Patent ID: 7941159

Claim:
A radio device, comprising: a receiver configured to receive a plurality of broadcast radio signals within the FM frequency band, each broadcast from a respective one of a plurality of broadcast radio signal sources; and processing circuitry coupled to said receiver and configured to: determine respective call station identification information associated with each of said plurality of broadcast radio signals from each of said plurality of broadcast radio signals, each said call station identification information identifying a respective one of said plurality of broadcast radio signal sources; measure respective signal quality characteristics for each of said plurality of broadcast radio signals from said respective broadcast radio signals, identify station position data associated with each of said broadcast radio signal sources from said respective call station identification information, said station position data indicating a respective location of each of said broadcast radio signal sources, and calculate geographical coordinates representing a location of said radio device using said signal quality characteristics and said station position data associated with at least three of said broadcast radio signal sources, wherein said processing circuitry is configured to multiply a respective weighting factor to each of said signal quality characteristics to produce weighted signal quality characteristics and utilize said weighted signal quality characteristics to calculate said location of said radio device, each said respective weighting factor being predetermined based on prior radio device positioning using said broadcast radio signals from said broadcast radio signal sources.