Wireless localization with antenna arrays

Abstract

The United States Federal Communication Commission (FCC) regulation mandating wireless system operators to be capable of providing location information of mobile subscribers who request emergency assistance via 911 has driven much of the research in the area of network-based wireless localization during the last decade. Although 911 callers are cooperative, i.e. the cellular receivers can obtain timing/power information from the mobile handsets, yet little progress has been made to meet the FCC regulation mainly due to the complex propagation in dense urban areas resulting in the dominating non-line-of-sight propagation between a mobile handset and the receivers.

This thesis is focused on developing techniques for localizing non-cooperative transceivers using terrestrial communication systems that are equipped with antenna arrays and using high altitude platforms that are equipped with two-dimensional antenna arrays. Non-cooperative transceivers are unlicensed relaying base stations or illegal unlicensed transceivers that generate interference in the existing wireless systems. The non-cooperative nature of such transceivers and the complex multipath propagation in dense urban areas preclude the employment of traditional triangulation-based localization techniques.

The techniques developed and explored in this thesis enabled us to localize not only the cooperative mobile subscribers but also non-cooperative transceivers with accuracy that exceeds the FCC requirements on cooperative wireless localization systems.