We analyze the secrecy outage probability of a dual-hop radio frequency (RF)-free space optical (FSO) transmission systems. We assume that the eavesdropping occurs at the RF channel which experiences Nakagami-m fading while the FSO link suffers from Málaga turbulence-induced fading. More precisely, we derive an analytical expression for the lower bound of secrecy outage probability (SOP) to study the secrecy performance of dual-hop RF-FSO transmission system with the fixed-gain amplify-and-forward relaying protocol.
We analyze the secrecy outage probability of a dual-hop radio frequency (RF)-free space optical (FSO) transmission systems. We assume that the eavesdropping occurs at the RF channel which experiences Nakagami-m fading while the FSO link suffers from Málaga turbulence-induced fading. More precisely, we derive an analytical expression for the lower bound of secrecy outage probability (SOP) to study the secrecy performance of dual-hop RF-FSO transmission system with the fixed-gain amplify-and-forward relaying protocol.
In this paper, the secrecy performance from the perspective of secrecy outage probability(SOP) for a free space optical-radio frequency (FSO-RF) network with an amplify-and-forward (AF) relaying under the wiretapping of an eavesdropper is investigated. Specifically, a superimposed signal of two users is first transmitted from a source (S) to a relay (R) over an FSO link, and then converted by R into an electrical one and broadcasted to their corresponding users over the RF links, while an eavesdropper is overhearing this transmission. In addition, the information transmission in both hops is incorporated with a non-orthogonal multiple access technique. Assuming the FSO and the RF links undergo Gamma-Gamma fading and Nakagami-mfading respectively, the analytical expression for SOP is first obtained and then verified with simulation results.
In this paper, the secrecy performance of a mixed radio frequency-free space optical (RF-FSO) communication system that consists of a source (S), a relay (R), a destination (D), and an eavesdropper (E), is studied. In this system, it is assumed that the E can overhear the free space optical (FSO) link between R and D as it is close to D. It is further assumed that the radio frequency (RF) and FSO links experience Rayleigh and Gamma-Gamma fading, respectively. Considering atmospheric turbulence, pointing errors, two types of detection techniques, and decode-and-forward scheme, the closed-form expressions for the lower bound of secrecy outage probability and the probability of strictly positive secrecy capacity are derived. Monte Carlo simulation results are also presented to validate the accuracy of the derivations.
Physical-Layer Security for Mixed η – μ and M -Distribution Dual-Hop RF/FSO Systems
In this correspondence, we investigate the physical-layer security of a mixed radio frequency/free space optical (RF/FSO) dual-hop communication system for both fixed-and variable-gain relaying schemes. More specifically, we only assume that the eavesdropping happens at the RF link because the optical link has high security. We assume that all RF channels suffer from η-μfading, while the FSO link experiences M-distributed fading. Then, we derive some analytical results for the average secrecy rate and the secrecy outage probability.
Abstract Free space optical (FSO) communication system is a promising candidate for day-to-day progressing networks because of its potential advantages such as, large bandwidth, line-of-sight communication, non-licensed spectrum, high data rates and many more. Relay-assisted communication provides an additional hike to the system’s performance by expanding its coverage range, enhancing data rates, capacity and mitigating the effect of turbulence. In this manuscript, FSO-radio frequency (RF) dual hop system is considered using decode and forward (DF) relaying protocol. Furthermore, chaotic signals are incorporated in the proposed system to enhance their confidentiality using differential chaos shift keying (DCSK). This is demonstrated by performing secrecy analysis of the proposed system. Here, it is assumed that FSO link experiences Gamma-Gamma turbulence along with pointing errors while RF link experiences Nakagami-m fading. The probability of error of the proposed system is analyzed, and the results indicated huge gain in the SNR requirements in FSO-RF-DCSK system. Also, secrecy analysis is performed using secrecy outage probability (SOP) as a metric for the proposed system. The findings are noteworthy as FSO-RF-DCSK system presents superior performance in terms of secrecy.
The emergence of an array of new wireless networks has led researchers to evaluate the prospect of utilizing the physical properties of the wireless medium in order to design secure systems. In this paper, the physical layer secrecy performance of a mixed radio frequency-free space optical (RF-FSO) system with variable gain relaying scheme is investigated in the presence of an eavesdropper. We assume that the eavesdropper can wiretap the transmitted confidential data from the RF link only. It is further assumed that the main and eavesdropper RF links are modeled as generalized Gamma (GG) fading channel, and the free space optical (FSO) link experiences Málaga turbulence with pointing error impairment. Our primary concern is to protect this confidential information from being wiretapped. Besides pointing error, the atmospheric turbulence and two types of detection techniques (i.e. heterodyne detection and intensity modulation with direct detection) are also taken into consideration. Utilizing amplify-and-forward (AF) scheme, the novel mathematical closed-form expressions for average secrecy capacity, lower bound of secrecy outage probability, and strictly positive secrecy capacity are derived. As both the links (RF and FSO) undergo generalized fading channels, the derived expressions are also general. We present a unification of some existing works utilizing the proposed model to better clarify the novelty of this work. Finally, all the derived expressions are justified via Monte-Carlo simulations.
We analyze the secrecy outage performance of a mixed radio frequency-free space optical (RF-FSO) transmission system with imperfect channel state information (CSI). We deal with a single-input multiple-output wiretap model, where a base station (works as the relay) forwards the signal transmitted from a user (source) to a data center (works as the destination), while an eavesdropper wiretaps the confidential information by decoding the received signal. Both the relay and the eavesdropper are armed with multiple antennas, and maximal ratio combining scheme is utilized to improve the received signal-to-noise ratio (SNR). The effects of imperfect CSI of the RF link and the FSO link, misalignment, detection schemes, and relaying schemes on the secrecy outage performance of mixed RF-FSO systems are studied. First, the cumulative distribution function and probability density function of FSO links with pointing error and two different detection technologies are derived. Then, we derive the closed-form expressions for the lower bound of the secrecy outage probability (SOP) with fixed-gain relaying and variable-gain relaying schemes. Furthermore, asymptotic results for the SOP are investigated by exploiting the unfolding of Meijer's G-function when the electrical SNR of FSO link approaches infinity. Finally, Monte Carlo simulation results are presented to corroborate the correctness of the analysis.