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.
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.
In this paper, we investigate the impact of side information (SI) on the performance of physical layer security (PLS) under correlated fading channels. By considering non-causally known SI at the transmitter and exploiting the copula technique to describe the fading correlation, we derive closed-from expressions for the average secrecy capacity (ASC) and secrecy outage probability (SOP) under positive/negative dependence conditions. We indicate that considering such knowledge at the transmitter is beneficial for system performance and ensures reliable communication with higher rates, as it improves the SOP and brings higher values of the ASC.
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.
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.
In this paper, under correlated shadowing channels-a propagation model that accurately reflects real-world wireless environment-we consider a multi-eavesdropper wiretap channel, in which several passive eavesdroppers independently try to intercept the legitimate transmission over the primary communication path from the transmitter (Tx) to the authorized receiver (Rx), constituting a realistic threat model, and analyze the achievable physical layer security (PLS) of wireless system, where, motivated by the proven positive impact of side information (SI) at the Tx on PLS performance, SI is assumed to be available at the Tx. Unlike previous studies that either considered (i) a single eavesdropper under correlated fading channels, with SI present or absent, or (ii) multiple eavesdroppers under independent fading channels, in the absence of SI, this work jointly incorporates SI at the Tx and multiple eavesdroppers under correlated shadowing conditions, yielding a more realistic and effective system model for secure wireless communication. There is no intercorrelation among the eavesdroppers, and the probability of information leakage is zero if none of them can successfully eavesdrop on the transmission. The shadowing experienced over the Tx–authorized Rx channel and the eavesdropper channels (the link between the Tx and each eavesdropper) is modeled using a Log-normal (LN) probability model, which is widely used in communication platforms that rely on wireless transmission to characterize shadowing caused by obstacles and environmental inhomogeneities, based on which we derive fast and accurate approximate closed-form expressions using the Holtzman method (HM) for the average secrecy capacity (ASC), secrecy outage probability (SOP), and the probability of non-zero secrecy capacity (PNSC).The resulting analytical expressions are mathematically tractable, and their validity is confirmed by benchmarking them against Monte Carlo (MC) simulations, and they offer reduced computational complexity and faster execution compared to simulation-based outcomes.
This paper investigates the performance of physical layer security (PLS) in fluid antenna-aided communication systems under arbitrary correlated fading channels. In particular, it is considered that a single fixed-antenna transmitter aims to send confidential information to a legitimate receiver equipped with a planar fluid antenna system (FAS), while an eavesdropper, also taking advantage of a planar FAS, attempts to decode the desired message. For this scenario, we first present analytical expressions of the equivalent channel distributions at the legitimate user and eavesdropper by using copula, so that the obtained analytical results are valid for any arbitrarily correlated fading distributions. Then, with the help of Gauss-Laguerre quadrature, we derive compact analytical expressions for the average secrecy capacity (ASC), the secrecy outage probability (SOP), and the secrecy energy efficiency (SEE) for the FAS wiretap channel. Moreover, for exemplary purposes, we also obtain the compact expression of ASC, SOP, and SEE by utilizing the Gaussian copula under correlated Rayleigh fading channels as a special case. Eventually, numerical results indicate that applying the fluid antenna with only one activated port to PLS can guarantee more secure and reliable transmission, when compared to traditional antenna systems (TAS) exploiting maximal ratio combining (MRC) and antenna selection (AS) under selection combining (SC).
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.