Secrecy Performance of Wirelessly Powered Wiretap Channels
Secrecy Performance of Wirelessly Powered Wiretap Channels
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DOI：
10.1109/tcomm.2016.2592529
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发表时间：
2016-07
影响因子：
8.3
通讯作者：
Xin Jiang;C. Zhong;Xiaoming Chen;T. Duong;T. Tsiftsis;Zhaoyang Zhang
中科院分区：
文献类型：
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作者：
Xin Jiang;C. Zhong;Xiaoming Chen;T. Duong;T. Tsiftsis;Zhaoyang Zhang
本文考虑了一种无线供电窃听信道，其中一个能量受限的多天线信息源，由一个专用的电源信标供电，与一个合法的用户在一个被动窃听者的存在进行通信。基于一个简单的时间交换协议，其中功率传输和信息传输在时间上是分开的，我们研究了两种流行的多天线传输方案在信息源，即，最大比传输和发射天线选择。封闭形式的表达式推导出可实现的秘密中断概率和平均保密率为两个计划。此外，在高信噪比（SNR）的制度，得到简单的近似。我们的研究结果表明，通过充分利用信道状态信息（CSI）的知识，我们可以实现更好的保密性能，例如，利用主信道的全CSI，系统可以获得相当大的保密分集增益。另一方面，在没有主信道的CSI的情况下，不能获得分集增益。此外，我们表明，无线功率传输引起的额外的随机性水平不会影响在高SNR制度的保密性能。最后，数值结果验证了我们的理论结论.
This paper considers a wirelessly powered wiretap channel, where an energy constrained multi-antenna information source, powered by a dedicated power beacon, communicates with a legitimate user in the presence of a passive eavesdropper. Based on a simple time-switching protocol, where power transfer and information transmission are separated in time, we investigate two popular multi-antenna transmission schemes at the information source, namely, maximum ratio transmission and transmit antenna selection. Closed-form expressions are derived for the achievable secrecy outage probability and average secrecy rate for both schemes. In addition, simple approximations are obtained at the high signal-to-noise ratio (SNR) regime. Our results demonstrate that by exploiting the full knowledge of channel state information (CSI), we can achieve a better secrecy performance, e.g., with full CSI of the main channel, the system can achieve substantial secrecy diversity gain. On the other hand, without the CSI of the main channel, no diversity gain can be attained. Moreover, we show that the additional level of randomness induced by wireless power transfer does not affect the secrecy performance in the high SNR regime. Finally, our theoretical claims are validated by the numerical results.