Land Mobile Propagation Fade Duration Modelling by Markov Chains

Abstract

Fade duration is one of the most important dynamic aspects of path attenuation that corresponds to the time length during which a fixed threshold is exceeded by path attenuation. Precise estimation of the fade duration parameter is essential to be taken into account in wireless communication system design for several reasons like calculating the system outage or unavailability period, sharing the system resource during the events, apply fade mitigation techniques, select the right coding scheme etc. In this paper we are presenting a digital model with N-state partitioned Markov chain for the statistical prediction of the fade duration at different attenuation thresholds. The parameter set of the digital model has been derived from the fade duration statistics of a land mobile satellite link measurement at 1.54 GHz. The parameterizations of this model includes beside the fade events also the interfade periods, therefore leads to a more precise fade duration model and provide the possibility of the implementation of joint fade-interfade duration modelling. The threshold dependence of the Markov chain's stochastic matrix elements are determined by an empirical equation