Rain attenuation time series synthesis with simulated rain cell movement

This paper proposes a stochastic modeling method to simulate the rain attenuation process in order to generate time series for high frequency terrestrial radio links. It is also the subject of this research to express the local attenuation differences on converging radio links belonging to the same node. The simulation scene (some tenth square kilometers) is a cellular mobile radio system which consists of a backbone node and some millimeter band radio links forming a star network around the node. The model parameters are extracted from the long-term measurement of different local meteorological parameters of an active radio network. The essentials of the model is the simulation of rain cell translation across the scene by a two dimensionalnon-symmetrical random walk (discrete time and discrete state homogenous Markov model). A second Markov model is applied to embed in the model the rain cell translation speed. The structure of the rain cells is approximated with an elliptical model to express the point rainfall rate in order to calculate the path attenuation at discrete time steps during the simulation. The local precipitation field allows the evaluation of the rainfall impact on the considered radio links in terms of single-link attenuation distributions. The model is also applicable to simulate the annual attenuation statistics which will be compared with the real measurement statistics for evaluation purposes. © Periodica Polytechnica 2009.