Modelling radio link performance in UMTS W-CDMA network simulations

This article presents a method to model the W-CDMA radio receiver performance, which is usable in network simulation tools for third generation mobile cellular systems. The method represents a technique to combine link level simulations with network level simulations. The method is derived from that of Malkamaki, de Ryck and Mourot (1994), which defines a stochastic mapping function from a signal-to-interference ratio into a bit-error-rate for a TDMA system. However, in order to work in a W-CDMA based system, the fact that the multiple access interference in the downlink consists of both Gaussian inter-cell interference and orthogonal intra-cell interference must to taken into account. The mapping function was used to estimate the BER for a number of different simulation setups, and good agreement with link simulation results is demonstrated. Finally, an extension of the method to a soft handover situation is considered.