Secure Communications for Dual-Polarized MIMO Systems

Abstract

Abstract-To enhance secure communications, we deploy the dual-polarized antenna arrays at communication nodes of the multi-input multi-output (MIMO) system where the base station communicates with multiple legitimate users in the presence of an eavesdropper. We also adopt the dual-structured precoding in which a preprocessing matrix based on the polarized array spatial correlation and a linear precoding based on the instantaneous channel state information (CSI) are concatenated. We design this dual-structured multi-user linear precoding under three cases. In the first case, given perfect global CSI, the secrecy rate optimization problem is formulated and transformed into the weighted minimum mean square error problem, which can be effectively solved by the block coordinate decent method. In the second case where the eavesdropper's CSI is unavailable, an artificial noise is generated to confuse the eavesdropper by minimizing the information transmit power subject to a preset mean square error (MSE) threshold for the recovered confidential signals, which can be solved by an efficient iterative algorithm. In the third case of imperfect global CSI, the robust optimization for secure communications is performed by minimizing the largest received MSE among the users subject to the total transmit power constraint, which can be reformulated into a biconvex semidefinite programming problem and solved by an efficient alternating convex optimization. Simulation results are included to demonstrate the excellent performance of our proposed designs over the conventional single-polarized array based designs, in terms of achievable secrecy rate, minimum transmit power and the MSE of recovered confidential signals.Index Terms-Physical layer security, dual-polarized MIMO system, dual-structured multi-user linear precoding

Secrecy Outage of Max–Min TAS Scheme in MIMO-NOMA Systems

“…Physical layer security has been regarded as a promising safeguard technology for wireless communications through utilizing the time-varying nature of the wireless fading channels [23], [24]. In the last several years, the secrecy performance of wireless fading systems was studied in many literatures [25]- [33].…”

A Survey of Optimization Approaches for Wireless Physical Layer Security

“…In [68], the linear precoding strategies for secrecy rate maximization in multiuser multiantenna networks are investigated in the broadcasting and multicasting scenarios, and an iterative algorithm based on second-order cone programming is proposed with low complexity and provable convergence. Focusing on the secure communications in dual-polarized MIMO systems, a scheme of dual-structured precoding is addressed in [217] in which a preprocessing matrix based on the polarized array spatial correlation and a linear precoding To balance the intended signal and information leakage by designing a regularization parameter α. The secrecy performance of this strategy can be improved by power allocation.…”

Multi-Antenna Covert Communication via Full-Duplex Jamming Against a Warden With Uncertain Locations

“…With the extremely large amount of personal data in the open wireless networks, wireless transmission is at the risk of adversarial eavesdropping. In order to protect wireless privacy, many researchers have worked on the physical layer security (PLS), e.g., beamforming [2]- [4], artificial jamming [5]- [8], and polarization [9], [10], etc. However, PLS alone is not enough, as it only prevents the eavesdropping but does not hide the existence of communication.…”