Secrecy Outage Probability of NOMA Network under Amplify and Forward Scheme

6G and beyond networks require massive data transfer speeds and exceptionally secure long-distance communication systems. In recent years, Non-orthogonal multiple access (NOMA) has come up with a highly efficient signal transmission technique. It enables broadcast to numerous users within the same frequency band and time slot, allowing for signal transmission through a single channel. However, the presence of internal or external eavesdroppers poses a big challenge to the physical layer security of a network. This paper analyzes the secrecy performance of the hybrid free space optical-radio frequency (FSO-RF) -aided NOMA network. A novel closed-form expression for secrecy outage probability under amplify and forward scheme (AF) is presented. Additionally, the effects of weak, moderate, and strong turbulence are considered under different decoding techniques. It is noteworthy to mention that the proposed results show perfect agreement with theoretical concepts.