Beamforming Design and Antenna Position Optimization for IRS-aided Secure Wireless Transmission with Movable-Antenna

With the rapid development of wireless communication technology towards the sixth generation (6 G) network, there is an urgent need to improve channel conditions and communication performance. To solve this challenge, we propose a new active intelligent reflecting surface (IRS)-aided movable antennas (MAs) secure transmit wireless communication network, which MA and active IRS are used to improve channel conditions to enhance the physical layer security. Specifically, MAs are equipped in base station (BS), and they can adjust their positions within a predefined 2 D area to optimize channel conditions and thereby improve the SR. Meanwhile, IRS is divided into two IRSs, one for enhancing the received signals of legitimate user and the other for suppressing the received signals of eavesdropper. To maximize the SR, a joint optimization framework is developed, including antenna position optimization, beamforming design and IRS phase shift design. Two algorithms, Particle Swarm Optimization (PSO) and Simulated Annealing (SA), are proposed to solve the non-convex MA position optimization problem, balancing global exploration and local optimization. Simulation results show that this system improves the SR by $20 \%-30 \%$ compared with the traditional fixed-position antennas (FPAs), highlighting the benefits of MAs.