Rethinking Secure Precoding via Interference Exploitation: A Smart Eavesdropper Perspective
Rethinking Secure Precoding via Interference Exploitation: A Smart Eavesdropper Perspective
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DOI：
10.1109/tifs.2020.3016836
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发表时间：
2019-08
影响因子：
6.8
通讯作者：
Qian Xu;Pinyi Ren;A. L. Swindlehurst
中科院分区：
文献类型：
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作者：
Qian Xu;Pinyi Ren;A. L. Swindlehurst
基于相长干扰（CI）的概念，多用户干扰（MUI）最近被证明是有益的通信保密。已经提出了几种基于CI的安全预编码算法，其使用信道状态信息（CSI）和瞬时发送符号的知识。在这篇文章中，我们研究了基于CI的安全预编码问题，重点是利用从预编码数据中收集的统计信息进行符号检测的智能窃听器。此外，主信道和窃听信道之间的相关性的影响被考虑在内。我们首先修改现有的基于CI的预编码方案，以更好地利用干扰的破坏性影响。然后，我们指出了现有的和新的修改后的CI为基础的预编码器的缺点时，面对一个智能窃听。为了解决这个问题，我们提供了一个预编码器设计的一般原则，然后给出两个具体的设计实例。最后，研究了窃听者的CSI不可用的情况。数值结果表明，虽然我们修改后的CI为基础的预编码器可以实现更好的能量保密权衡比现有的方法，都有一个有限的保密利益。相反，使用新的CI设计原则开发的预编码器可以实现更好的折衷，并显着降低窃听者的性能。
Based on the concept of constructive interference (CI), multiuser interference (MUI) has recently been shown to be beneficial for communication secrecy. A few CI-based secure precoding algorithms have been proposed that use both the channel state information (CSI) and knowledge of the instantaneous transmit symbols. In this article, we examine the CI-based secure precoding problem with a focus on smart eavesdroppers that exploit statistical information gleaned from the precoded data for symbol detection. Moreover, the impact of correlation between the main and eavesdropper channels is taken into account. We first modify an existing CI-based precoding scheme to better utilize the destructive impact of the interference. Then, we point out the drawback of both the existing and the new modified CI-based precoders when faced with a smart eavesdropper. To address this deficiency, we provide a general principle for precoder design and then give two specific design examples. Finally, the scenario where the eavesdropper’s CSI is unavailable is studied. Numerical results show that although our modified CI-based precoder can achieve a better energy-secrecy trade-off than the existing approach, both have a limited secrecy benefit. On the contrary, the precoders developed using the new CI-design principle can achieve a much improved tradeoff and significantly degrade the eavesdropper’s performance.