Exact performance analysis of DF based mixed triple-hop RF/FSO/RF communication system

This paper evaluates the exact performance of the triple-hop decode-and-forward (DF) based mixed radio fre-quency/free space optical/radio frequency (RF/FSO/RF) cooperative communication system. The mixed RF/FSO/RF system finds application where the FSO link can be used to provide high speed optical connectivity between two RF networks. The RF links are characterized by independent but not identically distributed (i.n.i.d.) Nakagami-m fading links and the FSO link is characterized by path loss, Double Generalized Gamma (DGG) distributed turbulence, and pointing errors. For this mixed triplehop communication system, novel analytical expressions are derived for the key performance metric, i.e., the average bit error rate for various modulation techniques. Numerical results show the effect of fading parameters and pointing errors on the performance of the considered cooperative system.