Optimal Power Allocation by Imperfect Hardware Analysis in Untrusted Relaying Networks

By taking a variety of realistic hardware imperfections into consideration, we propose an optimal power allocation (OPA) strategy to maximize the instantaneous secrecy rate of a cooperative wireless network comprised of a source, a destination and an untrusted amplify-and-forward (AF) relay. We assume that either the source or the destination is equipped with a large-scale multiple antennas (LSMA) system, while the rest are equipped with a single antenna. To prevent the untrusted relay from intercepting the source message, the destination sends an intended jamming noise to the relay, which is referred to as destination-based cooperative jamming (DBCJ). Given this system model, novel closed-form expressions are presented in the high signal-to-noise ratio (SNR) regime for the ergodic secrecy rate (ESR) and the secrecy outage probability (SOP). We further improve the secrecy performance of the system by optimizing the associated hardware design. The results reveal that by beneficially distributing the tolerable hardware imperfections across the transmission and reception radio-frequency (RF) front ends of each node, the system's secrecy rate may be improved. The engineering insight is that equally sharing the total imperfections at the relay between the transmitter and the receiver provides the best secrecy performance. Numerical results illustrate that the proposed OPA together with the most appropriate hardware design significantly increases the secrecy rate.Comment: 29 pages, 7 figures, Submitted to IEEE Transactions on Wireless Communication

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 Hyper-Gamma and Gamma-Gamma Cooperative Relaying System

Peer reviewe

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