Performance enhancement of soft handoff in WCDMA cellular systems

Abstract

The rapid development of mobile communication technology has facilitated people to communicate with each other anytime anywhere on the move without the restriction of fixed line connection points. The significant increase in subscribers and traffic, new bandwidth consuming applications such as gaming, music downloading and video streaming will place new demands on capacity. The answer to the capacity demand is the provision of new spectrum and the development of a new technology Wideband Code Division Multiple Access (WCDMA). Wireless communication is going to move towards universal communication that uses a very flexible networking infrastructure and dynamically adapts to the changing requirements. WCDMA allows very high-speed multimedia services such as voice, internet access and videoconferencing. In order to provide the multiple services, handoff is essential for seamless communication. Soft handoff is an important feature of cellular WCDMA systems wherein mobile stations within a handoff region use multiple radio channels and receive their signals from multiple base stations simultaneously. newlineThere are some fundamental aspects of wireless communication that make the handoff problem challenging and interesting. Radio Resource Management (RRM) in 3G networks is responsible for improving the utilization of the air interface resources. The objectives of using RRM are guaranteeing the quality of service (QoS), maintaining the planned coverage and optimization of system capacity. Radio resource management can be divided into power control, handoff, admission control and load control functionalities. The crucial component of RRM is the handoff and this is the focus of the current work. This thesis deals with the study of soft handoff in WCDMA systems to enhance its performance. The performance of soft handoff in WCDMA systems are studied in different categories namely link level analysis, system level analysis and the resource efficiency indicators.