Physical layer security for dual-hop FSO/RF system using generalized ΓΓ/η - μ fading channels

We investigate the physical layer security of decode-and-forward-relayed free space optics (FSO)/radio frequency (RF) communication system. In this network, the eavesdropper exists after relay node and overhears RF transmission. Further, FSO being a line-of-sight transmission is assumed to be secure from eavesdroppers. Here, we have the Gamma-Gamma () distribution for FSO link and generalized eta-mu distribution for RF link. The security for information transmission to the legitimate user in the presence of an eavesdropper is measured in terms of secrecy capacity and secrecy outage probability. Deriving the probability density function and cumulative distribution function of end-to-end signal-to-noise ratio, the closed-form expressions for security parameters are achieved. The numerical analysis of the proposed system is done under the influence of atmospheric turbulence effects and various fading conditions. The results have been verified through simulation.