Outage analysis of a variable-gain amplify and forward relayed mixed RF-FSO system

In this work, we present the outage analysis for a variable gain amplify-and-forward relayed dual-hop link that comprises of a radio frequency (RF) first-hop link and a free space optical (FSO) link for the second-hop. We assume that no direct RF and FSO link exists between the source and destination nodes. The RF link experiences a composite multi-path fading and shadowing effects, and is modeled by Generalized-K fading distribution, whereas, the atmospheric turbulent FSO channel follows the Gamma-Gamma distribution statistics. Further, significant pointing error impairments are assumed to be present over the FSO link. The analytical closed form expressions for the outage performance of the system model under consideration are derived and illustrated by numerical plots.