Performance of Dual-Hop Relaying Over Mixed Gamma-Gamma and TWDP Fading Channels

Abstract

To meet the significant increase in connectivity, 6G communication technologies employ low- and high-altitude platforms (LAP/HAP) to fulfil the demand for high-speed and reliable communication requirements. A free-space optical communication (FSO) link is the current state-of-theart at HAP for maximizing point-to-point communication. In contrast, LAP-to-ground-station links are vulnerable to various fading scenarios due to the availability of specular/diffuse components and can be appropriately modelled using generalized fading channels. This paper analyzes the performance of cooperative dual-hop over a mixed fading system to reap the benefits of relaying schemes for long-haul communication, considering LAP/HAP. The Gamma-Gamma (GG) and the generalized fading model the FSO and the twowave with diffuse power (TWDP) distribution, respectively. Aiding a cooperative decode-and-forward relaying scheme, the end-to-end closed-form expression of the outage probability is derived. Furthermore, the results are presented over various key parameters, including TWDP fading parameters, FSO turbulence parameters and distinct transmission rates. Corroboration of analytical and Monte-Carlo simulations endorses the correctness of the analysis.