On the Performance Analysis of Mixed Underlay Cognitive RF/SIMOFSO System over k-µ Shadowed and M Distribution Channels

In this paper, we investigate the performance of mixed underlay cognitive radio frequency (RF) and single-input multiple-output SIMO free space optical (FSO) system. In the dual-hop decode-and-forward (DF) configuration, considering the combined attenuation of atmospheric turbulence, path loss and pointing error on atmospheric turbulence channel, we use the mixed K-µ shadow/M distribution statistical model that can represent most channels. For the RF link, we consider an underlay cognitive radio network (CRN), where the secondary user (SU) shares the spectrum with the primary user (PU). For the FSO link, we use switch-and-examine combining (SEC) at the SIMOFSO destination. The closed-form outage probability is derived in term of Meijer-G function, and the effects of channel fading, SU peak transmit power, interference temperature user and the number of SIMO receivers on the outage performance are analyzed through simulation and verified by the Monte Carlo simulations. The mixed underlay cognitive RF/SIMOFSO system we proposed can provide a theoretical reference for the engineering practice for the mixed CRN RF/FSO system.