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Systems and methods for geographic positioning using radio spectrum signatures

Systems and methods for geographic positioning using radio spectrum signatures description/claims

The present invention relates to the determination of the location of a radio receiver by comparing a measured radio signature to a lookup table comprising a plurality of radio signatures from known locations.

Present techniques for locating electronic devices (e.g., cellular phone, personal digital assistants, computer, etc.) require technology such as (i) satellite signals (global positioning signals “GPS”), (ii) GPS and assistance via cellular signals to penetrate, building structures, or (iii) triangulation using a cellular system. Each of these techniques, while useful in their own right, has the drawback that they require relatively expensive equipment and/or a subscription to an expensive data service. What is needed in the art are cheaper methods for locating the global position of an electronic device.

The present invention addresses the shortcomings found in the prior art. The present invention provides a mechanism for determining the geographic position of an electronic device using radio signals. One embodiment of the present invention provides a method of localizing a geographic position of a radio receiver. In the method, a current radio signature is obtained. This current radio signature comprises a plurality of measured signal qualities that collectively represent a frequency spectrum. Each measured signal quality in the plurality of measured signal qualities corresponds to a portion of the frequency spectrum. The current radio signature is compared to a plurality of reference radio signatures. Each reference radio signature in the plurality of reference radio signatures is associated with a global position. When the comparing identifies a unique match between the current radio signature and a reference radio signature in the plurality of reference radio signatures, the radio receiver is deemed to be localized to the global position associated with the reference radio signature.

In some embodiments, the frequency spectrum is all or a portion of the FM frequency spectrum, all or a portion of the AM frequency spectrum, all or a portion of the spectrum between 300 KHz and 3 MHz, all or a portion of the spectrum between 3 MHz and 30 MHz, or a portion of the spectrum between 30 MHz and 300 MHz, or all or a portion of the spectrum between 300 MHz and 3000 MHz. In some embodiments, a measured signal quality in the plurality of measured signal qualities is a decibel rating of a frequency in the frequency spectrum. In some embodiments, the measured signal quality in the plurality of measured signal qualities is a voltage representing a frequency in the frequency spectrum.

In some embodiments, the portion of the frequency spectrum corresponding to a first measured signal quality in the plurality of measured signal qualities is a first frequency window. In some embodiments, this first frequency window comprises a frequency spectrum that has a spectral width that is between 1 KHz and 200 KHz or between 200 KHz and 400 KHz. In some embodiments, the portion of the frequency spectrum corresponding to a second measured signal quality in the plurality of measured signal qualities is a second frequency window and a spectral width of the first frequency window and the second frequency window is the same or different.

In some embodiments, the first measured signal represents a strongest observable signal in the portion of the frequency spectrum corresponding to the first measured signal quality. In some embodiments, a second measured signal quality also corresponds to the first frequency window. In some embodiments the first measured signal quality and the second signal quality are each independently selected from the group consisting of an RDS quality, an FM multipath reading, FM level, AM level, or a phase lock.

Another aspect of the invention provides a device comprising instructions for accessing a radio signature lookup table. The radio signature lookup table comprises a plurality of reference radio signatures that collectively represent a frequency spectrum. Each reference radio signature in the plurality of reference radio signatures is associated with a global position. The device further comprises a radio signature measurement model for localizing a geographic position of a device. The radio signature measurement model comprises instructions for obtaining a current radio signature. The current radio signature comprises a plurality of measured signal qualities. Each measured signal quality in the plurality of measured signal qualities corresponds to a portion of the frequency spectrum. The device further comprises a radio signature comparison module having instructions for comparing the current radio signature to the plurality of reference radio signatures.

In some embodiments, the device further comprises instructions for accessing a radio display table. This radio display table comprises information for each global position in a plurality of global positions. Such embodiments further include a radio display module for obtaining information from the radio display table as a function of an identity of a reference radio signature uniquely identified by the instructions for comparing. In some embodiments, the device further comprises a table update module. The table update module comprises instructions for updating information in the radio display table. In some embodiments, the device further comprises a table update module. The table update module comprises instructions for updating a reference radio signature in the radio signature lookup table. The instructions for accessing a radio signature lookup table and the radio signature measurement model is embedded in one or more application specific integrated circuits (ASICs), one or more field-programmable gate arrays (FPGAs), or any combination thereof. In some embodiments, the device comprises an ASIC or FPGA. In some embodiments, the device is a component of an RDS or an HD radio.

Another aspect of the invention comprises a radio comprising means for accessing a radio signature lookup table. The radio signature lookup table comprises a plurality of reference radio signatures. Each reference radio signature in the plurality of reference radio signatures is associated with a global position. The radio further comprises means for localizing a geographic position of the radio. The radio signature measurement model further comprises instructions for obtaining a current radio signature. This current radio signature comprises a plurality of measured signal qualities that collectively represent a frequency spectrum. Each measured signal quality in the plurality of measured signal qualities corresponds to a portion of the frequency spectrum. The radio further comprises means for comparing the current radio signature to the plurality of reference radio signatures.

FIG. 1A illustrates a radio receiver capable of determining geographical position in accordance with an embodiment of the present invention.

FIG. 1B illustrates data structures that are measured by a radio receiver capable of determining geographical position in accordance with an embodiment of the present invention.

FIG. 2 illustrates a method for determining geographic position in accordance with an embodiment of the present invention.

FIG. 3 illustrates a method for assigning a global position to a current radio signature in accordance with an embodiment of the present invention.

FIG. 4 illustrates a circuit diagram for an exemplary system for measuring signal strength across a spectrum of wavelengths for use in populating a radio signature lookup table in accordance with an embodiment of the present invention.

FIG. 5 illustrates a system component diagram for an exemplary system for measuring signal strength across a spectrum of wavelengths for use in populating a radio signature lookup table in accordance with an embodiment of the present invention.

FIG. 6 illustrates a graphical user interface for monitoring data used to populate a radio signature lookup table in accordance with an embodiment of the present invention.

• Provisional Patent
• Utility Patent

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