Wireless sensor networks (WSNs) are vulnerable to eavesdropping as the sensor nodes (SNs) communicate over an open radio channel. Intelligent reflecting surface (IRS) technology can be leveraged for physical layer security in WSNs. In this paper, we propose a joint transmit and reflective beamformer (JTRB) design for secure parameter estimation at the fusion center (FC) in the presence of an eavesdropper (ED) in a WSN. We develop a semidefinite relaxation (SDR)-based iterative algorithm, which alternately yields the transmit beamformer at each SN and the corresponding reflection phases at the IRS, to achieve the minimum mean-squared error (MSE) parameter estimate at the FC, subject to transmit power and ED signal-to-noise ratio constraints. Our simulation results demonstrate robust MSE and security performance of the proposed IRS-based JTRB technique.
翻译:无线传感器网络容易被窃听,因为传感器节点在开放的无线电频道上进行交流。智能反射表面技术可以用来保证无线传感器的物理层安全。在本文中,我们提议在无线传感器中,在有窃听器的情况下,联合传输和反射波束(JTRB),在聚变中心进行安全参数估计设计。我们开发了基于半无线放松(SDR)的迭代算法,在每次无线传感器和IRS的相应反射阶段,轮流生成传输信号,以实现FC最小的中度误差(MSE)参数估计,但以传输功率和ED信号到噪音比限制为条件。我们的模拟结果表明,基于IRS的JTRB技术具有很强的MSE和安全性能。