In this paper, we investigate the secrecy outage performance in simultaneous wireless information and power transfer (SWIPT) systems taking artificial noise assistance into account. Multiple antennas in the source and a single antenna in both the legitimate receiver and the eavesdropper are assumed. Specifically, the transmitted signal at the source is composed of two parts, where the first part is the information symbols and the other is the noise for the eavesdropper. To avoid making noise in the legitimate receiver, these two parts in the transmitted signals are modulated into two orthogonal dimensions according to the instantaneous channel state between the source and the legitimate receiver. We derive an approximate closed-form expression for the secrecy outage probability (SOP) by adopting the Gauss-Laguerre quadrature (GLQ) method, where the gap between the exact SOP and our approximate SOP converges with increase of the summation terms in the GLQ. To obtain the secrecy diversity order and secrecy array gain for the considered SWIPT system, the asymptotic result of the SOP is also derived. This is tight in the high signal-to-noise ratio region. A novel and robust SOP approximation is also analyzed given a small variance of the signal-to-interference-plus-noise ratio at the eavesdropper. Some selected Monte-Carlo numerical results are presented to validate the correctness of the derived closed-form expressions.

本文中，我们在考虑人工噪声辅助的情况下研究了同时无线信息和电力传输（SWIPT）系统中的保密中断性能。假设源中有多个天线，而合法接收者和窃听者中都只有一个天线。具体来说，源处的发射信号由两部分组成，其中第一部分是信息符号，另一部分是窃听者的噪声。为了避免在合法接收器中产生噪声，根据源和合法接收器之间的瞬时信道状态，将发射信号中的这两个部分调制为两个正交维度。我们采用高斯-拉格瑞正交（GLQ）方法得出保密中断概率（SOP）的近似闭合形式表达式，确切的SOP和我们的近似SOP之间的差距随着GLQ中总和项的增加而收敛。为了获得所考虑的SWIPT系统的保密分集阶数和保密阵列增益，还得出了SOP的渐近结果。在高信噪比区域中，这是很严格的。考虑到窃听者的信噪比加噪声比有很小的变化，还分析了一种新颖而强大的SOP近似值。给出了一些选定的蒙特卡洛数值结果，以验证导出的闭合形式表达式的正确性。在高信噪比区域中，这是很严格的。考虑到窃听者的信噪比加噪声比有很小的变化，还分析了一种新颖而强大的SOP近似值。给出了一些选定的蒙特卡洛数值结果，以验证导出的闭合形式表达式的正确性。在高信噪比区域中，这是很严格的。考虑到窃听者的信噪比加噪声比有很小的变化，还分析了一种新颖而强大的SOP近似值。给出了一些选定的蒙特卡洛数值结果，以验证导出的闭合形式表达式的正确性。