Clustering of scatterers in mobile radio channels-evaluation and modeling in the COST259 directional channel model

We analyze the clustering of scatterers in mobile radio channels, i.e, the fact that scatterers are usually not located uniformly in the whole coverage area, but tend to occur in clusters. While this has been recognized for some time, a realistic model for this phenomenon has been lacking up to now. We first analyze measurements to extract the distribution of the number of observed clusters. We then present a model that reflects not only this distribution, but also reproduces the appearance and disappearance of clusters as the mobile station moves through the cell. Our approach has been adopted as an important part of the COST259 directional channel model, a standard model for directional mobile radio channels. Finally, we discuss the implications of the model for the system performance of CDMA and SDMA systems.