Partial-NOMA Based PLS: Following NOMA Decoding Principle or Enhanced Decoding Design?

In the insecure transmission environment, compared with the passive eavesdropper (Eve), the active Eve plays a more threatening role in the physical layer security (PLS), since it can wiretap and jam the signals. To simultaneously decrease the wiretap massage for Eve and improve secrecy outage probability (SOP) for the legitimate users, an enhanced decoding protocol in PLS is proposed for the device-to-device (D2D) non-orthogonal multiple access (NOMA) system under an active Eve attack. In addition, the partial NOMA (P-NOMA) is firstly introduced into PLS to further enhance the performance of the proposed system. The provided closed-forms of SOPs are verified via simulations, whose results show the superiority of our proposed schemes over the conventional NOMA schemes.