Bo Engström

WCDMA system level performance with fast fading and non-ideal power control

This paper shows the need to include detailed link level characteristics in a system performance analysis and how this is implemented in a system simulator. It is a well-known fact that CDMA systems need accurate power control to achieve good performance. Detailed models of link level characteristics are needed in order to achieve reliable system level performance estimates of the power control algorithms. By including characteristic link level parameters such as FER, C/I and BER, together with multipath fading and a complete implementation of the closed and outer loop power control algorithms, we have created an environment for realistic simulations of the system algorithms. This enables us to study the effects on the system performance of e.g. delay, measurement errors, velocities of mobiles, multipath fading, and our power control algorithms in a dynamic cellular environment. The driving force behind our simulator implementation is to continuously improve the performance of the system algorithms and thus, in the end, to increase the capacity. The results show that a system simulator which includes detailed link level characteristics is a useful tool when studying the effects of the non-ideal power control.