Cooperative Jamming Secure Scheme for Untrusted Full-Duplex Relay System

In this paper, we focus on a practical communication system, an untrusted full-duplex relay (UFDR) network with a transmitter Alice and a full-duplex receiver Bob. The relay is untrusted who is supposed to forward the signal to Bob and at the same time, acts as a potential eavesdropper to intercept the message from Alice. Since there is no direct link between Alice and Bob, positive secrecy rate can not be obtained. To handle with this issue, based on the precondition that in-band full-duplex technology has been basically matured and can be applied in relay communication, we propose a destination-aided cooperative intended jamming scheme (UFDR-IJ scheme for short). We study the secure performance of the communication system model described in this paper, and obtain a closed-form expression for the secrecy outage probability which verifies the fact that the UFDR-IJ scheme can significantly enhance the secure performance while double the secrecy capacity of the communication system comparing to the traditional cooperative communication scheme.