User-pair selection in amplify-and-forward based FSO networks

This paper describes a single amplify-and-forward relay assisted multiple user-pair free space optical (FSO) communication system. It is assumed a line-of-sight link does not exist between the nodes of a user-pair and the communication link between them is established using a relay. Among the multiple user-pairs, the user-pair having the maximum instantaneous signal-to-noise ratio is selected by the relay. For the considered system model, closed form expression of the system outage probability is derived in terms of the Meijer's-G function considering independent but not necessarily identically distributed (i.n.i.d.) fading channels. It is shown by numerical analysis that by carrying out user-pair selection the system performance significantly improves.