Position determination using received broadcast signals

• US 8,078,194 B2
• Filed: 10/15/2010
• Issued: 12/13/2011
• Est. Priority Date: 05/25/2007
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Walley, John, Seshadri, Nambirajan, Bibaud, Scott
• Primary Examiner(s): PHUONG, DAI
• Application Number:
  US12/905,159
• Publication Number:
  US 20110034180A1
• Time in Patent Office: 424 Days
• Field of Search: 455436-453, 4554561-457
• US Class Current: 455/456.1
• CPC Class Codes: G01S 5/02521 using a radio-map
• CPC Class Codes: G01S 5/10 Position of receiver fixed by co-ordinating a plurality of position lines defined by path-difference measurements , e.g. omega or decca systemsG01S5/12 takes precedence ; beacons and receivers cooperating therewith G01S1/306, G01S1/308
• CPC Class Codes: H04H 60/44 for identifying broadcast stations
• CPC Class Codes: H04H 60/51 of receiving stations

Abstract

A radio device that is capable of positioning itself within a broadcast radio system includes a receiver operable to receive a plurality of broadcast radio signals, each broadcast from a respective one of a plurality of broadcast radio signal sources. The radio device further includes processing circuitry operable to determine respective call station identification information for each of the broadcast radio signal sources from the broadcast radio signals, measure respective signal quality characteristics for each of the received broadcast radio signals, identify station position data associated with each of the broadcast radio signal sources from the respective call station identification information, and calculate a location of the radio device using the signal quality characteristics and station position data associated with at least three broadcast radio signal sources.

Claims

1. A device for assisting locating a mobile radio device, the device being a network device in wireless communication with the mobile radio device via a wireless network, comprising:

a table maintaining signal measurement data for each of a plurality of broadcast radio signal sources, the broadcast radio signal sources broadcasting radio signals within the FM frequency band, the signal measurement data corresponding to a plurality of previously measured signal quality information indicating associated radial distances from the broadcast radio signal sources; and

processing circuitry for;

determining respective source locations of each of three or more broadcast radio signal sources,

receiving signal quality characteristics measured by the mobile radio device for each of the broadcast radio signals from each of the three or more broadcast radio signal sources,

comparing the respective signal quality characteristics to the table to identify respective radial distances from the three or more broadcast radio signal sources, and

calculating geographical coordinates representing a mobile location of the mobile radio device using the identified radial distances and the source locations.

2. The device of claim 1, wherein the network device further transmits at least one of the identified radial distances to the mobile radio device via the wireless network.

3. The device of claim 1, wherein the processing circuitry further transmits the calculated location to the mobile radio device.

4. The device of claim 1, wherein the signal measurement data is updated with the measured signal quality characteristics.

5. The device of claim 4, wherein the mobile radio device further provides a Global Positioning System (GPS) location thereof to enable updating of the signal measurement data.

6. The device of claim 1, wherein the signal quality information includes received signal strength indicators (RSSIs) or signal-to-noise ratios (SNRs).

7. The device of claim 1, wherein the processing circuitry is operable to average a plurality of the signal quality characteristics received from the mobile radio device and utilize average signal quality characteristics to identify at least one of the radial distances.

8. The device of claim 1, wherein the signal measurement data includes signal fingerprints determined from the plurality of previously measured signal quality information and associated radial distances for each of the signal fingerprints.

9. A method for assisting locating a mobile radio device, comprising:

providing, within a network device in wireless communication with the mobile radio device via a wireless network, a table of signal measurement data for each of a plurality of broadcast radio signal sources, the broadcast radio signal sources broadcasting radio signals within the FM frequency band, the signal measurement data corresponding to a plurality of previously measured signal quality information indicating associated radial distances from the broadcast radio signal sources;

determining respective source locations of each of three or more broadcast radio signal sources,

receiving at the network device signal quality characteristics measured by the mobile radio device for each of the broadcast radio signals from each of the three or more broadcast radio signal sources;

comparing, by the network device, the respective signal quality characteristics to the table to identify respective radial distances from the three or more broadcast signal sources; and

calculating, by the network device, geographical coordinates representing a mobile location of the mobile radio device using the identified radial distances and the source locations.

10. The method of claim 9, further comprising:

downloading the table from the wireless network to the mobile radio device.

11. The method of claim 9, further comprising:

downloading the table from the network device to the mobile radio device via an additional mobile radio device in wireless communication therewith.

12. The method of claim 9, further comprising:

transmitting at least one of the identified radial distances to the mobile radio device via the wireless network.

13. The method of claim 9, further comprising:

transmitting the calculated location to the mobile radio device.

14. The method of claim 9, further comprising:

updating the signal measurement data with the measured signal quality characteristics.