Two Composite Fading Models for Diversity Reception in Mobile Wireless Networks

Abstract

Composite Rayleigh-lognormal fading, also known as Suzuki fading, is a cascaded product of a multipath fast fading channel and a shadowing slow fading channel. In spatial diversity reception using maximum ratio combining, the Suzuki fading model only provides diversity in the local multipath fast fading Rayleigh component, here called the micro-diversity fading model. In this paper, we propose the macro-diversity composite fading model by which diversity is obtained over the whole transmission link from the transmitter to the mobile receiver, ie. in both the slow lognormal fading and the fast Rayleigh fading. Methods for solving the “sum of Suzuki random variables” problem involved in the macro-diversity model is presented in the paper. The Gauss-Hermite quadrature polynomial is extensively used to avoid sensitive integrations and to derive elegant and computationally fast closed-form expressions for bit error rate of micro-diversity and macro-diversity reception in mobile networks.