MixedMUD-RF/FSO Two Way Dcode and Forward Relaying Networks in the Presence of Co-Channel Interference

In this research work, mixed radio frequency (RF)/free-space optical (FSO) decode-and-forward (DF) two-way relaying (TWR) system is investigated in the presence of interference. In order to improve the performance of the RF link, multiuser diversity (MUD) scheme has been implemented. The multiple RF users undergo Nakagami-m distributed fading. The atmospheric turbulence on the FSO link is assumed to follow the double generalized Gamma (D-GG) scintillation model. The model on the FSO link considers two kinds of optical detection schemes, i.e., intensity modulation/direct detection (IM/DD) and coherent demodulation scheme, and also includes the effect of pointing errors. Furthermore, multiple co-channel interferers (CCIs) at the relay node are assumed to undergo Nakagami-m fading. For the considered TWR system, exact closed-loop expressions for the outage probability and bit error rate (BER) have been derived. These exact closed-form expressions have been further simplified for the case of high signal-to-noise (SNR) to derive the asymptotic expressions for the outage probability and BER of the considered system. Finally, the analytical framework developed in the research work has been validated using numerical examples.