Systems, methods, and computer programs for wireless local area network localization

Patent metadata

Field	Value
Publication number	US-11212018-B2
Application number	US-201916695469-A
Country	US
Kind code	B2
Filing date	Nov 26, 2019
Priority date	Oct 14, 2016
Publication date	Dec 28, 2021
Grant date	Dec 28, 2021

Abstract

Disclosed are various embodiments that enable the identification of the location of a computing device based on radio data. A radio map can be identified for an area. The computing device can measure signal strengths to reference points. The signal strengths can be compared to the radio map. The computing device can determine its location based on the comparison of the signal strengths to the radio map.

First claim

Therefore, at least the following is claimed:

1. A method comprising:
identifying a radio map for an area, wherein the radio map comprises a plurality of entries that represents a plurality of sets of location-dependent measurements from individual ones of a plurality of reference points for the area;
determining a plurality of access points within the area;
determining, via a computing device, a set of location-dependent measurements characterizing signals received from at least one of the plurality of access points; and
determining a position vector corresponding to a location of the computing device based at least in part on the set of location-dependent measurements according to an optimization of a multi-objective cost function that optimizes at the same time:
a first objective for minimizing a distance between the set of location-dependent measurements of individual ones of the plurality of access points and the plurality of entries in the radio map; and
a second objective for isolating an impact of a potentially faulty location-dependent measurement detected from one of the plurality of access points, wherein the potentially faulty location is detected based at least in part on a measurement difference between the potentially faulty location-dependent measurement and at least one of the plurality of entries in the radio map exceeding a threshold, and the potentially faulty location-dependent measurement is discarded from the multi-objective cost function.

2. The method of claim 1 ,
wherein each of the plurality of sets of location-dependent measurements comprising a location-dependent measurement for individual ones of a respective subset of the plurality of access points, and further comprising:
generating the radio map based at least in part on the plurality of sets of location-dependent measurements.

3. The method of claim 1 , wherein the radio map is generated using a coarser radio map through interpolation.

4. The method in claim 1 , wherein a coarser radio map is obtained through fingerprint collection associated with known locations.

5. The method of claim 1 , wherein the multi-objective cost function is applied for radio map design.

6. The method of claim 1 , wherein the multi-objective cost function depends on at least one of the radio map, the measurements, or the position vector.

7. The method of claim 1 , wherein the position vector is determined by additional processing of results of the optimization of the multi-objective cost function.

8. The method of claim 1 , wherein objective functions in the multi-objective cost function are parameterized.

9. The method of claim 8 , wherein parameters of the objective functions depend at least in part on the radio map and the measurements.

10. The method in claim 1 , wherein the location-dependent measurements are received signal strengths.

11. The method of claim 1 , wherein determining the position vector is based at least in part on at least one of: a LASSO algorithm, a GLMNET algorithm, a GS algorithm, a modified CS algorithm, a modified LASSO algorithm, a modified GLMNET algorithm, and a modified GS algorithm.

12. The method of claim 1 , wherein detecting at least one outlier based at least in part on a positioning algorithm.

13. The method in claim 12 , wherein detection of the at least one outlier is performed in part based on optimization techniques.

14. A system comprising:
a memory comprising at least one radio map;
at least one computing device in communication with the memory, the at least one computing device being configured to at least:
identify a radio map for an area from the at least one radio map in the memory, wherein the radio map comprises a plurality of entries that represents a plurality of sets of location-dependent measurements from individual ones of a plurality of reference points for the area;
determine a plurality of access points within the area;
determine a set of location-dependent measurements characterizing signals received from at least one of the plurality of access points; and
determine a position vector corresponding to a location of the at least one computing device based at least in part on the set of location-dependent measurements according to an optimization of a multi-objective cost function that optimizes at the same time:
a first objective for minimizing a distance between the set of location-dependent measurements of individual ones of the plurality of access points and plurality of entries in the radio map; and
a second objective for isolating an impact of a potentially faulty location-dependent measurement detected from one of the plurality of access points, wherein the potentially faulty location is detected based at least in part on a measurement difference between the potentially faulty location-dependent measurement and at least one of the plurality of entries in the radio map exceeding a threshold, and the potentially faulty location-dependent measurement is discarded from the multi-objective cost function.

15. The system of claim 14 , wherein each of the plurality of sets of location-dependent measurements comprising a location-dependent measurement for individual ones of a respective subset of the plurality of access points and the at least one computing device is further configured to at least:
generate the radio map based at least in part on the plurality of sets of location-dependent measurements.

16. The system of claim 14 , wherein the radio map is generated using radio map interpolation.

17. The system of claim 14 , wherein determining the position vector is based at least in part on a positioning algorithm, the positioning algorithm being modified to perform outlier detection.

18. The system in claim 14 , wherein the location-dependent measurements are received signal strengths.

19. A method comprising:
identifying a radio map for an area, wherein the radio map comprises a plurality of entries that represents a plurality of sets of location-dependent measurements from individual ones of a plurality of reference points for the area;
determining a plurality of access points within the area;
determining, via a computing device, a set of location-dependent measurements characterizing signals received from at least one of a plurality of access points;
generating a finer radio map based at least in part on an optimization of an unconstrained multi-objective cost function that at least searches for a sparse solution over a plurality of possible reference points, the unconstrained multi-objective cost function optimizing at the same time:
a first objective for minimizing a distance between the set of location-dependent measurements of individual ones of the plurality of access points and the plurality of entries in the radio map; and
a second objective for isolating an impact of a potentially faulty location-dependent measurement detected from one of the plurality of access points, wherein the potentially faulty location is detected based at least in part on a measurement difference between the potentially faulty location-dependent measurement and at least one of the plurality of entries in the radio map exceeding a threshold, and the potentially faulty location-dependent measurement is discarded from the multi-objective cost function; and

determining a position vector corresponding to a location of the computing device within the finer radio map based at least in part on the set of location-dependent measurements according to the optimization of the multi-objective cost function.

Assignees

• Khalajmehrabadi Ali
• Gatsis Nikolaos
• Akopian David
• Univ Texas

Inventors

• Khalajmehrabadi Ali
• Gatsis Nikolaos
• Akopian David

Classifications

• H04B17/318

  Received signal strength · CPC title

• G01S5/02524

  Creating or updating the radio-map · CPC title

• H04B17/24

  with feedback of measurements to the transmitter · CPC title

• H04B17/391

  Modelling the propagation channel · CPC title

• H04W64/00

  Locating users or terminals {or network equipment} for network management purposes, e.g. mobility management · CPC title