Abstract Securing unmanned aerial vehicle (UAV) communications against eavesdropping is critical due to the vulnerability of dominant air-to-ground line-of-sight links. This work examines physical-layer security under a practical yet often neglected condition: statistical correlation between the fading channels of the legitimate receiver and the eavesdropper. We propose an analytical framework employing the Farlie–Gumbel–Morgenstern (FGM) copula to model this correlation within a Rician fading environment, which accurately captures UAV channel characteristics. Mathematical expressions for the joint distribution, the average secrecy capacity (ASC), the secrecy outage probability (SOP) are derived. The numerical analysis demonstrates that negative dependence parameter substantially improves both ASC and SOP compared to independent and positive dependence parameter in correlated fading, providing approximately 23% gain in ASC and 46% reduction in SOP at low transmit power. These performance advantages diminish at high SNR, where dependence parameter effects become less dominant.
Abstract Securing unmanned aerial vehicle (UAV) communications against eavesdropping is critical due to the vulnerability of dominant air-to-ground line-of-sight links. This work examines physical-layer security under a practical yet often neglected condition: statistical correlation between the fading channels of the legitimate receiver and the eavesdropper. We propose an analytical framework employing the Farlie–Gumbel–Morgenstern (FGM) copula to model this correlation within a Rician fading environment, which accurately captures UAV channel characteristics. Mathematical expressions for the joint distribution, the average secrecy capacity (ASC), the secrecy outage probability (SOP) are derived. The numerical analysis demonstrates that negative dependence parameter substantially improves both ASC and SOP compared to independent and positive dependence parameter in correlated fading, providing approximately 23% gain in ASC and 46% reduction in SOP at low transmit power. These performance advantages diminish at high SNR, where dependence parameter effects become less dominant.
This paper studies performance analysis of physical layer security in a Rayleigh fading wiretap channel, where, the main (transmitter-to-legitimate receiver) and eavesdropper (transmitter-to-eavesdropper) channel coefficients are correlated. By exploiting the novel approach called Copula theory, we derive closed-form expressions for average secrecy capacity (ASC), secrecy outage probability (SOP), and secrecy coverage region (SCR). Moreover, to more evaluate the impact of channel correlation, the asymptotic behavior of SOP in high signal-to-noise ratio (SNR) regime and other scenarios is studied, and finally, the analytical results are illustrated numerically under the positive dependence, independence, and negative dependence structures. Based on the insights from this analysis, we found that the effect of correlated fading on the performance of physical layer security can be helpful or harmful in different scenarios, depending on the structure of dependency between the main and eavesdropper channels.
In this paper, we analyze the performance of physical layer security (PLS) in Weibull fading wiretap channels (WTC), leveraging realistic channel propagation models in which the channel coefficients of the main (transmitter-to-legitimate receiver) and eavesdropper (transmitter-to-eavesdropper) channels are correlated. Additionally, by incorporating non-causally known side information (SI) at the transmitter, we enhance PLS in this context. We utilize the Farlie–Gumbel–Morgenstern (FGM) copula to model the correlation between the main and eavesdropper channels, enabling us to derive analytical expressions for the average secrecy capacity (ASC), secrecy outage probability (SOP), the lower bound of SOP (LSOP), and the strictly positive secrecy capacity (SPSC) across various dependence scenarios (i.e., negative, positive, and independent). The numerically evaluated results, validated through corresponding computer simulations, provide valuable insights into the impact of channel correlation and SI at the transmitter on the system’s PLS performance.
Abstract Physical layer security, as an important practical concept, in unmanned aerial vehicle (UAV) assisted channels has been studied in the literature, where, impacts of side information and or correlation of wireless channel coefficients have not been considered. In this paper, having briefly reviewed (the discrete memoryless side information channel, physical secure rate and copula function theory), a continuous alphabet wiretap channel with UAV transmitter and two-sided side information is considered. For this channel, we obtain closed form expressions for secrecy capacities in two cases: (i) Gaussian channel with constant channel coefficients; (ii) Gaussian wireless channel with correlated coefficients by using FGM copula function to describe the correlations. Through obtained secrecy rates, we analyse the impacts of (a) UAV situation for transmitter (b) two-sided non-causal side information and (c) correlation between channel coefficients on the achievable rates. Then, analytical results are numerically assessed across various correlation structures, both with and without side information. The findings demonstrate that correlated fading adversely impacts security performance in different scenarios, while the presence of side information enhances security performance.
With the notable interest in unmanned aerial vehicle (UAV)-to-ground communications, new fading channel models that take into account the effects of shadowing have been proposed for beyond 5G networks. Guaranteeing physical layer security of the UAV-to-ground channels is essential for the transmission of confidential messages in the presence of an eavesdropper. In this paper, we examine physical layer security metrics, such as the average secrecy capacity, the secrecy outage probability, and the probability of strictly positive secrecy capacity, in UAV-to-ground communications with shadowing. Monte Carlo simulations are performed to verify the analytical expressions. Finally, the effect of the fading parameters on the system performance is studied.
Owing to flexible management and low overhead, wireless physical layer security (PLS) has been applied to support many critical applications (e.g., data dissemination) of unmanned aerial vehicles (UAVs)-based mobile communication networks in emergency scenarios. Although the impact of static network scenarios or receiver mobility on PLS has been well studied, there is no much work that studies the impact of UAV-based transmitter mobility on PLS. To fill this gap, in this paper, we investigate PLS of a scenario, where a random mobile UAV-based transmitter transmits information to a static ground entity under Rayleigh fading channel. More specifically, we consider a communication system, in which a mobile UAV hovers over a region to collect information and then disseminates this information to a static ground network entity in a confidential manner under the presence of an eavesdropper. Because of popularity and practicality, the UAV is assumed to hover following the random way point (RWP) mobility model. We investigate the secrecy characteristics of the UAV under steady running state in terms of ergodic secrecy capacity (ESC), positive secrecy capacity probability (PSCP) and secrecy outage probability (SOP) for the communication between the UAV and the receiver. We then investigate the secrecy performance of the proposed system while considering the pause time of the RWP mobility model adopted by the UAV. We further extend our proposed theoretical model to other realistic scenarios, including the presence of multiple cooperative and non-cooperative eavesdroppers, and study the PSCP and SOP metrics of the corresponding system. Furthermore, we propose three types of secrecy improvement strategies for the considered communication model. We strike a good trade-off between the secrecy improvement and transmit outage probability. Extensive simulations have been conducted to validate our theoretical analysis as well as the effectiveness of the proposed secrecy improvement strategies.
In this paper, physical layer security issue for a down-link wireless communication system is examined, composed of an unmanned aerial vehicle (UAV), a legitimate receiver and a passive eavesdropper. The destination is equipped with two antennas and applies the full-duplex (FD) Bob-based jamming (FD-BBJ) strategy to achieve secure transmission. Considering that practical air-to-ground (A2G) channels experience Nakagami-m fading and the FD legitimate receiver is affected by self-interference (SI), closed-form expressions of approximate ergodic achievable secrecy rate (EASR) with help of Gauss-Laguerre Quadrature (GLQ) and compact secrecy outage probability (SOP) expression are derived, respectively. To gain more insights, asymptotic secrecy performance is analysed in the case of extreme total system transmit power, via deriving closed-form expression for asymptotic EASR and compact expression for asymptotic SOP. Numerical results have verified the correctness of our theoretical analysis and proved that the FD-BBJ strategy applied in the UAV-aided wireless communication system can help achieve considerable secrecy performance gain.