On the Capacity of multi-cell UMTS

In this paper, we focus on the capacity of a multicell UMTS system. We first determine an upper bound on the othercell interference and obtain novel expressions for the SIR and powers for both the uplink and the downlink. The former is an asynchronous CDMA system, often using one of three types of receivers : matched filter, Minimum Mean-Square Error (MMSE) and decorrelator. In the latter, the SIR depends on the distance between the user and the base station. We show that the intercell interference alters the capacity of the system for all kinds of receivers, though the effective bandwidth expressions remain identical to the ones obtained in the single-cell case. As an application, we show how to use this analytical model to develop a new efficient Connection Admission Control (CAC) algorithm.