The physical layer security (PLS) is explored in quasi-static Fisher-Snedecor F Fading Channels with maximal ratio combining (MRC), which have been used to model the conventional and emerging realistic wireless communication channels. We consider the secure transmission of privileged information from a single antenna legitimate transmitter to L-antenna legitimate receiver are wiretapped by L-antenna eavesdropper. The receiver maximizes the probability of secure transmission by adopting MRC, whereas eavesdropper maximizes the probability of eavesdropping by adopting MRC. We derive PLS secrecy metrics for a system setup where the transmitter is having no channel state information (CSI) of both the receiver and eavesdropper. Specifically, we derive a novel closed-form expressions for secure outage probability (SOP) and strictly positive secrecy capacity (SPSC). Furthermore, to obtain important insight into the effect of channel parameters on the secrecy performance, an asymptotic analysis is conducted for SOP at high signal-to-noise ratio (SNR) regime.
Physical Layer Security of MRC in Fisher–Snedecor F Fading Channels
The physical layer security (PLS) is explored in quasi-static Fisher-Snedecor F Fading Channels with maximal ratio combining (MRC), which have been used to model the conventional and emerging realistic wireless communication channels. We consider the secure transmission of privileged information from a single antenna legitimate transmitter to L-antenna legitimate receiver are wiretapped by L-antenna eavesdropper. The receiver maximizes the probability of secure transmission by adopting MRC, whereas eavesdropper maximizes the probability of eavesdropping by adopting MRC. We derive PLS secrecy metrics for a system setup where the transmitter is having no channel state information (CSI) of both the receiver and eavesdropper. Specifically, we derive a novel closed-form expressions for secure outage probability (SOP) and strictly positive secrecy capacity (SPSC). Furthermore, to obtain important insight into the effect of channel parameters on the secrecy performance, an asymptotic analysis is conducted for SOP at high signal-to-noise ratio (SNR) regime.
This paper advocates physical layer security of maximal ratio combining (MRC) in wiretap two-wave with diffuse power fading channels. In such a wiretap channel, we consider that confidential messages transmitted from a single antenna transmitter to an M-antenna receiver are overheard by an N-antenna eavesdropper. The receiver adopts MRC to maximize the probability of secure transmission, whereas the eavesdropper adopts MRC to maximize the probability of successful eavesdropping. We derive the secrecy performance for two practical scenarios: 1) the eavesdropper's channel state information (CSI) is available at the transmitter and 2) the eavesdropper's CSI is not available at the transmitter. For the first scenario, we develop a new analytical framework to characterize the average secrecy capacity as the principal security performance metric. Specifically, we derive new closed-form expressions for the exact and asymptotic average secrecy capacity. Based on these, we determine the high signal-to-noise ratio power offset to explicitly quantify the impacts of the main channel and the eavesdropper's channel on the average secrecy capacity. For the second scenario, the secrecy outage probability is the primary security performance metric. Here, we derive new closed-form expressions for the exact and asymptotic secrecy outage probability. We also derive the probability of nonzero secrecy capacity. The asymptotic secrecy outage probability explicitly indicates that the positive impact of M is reflected in the secrecy diversity order and the negative impact of N is reflected in the secrecy array gain. Motivated by this, we examine the performance gap between N and N+1 antennas based on their respective secrecy array gains.
We investigate the physical layer security limits of Wyner's wiretap model over Fisher-Snedecor .T composite fading channels. .T fading conditions have been recently shown to provide an accurate characterization of multipath fading and shadowing effects in emerging wireless transmission scenarios such as body centric, cellular and vehicular communications. To this end, we utilize a redefined analytic expression for the Fisher-Snedecor .T distribution in order to ensure unconstrained validity and reliability when used in the analysis of various performance metrics of interest. In this context, we assume that the main channel (i.e., between the source and the legitimate destination) and the eavesdropper's channel (i.e., between the source and the illegitimate destination) undergo independent quasi-static Fisher-Snedecor .T composite fading. Novel exact analytic expressions are then derived for the corresponding average secrecy capacity (ASC), secure outage probability (SOP) and probability of strictly positive secrecy capacity (SPSC) along with their insightful asymptotic representations. In addition, analytical expressions for the ASC, SOP and SPSC over mixed fading channels such as Nakagami-m/Nakagami-m, Nakagami-m/Fisher-Snedecor .T and Fisher-Snedecor .T/Nakagami-m are derived. The new formulations are validated through comparisons with Monte-Carlo simulations and analyzed to gain useful insights into the impact of the fading parameters on the achievable accuracy and the overall system performance.
This paper advocates physical layer security in wiretap channels with two-wave with diffuse power fading. In such a wiretap channel, we consider that confidential messages transmitted from a single antenna transmitter to an M-antenna receiver is overheard by an N-antenna eavesdropper. The receiver adopts maximal-ratio combining (MRC) to enhance transmission security, whereas the eavesdropper adopts MRC to maximize the probability of successful eavesdropping. We develop a new analytical framework to characterize the average secrecy capacity as the principal security performance metric in active eavesdropping. Specifically, we derive new closed-form expressions for the exact and asymptotic average secrecy capacity. Based on these, we determine the high signal-to-noise ratio power offset to explicitly quantify the impact of the main channel and the eavesdropper's channel on the average secrecy capacity.
This paper investigates the impact on the achievable secrecy performance of multiple-input multiple-output systems by dealing with realistic propagation conditions. Specifically, we focus on the κ-μ shadowing fading model, which has proven to be more accurate in characterizing mm-wave scenarios than traditional Rice and Rayleigh ones. By considering transmit antenna selection and maximal ratio combining at the receiver ends, we study two different scenarios, namely: (i) the transmitter has knowledge of the channel state information (CSI) of the eavesdropper link, and (ii) the transmitter does not know eavesdropper's CSI. Based on these assumptions, we derive novel analytical expressions for the secrecy outage probability (SOP) and the average secrecy capacity (ASC) to assess the secrecy performance in passive and active eavesdropping scenarios, respectively. Moreover, we develop analytical asymptotic expressions of the SOP and ASC at high signal-to-noise ratio regime. Some useful insights on how to obtain noticeable improvements in the secrecy performance are also provided.
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).
The impact of both maximal ratio combining (MRC) and relay selection on the physical layer security in wireless communication systems is studied by analyzing some important factors, including the probability characteristic of the legitimate receiver (Bob) and malicious eavesdropper (Eve)'s end-to-end signal-to-noise ratio (SNR), the secrecy outage probability, and the average secrecy channel capacity over Rayleigh fading Channel. We assume that Bob receives its data from both the relay and the source by cooperative communication, provided that MRC is employed at the receiver. Compared to the conventional MRC methods, a higher spatial diversity order can be exploited by performing relay selection in the proposed method, as validated via both theoretical analysis and numerical simulation. The theoretical closed-form expressions for some figures of merit, e.g., the secrecy outage probability and the average secrecy capacity, are all consistent with the numerical results.