Enhanced Cell ID Location Method Using Non Uniform Subsectors and Neighboring Cell Centroid

• US 20140171105A1
• Filed: 03/15/2013
• Published: 06/19/2014
• Est. Priority Date: 12/14/2012
• Status: Active Grant

• Current Assignee: TeleCommunication Systems Inc (Comtech Telecommunications Corporation)
• Original Assignee: Andrew LLC (CommScope Holding Company, Inc.)
• Inventors: Al-Mufti, Khalid, Hannan, Ariful, Kalenahalli, Suryanarayana, Srinivasan, Navin
• Granted Patent: US 9,176,216 B2
• Time in Patent Office: Days
• US Class Current: 455/456.1
• CPC Class Codes: G01S 5/02955 by computing a weighted average of the positions of the signal transmitters
• CPC Class Codes: G01S 5/12 by co-ordinating position lines of different shape, e.g. hyperbolic, circular, elliptical or radial
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

A system and method of determining the location of a mobile device. Network measurement report information may be received from a target mobile device, the NMR having measurement information and range information of the target mobile device from a cell serving the device. The serving cell may be divided a plurality of subsectors and candidate locations placed on an intersection of a range formed from the range information and bisectors of the plurality of subsectors. A subset of neighboring and serving cells may be selected as a function of the NMR measurement information and a radio frequency (RF) coverage centroid determined for each of the selected neighboring cells. A centroid of the determined RF centroids may be determined, and a location of the target mobile device estimated as the candidate location having a minimum distance to the determined centroid.

Claims

24. A method of determining the location of a mobile device in a communications network in communication with a serving cell comprising the steps of:

receiving measurement information from cells neighboring the serving cell and range information from the serving cell;

determining a centroid for each of a plurality of neighboring and serving cells;

determining a centroid for the plurality of centroids of neighboring and serving cells;

determining a plurality of candidate locations as a function of an intersection of bisecting serving cell lines and the received range information; and

determining a location of the mobile device as the candidate location having a minimum distance to the determined centroid of the plurality of centroids.

1. A method of determining the location of a mobile device comprising the steps of:

(a) receiving measurement information from cells neighboring the serving cell and range information from the serving cell;

(b) dividing the serving cell into a plurality of subsectors;

(c) placing candidate locations on an intersection of bisectors of the plurality of subsectors and a range determined using the range information;

(d) selecting a subset of neighboring and serving cells as a function of the measurement information;

(e) determining a radio frequency (RF) coverage centroid for each of the selected neighboring cells;

(f) determining a centroid of the determined RF centroids;

(g) determining a location of the target mobile device as the candidate location having a minimum distance to the determined centroid.

2. The method of claim 1 wherein the measurement information is selected from the group consisting of an absolute received signal power level observed at the target mobile device, a ratio of received signal power to maximum received power, and combinations thereof.

3. The method of claim 1 wherein the step of selecting a subset of neighboring and serving cells further comprises weighting measurement information for one or more of the neighboring and serving cells as a function of cell size.

4. The method of claim 3 wherein cell size is determined as a function of transmission power level of the respective cell, timing advance values from mobile devices within the respective cell, and combinations thereof.

5. The method of claim 1 further comprising the step of determining radial or angular uncertainties of the mobile device location.

6. The method of claim 5 wherein radial uncertainty is determined as a function of type of range information.

7. The method of claim 5 wherein angular uncertainty is determined as a function of the selected subsector.

8. The method of claim 1 wherein the step of determining a centroid of the determined RF centroids further comprises performing an equally weighted average of selected neighboring cell centroids.

9. The method of claim 1 wherein the step of determining a centroid of the determined RF centroids further comprises performing an unequally weighted average of selected neighboring cell centroids.

10. The method of claim 9 wherein the weights are a function of values selected from the group consisting of neighboring cell power level, serving cell power level, inter-site distance between neighboring and serving cells, and combinations thereof.

11. The method of claim 1 wherein one determined RF centroid is a midpoint of the RF coverage area of the serving cell.

12. The method of claim 1 wherein one determined RF centroid is a function of values selected from the group consisting of antenna pattern, transmit power of the broadcast signal from a neighboring or serving cell, and combinations thereof.

13. The method of claim 1 wherein the determined RF cell centroid and bisectors are predetermined.

14. The method of claim 1 wherein the bisectors are determined as a function of cell geometry, user density, inter-cell distance, power level, and combinations thereof.

15. The method of claim 1 wherein the subsectors are asymmetrically distributed in the serving cell about an equatorial line of a respective sector.

16. The method of claim 15 wherein the subsectors are determined as a function of cell geometry, user density, inter-cell distance, power level, and combinations thereof.

17. The method of claim 1 wherein the subsectors are distributed in the serving cell as a function of beam width.

18. The method of claim 1 wherein the determined range is a function of timing advance or round trip time.

19. The method of claim 1, wherein the location of the RF coverage centroid is a function of a value selected from the group consisting of an RF configuration parameter, transmit power, antenna pattern, antenna down tilt, antenna gain, and combinations thereof.

20. The method of claim 1, wherein the serving cell is an Omni cell and the determined location of the target device is determined as a function of an intersection of the reported range information and a line connecting the determined centroid of RF coverage centroids and serving cell location.

21. The method of claim 1 further comprising the step of re-determining the centroid of the determined RF centroids as a function of information from a self-organizing network selected from the group consisting of transmission power, antenna tilt, antenna azimuth, antenna beam width, and combinations thereof.

22. The method of claim 21 further comprising the step of using the determined location of the mobile device to update information in the self-organizing network.

23. The method of claim 1 further wherein the step of determining a centroid of the determined RF centroids further comprises the steps of:

determining whether a repeater is present in the serving or neighboring cells;

if the presence of a repeater is determined, then using a location of the repeater as one of the plural determined RF centroids; and

weighting the location of the repeater as a function of information received from the repeater.

25. The method of claim 24 wherein the measurement information is from a network measurement report.

26. The method of claim 24 further comprising the step of determining radial or angular uncertainties of the mobile device location.

27. The method of claim 24 wherein the step of determining a centroid for plurality of centroids further comprises performing a weighted average of selected neighboring cell centroids.

28. The method of claim 24 further comprising the step of re-determining the centroid of the determined centroids as a function of information from a self-organizing network selected from the group consisting of transmission power, antenna tilt, antenna azimuth, antenna beam width, and combinations thereof.

29. The method of claim 28 further comprising the step of using the determined location of the mobile device to update information in the self-organizing network.

29-1. The method of claim 24 further wherein the step of determining a centroid for the plurality of centroids further comprises the steps of:

determining whether a repeater is present in the serving or neighboring cells;

if the presence of a repeater is determined, then using a location of the repeater as one of the plural determined centroids; and

weighting the location of the repeater as a function of information received from the repeater.