The article presents an analysis of the physical layer security of a wireless communication system functioning in the presence of multipath fading and a wiretap. Under the assumption of the equal propagation conditions (both for the legitimate receiver and the eavesdropper) described by the shadowed Beaulieu–Xie model, a closed-form expression for the secrecy outage probability was derived. The correctness of the obtained expression was numerically verified via comparison with the direct numerical integration. The truncated version of the obtained expression was analyzed for various channel parameters to establish the requirements for numerically efficient implementation (in terms of the number of summands delivering the desired precision). An in-depth study of the secrecy outage probability dependence from all the possible channel parameters for different fading scenarios was performed, including heavy fading and light fading, with and without strong dominant and multipath components. The performed research demonstrated the existence of the secrecy outage probability non-uniqueness with the respect to the average signal-to-noise ratio in the main channel and the relative distance between the legitimate and wiretap receivers.
The article presents an analysis of the physical layer security of a wireless communication system functioning in the presence of multipath fading and a wiretap. Under the assumption of the equal propagation conditions (both for the legitimate receiver and the eavesdropper) described by the shadowed Beaulieu–Xie model, a closed-form expression for the secrecy outage probability was derived. The correctness of the obtained expression was numerically verified via comparison with the direct numerical integration. The truncated version of the obtained expression was analyzed for various channel parameters to establish the requirements for numerically efficient implementation (in terms of the number of summands delivering the desired precision). An in-depth study of the secrecy outage probability dependence from all the possible channel parameters for different fading scenarios was performed, including heavy fading and light fading, with and without strong dominant and multipath components. The performed research demonstrated the existence of the secrecy outage probability non-uniqueness with the respect to the average signal-to-noise ratio in the main channel and the relative distance between the legitimate and wiretap receivers.
The paper considers the problem of a wireless communication system’s physical level security for a multipath signal propagation channel and the presence of a wiretap channel. To generalize the propagation effects, the Beaulieu-Xie shadowed channel model was assumed. To describe the security of the information transfer process, such a metric as the secure outage probability of was considered. An analytical expression of the secure outage probability was obtained and analyzed depending on the characteristics of the channel and the communication system: the average value of the signal-to-noise ratio in the main channel and the wiretap channel, the effective path-loss exponent, the relative distance between the legitimate receiver and the wiretap and the threshold bandwidth, normalized to the bandwidth of a smooth Gaussian channel. The analysis considers the sets of parameters that cover all practically important scenarios for the functioning of a wireless communication systems: both deep fading (corresponding to the hyper-Rayleigh scenario) and small fading, both in the case of a significant line-of-sight component and a significant number of multipath clusters, and with significant shadowing of the dominant component and a small number of multipath waves, as well as all intermediate options. It is found out that the value of the energy requirements for guaranteed secure communication at a given speed is determined primarily by the power of multipath components, as well as the existence of an irreducible secure outage probability of a communication session with an increase for channels with strong overall shadowing of the signal components, which from a practical point of view is important to take into account when imposing requirements for the values of the signal-to-noise ratio and the data transfer rate in the direct channel, providing the desired degree of security of the wireless communication session.
In this study, the secrecy performance of physical layer when both the main and wiretap channels undergo shadowed fading conditions is analysed. In particular, the average secrecy capacity, secure outage probability (SOP), the lower bound of SOP (SOP ), and the probability of strictly positive secrecy capacity are derived by using the classic Wyner's wiretap model. Two different scenarios for the fading parameters, namely, and m , which represent the real extension of the number of the multipath clusters and the shadowing index, respectively, have been studied. These parameters are chosen first as arbitrary numbers, thus the performance metrics are given in exact closed‐form in terms of the extended generalised bivariate Fox's H ‐function that has been widely implemented in the open literature using various software packages. In the second scenario, both the fading parameters are assumed to be integer numbers to obtain the derived results in simple exact closed‐form mathematically tractable expressions in terms of some analytic functions. The numerical results of this analysis are verified via the Monte Carlo simulations.
The research considers the physical layer security problem for wireless devices communicating through a full hyper-Rayleigh fading channel. Two distinct scenarios are assumed: asymmetric (the links have different channel statistical descriptions) and symmetric (the channel statistical parameters are identical for both the main and wiretap links); and two particular cases are studied: the wiretap-dominating case (i.e., the average signal-to-noise ratio (SNR) in the wiretap channel is much greater than in the main channel) and the main channel-dominating case (that is, when the opposite situation is observed). For the assumed problem, a closed-form expression for the probability of strictly positive secrecy capacity is derived, and closed-form approximations for both scenarios and both cases are provided. The presented numerical analysis demonstrates the correctness of the derived expressions and provides insights into the impact of various channel parameters on communication secrecy in severe fading environments.
Secrecy Analysis of Physical Layer over κ−μ Shadowed Fading Scenarios
In this paper, the secrecy analysis of physical layer when both the main and wiretap channels undergo κ−μ shadowed fading channel is investigated. In particular, the average secrecy capacity (ASC), secure outage probability (SOP), the lower bound of SOP (SOPL), and the probability of strictly positive secrecy capacity (SPSC) are derived by using the classic Wyner's wiretap model. Two different scenarios for the fading parameters, i.e., μ and m which represents the shadowing impact have been studied. These parameters are chosen first as arbitrary numbers, thus the performance metrics are expressed in single infinite series with multivariate Meijer G-function. In the second scenario, both the aforementioned fading parameters are assumed to be integer numbers in order to obtain the derived results in simple exact closed-form analytic mathematically tractable expressions. The numerical results of this analysis are verified via Monte Carlo simulations.
The wiretap channel model in a wireless scenario is analyzed where there is a transmitter, multiple legitimate receivers, non-colluding and colluding eavesdroppers; each of them is equipped with one antenna. Furthermore, all the channels are mutually independent and experiencing quasi-static Nakagami-m fading. We derive closed-form expressions for the exact secrecy outage probability as well as the average secrecy capacity with both non-colluding and colluding eavesdroppers. Such performance metrics are used to analyze the impacts of the number of receivers and eavesdroppers on the system. Remarkably, our results reveal that, for non-colluding eavesdroppers, increasing the number of users will cause greater secrecy degradation than the number of eavesdroppers, especially when the main channel is far superior to the wiretap channel or the value of the fading parameter is high. And for the colluding case, it turns out to be the opposite.
This paper deals with the physical layer security for the satellite-terrestrial communication system in the presence of an eavesdropper. In the analysis, the satellite has no knowledge of the eavesdropper’s channel state information referring to the passive eavesdropping scenario. The main, as well as the wiretap link, are both characterized as gamma-shadowed Ricean fading channels. The analytical expressions for the secrecy outage probability and the probability of strictly positive secrecy capacity are derived. The secrecy diversity order is also determined. The impact of the fading/shadowing parameters and the average signal-to-noise ratios of the legitimate/illegitimate channels on the aforementioned secrecy metrics is investigated. The results illustrate that specific, either main or wiretap channel nature can enhance system security at the physical layer.