Secure Performance of AF and DF Relaying in Cooperative Noma Systems

In this paper, we study the secrecy outage probability (SOP)and the strictly positive secrecy capacity (SPSC)of cooperative non-orthogonal multiple access (NOMA)system with a single antenna over Rayleigh fading channel in which there are a source, a relay node, two destinations and one eavesdropper. The relay adopts amplify-and-forward (AF)and decode-and-forward (DF)relaying schemes. The SOP and SPSC performance are analyzed to evaluate the level of security granted to legitimate users for both AF and DF protocols. The effects of the optimal power allocation value on system performance are also discussed and provided through numerical results.