Cooperative localization for wireless networks

• US 9,329,257 B2
• Filed: 10/25/2007
• Issued: 05/03/2016
• Est. Priority Date: 10/25/2006
• Status: Active Grant

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Wymeersch, Henk, Win, Moe Z., Lien, Jaime
• Primary Examiner(s): Appiah, Charles
• Assistant Examiner(s): Zhang, Edward
• Application Number:
  US11/977,754
• Publication Number:
  US 20080268873A1
• Time in Patent Office: 3,113 Days
• Field of Search: 4554561-4566, 455/41.2, 370/331, 370/332, 370/338
• US Class Current: 1/1
• CPC Class Codes: G01S 5/0284 Relative positioning
• CPC Class Codes: G01S 5/0289 of multiple transceivers, e.g. in ad hoc networks
• CPC Class Codes: H04W 4/025 using location based information parameters

Abstract

A system and corresponding method using a cooperative localization technique for self identifying a location of a wireless device in a wireless network is presented. The system may estimate an arbitrary signal metric as a function of a signal received by the wireless device from the at least one other wireless device in the wireless network. The system may also convert at least one belief representing a distribution of at least one possible location of the at least one other wireless device to generate at least one converted belief. The system may further determine a self-belief as a function of the at least one converted belief and identify a self location, as a function of the self-belief, within the wireless network.

Claims

1. A method for a wireless device to identify a self location in a wireless network comprising:

by a processor of the wireless device, converting at least one belief to a converted belief, the at least one belief representing a first distribution of at least one possible location of the wireless device within the wireless network, the at least one converted belief being a function of an arbitrary signal metric associated with a wireless signal received by the wireless device from at least one other wireless device and at least one received self-belief from the at least one other wireless device to the wireless device, the at least one received self-belief representing a second distribution of at least one possible location of the at least one other wireless device within the wireless network;

by the processor of the wireless device, determining a self-belief as a function of the at least one converted belief, the at least one converted belief representing a third distribution of the at least one possible location of the wireless device generated by considering all possible positions of the at least one other wireless device represented in the second distribution; and

by the processor of the wireless device, identifying a self location, as a function of the self-belief, within the wireless network.

2. The method of claim 1 wherein a physical configuration of the wireless network is time varying.

3. The method of claim 1 wherein at least a subset of multiple other wireless devices is mobile relative to at least one other subset of multiple other wireless devices.

4. The method of claim 1 wherein at least a subset of multiple other wireless devices estimates the arbitrary signal metric of a first type, and at least one other subset of multiple other wireless devices estimates the arbitrary signal metric of a second type.

5. The method of claim 4 wherein the arbitrary signal metric is used to calculate a characteristic of the wireless device with respect to the at least one other wireless device, the characteristic selected from the group consisting of:

angle, distance, connectivity, position, pose, velocity, and angular velocity information.

6. The method of claim 4 wherein the arbitrary signal of the first type is asymmetrical with respect to the arbitrary signal of the second type.

7. The method of claim 1 wherein converting the at least one belief and determining the self-belief are based on factor graph principles.

8. The method of claim 1 wherein converting the at least one belief further comprises self accounting for a capability related to estimating the arbitrary signal metric.

9. The method of claim 1 wherein determining the self-belief further comprises updating a previously determined self-belief or determining a new self-belief.

10. The method of claim 1 further comprising identifying a location of the at least one other wireless device in the wireless network.

11. The method of claim 1 wherein the distribution is a probability density or a mass function.

24. The method of claim 1 wherein considering all possible positions of the at least one other wireless device represented in the second distribution includes performing a multi-dimensional integration performed over all of the possible positions.

12. A location indicator apparatus for identifying a self location of a wireless device in a wireless network, the apparatus comprising:

a converting unit configured to convert at least one belief into a converted belief, the at least one belief representing a first distribution of at least one possible location of the wireless device within the wireless network, the at least one converted belief being a function of an arbitrary signal metric associated with a wireless signal received by the wireless device from at least one other wireless device and at least one received self-belief from the at least one other wireless device to the wireless device, the at least one received self-belief representing a second distribution of at least one possible location of the at least one other wireless device within the wireless network;

a self-belief determining unit configured to determine a self-belief as a function of the at least one converted belief, the at least one converted belief representing a third distribution of the at least one possible location of the wireless device generated by considering all possible positions of the at least one other wireless device represented in the second distribution; and

an identifying unit configured to identify a self location, as a function of the self-belief, within the wireless network.

13. The apparatus of claim 12 wherein a physical configuration of the wireless network is time varying.

14. The apparatus of claim 12 wherein at least a subset of multiple other wireless devices is mobile relative to at least one other subset of multiple other wireless devices, wherein the respective calculating, self-belief determining, and identifying units are further configured to account for mobility.

15. The apparatus of claim 12 wherein respective calculating units of at least a subset of multiple other wireless devices is configured to estimate the arbitrary signal metric of a first type, and respective calculating units of at least one other subset of the at least one other wireless device is configured to estimate the arbitrary signal metric of a second type.

16. The apparatus of claim 15 wherein the arbitrary signal metric measures a characteristic of the wireless device with respect to the at least one other wireless device, the characteristic selected from the group consisting of:

angle, distance, connectivity, position, pose, velocity, and angular velocity information.

17. The apparatus of claim 15 wherein the arbitrary signal of the first type is asymmetrical with respect to the arbitrary signal of the second type.

18. The apparatus of claim 12 wherein the converting unit is further configured to convert the at least one belief, and the determining unit is configured to determine the self-belief, based on factor graph principles.

19. The apparatus of claim 12 wherein the calculating unit is further configured to self account for a capability related to estimating the arbitrary signal metric.

20. The apparatus of claim 12 wherein the determining unit is further configured to update a previously determined self-belief or determine a new self-belief.

21. The apparatus of claim 12 the identifying unit is further configured to identify a location of at least one other wireless device in the wireless network.

22. The apparatus of claim 12 wherein the distribution is a probability density or a mass function.

23. A non-transitory computer program product having a computer program stored thereon, the computer program defined by instructions which, when executed by a processor in a wireless device in a wireless network, cause the processor to:

convert at least one belief to a converted belief, the at least one belief representing a first distribution of at least one possible location of the wireless device within the wireless network, the at least one converted belief being a function of an arbitrary signal metric associated with a wireless signal received by the wireless device from at least one other wireless device and at least one received self-belief from the at least one other wireless device to the wireless device, the at least one received self-belief representing a second distribution of at least one possible location of the at least one other wireless device within the wireless network;

determine a self-belief as a function of the at least one converted belief, the at least one converted belief representing a third distribution of the at least one possible location of the wireless device generated by considering all possible positions of the at least one other wireless device represented in the second distribution; and

identify a self location, as a function of the self-belief, within the wireless network.