Reconfigurable Intelligent Surface-Assisted HAPS Relaying Communication Networks for Multiusers Under AF Protocol: A Performance Analysis

This research paper studies the performance analysis of a reconfigurable intelligent surface (RIS)-assisted high altitude platform station (HAPS) relaying communication network for multiple ground users. Owing to transmission blockage between the source and the destination, the source transmits its information to the HAPS via the RIS where the HAPS acts as an amplify-and-forward (AF) relay node for sending the source information to ground users. To characterize the transmission links, the channels between the source-RIS-HAPS are assumed to follow approximate generalized-K fading distribution while the links between the HAPS and multiple ground users experience Shadowing-Rician fading distribution. Since HAPS employs AF relaying scheme, the closed-form expressions of the cumulative distribution function (CDF) and probability density function (PDF) of the system end-to-end signal-to-noise ratio (SNR) are derived by exploiting the Meijer’s G and Fox’s H functions. Based on these expressions, the analytical expressions of the system outage probability, average bit error rate (BER) and average capacity are obtained to examine the system performance. Moreover, the asymptotic expressions are obtained to provide more physical insight about the system. In addition, the results unveil the significant effect of the system and channel parameters on proposed system. The results show that the system with RIS offers better performance compared the system without RIS. The analytical results are verified by Monte-Carlo simulation to justify the accuracy of the derived expressions.