Impact of Shadowing in Relayed Hybrid FSO-mmWave RF Transmission System

Integrating free space optics (FSO) and millimeter-wave (mmWave) technology presents a promising solution for far-field wireless communication. This paper analyzes a relayed FSO-mmWave RF downlink system in a line-of-sight (LoS) blockage terrain, exercising a decode-and-forward (DF) protocol. The Free Space Optics (FSO) link uses a Gamma-Gamma (G-G) distribution to address atmospheric turbulence and pointing inaccuracies, while the millimeter-wave (mmWave) RF link is characterized by a generalized K (G-K) distribution to account for fading and shadowing. We estimate the system’s performance in terms of outage probability, average BER, and capacity. Additionally, computer simulations of each metric are furnished to confirm our analytical findings. The results highlight the significant impact of shadowing in the RF link and atmospheric turbulence, and pointing errors in the FSO link. This reflects the necessity for maintaining high-quality FSO and RF links for reliability.