Artificial-Noise-Aided Precoding Design for Multi-User Visible Light Communication Channels
Artificial-Noise-Aided Precoding Design for Multi-User Visible Light Communication Channels
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DOI：
10.1109/access.2018.2889119
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发表时间：
2019-01-01
期刊：
影响因子：
3.9
通讯作者：
Pham, Anh T.
中科院分区：
文献类型：
--
作者：
Pham, Thanh, V;Hayashi, Takafumi;Pham, Anh T.
可见光通信（VLC）的最新发展集中在增强其安全性和隐私性上。研究了多用户VLC网络中存在单个窃听者时的物理层安全问题。特别是，我们的目标是设计最佳的人工噪声（AN）辅助预编码方案，以提高合法用户和窃听者的信号干扰噪声比（SINR）方面的保密性能。我们的AN辅助预编码设计的目的是确保合法用户的SINR的公平性，同时尽可能损害窃听者的信道质量。根据窃听者的信道状态信息（CSI）在发射机处的可用性，通常存在两种设计策略。当窃听者的CSI对于发射机是未知的（即，被动窃听者），AN被构造为与用户的聚合信道矩阵正交。在窃听者的CSI可用的情况下（即，主动窃听者），AN设计策略是将窃听者的SINR保持在某个预定义阈值以下。除了一般设计外，我们还使用迫零（ZF）技术研究了一种特定设计，并将其性能与一般设计进行了比较。在这两种设计中，数值结果表明，用户和窃听者的SINR之间的显着差距总是可以实现，从而保证了高的保密性能。还观察到，虽然一般设计在用户的SINR方面优于ZF设计，但与ZF设计相比，它不会导致窃听者的SINR更低，特别是在低发射功率区域中。
Recent developments in visible light communications (VLC) have focused on enhancing its security and privacy. This paper studies the physical layer security in VLC networks with multiple users when there is a single wiretap eavesdropper. In particular, our aim is to design the optimal artificial noise (AN)aided precoding scheme to improve the secrecy performance in terms of legitimate users and eavesdropper's signal-to-interference-plus-noise ratios (SINRs). The purpose of our AN-aided precoding design is to ensure a fairness of the legitimate users' SINRs while impairing the quality of eavesdropper's channel as much as possible. Depending on the availability of the eavesdropper's channel state information (CSI) at the transmitters, there are generally two design strategies. When the eavesdropper's CSI is unknown to the transmitters (i.e., passive eavesdropper), the AN is constructed to be orthogonal to the users' aggregate channel matrix. In case the eavesdropper's CSI is available (i.e., active eavesdropper), the AN design strategy is to keep the SINR of the eavesdropper below a certain predefined threshold. Aside from the general design, we also study a specific design with the zero-forcing (ZF) technique and compare its performance with that of the general design. In both designs, numerical results show that significant gaps between users' and eavesdropper's SINR can always be achieved, thus guaranteeing a high secrecy performance. It is also observed that while the general design outperforms the ZF one in terms of the users' SINRs, it does not result in lower eavesdropper's SINRs compared to the ZF design, especially in the low transmit power region.