Soft Handoff Analysis of Hierarchical CDMA Cellular Systems

Abstract

Abstract-A new soft handoff analysis for hierarchical code-division multiple-access (CDMA) cellular systems is presented. Hierarchical cellular architectures have been proposed to increase cellular system capacity and flexibility. In order to extend such architectures to CDMA-based systems, the performance of soft handoff in hierarchical architectures must be considered. We first develop an analytical method for studying the interference in hierarchical CDMA cellular systems. We then apply the obtained results to a soft handoff analysis model to study the performance of soft handoff in hierarchical architectures. It is observed that dynamic handoff parameter assignment, where parameters are dynamically adjusted according to given interference conditions, offers a more efficient handoff mechanism than fixed handoff parameter assignment.Index Terms-Active set, carrier-to-interference ratio (CIR), code-division multiple access (CDMA), hierarchical architectures, macrocell, microcell, soft handoff.