On the Performance of Dual-Hop Fixed Gain Relaying Systems over Composite Multipath/Shadowing Channels

In this paper we investigate the end-to-end performance of dual-hop fixed gain relaying systems under asymmetric fading conditions. In such conditions, the links associated with the relay network undergo different fading phenomena. In our analysis, the source-relay and the relay-destination links are subject to fading-only or composite multi-path/shadowing environments. An outage analysis of the considered system is performed and the proposed expressions are applicable to general fading and shadowing conditions. Based on the newly derived analytical expressions of the cumulative distribution function (CDF) of the end-to-end signal to noise ratio (SNR), the average bit error probability of arbitrary rectangular QAM modulations is also computed. Some representative numerical examples of the system performance in terms of the above metrics are provided and discussed. For instance, it is confirmed analytically that the relaying system exhibits better performance when the first hop undergoes better channel conditions.