Capacity performance analysis for multi-service CDMA cellular systems

The 3G mobile communication systems based on CDMA are expected to provide multi-services to mobile users. This paper presents a comprehensive analysis on the capacity performance of both uplink and downlink of a multi-service CDMA cellular system. For the uplink, the statistics of the interference at the base station can be approximated by a log normal distributed random variable, and the capacity performance is analyzed through a mathematical approximation method. For the downlink, the distribution of the interference at the mobile user's receiver is hard to gain, thus computer simulation is used to investigate the capacity performance. In addition, the impact of the shadowing, power control error and orthogonality factor on the system capacity performance are evaluated.