RIS-Assisted Secure Communications: Low-Complexity Beamforming Design
- Resource Type
- Periodical
- Authors
- Cheng, Z.; Li, N.; Zhu, J.; She, X.; Ouyang, C.; Chen, P.
- Source
- IEEE Wireless Communications Letters IEEE Wireless Commun. Lett. Wireless Communications Letters, IEEE. 12(6):1012-1016 Jun, 2023
- Subject
- Communication, Networking and Broadcast Technologies
Computing and Processing
Signal Processing and Analysis
Array signal processing
Optimization
Computational complexity
Security
Transmitting antennas
Convergence
Communication system security
Low-complexity design
phase shift optimization
physical layer security
reconfigurable intelligent surface
- Language
- ISSN
- 2162-2337
2162-2345
Joint active and passive beamforming optimization is investigated to enhance the physical layer security of a reconfigurable intelligent surface (RIS)-assisted multiple-antenna communication system. The problems are formulated under two criteria: secrecy rate maximization and power consumption minimization. For each design problem, a novel collaborative design algorithm is proposed by capitalizing on the mathematical structure of the optimal active beamforming vector, which requires no iterative updating between the transmit beamformer and the RIS-reflecting beamformer. Numerical results demonstrate that the proposed algorithms enjoy much lower computational complexity than the state-of-the-art alternating optimization-based methods while achieving almost identical secrecy performance.