Method for incorporating invisible access points for RSSI-based indoor positioning applications

Patent metadata

Field	Value
Publication number	US-9955300-B2
Application number	US-201313901777-A
Country	US
Kind code	B2
Filing date	May 24, 2013
Priority date	Dec 31, 2012
Publication date	Apr 24, 2018
Grant date	Apr 24, 2018

Abstract

A method for incorporating invisible APs for RSSI based indoor positioning is presented. An empirical estimate of the probability of invisible APs versus distance is computed. An estimated position of the receiver can be computed using any statistical estimator based on the probability. In one embodiment, an estimate of the probability is computed by combining the probability over a set of visible APs and the probability over a set of invisible APs with the probability of individual contribution. In one embodiment a dynamic procedure is used to update the invisible probability that is computed using an AP dictionary built on the fly as new APs are detected. Incorporating invisible APs for estimating user position from the RSSI measurements for indoor positioning provides a better positioning accuracy as compared to typical estimators which rely only on the visible APs.

First claim

What is claimed as new and desired to be protected by Letters Patent of the United States is:

1. A wireless communication device for use with a plurality of access points, the wireless communication device comprising:
a scanning module operable to scan for access points and to receive a communication packet from each access point that is detected by the scanning module; and
a position estimator operable to estimate a position of the wireless communication device based on information in the communication packets received from each access point that is detected by the scanning module and further based on location information pertaining to an access point that was not detected by the scanning module, wherein the location information pertaining to the access point that was not detected is retrieved from a database including location information of the access points.

2. The wireless communication device of claim 1 , wherein the communication packet received from each detected access point by the scanning module includes location information pertaining to the access point that transmitted the corresponding communication packet, and wherein the position estimator is operable to estimate a position of the wireless communication device based in part on the location information pertaining to the access points that transmitted the corresponding communication packets.

3. The device of claim 1 , wherein the communication packet received from each detected access point includes distance information related to a distance between the wireless communication device and the access point that transmitted the corresponding communication packet, the wireless communication device further comprising:
a distance calculating portion operable to calculate a distance between the wireless communication device and each access point from which a communication packet was received based on the distance information in each received communication packet, and
wherein the position estimator is operable to estimate the position of the wireless communication device based on the calculated distances and the location information pertaining to an access point that was not detected by the scanning module.

4. The wireless communication device of claim 3 , wherein the distance calculating portion is operable to calculate the distance between the wireless communication device and an access point from which a communication packet was received based on a received signal strength indicator included in the distance information included in the communication packet received from the corresponding access point.

5. The wireless communication device of claim 3 , wherein the distance calculating portion is operable to calculate the distance between the wireless communication device and an access point from which a communication packet was received based on a probability vector.

6. The wireless communication device of claim 3 , further comprising a probability generating portion operable to receive location information pertaining to the access points detected by the scanning module and to generate a probability vector based on a position of the wireless communication device and the location information pertaining to at least one detected access point.

7. The wireless communication device of claim 6 , wherein the distance calculating portion is operable to calculate the distance between the wireless communication device and an access point from which a communication packet was received based on the probability vector.

8. The wireless communication device of claim 1 , further comprising an access point dictionary portion operable to store location information pertaining to access points listed in the access point dictionary portion.

9. The wireless communication device of claim 8 , further comprising a probability generating portion operable to generate a probability vector based on a position of the wireless communication device and the location information pertaining to at least one access point detected by the scanning module.

10. The wireless communication device of claim 1 , further comprising a probability generating portion operable to generate a probability vector based on a position of the wireless communication device and location information pertaining to at least one access point detected by the scanning module.

11. The wireless communication device of claim 1 , further comprising a probability generating portion operable to generate a probability vector based on a position of the wireless communication device and location information pertaining to an access point that was not detected by the scanning module.

12. A method of operating a wireless communication device, the method comprising:
scanning, via a scanning module, for access points;
receiving, via the scanning module, a communication packet from each access point that is detected by the scanning module;
estimating, via a position estimator, a position of the wireless communication device based on information in the communication packets received from each access point that is detected by the scanning module and further based on location information pertaining to an access point that was not detected by the scanning module, wherein the location information pertaining to the access point that was not detected is retrieved from a database including location information 2 access points.

13. The method of claim 12 , wherein the communication packet received from each detected access point includes location information pertaining to the access point that transmitted the corresponding communication packet, and wherein the estimating the position of the wireless communication device is based in part on the location information pertaining to the access points that transmitted the corresponding communication packets.

14. The method of claim 12 , wherein the communication packet received from each detected access point includes distance information related to a distance between the wireless communication device and the access point that transmitted the corresponding communication packet, the method further comprising:
calculating, via a distance calculating portion, a distance between the wireless communication device and each access point from which a communication packet was received based on the distance information in each received communication packet, and
wherein estimating, via a position estimator, a position of the wireless communication device comprises estimating the position based on the calculated distances and the location information pertaining to an access point that was not detected by the scanning module.

15. The method of claim 14 , wherein calculating the distance between the wireless communication device and an access point from which a communication packet was received based on the distance information in each received communication packet comprises calculating the distance based on a received signal strength indicator included in the distance information included in the communication packet received from the corresponding access point.

16. The method of claim 14 , wherein calculating the distance between the wireless communication device and an access point from which a communication packet was received based on the distance information in each received communication packet comprises calculating the distance based on a probability vector.

17. The method of claim 14 , further comprising:
receiving, via a probability generating portion, location information pertaining to the access points detected by the scanning module; and
generating, via the probability gen

Assignees

• Texas Instruments Inc

Inventors

• Mansour Mohamed Farouk
• Waters Deric Wayne
• Ramakrishnan Sthanunathan

Classifications

• H04W4/043

  Electricity · mapped topic

• H04W4/023 Primary

  using mutual or relative location information between multiple location based services [LBS] targets or of distance thresholds · CPC title

• H04W4/33

  for indoor environments, e.g. buildings · CPC title