THz-RF Cooperative NOMA Communication System Incorporating Practical Constraints

In this letter, we propose a novel communication system for multiple Non-Orthogonal Multiple Access (NOMA)-based end-users, leveraging a mixed THz-RF wireless communication approach. The THz link serves as the backhaul communication link and is characterized by an <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\alpha -\mu $ </tex-math></inline-formula> fading channel, path loss, absorption loss, and pointing errors. The sub-6 GHz RF carrier has been utilized for end-user connectivity. We incorporate hardware impairments (HI), channel state information (CSI) and, successive interference cancellation (SIC) errors at the receiver to capture realistic operating conditions. We have presented a mathematical framework for outage probability and average bit error rate and the asymptotic results to evaluate the proposed system’s effectiveness. The results are analyzed for various system parameters to provide further insights into system performance. Further, Monte Carlo simulations are performed to validate the analytical results.