论文标题
RIS辅助绿色安全通信：主动RIS或被动RIS？
RIS-Assisted Green Secure Communications: Active RIS or Passive RIS?
论文作者
论文摘要
可重新配置的智能表面（RIS）是6G无线通信的有前途的技术之一，最近也被证明能够改善安全的通信。但是，在基站和用户之间的反射链接中存在“双重褪色”效果，因此被动ris仅在典型的通信方案中获得可忽略不计的保密增益。在这封信中，我们提出了一种主动的RIS辅助Multi-Antenna物理层保密传输方案，在该方案中，主动RIS可以在此启动信号积极地启动信号。我们的目的是最大程度地减少受保密率限制的发射功率。为了解决非凸优化问题，提出了基于罚款的交替最小化（Altmin）算法，以优化发射机处的光束形式和RIS的反射矩阵。仿真结果表明，主动RI可以有效抵抗“双重褪色”效果的影响，并且比被动RIS更节能。
Reconfigurable Intelligent Surface (RIS) is one of the promising techniques for 6G wireless communications, and recently has also been shown to be able to improve secure communications. However, there is a "double fading" effect in the reflection link between base station and user, thus passive RIS only achieves a negligible secrecy gain in typical communications scenarios.In this letter, we propose an active RIS-aided multi-antenna physical layer secrecy transmission scheme, where the active RIS can amplify the signal actively. Our aim is to minimize the transmit power subject to the constraint of secrecy rate. To solve the non-convex optimization problem, a penalty-based alternating minimization (AltMin) algorithm is proposed to optimize both the beamformer at the transmitter and the reflection matrix at RIS. Simulation results show that active RIS can resist the impact of "double fading" effect effectively, and is more energy efficient than passive RIS.
