A Survey of Physical Layer Security Techniques for 5G Wireless Networks and Challenges Ahead

Physical layer security which safeguards data confidentiality based on the information-theoretic approaches has received significant research interest recently. The key idea behind physical layer security is to utilize the intrinsic randomness of the transmission channel to guarantee the security in physical layer. The evolution towards 5G wireless communications poses new challenges for physical layer security research. This paper provides a latest survey of the physical layer security research on various promising 5G technologies, including physical layer security coding, massive multiple-input multiple-output, millimeter wave communications, heterogeneous networks, non-orthogonal multiple access, full duplex technology, etc. Technical challenges which remain unresolved at the time of writing are summarized and the future trends of physical layer security in 5G and beyond are discussed. Y. Wu is with Department of Electrical Engineering, Shanghai Jiao Tong University, Minhang, Shanghai, China 200240(Email:[email protected]; [email protected]). A. Khisti is with Signal Multimedia and Security Lab, University of Toronto, Bahen Building, Toronto, Canada (Email: [email protected]). C. Xiao is with Department of Electrical and Computer Engineering, Lehigh University, Bethlehem, PA 18015, USA (Email: [email protected]). G. Caire is with Institute for Telecommunication Systems, Technical University Berlin, Einsteinufer 25, 10587 Berlin, Germany (Email: [email protected]). K.-K. Wong is with Department of Electronic and Electrical Engineering, University College London, London WC1E 6BT, UK (Email:[email protected]). X. Q. Gao is with the National Mobile Communications Research Laboratory, Southeast University, Nanjing, 210096, P. R. China (Email: [email protected]).