In this work, we investigate the transmission sum rate as well as the secrecy sum rate of indoor visible light communication (VLC) networks for mobile devices with the power domain non-orthogonal multiple access (NOMA) transmission, where multiple legitimate users are equipped with photodiodes (PDs). We introduce a body blockage model of the legitimate users as well as the eavesdropper to focus on the case where the communications from transmitting light-emitting diodes (LEDs) to receiving devices are blocked by the bodies of receiving users. Furthermore, in order to improve the secrecy without any knowledge of the channel state information (CSI) of the eavesdropper, a novel LED arrangement is introduced to reduce the overlapping area covered by LED units supporting different users. We also propose two LED operation strategies, called simple and smart LED linking, and evaluate their performance against the conventional broadcasting in terms of transmission sum rate and secrecy sum rate. Through computer simulations, the superiority of our proposed strategies is demonstrated.

翻译：本文研究了面向移动设备的室内可见光通信网络中功率域非正交多址接入传输下的传输和速率与保密和速率问题，其中多个合法用户配备光电二极管。我们引入了合法用户及窃听者的身体遮挡模型，重点分析发射端发光二极管与接收设备间的通信被接收用户身体遮挡的情形。进一步地，为在未知窃听者信道状态信息的情况下提升保密性，提出了一种新型LED布局方案以减小不同用户对应的LED单元覆盖重叠区域。我们同时提出了简单LED链接与智能LED链接两种LED工作策略，并在传输和速率与保密和速率方面评估了其相较于传统广播模式的性能。通过计算机仿真，验证了所提策略的优越性。