Examiner: Advisers:

In 3rd generation of mobile communication systems the demand on high bit rates in the downlink has become an important topic. WCDMA uses fast power control in the downlink to reach a high capacity. This study considers modified power control algorithms in a WCDMA system, to reach additional capacity in the downlink. The first considered algorithm employs a non-equal distribution of quality among the users. Users that are consuming high power are given less quality and the resource that is made available is used to improve the quality for others. There is a tradeoff between the amount of enhanced quality in some channels and loss of quality in others. However this study clearly indicates that enhanced quality or capacity in the downlink can be reached with this method. A drawback with fast power control used in WCDMA is power drift between base stations during soft handover. Power drift is caused by independently received errors in transmit power control commands at the base stations. A new proposed algorithm to combat power drift is studied and also compared to other existing algorithms. Simulation shows that enhanced quality at the receiver is reached with this algorithm. Another benefit is that no extra signaling within the system is needed