Computational Study of the Effects of Shadowing in Double Scattering Wireless Channels

Abstract

Wireless channels with severe fading conditions are often described using double scattering models. In these models, the signal-to-noise ratio is treated as the product of two identical random variables leading to the double Nakagami, double generalised gamma, double Hoyt channels, etc. While double scattering can also incorporate shadowing in Nakagami channels by allowing the one of the variables to be of gamma type and the other to be lognormal, the concept can be extended to triple scattering to explore the effects of shadowing in double scattering channels. While analytical solutions to the error rates and outage probabilities might not be possible in such triple scattering channels, computational approaches using Matlab can be employed to evaluate the performance of these channels. Such a study is undertaken here for double scattering Nakagami type channels in shadowing. Through computer simulation and other numerical techniques, an exact analysis demonstrated the worsening conditions existing in these channels, with the double Hoyt channels performing the best. The approach undertaken in this work can be easily extended to other multiple scattering channels making it possible to study the channel degradation in wireless channels.