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Kent, Claudia A., Dowla, Farid
• Granted Patent: US 7,383,053 B2
• Time in Patent Office: Days
• US Class Current: 455/456.500
• CPC Class Codes: G01C 21/206 specially adapted for indoor navigation
• CPC Class Codes: G01S 13/878 Combination of several spaced transmitters or receivers of known location for determining the position of a transponder or a reflector G01S13/874 takes precedence
• CPC Class Codes: G01S 5/02213 Receivers arranged in a network for determining the position of a transmitter

Abstract

This invention provides a system and method using wireless communication interfaces coupled with statistical processing of time-of-flight data to locate by position estimation unknown wireless receivers. Such an invention can be applied in sensor network applications, such as environmental monitoring of water in the soil or chemicals in the air where the position of the network nodes is deemed critical. Moreover, the present invention can be arranged to operate in areas where a Global Positioning System (GPS) is not available, such as inside buildings, caves, and tunnels.

Claims

1. A wireless position estimation method, comprising:

statistically filtering time of flight information resulting from replies to queries to produce a plurality of range measurements; and

calculating a position estimate as a result of processing a predetermined collected number of filtered said range measurements.

2. The method of claim 1, wherein said statistical filtering includes a first filtering stage of removing data outliers from said filtered time-of flight information.

3. The method of claim 1, wherein said statistical filtering includes a second filtering stage utilizing a recursive weighted least squares estimator algorithm.

4. The method of claim 1, wherein said position estimation is capable of being determined down to about 1 ft.

5. The method of claim 1, wherein said method includes one or more transmitters and one or more receivers selected from cell phones, pagers, personal identification cards, laptops, and personal digital assistants (PDA'"'"'s).

6. The method of claim 5, wherein said one or more receivers are adapted to operate using a commercial wireless communication standard.

7. The method of claim 6, wherein said wireless communication standard includes UWB frequencies.

8. The method of claim 6, wherein said wireless communication standard includes IEEE802.

9. The method of claim 6, wherein said wireless communication standard includes Bluetooth.

10. The method of claim 1, wherein said position estimation method can be adapted with a GPS system.

20. The method of claim 7, wherein said wireless communication standard includes IEEE802.

21. The method of claim 6, wherein said wireless communication standard includes Bluetooth.

22. The method of claim 1, wherein said position estimation method can be adapted with a GPS system.

11. A wireless position estimation method, comprising:

transmitting from one or more known positions, a plurality of queries;

continuously collecting a plurality of replies from one or more receivers that receive said plurality of queries;

filtering time of flight information resulting from said transmission and said one or more replies to produce a plurality of range measurements;

wherein said filtering includes a two-stage statistical analysis; and

calculating a position estimate of each of said one or more receivers as a result of a predetermined collected number of filtered range measurements from said one or more known positions.

12. The method of claim 11, wherein said two-stage statistical analysis includes removing data outliers from said collected plurality of replies.

13. The method of claim 11, wherein said two-stage statistical analysis includes a recursive weighted least squares estimator algorithm.

14. The method of claim 11, wherein a single transmitter is capable of being physically moved to said known positions.

15. The method of claim 11, wherein said transmitting step includes at least 3 transmitters arranged at said known positions.

16. The method of claim 11, wherein said position estimation is capable of being determined down to about 1 ft.

17. The method of claim 11, wherein said one or more receivers and one or more transmitters can include an apparatus selected from cell phones, pagers, personal identification cards, laptops, and personal digital assistants (PDA'"'"'s).

18. The method of claim 17, wherein said one or more transmitters and said one or more receivers are configured to operate using a commercial wireless communication standard.

19. The method of claim 17, wherein said wireless communication standard includes UWB frequencies.

23. A wireless position estimation system, comprising:

at least one receiver, capable of sending a wireless reply upon receipt of each of one or more wireless queries;

one or more transmitters capable of being arranged from known positions and capable of transmitting a plurality of said wireless queries; and

wherein said one or more transmitters are capable of statistically filtering each said wireless reply to produce a plurality of range measurements that can be further utilized to calculate a position estimate of each said receiver.

24. The system of claim 23, wherein said statistical filtering includes removing data outliers from said collected plurality of replies.

25. The system of claim 23, wherein said statistical filtering includes a recursive weighted least squares estimator algorithm.

26. The system of claim 23, wherein a single transmitter is capable of being physically moved to said known positions.

27. The system of claim 23, wherein at least 3 transmitters are arranged at said known positions.

28. The system of claim 23, wherein said position estimation is capable of being determined down to about 1 ft.

29. The system of claim 23, wherein said at least one receiver and said one or more transmitters can include an apparatus selected from cell phones, pagers, personal identification cards, laptops, and personal digital assistants (PDA'"'"'s).

30. The system of claim 23, wherein said one or more transmitters and said at least one receiver are configured to operate using a commercial wireless communication standard.

31. The system of claim 30, wherein said wireless communication standard includes UWB frequencies.

32. The system of claim 30, wherein said wireless communication standard includes IEEE802.

33. The system of claim 30, wherein said wireless communication standard includes Bluetooth.

34. The system of claim 23, wherein said wireless position estimation system includes a GPS system.