LOCATION ESTIMATION IN END-USER DEVICES USING PUBLIC RADIO SIGNALS

• US 20080280564A1
• Filed: 05/11/2007
• Published: 11/13/2008
• Est. Priority Date: 05/11/2007
• Status: Abandoned Application

• Current Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Hoekstra, Geert Jan, Meeuwissen, Hendrik Bernard
• Application Number:
  US11/747,422
• Publication Number:
  US 20080280564A1
• Time in Patent Office: Days
• US Class Current: 455/66.1
• CPC Class Codes: G01S 5/14 Determining absolute distances from a plurality of spaced points of known location

Abstract

A device (20) is capable of making location determinations from publicly available broadcasting signals that contain programming such as radio or television programming. A location estimating portion (26) in one example uses a determined received power of a detected signal from a transmitter and information regarding the location and transmit power of the transmitter for determining a distance between the device (20) and the known location of the transmitter. At least one other location indicator is used for making a determination regarding the location of the device (20). In one example, the other location indicator is a determined distance between the device and at least one other transmitter, which is based upon a determined received power of a signal from the other transmitter and the transmit power used by that transmitter. Another example includes determining where the coverage areas of a plurality of transmitters overlap as an indication of the location of the device (20). In one example, the coverage areas and identities of the transmitters are determined based upon the carrier frequencies of a plurality of detected signals.

Claims

1. A method of locating a portable device comprising the steps of:

detecting a signal from a transmitter that broadcasts publicly available programming, the transmitter having a known location and a known transmit power used for transmitting the signal on a known carrier frequency;

characterized by

determining a received power of the detected signal;

determining a distance range between the device and the location of the transmitter from the determined received power and the transmit power; and

determining an area as an indicator of a location of the device based on the determined distance range and at least one other location indicator.

2. The method of claim 1, wherein the at least one other location indicator comprises a second distance range between the device and a second, different transmitter.

3. The method of claim 2, comprising

detecting a second signal from the second transmitter that broadcasts publicly available programming, the second transmitter having a known location and transmit power used for transmitting the signal on a known carrier frequency;

determining a received power of the second signal; and

determining the second distance range between the second transmitter and the device from the determined received power of the second signal and the transmit power of the second transmitter.

4. The method of claim 2, comprising

determining a first plurality of possible locations based upon the determined distance range between the device and the transmitter;

determining a second plurality of possible locations based upon the second distance range between the device and the second transmitter;

determining at least one location area where there is at least one of the first plurality of possible locations and at least one of the second plurality of possible locations; and

using the at least one determined location area as the determined area that is an indicator of the location of the device.

5. The method of claim 2, wherein the at least one other location indicator comprises another distance between the device and another, different transmitter.

6. The method of claim 1, comprising

determining the location and transmit power of the transmitter from at least one of

a database that includes transmitter location and transmit power information corresponding to each of a plurality of transmitters,

radio data system information available from the detected signal, or

information obtained from another signal available from a broadcasting station that provides such information regarding a plurality of transmitters.

7. The method of claim 1, comprising

detecting a plurality of signals from a plurality of transmitters, respectively, each of the plurality of transmitters having a known location, a known carrier frequency for transmitting the signal and a known coverage area within which the transmitter provides the signal;

identifying each of the transmitters corresponding to each of the detected signals from at least one characteristic of each detected signal;

determining an overlap area in which the coverage of all of the identified transmitters overlaps; and

using the determined overlap area for determining the area that is an indicator of the location of the device.

8. The method of claim 7, comprising

determining where the determined area and the determined overlap area coincide to provide the indicator of the location of the device.

9. A method of locating a portable device, comprising the steps of:

detecting a plurality of signals from a plurality of transmitters, respectively, each of the plurality of transmitters having a known location, a known carrier frequency for transmitting the signal and a known coverage area within which the transmitter provides the signal;

characterized by

identifying each of the transmitters corresponding to each of the detected signals from at least one characteristic of each detected signal;

determining an area in which the coverage of all of the identified transmitters overlaps; and

using the determined area as an indicator of the location of the device.

10. The method of claim 9, comprising

providing an indication of the location of the device based upon at least one location within the determined area.

11. The method of claim 10, comprising

providing an indication of a likely accuracy of the determined location.

12. The method of claim 9, comprising

providing an indication of a boundary around the determined area as an indication of the determined location.

13. The method of claim 12, comprising

providing geographic coordinates regarding a plurality of locations corresponding to the boundary of the determined area.

14. The method of claim 9, comprising

determining at least one signal quality characteristic of at least one of the detected signals;

and

determining the coverage area of the transmitter of the at least one of the detected signals based upon the determined quality characteristic.

15. The method of claim 14, comprising

determining a plurality of ranges within a maximum coverage area of the corresponding transmitter, wherein the signal quality characteristic in each range is different than the signal quality characteristic in the other ranges;

and

determining which of the plurality of ranges corresponds to a possible location of the device based upon the signal quality characteristic of the corresponding detected signal.

16. The method of claim 9, comprising

detecting a signal from a transmitter that broadcasts publicly available programming, the transmitter having a known location and a known transmit power used for transmitting the signal on a known carrier frequency;

determining a received power of the detected signal;

determining a distance range between the device and the location of the transmitter from the determined received power and the transmit power; and

providing the indicator of the location of the device based on the determined area, the determined distance range and the at least one other location indicator.

17. The method of claim 9, comprising

determining the location and coverage area of the transmitter from at least one of

a database that includes transmitter location and coverage area information corresponding to each of a plurality of transmitters,

radio data system information available from the detected signal,

information obtained from another signal available from a broadcasting station that provides such information regarding a plurality of transmitters.

18. A receiver device having an on-device location capability, comprising:

means for detecting a signal from a transmitter that broadcasts publicly available programming, the transmitter having a known location and a known transmit power used for transmitting the signal on a known carrier frequency;

characterized by

means for determining a received power of the detected signal;

means for determining a distance range between the device and the location of the transmitter from the determined received power and the transmit power; and

means for determining an area as an indicator of a location of the device based on the determined distance range and at least one other location indicator.