Wireless mobile phones are used a great deal for emergency phone calls. However, most cellular networks provide only the most basic 911 services. In response to this, the Federal Communications Commission passed a series of regulations in 1996 that require all cellular service providers to provide Enhanced 911 (E-911) service. When the nal phase of E-911 is implemented in 2001, every cellular network in the United States will have to be able to determine the position of each mobile in their coverage areas to an accuracy of 125 meters, RMS.
This thesis addresses the problem of determining the position of IS-95 cellular mobiles. First, an analysis of the mobile's received signal level is performed in order to determine what location methods are practical. Then, two strategies of locating the mobile are investigated. First, a system locating the mobile using the time-of-arrival of its signal at several base stations is proposed and evaluated. Second, two systems that locate the mobile using measurements it makes on the base station pilots are presented and analyzed.PDF file, 560 kBytes