On Secure NOMA-Aided Semi-Grant-Free Systems

Semi-grant-free (SGF) transmission scheme enables grant-free (GF) users to utilize resource blocks allocated for grant-based (GB) while maintaining the quality of service GB users. This work investigates secrecy performance non-orthogonal multiple access (NOMA)-aided SGF systems. First, analytical expressions exact and asymptotic outage probability (SOP) NOMA-aided systems with a single GF user are derived. Then, best-user scheduling is considered. By utilizing order statistics theory, SOP Monte Carlo simulation results provided compared two benchmark schemes. The effects system parameters on considered demonstrated accuracy developed verified. indicate that both target rate secure main factors