On secrecy performance of mixed generalized Gamma and Málaga RF-FSO variable gain relaying channel

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

Secrecy Performance Analysis of Mixed α - μ and Exponentiated Weibull RF-FSO Cooperative Relaying System

Funding Information: This work was supported in part by the National Research Foundation of Korea—Grant funded by the Korean Government under Grant Ministry of Science and ICT-NRF-2020R1A2B5B02002478, and in part by Sejong University through its Faculty Research Program under Grant 20212023.Peer reviewedPublisher PD

On the Intercept Probability and Secure Outage Analysis of Mixed (α-κ-μ)-Shadowed and Málaga Turbulent Models

This work was supported in part by the National Research Foundation of Korea-Grant funded by the Korean Government (Ministry of Science and ICT) under Grant NRF 2020R1A2B5B02002478, and in part by Sejong University through its Faculty Research Program under Grant 20212023Peer reviewedPublisher PD

Impact of Correlation and Pointing Error on Secure Outage Performance over Arbitrary Correlated Nakagami Turbulent Fading Mixed RF-FSO Channel

Funding Information: Manuscript received September 8, 2020; revised February 11, 2021; accepted February 14, 2021. Date of publication February 16, 2021; date of current version March 10, 2021. This research was supported in part by the National Research Foundation of Korea grant funded by the Korean government (Ministry of Science and ICT; 2019R1A2C1083988), in part by the Ministry of Science and ICT, Korea, under the Information Technology Research Center support program (IITP-2020-2016-0-00313) supervised by the Institute for Information & Communications Technology Planning & Evaluation, and in part by Sejong University through its faculty research program (20212023). (Sheikh Habibul Islam, A. S. M. Badrud-duza, and S. M. R. Islam contributed equally to this work and co-first authors.) Corresponding authors: A. S. M. Badrudduza; Heejung Yu (e-mail: [email protected]; [email protected]).)Peer reviewedPublisher PD

Enhancing Physical Layer Secrecy Performance for RIS-assisted RF-FSO Mixed Wireless System

Peer reviewedPublisher PD

On effective secrecy throughput of underlay spectrum sharing α - μ/ Málaga hybrid model under interference-and-transmit power constraints

The underlay cognitive radio-based hybrid radio frequency/free-space optical (RF/FSO) systems have emerged as a promising technology due to their ability to eliminate spectrum scarcity and spectrum under-utilization problems. The physical layer security of such a network with a primary user, a secondary source, a secondary receiver, and an eavesdropper is therefore examined in this work. In this network, secret communication occurs between two reliable secondary peers over the RF and FSO links simultaneously, and the eavesdropper can only overhear the RF link. In particular, the maximum transmits power limitation at the secondary user as well as the permissible interference power restriction at the primary user are also taken into consideration. All the RF and FSO links are modeled with α - μ fading and Málaga turbulence with link blockage and pointing error impairments. At the receiver, the selection combining diversity technique is utilized to select the signal with the best electrical signal-to-ratio (SNR). Furthermore, to examine the secrecy performance taking into account the effects of each system parameter, closed-form expressions for the secrecy outage probability and effective secrecy throughput are derived. The resultant expressions are finally verified by Monte-Carlo simulations

Physical Layer Security of a Dual-Hop Regenerative Mixed RF/UOW System

Ensuring physical layer security is a crucial task in conventional and emerging communication systems, which are typically characterized by stringent quality of service and security requirements. This also accounts for wireless technologies in the context of the Internet of Things paradigm, which are expected to exhibit considerably increased computational complexity. Based on this, the present contribution investigates the secrecy outage performance of a dual-hop decode-and-forward (DF) mixed radio-frequency/underwater optical wireless communication (RF/UOWC) system. Such wireless network configurations are particularly useful in efficient and demanding scenarios, such as military communications. Therefore, our analysis considers one single-antenna source node $(S)$ communicating with one legitimate destination node $(D)$ via a DF relay node $(R)$ equipped with multiple antennas for reception. Particularly, the relay receives the incoming signal from S via an RF link, applies selection-combining (SC) technique, fully decodes it, re-encodes it and then forwards it to the destination via a UOWC link. The communication is performed under the eavesdropper's attempt to intercept the $S-R$ hop (RF side). In this context, a closed-form expression for the secrecy outage probability is derived along with a thorough asymptotic analysis in the high SNR regime, based on which the achievable diversity order is provided. The offered results provide useful insights on the impact of some key system and channel parameters on the secrecy outage performance, such as the number of eavesdroppers, the number of relay antennas, fading severity parameters of RF links, and water turbulence severity of the UOWC link. The conducted analysis shows that the secrecy outage probability is dominated only by the $R-D$ link in the high SNR regime, regardless of the $S-R$ parameters, such as the number of relay antennas and the average SNR at the relay branches. The offered analytic results are corroborated with respective results from computer simulations. Since these parameters are closely related with the computational complexity at the involved terminals, the offered insights are useful for the design and deployment of such systems.acceptedVersionPeer reviewe

Security at the Physical Layer over GG Fading and mEGG Turbulence Induced RF-UOWC Mixed System

This work was supported in part by the National Research Foundation of Korea grant funded by the Korean Government (Ministry of Science and ICT) under Grant 2019R1A2C1083988, in part by the Ministry of Science and ICT, South Korea, under the Information Technology Research Center Support Program supervised by the Institute for Information and Communications Technology Planning and Evaluation, under Grant IITP-2021-2016-0-00313, and in part by Sejong University through its Faculty Research Program under Grant 20202021.Peer reviewedPublisher PD