Performance of Hyperbolic Position Location Techniques for Code Division Multiple Access

The Federal Communications Commission (FCC) recently adopted rules requiring cellular telephone, Personal Communication System (PCS) and Specialized Mobile Radio (SMR) licensees to provide two dimensional automatic location information (ALI) for a user requesting E-911 service. These wireless service providers will need to utilize effective position location (PL) technology in order to meet FCC rules. Hyperbolic PL systems are one such technology that can provide accurate PL information using the existing cellular/PCS infrastructure and without requiring additional hardware/software implementation within the mobile unit. In recent years, the IS-95 Code Division Multiple Access (CDMA) system has gained increasing popularity in North America because of the many advantages it offers over existing air interfaces. However, CDMA systems present some unique challenges to the effectiveness of hyperbolic position location systems.

This thesis investigates the performance of the hyperbolic PL technique in CDMA systems. The effect of multipath and shadowed mobile radio environments, the location of the user within the cell, and configuration and number of base stations on the accuracy of the hyperbolic PL technique is investigated. The effect of the power control scheme required in CDMA system operation on the performance of the hyperbolic system is also demonstrated. The simulation results provide insight to the limitations and effectiveness of hyperbolic position location systems within CDMA systems.