Mixed FSO/RF Based Multiple HAPs Assisted Multiuser Multiantenna Terrestrial Communication

In this work, a mixed free-space optics (FSO)/radio-frequency (RF) based multiple serial high altitude platforms (HAPs) assisted multiuser multiantenna terrestrial communication system is considered. For the considered multi-hop system, earth station to HAP and links are assumed as FSO links, mobile users (MUs) link RF link. At detector both heterodyne detection intensity modulation direct techniques Atmospheric turbulence of ES modeled with Gamma-Gamma fading along pointing error impairments. As situates in stratosphere, negligible atmospheric exists at (20 km), hence, only for inter links. Further, consists array provide data-rates via be Nakagami-m distributed. The intermediate HAPs perform selective decode-and-forward relaying opportunistic user scheduling performed best selection. performance analysis, analytical expression overall outage probability obtained impact various selection parameters like error, type, MU selection, number antennas, severity observed on performance. Asymptotic also derived obtain diversity order system. considering schemes, generalized average bit-error-rate its Finally, results validated through Monte-Carlo simulations.