Channel (broadcasting)

Relaxation (psychology)

Computer network

Mathematics

Wireless

Transmitter power output

Semidefinite programming

Algorithm

Mathematical optimization

Regular polygon

Convex optimization

Optimization problem

Physical layer

Psychology

Antenna (radio)

Geometry

Constraint (computer-aided design)

Secrecy

Eavesdropping

Secure transmission

Computer science

Transmitter

Artificial noise

Computer security

Transmission (telecommunications)

Telecommunications

Social psychology

IEEE Wireless Communications Letters

In this letter, we propose intelligent reflecting surface (IRS) aided multi-antenna physical layer security. We present a power efficient scheme to design the secure transmit power allocation and the surface reflecting phase shift. It aims to minimize the transmit power subject to the secrecy rate constraint at the legitimate user. Due to the non-convex nature of the formulated problem, we propose an alternative optimization algorithm and the semidefinite programming (SDP) relaxation to deal with this issue. Also, the closed-form expression of the optimal secure beamformer is derived. Finally, simulation results are presented to validate the proposed algorithm, which highlights the performance gains of the IRS to improve the secure transmission.

Intelligent Reflecting Surface Aided Multi-Antenna Secure Transmission