AI 中文总结
本文针对配备可旋转天线的低空ISAC系统，联合优化发射波束成形矩阵与天线指向矩阵以最大化最小保密速率，提出MAPPO-T算法，仿真验证其性能优于标准MAPPO算法及传统固定定向天线系统。
AI 中文摘要
低空经济的发展推动了集成感知与通信（ISAC）系统中智能天线技术的创新。本文研究一种配备可旋转天线（RA）的低空ISAC系统，实际应用中，RA阵列可灵活调整各天线的三维波束方向以提升阵列定向增益，从而增强合法移动用户对抗潜在无人机窃听风险的通信安全性。本文的目标是通过联合优化发射波束成形矩阵、发射与接收RA的指向矩阵，最大化最小保密速率（SR）。为此，提出一种带有三种改进机制的多智能体近端策略优化（MAPPO-T）算法，以应对复杂的多智能体协同决策问题。仿真结果表明，与传统固定定向天线（FOA）系统相比，引入RA可有效提升SR性能；此外，所提MAPPO-T算法较标准MAPPO算法具有更优性能。
英文摘要
The development of the low-altitude economy has driven innovation in intelligent antenna systems within ISAC systems. In this paper, we investigate a Rotatable Antenna (RA)-enabled low-altitude integrated sensing and communication (ISAC) system. In practical terms, the RA array can flexibly adjust the three-dimensional (3D) beam direction of each antenna to enhance array directional gain, thereby improving the communication security of legitimate mobile users against potential eavesdropping risks from the unmanned aerial vehicle (UAV). Our objective is to maximize the minimum secrecy rate (SR) by jointly optimizing transmit beamforming matrix, transmit and receive RAs' pointing matrices. To this end, an multi-agent proximal policy optimization with three improvement mechanisms (MAPPO-T) algorithm is proposed to cope with the issue of complex multi-agent collaborative decision-making problem. Simulation results show that the introduction of RAs can effectively improve SR performance compared to the traditional fixed orientation antenna (FOA)-based system. In addition, the proposed MAPPO-T algorithm validate the superiority compared to the standard MAPPO algorithm.
