The authors propose to arrange the light emitting diodes (LEDs) on the ceiling for an indoor visible light communication system in order to minimise the secrecy outage probability (SOP) at the location of the legitimate user (LU). More precisely, by deriving the secrecy capacity for a multiple-input single-output-VLC system, we evaluate the SOP at the LU's location which is used as the appropriate metric to determine the position of the LEDs on the ceiling. To mitigate the effect of the eavesdropper, we derive the optimal beamforming coefficients which are used at the transmitter LED array with the aim of maximising the signal-to-noise ratio at the LU. Simulation results show that for a SOP of 10⁻⁴, the proposed SOP-based LED arrangement with optimal beamforming offers up to 3 dB gain in transmit power compared to the classical uniform LED arrangement with sub-optimal zero-forcing beamforming. Moreover, they show that by using the proposed method, the SOP is kept below a desired threshold, over a wider area inside the indoor environment compared to classical methods.

中文翻译：

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通过光束形成和改进的发光二极管部署，增强多输入单输出 VLC 系统的保密中断概率

作者建议在室内可见光通信系统的天花板上布置发光二极管（LED），以最大限度地减少合法用户（LU）所在位置的保密中断概率（SOP）。更准确地说，通过推导多输入单输出 VLC 系统的保密能力，我们评估 LU 位置处的 SOP，将其用作确定天花板上 LED 位置的适当度量。为了减轻窃听者的影响，我们得出了在发射器 LED 阵列中使用的最佳波束形成系数，目的是最大化 LU 的信噪比。^{模拟结果表明，对于 10 −4}的 SOP，与具有次优迫零波束形成的经典均匀 LED 布置相比，所提出的具有最佳波束形成的基于 SOP 的 LED 布置可提供高达 3 dB 的发射功率增益。此外，他们表明，与传统方法相比，通过使用所提出的方法，SOP在室内环境内更广泛的区域内保持在所需阈值以下。