Capacity Analysis of a Multiuser Mixed RF/FSO

In this work, we consider a relay-assisted free-space optical (FSO) communication scheme in which the relay services multiple users and only the best user is selected so that the channel fluctuations can be effectively exploited to produce a selection diversity gain. We assume that the link from the source to the relay is a radio-frequency (RF) link while the link between the relay and the destination is an FSO link. More specifically, we first present a statistical analysis for the systems under consideration over both weak and strong atmospheric turbulence channels. Based on these results, the capacity of these systems with and without adaptive transmission is analyzed.