Rain attenuation time series synthesis with combined Markov models for microwave terrestrial links

This contribution provides a method to synthesise rain attenuation time series for microwave terrestrial radio links. The time series generator is based on the combination of a two-state Markov chain to model the long-term attenuation behaviour of the link, and a Hidden Markov Model (HMM) which generates the fine structure of the attenuation. This combined method is required due to the non-stationary behaviour of the attenuation process. The parameters of the two-state model are determined from the fade duration statistics of the link. The HMM will be parameterised with the Baum-Welch Algorithm (BWA) applying a measurement database containing attenuation time series of a 38 GHz terrestrial radio link. The combination of the long-term model with the HMM can be applied to synthesise time series for any duration by taking into account that the model parameters may vary depending on the local climatic variations. Copyright © 2007 Inderscience Enterprises Ltd.