IEEE Open Journal of the Communications Society
Movable Antennas-Assisted Secure Transmission for Cooperative Wireless Communication
Zhihui Shang, Tao Zhang, Ruoyu Zhang, Weiwei Yang, Hao Wu, Xiaoqiang Qiao
Abstract
Wireless communication is vulnerable to deep fading and eavesdropping, especially in long-distance double-hop scenarios. To address these issues, this paper proposes the movable antenna (MA-assisted secure transmission scheme. This scheme is designed for a cooperative wireless communication system in the presence of multiple single-antenna eavesdroppers. Our objective is to maximize the achievable secrecy rate, by jointly optimizing the transmit beamforming and antenna positions vectors. To solve the highly non-convex problem due to the strongly coupled variables, the alternating optimization and projected gradient ascent (PGA) methods are designed to the joint update of MA position and beamforming. Furthermore, an artificial noise (AN) interference signal is introduced. Specifically, the legitimate link actively transmits jamming noise to eavesdroppers during signal transmission, thereby enhancing the channel capacity of the secure communication system. Finally, the simulation results show that the proposed MA-assisted secure transmission for the cooperative wireless communication system significantly outperforms conventional fixed-position antenna (FPA)-assisted systems by up to 70% and existing benchmarks in terms of secrecy rate.