Intelligent reflecting surface-aided secure and covert communications

• Published in: China communications Vol. 21; no. 9; pp. 1 - 10
• Main Authors: Xiaobo, Zhou, Yong, Jiang, Tingting, Xia, Guiyang, Xia, Tong, Shen
• Format: Journal Article
• Language: English
• Published: China Institute of Communications 01.09.2024; School of Information and Artificial Intelligence,Anhui Agricultural University,Anhui 230036,China
• Subjects: Array signal processing; covert communications; intelligent reflecting surface; Noise; Optimization; Physical layer security; Radio transmitters; Receivers; Reflection; reflection beamforming; Transmitters; Uncertainty; Wireless communication; reflection beamforming; intelligent re-flecting surface; physical layer security; covert communications
• ISSN: 1673-5447
• DOI: 10.23919/JCC.fa.2023-0567.202409

This work employs intelligent reflecting surface (IRS) to enhance secure and covert communication performance. We formulate an optimization problem to jointly design both the reflection beam-former at IRS and transmit power at transmitter Alice in order to optimize the achievable secrecy rate at Bob subject to a covertness constraint. We first develop a Dinkelbach-based algorithm to achieve an upper bound performance and a high-quality solution. For reducing the overhead and computational complexity of the Dinkelbach-based scheme, we further conceive a low-complexity algorithm in which analytical expression for the IRS reflection beamforming is derived at each iteration. Examination result shows that the devised low-complexity algorithm is able to achieve similar secrecy rate performance as the Dinkelbach-based algorithm. Our examination also shows that introducing an IRS into the considered system can significantly improve the secure and covert communication performance relative to the scheme without IRS.