DR.
Ali H. Sayed
Wireless
location finding has emerged as an essential public safety feature of future
cellular systems. This has been in response to a 1996 federal order that
mandates all wireless service providers to provide accurate location information
of an emergency 911 (E-911) caller to public safety answering points. The
mandate aims to solve a serious public safety problem that emerges from
the fact that today more than half of the 911 emergency calls originate
from mobile phones whose location cannot be determined with existing technology.
However, there are many difficulties that are characteristic of the wireless
environment that make meeting the mandated objective within the desiredaccuracy
rather challenging. This talk provides an overview of some of the signal
processing challenges that arise in this application and describes advances
that have been made in this regard. Some of these advances
include the development of enhanced techniques that are robust to fast
channel fading, low signal-to-noise ratio conditions, and severe multipath
propagation situations. Once fully developed and deployed, there will be
many other applications of the E-911 technology beyond its original motive
such as location sensitive billing, fraud protection, asset tracking, fleet
management, intelligent transportation systems,mobile
yellow pages, and even cellular system design and management.