Matching receive signal strenth data associated with radio emission sources for positioning applications

• US 20060128311A1
• Filed: 12/13/2004
• Published: 06/15/2006
• Est. Priority Date: 12/13/2004
• Status: Abandoned Application

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Tesfai, Yohannes
• Application Number:
  US11/010,867
• Publication Number:
  US 20060128311A1
• Time in Patent Office: Days
• US Class Current: 455/67.110
• CPC Class Codes: G01S 5/0252 Radio frequency fingerprinting

Abstract

A system, method and software for determining a position of a source of a radio emission. Receive signal strength data associated with reception of radio emissions is generated at each of a plurality of radio sensor devices that are at corresponding known positions in an area where the radio emissions are occurring. Using characteristics associated with reception of the radio emissions at each of the sensor devices, the receive signal strength data generated by each of the sensors is matched as corresponding to a radio emission from the same source. The characteristics used to match receive signal strength data may include spectrum analysis data and/or timing analysis data. Once the receive signal strength data is matched, position computations may be performed on the appropriate set of receive signal strength data to compute the position of the source of the radio emission.

Claims

1. A method for determining a position of a source of a radio emission, comprising:

a. generating receive signal strength data associated with reception of radio emissions at each of a plurality of sensor devices at corresponding known positions in an area;

b. matching receive signal strength data generated at each of the plurality of sensor devices as corresponding to a radio emission from the same source based on characteristics associated with reception of the radio emission at each sensor device; and

c. processing the receive signal strength data determined to be associated with reception of a radio emission from the same source at each of the sensor devices to determine a position of the source of the radio emission.

2. The method of claim 1, and further comprising performing spectrum analysis on a radio emission received at each sensor device to produce spectrum analysis data, wherein matching comprises analyzing the spectrum analysis data associated with reception of radio emissions at each of the plurality of sensor devices.

3. The method of claim 2, wherein performing spectrum analysis comprises generating spectrum data including one or more of:

power versus frequency data, power level, center frequency and bandwidth of the radio emission received at each of the sensor devices.

4. The method of claim 3, and further comprising performing timing analysis on radio emissions received at each sensor device to produce timing data, wherein matching comprises analyzing the spectrum data and timing data associated with reception of radio emissions at each of the plurality of sensor devices.

5. The method of claim 4, wherein performing timing analysis comprises producing time duration data for radio emissions received at each of the sensor devices.

6. The method of claim 1, wherein generating comprises generating receive signal strength data associated with reception of a plurality of radio emissions from corresponding ones of a plurality of sources.

7. The method of claim 6, wherein matching comprises matching receive signal strength data generated at each of the plurality of sensor devices as corresponding to a radio emission from a corresponding one of the plurality of sources.

8. The method of claim 7, wherein processing comprises processing the receive signal strength data associated with reception of each of the plurality of radio emissions at each of the plurality of sensor devices to determine a position of each of the plurality of sources.

9. The method of claim 1, and further comprising classifying radio emissions according to type at each of the plurality of sensor devices, and wherein matching comprises matching receive signal strength data generated at each of the plurality of sensor devices as corresponding to the same source based on the type of the radio emission source.

10. The method of claim 9, wherein classifying comprises comparing frequency domain and time domain characteristics generated from reception of radio emissions at each of the plurality of sensor devices with templates of frequency domain and time domain characteristics associated with known signal types.

11. The method of claim 10, wherein classifying comprises classifying a radio emission as one of:

a Bluetooth™

SCO signal, a Bluetooth™

ACL signal, a microwave oven emission, a cordless telephone handset and/or base station, a wireless video camera device and a radar device.

12. The method of claim 1, and further comprising demodulating radio emissions received at each of the plurality of sensor devices thereby determining the type of radio emission received at each sensor device, wherein matching comprises matching the received signal strength data based on the type of radio emission determined by demodulating the radio emissions.

13. The method of claim 12, and further comprising recovering an identifier of the source of a radio emission from demodulation of the radio emission at each sensor device, and wherein matching comprises matching the received signal strength data from the plurality of sensor devices using the identifier.

14. The method of claim 1, and further comprising transmitting a signal from a first sensor device, the signal including timestamp information related to the clock of the first sensor device, wherein the other sensor devices receive the signal and synchronize their internal clocks based on the time stamp information included in the signal.

15. The method of claim 14, wherein transmitting comprises transmitting the signal from the first sensor device on a periodic basis.

16. A system for determining a position of a source of a radio emission, comprising:

a. a plurality of sensor devices at corresponding known positions in an area, wherein each sensor device receives radio emissions in the area and generates receive signal strength data associated with reception of radio emissions; and

b. a computing device coupled to each of the plurality of sensor devices, wherein the computing device matches receive signal strength data generated at each of the plurality of sensor devices as corresponding to a radio emission from the same source based on characteristics associated with reception of the radio emission at each sensor device, and processes the receive signal strength data associated with reception of a radio emission from said same source at each of the sensor devices to determine a position of the source of the radio emission.

17. The system of claim 16, wherein each sensor device performs spectrum analysis on a radio emission that it receives to produce spectrum analysis data that is supplied to the computing device, wherein the computing device matches the received signal strength data based on the spectrum data.

18. The system of claim 17, wherein each sensor device performs spectrum analysis to generate spectrum data including one or more of:

power versus frequency data, power level, center frequency and bandwidth of the radio emission received at each of the sensor devices.

19. The system of claim 17, wherein each sensor device performs timing analysis on radio emissions it receives to produce timing data, and wherein the computing device matches receive signal strength data based on the spectrum data and timing data received from each of the sensor devices.

20. The system of claim 19, wherein each sensor device performs timing analysis to produce time duration data for radio emissions received at each of the sensor devices.

21. The system of claim 16, wherein each of the sensor devices generates receive signal strength data associated with reception of a plurality of radio emissions from corresponding ones of a plurality of sources.

22. The system of claim 21, wherein the computing device matches receive signal strength data generated at each of the plurality of sensor devices as corresponding to a radio emission from a corresponding one of the plurality of sources.

23. The system of claim 22, wherein the computing device processes the receive signal strength data associated with reception of each of the plurality of radio emissions at each of the plurality of sensor devices to determine a position of each of the plurality of sources.

24. The system of claim 16, wherein each sensor device classifies the radio emission it receives according to type, and wherein the computing device matches receive signal strength data generated at each of the plurality of sensor devices as corresponding to a radio emission from the same source based on the type determined by classifying the radio emissions.

25. The system of claim 24, wherein each sensor device classifies the radio emission by comparing frequency domain and time domain characteristics generated from reception of radio emissions at each of the plurality of sensor devices with templates of frequency domain and time domain characteristics associated with known signal types.

26. The system of claim 24, wherein each sensor device classifies the radio emission as one of:

a Bluetooth™

SCO signal, a Bluetooth™

ACL signal, a microwave oven emission, a cordless telephone handset and/or base station, a wireless video camera device and a radar device.

27. The system of claim 26, wherein each radio sensor device demodulates radio emissions it receives thereby determining the type for the radio emission, wherein the computing device matches the received signal strength data based on the type of radio emission determined by demodulating the radio emissions.

28. The system of claim 27, wherein each sensor device recovers an identifier of the source of a radio emission from demodulation of the radio emission, and wherein the computing device matches the received signal strength data from the plurality of sensor devices using the identifier.

29. The system of claim 16, wherein a first sensor device transmits a signal including timestamp information related to the clock of the first sensor device, wherein the other sensor devices receive the signal and synchronize their internal clocks based on the timestamp information included in the signal.

30. A method for determining a position of a source of a radio emission, comprising:

a. generating receive signal strength data associated with reception of radio emissions at each of a plurality of sensor devices at corresponding known positions in an area;

b. classifying radio emissions by type at each of the plurality of sensor devices;

c. matching receive signal strength data generated at each of the plurality of sensor devices as corresponding to a radio emission from the same source based on the type determined by classifying the radio emissions; and

d. processing receive signal strength data associated with reception of a radio emission from the same source at each of the sensor devices to determine a position of the source of the radio emission.

31. The method of claim 30, wherein classifying comprises comparing frequency domain and time domain characteristics generated from reception of radio emissions at each of the plurality of sensor devices with templates of frequency domain and time domain characteristics associated with known signal types.

32. The method of claim 31, wherein classifying comprises classifying a radio emission as one of:

a Bluetooth™

SCO signal, a Bluetooth™

ACL signal, a microwave oven emission, a cordless telephone handset and/or base station, a wireless video camera device and a radar device.

33. A processor readable medium storing instructions that, when executed by a processor, perform steps of:

a. matching receive signal strength data generated at each of the plurality of sensor devices as corresponding to a radio emission from the same source based on characteristics associated with reception of the radio emission at each sensor device; and

b. processing the receive signal strength data determined to be associated with reception of a radio emission from the same source at each of the sensor devices to determine a position of the source of the radio emission.