Assuming millimeter wave (mmWave) systems, we consider an analog beamforming-based physical layer security (PLS) technique, which has considerably lower complexity compared to the digital beamforming-based PLS. Motivated by the limitations of the related prior arts assuming a uniform linear array (ULA), we employ a uniform planar array (UPA) to take advantage of both azimuth and elevation domains to realize three-dimensional (3D) beamforming. Also, in contrast to the approximate analysis on the secrecy rate (SR) in the existing studies, we derive the exact SR without any approximation. Based on this analysis, we analyze the optimal size of random antenna subset, which is the key parameter to maximize the SR.

中文翻译：

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在毫米波网络中使用均匀平面阵列进行随机模拟波束成形的最佳子集大小分析

假设毫米波 (mmWave) 系统，我们考虑基于模拟波束成形的物理层安全 (PLS) 技术，与基于数字波束成形的 PLS 相比，该技术的复杂性要低得多。受到假设均匀线性阵列 (ULA) 的相关现有技术的限制，我们采用均匀平面阵列 (UPA) 来利用方位角和仰角域来实现三维 (3D) 波束成形。此外，与现有研究中对保密率 (SR) 的近似分析相反，我们在没有任何近似值的情况下推导出确切的 SR。在此分析的基础上，我们分析了随机天线子集的最佳大小，这是最大化SR的关键参数。