Performance analysis of lognormally shadowed generalized Gamma fading channels

摘要

A new composite channel model is proposed for the performance analysis of shadowed fading channels. This model is represented as a mixture of generalized Gamma (GG) multipath fading and lognormal shadowing. GG distribution includes the Rayleigh, Nakagami, and Weibull as special cases; hence the presented model, which is referred to as GG-L, is a generic model that covers many well-known composite fading models, including the Rayleigh-lognormal (R-L), Nakagami-lognormal (N-L), and Weibull-lognormal (W-L). The main drawback of the lognormal-based composite models is that the composite probability density function (PDF) is not in closed form, thereby making the performance evaluation of communication links in these channels cumbersome. To bypass this problem, an approximation method is developed which makes it possible to derive a closed-form, analytical expression for GG-L composite distribution. The proposed method only needs the mean and the variance of the underlying lognormal distribution, and hence, bypasses the required complicated integration needed to calculate the PDF of the received signal envelope in GG-L channel. Based on this method, the most statistical characteristics, such as cumulative density function (CDF) and moments of the GG-L composite distribution, are derived and used for the performance analysis of a single receiver operating over GG-L fading channel.