On the Fade Duration Distribution in Nakagami Fading Channels

During almost fifty years the fade duration distribution (FDD) of random signals has been an open research topic. However, for Nakagami fading channels, and in general for the great majority of non-Gaussian processes, closed form general solutions are still unknown. In this paper we apply an orthogonal series expansion that allows to characterize the FDD. Our results show that the FDD in Nakagami wireless channels can be approximated, for both asymptotic and non-asymptotic threshold levels (C), by a simple closed form function: the Gamma distribution. This approximation is validated in different ways. We show how it is possible to compute (a priori) the parameters of the approximate Gamma distribution through the analytical fade statistics. We also examine the influence of different autocorrelation functions on the FDD.