Abstract

In wireless communication the effect of multipath as well as shadowing takes place simultaneously over the channel and this phenomena leads to composite fading. G-distribution is frequently encountered distribution in wireless fading environment. Combination of multipath fading and shadowing model are used as composite fading model. This composite fading model is named as G-distribution. G-distribution is a combination of the Inverse-Gaussian distribution and the distribution. In this paper the Pade approximation approach is used to analyze the performance of composite multipath/shadowed fading channel. This distribution is used to approximate any system in form of closed form solution as well as for accurate approximation in several shadowing conditions. The Pade approximation is applied over the general expression that is given in terms of moment generating function and results are obtained by varying shadowing parameters as well as signal to noise power threshold ratio. Our study start by deriving the moment generating function of the G-distribution and approximate them by using the Pade approximation for the calculation of bit error rate and outage probability for different values of average Signal to noise ratio (SNR). All simulations are done using Maple-13 software tool and results are obtained for outage probability and bit error rate versus average SNR.

Key words: Pade’s approximation, G-distribution, moment generating function, inverse Gaussian distribution, Nakagami distribution and composite distributions, average signal to noise ratio, outage probability, bit error probability.