Joint Relay and Jammer Selection for Secure Decode-and-Forward Two-Way Relay Communications

In this paper, we investigate joint relay and jammer selection in a two-way relay network with secrecy constraints, in which there are two sources, a cluster of intermediate nodes, and one eavesdropper. Under a decode-and-forward (DF) protocol, the considered two-way relay network implements a complete transmission in three phases. An intermediate node is selected as conventional relay and another two are selected as jammers during these phases, in order to improve security against the malicious eavesdropper. We find that when the jamming power is higher than that of source nodes, the proposed scheme has a better and more stable secrecy performance than the conventional non- jamming schemes. In addition, the system´s security status gets increasingly better when more intermediate nodes are added into the relay/jamming cluster.