Secure Performance of RIS-NOMA System Under <i>κ - μ</i> Shadowed Fading Channel

This letter proposes <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\kappa -\mu $ </tex-math></inline-formula> shadowed fading to simulate complex channels in urban environments where links are affected by the presence or movement of buildings, cars, or pedestrians. The physical layer security performance of a reconfigurable intelligent surface-assisted non-orthogonal multiple access (RIS-NOMA) system subject to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\kappa -\mu $ </tex-math></inline-formula> shadowed fading with non-ideal radio residual hardware impairment (RHI) is analyzed. Analytical expressions for the users’ outage probability (OP), intercept probability (IP), and their asymptotic expressions are also derived. Finally, the results are validated through the Monte Carlo simulations. The results show that the channel distribution significantly impacts the system performance. The system’s reliability can be effectively improved by increasing the number of multipath clusters <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu $ </tex-math></inline-formula> and the LOS component <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\kappa $ </tex-math></inline-formula>. However, it is a trade-off between reliability and security which may be influenced by the RU number. Moreover, the RHI level has a slight impact on the system’s performance.