Analysis of the Multi-Cell Correlation of the Slow Fading from UMTS Measurements and Its Impact on Radio Network Planning

In order to further improve the cell edge throughput prediction for network planning and optimisation purposes the correlation properties of the received power from pairs of cells is investigated. Since the results should match the typical scenarios of UMTS and LTE networks in urban areas we analysed own measurements. A system of the standard drive test equipment is applied enabling to evaluate a comprehensive data set from four cities of different size. Although highly focussing base station antennas are used the received power from intra-site cells is observed to be highly correlated whereas the signals from widely separated base station antennas are clearly uncorrelated. That agrees with other studies and indicates that our proposed measurement set-up and post-process are suited for signal correlation analysis. Considering the outcome of this study in our RF planning tool the cell edge predictions are closer to the experience from throughput measurements.