He Wanxin, Zhang Jiliang
Appl Opt. 2021 Dec 20;60(36):11010-11017. doi: 10.1364/AO.440162.
In this paper, we study the secrecy performance of an energy-harvested relaying assisted free space optical-radio frequency (FSO-RF) network. In particular, a single-beam source sends an optical signal to a multi-aperture relay over an FSO channel, and then the relay converts it into an RF signal and adopts a decode-and-forward protocol to forward it to a multi-antenna destination under the wiretapping of a multi-antenna eavesdropper. We assume that the relay is power constrained, and it requires to harvest energy from a power beacon to assist the information transmission. It is also assumed that the FSO link and all RF links are subject to gamma-gamma fading with atmospheric turbulence and Rayleigh fading, respectively. Analytical expressions for secrecy outage probability (SOP) and the probability of strictly positive secrecy capacity are derived. In addition, the asymptotic expression for SOP is obtained to present insight into secrecy performance at high signal-to-noise ratio regimes. Finally, Monte Carlo simulations verify the correctness of the theoretical derivations.
在本文中，我们研究了能量收集中继辅助的自由空间光-射频（FSO-RF）网络的保密性能。具体而言，单波束源通过FSO信道向多孔径中继发送光信号，然后中继将其转换为射频信号，并采用解码转发协议在多天线窃听者的窃听下将其转发到多天线目的地。我们假设中继受功率限制，并且需要从功率信标收集能量以辅助信息传输。还假设FSO链路和所有射频链路分别受到大气湍流引起的伽马-伽马衰落和瑞利衰落的影响。推导了保密中断概率（SOP）和严格正保密容量概率的解析表达式。此外，获得了SOP的渐近表达式，以深入了解高信噪比情况下的保密性能。最后，蒙特卡罗仿真验证了理论推导的正确性。
