In this work, we carry out a unified performance analysis of a dual-hop fixed gain relay system over asymmetric links composed of both radio-frequency (RF) and unified freespace optics (FSO) under the effect of pointing errors. The RF link is modeled by the Nakagami-m fading channel and the FSO link by the Gamma-Gamma fading channel subject to both types of detection techniques (i.e. heterodyne detection and intensity modulation with direct detection (IM/DD)). In particular, we derive new

more »

... d closed-form expressions for the cumulative distribution function, the probability density function, the moment generation function, and the moments of the end-toend signal-to-noise ratio of these systems in terms of the Meijer's G function. Based on these formulas, we offer exact closed-form expressions for the outage probability, the higher-order amount of fading, and the average bit-error rate of a variety of binary modulations in terms of the Meijer's G function. Further, an exact closed-form expression for the end-to-end ergodic capacity for the Nakagami-m-unified FSO relay links is derived in terms of the bivariate G function. All the given results are verified via Computer-based Monte-Carlo simulations. Index Terms-Asymmetric dual-hop relay system, Free-space optical (FSO) communications, mixed radio frequency (RF)/FSO systems, Nakagami-m fading, atmospheric turbulence, pointing errors, outage probability (OP), bit-error rate (BER), amount of fading (AF), ergodic capacity, Meijer's G function.