Performance Analysis of NOMA-Based SATN for THz-RF link with Randomly Deployed Users

Abstract

This paper investigates the performance of a dualhop satellite-aerial-terrestrial network (SATN) in which a highaltitude platform (HAP) functions as an aerial relay to facilitate data transmission between a satellite and both aerial and terrestrial users. The first hop operates in the terahertz (THz) frequency band, while the second hop utilizes the radio frequency (RF) band. The THz link is influenced by the stochastic nature of wireless channels, further affected by environmental factors such as pressure, humidity, and temperature. The envelope of the THz link in the first hop follows a generalized α-μ distribution. In this setup, we analyze the outage performance of both terrestrial and low-altitude platform user, accounting for their random locations and the presence of shadowed-Rician and Rician fading environments, respectively. Additionally, the HAP communicate with both the users using non-orthogonal multiple access (NOMA). We also explore the impact of various parameters, including the fading coefficients of individual links, pointing errors, and the distance between nodes, on the system’s performance. The theoretical analysis is validated through simulations, offering key insights into system behaviour.