Local and Global Signal Variability Statistics in a Mobile Urban Environment

Signal variability in mobile radio communicationenvironments has been extensively studied. It isalways assumed that, for small areas, thevariability is Rayleigh-distributed, althoughexperimental results have proven that this is notalways the case. Other distributions present moreaccurated results. For large areas, the Suzukidistribution has been proposed based on the Rayleighassumption. This work presents a review of the mostcommonly used distributions for the local and globalstatistics of the received signal variability andthe theoretical foundation for a generalizeddistribution for large areas based on the assumptionof a Weibull distribution for short-termvariability. All distributions are presented in alinear and logarithmic form to facilitate comparisonwith experimental data. This new proposeddistribution gives better accuracy than the Suzukidistribution.