Wireless positioning and wireless positioning method and apparatus

• US 9,473,887 B2
• Filed: 05/26/2015
• Issued: 10/18/2016
• Est. Priority Date: 05/29/2014
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Lin, Yong Hua, Wang, Qing, Xue, Chao, Xiong, Xin
• Primary Examiner(s): Mehra, Inder
• Application Number:
  US14/721,457
• Publication Number:
  US 20150350829A1
• Time in Patent Office: 511 Days
• Field of Search: 455/456.1, 455/456.3, 455/456.2, 455/457, 455/404.2, 455/414.1, 455/440, 455/434, 370/338
• US Class Current: 1/1
• CPC Class Codes: G01S 5/0054 of actual mobile position, i.e. position calculation on base station
• CPC Class Codes: G01S 5/02524 Creating or updating the radio-map
• CPC Class Codes: H04W 4/021 Services related to particular areas, e.g. point of interest [POI] services, venue services or geofences
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

An apparatus for wireless positioning includes a first delimitation unit configured to delimit an initial boundary for a predetermined space to divide the predetermined space into at least two areas, each area of the at least two areas comprising multiple zones, the multiple zones including a boundary zone adjacent to the initial boundary; a detection unit configured to detect signal feature values of respective wireless access points in the boundary zone and determine an identifier set of the detected wireless access points; and a second delimitation unit configured to re-determine the boundaries of the at least two areas for the wireless positioning based on the detection results in the boundary zone. With the method and apparatus of embodiments of the present invention, it is possible to reduce the positioning calculation time while maintaining high positioning accuracy.

Claims

1. An apparatus for wireless positioning, comprising:

a first delimitation unit configured to delimit an initial boundary for a predetermined space to divide the predetermined space into at least two areas, each area of the at least two areas comprising multiple zones, the multiple zones including a boundary zone adjacent to the initial boundary;

a detection unit configured to detect signal feature values of respective wireless access points in the boundary zone and determine an identifier set of detected wireless access points; and

a second delimitation unit configured to re-determine the boundaries of the at least two areas for the wireless positioning based on the detection results in the boundary zone.

2. The apparatus according to claim 1, further comprising:

a determination unit configured to determine whether or not A″

is a subset of B′

, and if A″

is not a subset of B′

, determine that a first boundary zone in a first area of the at least two areas finally belongs to the first area, but if A″

is a subset of B′

, continue to determine whether the first boundary zone finally belongs to the first area or a second area;

wherein A″

represents the identifier set of detected wireless access points in the first boundary zone, and B′

represents the identifier set of detected wireless access points in all boundary zones in the second area of the at least two areas.

3. The apparatus according to claim 2, wherein the detection unit is further configured to perform n times of detection in time sequence in the first boundary zone, and the determination unit is also configured to determine that the first boundary zone finally belongs to the first area if a first ratio with which the first boundary zone is determined to finally belong to the first area is larger than a first threshold in the n times of detection, and otherwise determine that the first boundary zone finally belongs to the second area, where n is a positive integer.

4. The apparatus according to claim 2, wherein:

the determination unit is further configured to determine whether other boundary zones than the first boundary zone in the first area finally belong to the first area or the second area, and compare a second ratio with which the first boundary zone and the other boundary zones in the first area are determined to finally belong to the first area with a second threshold; and

the second delimitation unit is further configured to discard the initial boundary if the second ratio is lower than the second threshold.

5. The apparatus according to claim 4, wherein the detection unit is further configured to:

use the signal feature values of respective wireless access points detected by a terminal in each zone of the first area at different time points to constitute a signal feature matrix;

select the terminals with different number and location combinations as initial reference points;

use a first part of signal feature vectors of the initial reference points of the first area in the signal feature matrix and corresponding signal feature vectors of zones other than the initial reference points in the signal feature matrix to build a mathematical model which reflects distribution of the signal strength of respective wireless access points at the initial reference points in the first area and the signal strength of the zones other than the initial reference points, wherein the corresponding signal feature vectors are the signal feature vectors obtained in the same time period as the first part of signal feature vectors;

verify the mathematical model by using a second part of signal feature vectors other than the signal feature vectors for building the mathematical model, of the selected reference points with different number and location combinations, in the signal feature matrix to obtain an error probability of the mathematical model, wherein the second part of signal feature vectors are the signal feature vectors obtained in a different time period from the first part of signal feature vectors; and

determine the initial reference points of a number and location combination with the lowest error probability as the final reference points.

6. The apparatus according to claim 5, wherein the signal feature value of a first wireless access point detected by the terminal located in a first zone Z1 at time Tn is denoted as R¹_Z1,Tn, the signal feature value of a second wireless access point detected by the terminal located in the first zone Z1 at time Tn is denoted as R²_Z1,Tn, and thereby the obtained signal feature vector is [R¹_Z1,Tn, R²_Z1,Tn];

multiple signal feature vectors obtained through detecting by the terminals located in respective zones at the same time point constitute a group of signal feature vectors, and then multiple groups of signal feature vectors obtained through detecting by the terminals located in respective zones during a period of time constitute the signal feature matrix.

7. The apparatus according to claim 5, wherein the error probability represents the degree of the signal feature vectors in the zones other than the initial reference points evaluated by taking the number and location combination as the initial reference points matching with the actual signal feature vectors in the zones other than the initial reference points, and the lower the error probability, the better the degree of the mathematical model built by taking the number and location combination as the initial reference points matching with the actual situation.

8. The apparatus according to claim 2, wherein the determination unit is configured to continue to determine whether the first boundary zone finally belongs to the first area or the second area by:

forming a point X′

in vector space from an average value of the signal feature values of respective wireless access points detected in each boundary zone in the first area with respect to time;

forming a point X″

in vector space from an average value of the signal feature values of respective wireless access points detected in the first boundary zone in the first area with respect to time;

forming a point Y′

in vector space from an average value of the signal feature values of respective wireless access points detected in each boundary zone in the second area with respect to time;

setting a middle separation line between the point X′ and

the point Y′

;

determining that the first boundary zone finally belongs to the first area if X″

is located at the point X′

side of the separation line; and

determining that the first boundary zone finally belongs to the second area if X″

is located at the point Y′

side of the separation line.

9. A wireless positioning apparatus, comprising:

a receiving unit configured to receive a positioning request from a mobile terminal;

a positioning unit configured to locate the mobile terminal into at least one zone in at least one area of which boundary is re-determined according to claim 1 based on the positioning request; and

a transmitting unit configured to transmit location information of the at least one zone to the mobile terminal.