Active Reconfigurable Intelligent Surface Aided Secure Transmission

Reconfigurable Intelligent Surface (RIS) draws great attentions in academic and industry due to its passive low power consumption nature, has currently been used physical layer security enhance the secure transmission. However, existence of “double fading” effect on reflecting channel link between transmitter user, RIS helps achieve limited secrecy performance gain compared with case without RIS. In this correspondence, we propose a novel active design wireless transmission, where elements not only adjust phase shift but also amplify amplitude signals. To solve non-convex rate optimization based design, an efficient alternating algorithm is proposed jointly optimize beamformer at coefficient matrix Simulation results show that aid impact can be effectively relieved, resulting significantly higher existing solutions design.