Patent ID: 8781404

Claim:
A method comprising: determining an expected distance between a portable electronic device and a wireless transmitting device based, at least in part, on an initial position of said portable electronic device and a position of said wireless transmitting device; determining an experienced distance between said portable electronic device and said wireless transmitting device based, at least in part, on at least one parameter associated with at least one wireless signal transmitted between said portable electronic device and said wireless transmitting device, wherein said at least one parameter associated with said at least one wireless signal comprises at least one of: a propagation time, a code delay or shift, or a phase delay or shift; characterizing said wireless transmitting device as being at least one of a multipath source or a non-multipath source with respect to a current position of said portable electronic device based, at least in part, on said expected distance and said experienced distance; storing one or more electronic signals representing characterization information associated with at least said current position of said portable electronic device; and determining a current estimated location of said portable electronic device based, at least in part, on wireless signals received from a plurality of wireless transmitting devices, wherein at least one of said plurality of wireless transmitting devices has been characterized through corresponding characterization information as being said multipath source with respect to said current position.