Reconciling theory and practice

Abstract

The performance evaluation of w-cdma networks is intricate as cells are strongly coupled through interference. Pole equations have been developed as a simple tool to analyze cell capacity. Ample scientific contributions have been made on their basis. In the traditional forms, the pole equations rely on strong assumptions such as homogeneous traffic, uniform users, invariant downlink orthogonality. These assumptions are not met in reality. Hence, the pole equations are typically used during initial network dimensioning only. Actual network (fine-) planning requires a more faithful analysis of individual cell's capacity. Complex analytical analysis or Monte-Carlo simulations are used for this purpose.In this paper, we generalize the pole equations to include inhomogeneous data. The equations can be parametrized in a cell-specific way provided the base station transmit powers are known. This allows to carry over prior results to realistic settings. This is illustrated with by example: Based on the pole equation, we investigate the accuracy of "average snapshot" approximations for downlink transmit powers used in state-of-the-art network optimization schemes. We confirm that the analytical insights apply to practice-relevant settings. This is done on the basis of results from detailed Monte-Carlo simulation on realistic datasets.