Indoor positioning using joint likelihoods

• US 8,660,586 B2
• Filed: 12/19/2012
• Issued: 02/25/2014
• Est. Priority Date: 04/10/2012
• Status: Expired due to Fees

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Palanki, Ravi, Naguib, Ayman Fawzy
• Primary Examiner(s): PATEL, MAHENDRA R
• Application Number:
  US13/720,824
• Publication Number:
  US 20130267244A1
• Time in Patent Office: 433 Days
• Field of Search: 455/456.6, 455/522, 455/11.1, 455/456.3, 455/436, 455/12.1, 455/458, 455/456.1, 455/561, 455/423, 455/450, 455/226.2, 342/450, 342/457, 342/357.44, 342/357.62, 340/7.52, 340/988, 370/331, 370/335, 370/252, 370/342, 370/508, 702/60
• US Class Current: 455/456.6
• CPC Class Codes: G01S 5/02521 using a radio-map
• CPC Class Codes: G01S 5/0278 involving statistical or probabilistic considerations G01S5/0252, G01S5/0294 take precedence
• CPC Class Codes: H04W 4/025 using location based information parameters
• CPC Class Codes: H04W 4/33 for indoor environments, e.g. buildings

Abstract

A method in a mobile terminal for estimating a position of the mobile terminal includes: receiving an expected measurement map indicative of an expected measurement of a parameter by the mobile terminal; receiving parameters of a matrix corresponding to the expected measurement map; capturing, by the mobile terminal, actual measurements of the parameter for a plurality of communication devices; and utilizing the received parameters and actual measurements to estimate the position of the mobile terminal, where each of the actual measurements and the expected measurement map comprise values indicative of a delay in a communication path between the mobile terminal and one or more of the plurality of communication devices.

Claims

1. A method in a mobile terminal for estimating a position of the mobile terminal, the method comprising:

receiving an expected measurement map indicative of an expected measurement of a parameter by the mobile terminal;

receiving parameters of a matrix corresponding to the expected measurement map;

capturing, by the mobile terminal, actual measurements of the parameter for a plurality of communication devices; and

utilizing the received parameters and the actual measurements to estimate the position of the mobile terminal,

wherein each of the actual measurements and the expected measurement map comprise values indicative of a delay in a communication path between the mobile terminal and one or more of the plurality of communication devices,

wherein the expected measurement map is associated with the plurality of communication devices and a plurality of hypothesis locations, and

wherein utilizing the received parameters and the actual measurements to estimate the position of the mobile terminal further comprises

computing a respective interim vector from the actual measurements and the expected measurement map for each hypothesis location;

computing joint probability distribution values as an exponential of a matrix product using the interim vector and the matrix to produce a joint probability distribution value; and

filtering the joint probability distribution value to estimate the position of the mobile terminal.

2. The method of claim 1, wherein the parameters of the matrix comprise a covariance matrix.

3. The method of claim 1, wherein the parameters of the matrix comprise an inverse of a covariance matrix.

4. The method of claim 1, wherein the expected measurement map comprises values indicative of expected received signal strength by the mobile terminal.

5. The method of claim 1, wherein the interim vector comprises a difference between the actual measurements and corresponding expected measurements.

6. The method in of claim 1, wherein computing the interim vector comprises removing an unknown variable.

7. The method of claim 6, wherein the removing of the unknown variable comprises removing an antenna gain of the mobile terminal.

8. The method of claim 6, wherein the removing of the unknown variable comprises removing a fixed processing delay of one or more of the plurality of communication devices.

9. The method of claim 1, wherein the method is implemented in a server in communication with the mobile terminal, and further comprising receiving, from the mobile terminal, captured measurements, from the position of the mobile terminal, for the plurality of communication devices.

10. A mobile terminal for estimating a position of the mobile terminal, comprising:

a matrix reception unit configured to receive parameters of a matrix;

an expected measurement map reception unit configured to receive an expected measurement map indicative of an expected measurement of a parameter by the mobile terminal, wherein the expected measurement map is associated with the plurality of communication devices and a plurality of hypothesis locations;

a measurement capture unit to configured to capture actual measurements of the parameter, from the position of the mobile terminal, for a plurality of communication devices;

an interim vector computation unit configured to compute a respective interim vector from the actual measurements and the expected measurement map for each hypothesis location;

a joint probability distribution computation unit configured to compute joint probability distribution values as an exponential of a matrix product using the interim vector and the matrix; and

a filter configured to filter the joint probability distribution values to estimate the position of the mobile terminal,

wherein each of the actual measurements and the expected measurement map comprise values indicative of a delay in a communication path between the mobile terminal and one or more of the plurality of communication devices.

11. The mobile terminal of claim 10, wherein the parameters of the matrix comprise a covariance matrix.

12. The mobile terminal of claim 10, wherein the parameters of the matrix comprise an inverse of a covariance matrix.

13. The mobile terminal of claim 10, wherein computing the interim vector comprises removing an unknown variable.

14. The mobile terminal of claim 13, wherein the removing of the unknown variable comprises removing an antenna gain of the mobile terminal.

15. The mobile terminal of claim 13, wherein the removing of the unknown variable comprises removing a fixed processing delay of one or more of the plurality of communication devices.

16. A mobile terminal for estimating a position of the mobile terminal, the mobile terminal comprising:

means for receiving an expected measurement map indicative of an expected measurement of a parameter by the mobile terminal;

means for receiving parameters of a matrix corresponding to the expected measurement map;

means for capturing, by the mobile terminal, actual measurements of the parameter for a plurality of communication devices; and

means for estimating the position of the mobile terminal using the received parameters and the actual measurements,

wherein each of the actual measurements and the expected measurement map comprise values indicative of a delay in a communication path between the mobile terminal and one or more of the plurality of communication devices,

wherein the expected measurement map is associated with the plurality of communication devices and a plurality of hypothesis locations, and

wherein the means for estimating the position of the mobile device using the received parameters and the actual measurements further comprises;

means for computing a respective interim vector from the actual measurements and the expected measurement map for each hypothesis location;

means for computing joint probability distribution values as an exponential of a matrix product using the interim vector and the matrix to produce a joint probability distribution value; and

means for filtering the joint probability distribution value to estimate the position of the mobile terminal.

17. The mobile terminal of claim 16, wherein the means for estimating comprises means for removing an unknown variable.

18. The mobile terminal of claim 16, wherein the means for estimating comprises means for removing an antenna gain of the mobile terminal.

19. A device comprising:

a processor;

a transceiver operable to send and receive wireless signals, wherein the processor is coupled to receive data from the transceiver; and

a non-transitory memory having stored thereon instructions for configuring the processor for;

receiving an expected measurement map indicative of an expected measurement of a parameter by a mobile terminal;

receiving parameters of a matrix corresponding to the expected measurement map;

capturing actual measurements of the parameter for a plurality of communication devices; and

utilizing the received parameters and the actual measurements to estimate a position of the mobile terminal,

wherein each of the actual measurements and the expected measurement map comprise values indicative of a delay in a communication path between the mobile terminal and one or more of the plurality of communication devices,

wherein the expected measurement map is associated with the plurality of communication devices and a plurality of hypothesis locations, and

wherein utilizing the received parameters and the actual measurements to estimate a position of the mobile terminal further comprises;

computing a respective interim vector from the actual measurements and the expected measurement map for each hypothesis location;

computing joint probability distribution values as an exponential of a matrix product using the interim vector and the matrix to produce a joint probability distribution value; and

filtering the joint probability distribution value to estimate the position of the mobile terminal.

20. The device of claim 19, wherein the instructions comprise instructions for removing an unknown antenna gain of the mobile terminal.

21. The method of claim 19, wherein the instructions comprise instructions for removing an unknown processing delay of the plurality of communication devices.

22. A non-transitory computer-readable storage medium including program code stored thereon, comprising program code for:

receiving an expected measurement map indicative of an expected measurement of a parameter by a mobile terminal;

receiving parameters of a matrix corresponding to the expected measurement map;

capturing, by the mobile terminal, actual measurements of the parameter for a plurality of communication devices; and

utilizing the received parameters and the actual measurements to estimate a position of the mobile terminal,

wherein each of the actual measurements and the expected measurement map comprise values indicative of a delay in a communication path between the mobile terminal and one or more of the plurality of communication devices,

wherein the expected measurement map is associated with the plurality of communication devices and a plurality of hypothesis locations, and

wherein the program code for utilizing the received parameters and the actual measurements to estimate a position of the mobile terminal further comprises program code for;

computing a respective interim vector from the actual measurements and the expected measurement map for each hypothesis location;

computing joint probability distribution values as an exponential of a matrix product using the interim vector and the matrix to produce a joint probability distribution value; and

filtering the joint probability distribution value to estimate the position of the mobile terminal.

23. The non-transitory computer-readable storage medium including program code stored thereon of claim 22 wherein the program code for filtering the joint probability distribution value to estimate the position of the mobile terminal further comprises program code for Kalman filtering the joint probability distribution values derived for the received parameters and the actual measurements.