METHOD AND SYSTEM FOR DETERMINING POSITION OF A WIRELESS ELECTRONIC DEVICE WITHIN A VOLUME

• US 20090325598A1
• Filed: 10/16/2008
• Published: 12/31/2009
• Est. Priority Date: 06/30/2008
• Status: Active Grant

• Current Assignee: Intelligent Sciences, Ltd.
• Original Assignee: Intelligent Sciences, Ltd.
• Inventors: Pace, Nicholas G., Stacey, James A., Guigne, Jacques Y.
• Granted Patent: US 8,014,791 B2
• Time in Patent Office: Days
• US Class Current: 455/456.1
• CPC Class Codes: G01S 5/021 Calibration, monitoring or correction G01S5/0252 takes precedence
• CPC Class Codes: G01S 5/06 Position of source determined by co-ordinating a plurality of position lines defined by path-difference measurements G01S5/12 takes precedence

Abstract

A method for determining a position of a wireless electronic device within a volume includes detecting a signal transmitted by the wireless device during two-way communication to and from a first known position within the volume. The method further includes detecting the signal from at least three additional known positions within the volume, where the at least three additional known positions are spatially independent of each other. The method further includes determining a phase difference between the signal detected at the first position and the signal detected at each of the at least three additional positions, determining the position of the wireless electronic device using the phase differences, and at least one of displaying and storing the position of the wireless electronic device.

Claims

1. A method for determining a position of a wireless electronic device within a volume, comprising:

detecting a signal transmitted by the wireless electronic device for two-way communication from a first known position within the volume;

detecting the signal from at least three additional known positions within the volume, the at least three additional known positions being spatially independent of each other;

determining a phase difference between the signal detected at the first position and the signal detected at each of the at least three additional positions;

determining the position of the wireless electronic device using the phase differences; and

at least one of storing and displaying the position of the wireless electronic device.

2. The method of claim 1 wherein the transmitted signal is a Bluetooth two-way communication signal.

3. The method of claim 1 wherein the volume is disposed within a building.

4. The method of claim 1 wherein the position is determined in three dimensions.

5. The method of claim 1 wherein the wireless electronic device comprises a cellular telephone.

6. The method of claim 1 further comprising detecting the signal from at least one additional known position within the volume.

7. The method of claim 1 wherein the first known position is disposed approximately in the center of the volume.

8. The method of claim 1 wherein the phase difference is related to a frequency of the detected signals to determine at least one time difference between the detected signals.

9. An apparatus for determining a position of a wireless electronic device within a volume, comprising:

a reference receiver configured to detect a signal transmitted by the wireless electronic device and used as a corresponding reference signal;

at least three additional receivers which are spatially independent of each other, said additional receivers being coupled to the reference receiver to receive the reference signal and being configured to detect the signal transmitted by the wireless electronic device; and

a processor configured to compute the position of the wireless electronic device based on a phase difference between the reference signal generated by the reference receiver and the signals detected at each of the additional receivers.

10. The apparatus of claim 9, wherein the reference receiver is configured to detect a Bluetooth two-way communication signal.

11. The apparatus of claim 9, wherein each of the additional receivers comprises a phase detector circuit which produces an output that is indicative of the phase difference between the reference signal generated by the reference receiver and the signal detected at each of the additional receivers.

12. The apparatus of claim 9 wherein the processor is configured to determine a time difference between detection of the reference signal and the signals detected at at least one of the additional receivers based on a frequency of the detected signals.