Patent ID: 7800541

Claim:
A method of determining a location of an electronic device, the method comprising: transmitting one or more signals between a first electronic device at an unknown location and three or more electronic devices at three or more corresponding known locations, wherein the one or more signals each includes a plurality of simultaneous tones having different frequencies; determining at least one first phase difference between at least two tones having a first frequency difference in the one or more signals accumulated during transmission between the first electronic device at the unknown location and a first electronic device of said three or more electronic devices; determining at least one second phase difference between at least two tones having a second frequency difference in the one or more signals accumulated during transmission between the first electronic device at the unknown location and a second electronic device of said three or more electronic devices; determining at least one third phase difference between at least two tones having a third frequency difference in the one or more signals accumulated during transmission between the first electronic device at the unknown location and a third electronic device of said three or more electronic devices; and determining the location of said first electronic device at the unknown location using said first, second, and third phase differences and said first, second, and third frequency differences.