Downlink relative co-channel interference powers in cellular radio systems

One method to achieve high capacity in cellular radio systems involves interference cancellation techniques at the receivers. To design and evaluate the performance of such interference cancellation receivers, it is essential to use realistic models of the co-channel interference. In the paper we study the ordered statistic of the relative co-channel interference, i.e. the ratio between the power level of i:th strongest interferer and the total co-channel interference power. Results from Monte-Carlo simulations show that for base stations on a symmetric grid, hexagonal cells or half-square Manhattan like street cells, the probability density functions (pdf) of the interference ratios are almost independent of the cluster size and of the base station activities. The results demonstrate the dominance of the strongest interference and show that this dominance is even more pronounced in those situations when the signal to interference ratio is low. The presented results provide a base for more realistic models for performance evaluation in cellular systems than the commonly used Gaussian interference model