SUB ROOM LEVEL INDOOR LOCATION SYSTEM USING WIDEBAND POWER LINE POSITIONING

• US 20100109842A1
• Filed: 09/15/2009
• Published: 05/06/2010
• Est. Priority Date: 06/28/2006
• Status: Active Grant

• Current Assignee: Georgia Tech Research Corporation (University System of Georgia)
• Original Assignee: Georgia Tech Research Corporation (University System of Georgia)
• Inventors: Patel, Shwetak N., Reynolds, Matthew S., Stuntebeck, Erich, Robertson, Thomas, Abowd, Gregory D.
• Granted Patent: US 8,494,762 B2
• Time in Patent Office: Days
• US Class Current: 340/10.100
• CPC Class Codes: G01C 21/206 specially adapted for indoor navigation
• CPC Class Codes: G01S 5/02521 using a radio-map

Abstract

An indoor location system uses an electrical power line, power line signal injection devices, and portable position receivers (tags) to generate location data relating to positions of the tags in a structure such as a residence or business. The indoor location system fingerprinting of multiple signals transmitted along the power line to achieve sub-room-level localization of the positioning receivers. In one embodiment, the fingerprinting techniques utilizes wideband power line positioning (WPLP) that injects up to 44 different frequencies into the power line infrastructure of a structure. The WPLP technique improves upon overall positioning accuracy, improved temporal stability and may be implemented in commercial indoor spaces.

Claims

1. An indoor location apparatus for use with an electrical power line infrastructure disposed in a structure, the apparatus comprising:

at least one injector device electrically coupled to the electrical power line infrastructure at an electrical node within the electrical power line infrastructure, the injector device configured to inject a plurality of signals into the electrical power line infrastructure; and

at least one positioning tag disposed to detect the plurality of injected signals emanating from the electrical power line infrastructure.

2. The apparatus of claim 1 wherein the injector device comprises a signal generator capable of generating a plurality of signals having different frequencies;

3. The apparatus of claim 2 wherein the injector device further comprises an amplifier coupled to an output of the signal generator for amplifying the signals generated by signal generator.

4. The apparatus of claim 2 wherein the injector device further comprises a processor for providing control signals to signal generator;

5. The apparatus of claim 4 wherein the control signals provided to signal generator by the processor defined any of the amplitude, duration and frequency of the signals generated by the signal generator.

6. The apparatus of claim 2 wherein the positioning tag comprises an antenna for receiving plurality of injected signals emanating from the electrical power line infrastructure.

7. The apparatus of claim 6 wherein the positioning tag comprises an analog to digital converter operably coupled to the the output of the antenna for converting the received signal into digital data.

8. The apparatus of claim 7 wherein the positioning tag further comprises a software radio operably coupled to the output of the analog to digital converter.

9. The apparatus of claim 8 wherein the positioning tag further comprises a processor operably coupled to the output of the software radio.

10. The apparatus of claim 2 wherein the signal injector injects more than two signals having different frequencies into electrical power line infrastructure.

11. The apparatus of claim 2 wherein the signal injector injects a number of signals having different frequencies into the electrical power line infrastructure, the number of signals within the range from 3 to 44.

12. The apparatus of claim 11 wherein the signal injector injects a number of signals having different frequencies into the electrical power line infrastructure, the number of signals within the range from 5 to 35.

13. The apparatus of claim 2 wherein the plurality of signals injected into the electrical power line infrastructure by the signal injector have frequencies in the range of 400 kHz to 20 MHz.

14. The apparatus of claim 2 wherein the plurality of signals injected into the electrical power line infrastructure by the signal injector are injected sequentially.

15. The apparatus of claim 2 wherein the plurality of signals injected into the electrical power line infrastructure by the signal injector are injected in sequentially in a recurring pattern.

16. A method comprising:

injecting more than two electromagnetic signals into an electrical power line infrastructure disposed in a structure;

wirelessly detecting at least some of the electromagnetic signals using at least one positioning tag; and

processing the plurality of detected electromagnetic signals in the positioning tag to generate a signal fingerprint that is associated with the positioning tag.

17. The method of claim 16 further comprising:

processing the signal fingerprint remotely from the positioning tag to identify a location in the structure associated with the positioning tag.

18. The method recited in claim 16 wherein the fingerprint comprises at least the signal strength of the detected signals emanating from the electrical power line infrastructure.

19. The method recited in claim 16 wherein the fingerprint comprises at least the relative phase difference between detected signals emanating from the electrical power line infrastructure.

20. The method recited in claim 16 wherein the fingerprint comprises at least the phase shift between successive detected signals emanating from the electrical power line infrastructure.