Performance analysis of cooperative fixed‐gain relaying system in severe fading channels

Abstract

This study analyses the performance of a three-node cooperative relaying system with single amplify-and-forward fixed-gain relay. In most works, the source-to-destination (SD) link under deep fade condition is ignored. However, the link may experience a severe fading condition which can still contribute partially towards system diversity. Therefore, the authors assume that SD link undergoes severe fading (i.e. Weibull fading with severity parameter less than two), while the other asymmetric fading channels of the source-to-relay and the relay-to-destination links are subjected to Weibull and Rician fading, respectively. The derivations of analytical expressions for cumulative distribution function and probability density function of the instantaneous output signal-to-noise ratio at the destination terminal, allow the evaluation of outage probability, bit error probability with their diversity order of the particular system design. From the results, at a certain Weibull severity level, the SD link can be omitted and considered as deep fade since it offers insignificant diversity order.