A new adaptive estimation algorithm for wireless location finding systems

Wireless location finding is receiving increasing attention in the field of wireless communications. This is is due to an order issued by the Federal Communications Commission (FCC) that mandates all wireless service providers to locate an emergency 911 caller within a high accuracy, by the year 2001. We derive a new (sub-optimal) maximum likelihood estimation algorithm for the time and amplitude of arrival of a known transmitted sequence over a single path fading channel. The new algorithm is then applied to the case of CDMA wireless location finding. The paper discusses both simulation and field trial results, all of which demonstrate significant estimation accuracy improvement over known algorithms.