A stochastic geometrical vector model of macro- and megacellular communication channels

This paper describes a physically based stochastic approach that allows to predict the narrowband fading statistics for macro- and megacellular networks operating in urban areas. On one hand, macrocellular channels have been mainly covered in the literature by means of empirical models. On the other hand, megacells are typical of upcoming communication systems, such as broadband wireless access and high-altitude platform-based networks. Generally, the path gain of a wireless fading channel can be statistically characterized by a Ricean distribution, which includes Rayleigh fading as a particular case. The key parameter of the distribution is the K-factor K, defined as the ratio of the dominant component to the scatter contribution. The K-factor is estimated by means of a physical model, conditionally to a set of geometrical parameters, such as the building height, the street width and the base station-to-terminal distance. These parameters are statistically described by analytical distributions. The model is successfully compared with experimental data at 1.6 GHz and typical applications are presented. Finally, because of its physical background, the model performs very well in analyzing polarization (MIMO) multiplexing schemes.