A semi-analytic approach for CDMA systems performance evaluation with adjacent channel interference

The effects of adjacent channel interference (ACI) on WCDMA capacity are analyzed in the case of two operators allocated on adjacent radio channels or in the case of a single operator that uses two adjacent radio channels in a hierarchical cell structure. In contrast to existing literature, where ACI effects on system performance are generally evaluated by simulation, we propose a semi-analytical approach. The basic hypothesis is to model the ACI as a Gaussian random variable whose statistics, mean and variance, are obtained through simple and very fast simulation. Subsequently, the obtained statistics are used to calculate the outage probability using closed form equations. The advantage of this approach is that many different operating conditions can be analyzed with reduced computer calculation time as compared to the full Monte-Carlo method. Several performance results obtained by the application of the proposed approach are reported in the uplink case. Results are in very good agreement with those already presented in 3GPP reports.