MIMO Secret Communications Against an Active Eavesdropper

Abstract

This paper considers a scenario in which an Alice-Bob pair wishes to communicate in secret in the presence of an active Eve, who is capable of jamming as well as eavesdropping in Full-Duplex (FD) mode. As countermeasure, Bob also operates in FD mode, using a subset of its antennas to act as receiver, and the remaining antennas to act as jammer and transmit noise. With a goal to maximize the achievable secrecy degrees of freedom (S.D.o.F.) of the system, we provide the optimal transmit/receive antennas allocation at Bob, based on which we determine in closed form the maximum achievable S.D.o.F.. We further investigate the adverse scenario in which Eve knows Bob's transmission strategy and optimizes its transmit/receive antennas allocation in order to minimize the achievable S.D.o.F.. For that case we find the worst-case achievable S.D.o.F.. We also provide a method for constructing the precoding matrices of Alice and Bob, based on which the maximum S.D.o.F. can be achieved. Numerical results validate the theoretical findings and demonstrate the performance of the proposed method in realistic settings.

arXiv comment13 pages, 9 figures

References in corpus (8)

• Physical Layer Security for Massive MIMO: An Overview on Passive Eavesdropping and Active Attacks
• Improving Physical Layer Secrecy Using Full-Duplex Jamming Receivers
• MIMO Interference Alignment Over Correlated Channels with Imperfect CSI
• Jamming Games in the MIMO Wiretap Channel With an Active Eavesdropper
• Solutions for the MIMO Gaussian Wiretap Channel with a Cooperative Jammer
• Multiuser Diversity for Secrecy Communications Using Opportunistic Jammer Selection -- Secure DoF and Jammer Scaling Law
• Improving Wireless Physical Layer Security via Exploiting Co-Channel Interference
• Secure Massive MIMO Transmission in the Presence of an Active Eavesdropper