Modeling the evolution of number of clusters in indoor environments

In cluster-based channel models, the number of multipath clusters is an essential parameter. In order to model dynamic channels in a realistic way, it is necessary to investigate the evolution of the number of clusters as a function of the location of the terminals in addition to the average or instantaneous number of clusters. In this paper the number of clusters is studied by analyzing data from nine indoor dynamic double-directional measurements. In addition, the lifetimes of individual clusters are analyzed, and the corresponding radii of the visibility regions are extracted. The evolution of the total number of active clusters was modeled by a Markov chain. The modeling results revealed that the number of clusters is larger in line-of-sight (LOS) than in non-line-of-sight (NLOS) scenarios, and that the radii of the visibility regions are smaller in NLOS than in LOS. Accordingly, the number of active clusters changes more rapidly in NLOS than in LOS scenarios.