Patent ID: 7609207
Filing Date: 2009-10-27
Classification: G01S

Abstract:
1. A method, comprising: receiving data from a first wireless device representative of a time the first wireless device transmitted a first signal and a time the first wireless device received a second signal from a third wireless device based on a first clock associated with the first wireless device; receiving data from a second wireless device representative of a time the second wireless device received the first signal and the time the second wireless device received the second signal based on a second clock associated with the second wireless device; calculating a first time difference, the first time difference being the difference between the time the first wireless device received the second signal and the time the first wireless device transmitted the first signal; calculating a second time difference, the second time difference being the difference between the time second wireless device received the second signal and the time the second wireless device received the first signal; calculating a relative frequency difference between the first clock and the second clock; adjusting the second time difference by multiplying the second time difference by the relative frequency difference; and determining a time difference of arrival for the second signal based on a difference between the first time difference and the adjusted second time difference.