Physical‐layer security for cellular multiuser two‐way relaying networks with single and multiple decode‐and‐forward relays

Abstract

We investigate the secrecy performance of cellular multiuser two-way relay networks, where the bidirectional information exchange between a multiantenna base station (BS), and several users can be accomplished with the assistance of decode-and-forward relay(s) in the presence of a multiantenna passive eavesdropper. We employ low-complexity antenna selection strategy at the BS coupled with user scheduling for maximizing the end-to-end signal-to-noise ratios (SNRs). To enhance the wiretap probability, the eavesdropper applies a maximal ratio combining technique to combine the received signals. Under such considerations, in the single-relay scenario, we deduce the exact closed-form secrecy outage probability (SOP) expression under Rayleigh fading channels. For more insights into the system secrecy diversity order, we derive the closed-form asymptotic SOP expressions at high SNR based on the quality of the main and wiretap links. In the multirelay scenario, we formulate an opportunistic relay selection strategy, followed by its impact on the SOP performance in the presence of Rayleigh channels. To show the impact of multiple relays on the secrecy diversity order, we derive the asymptotic SOP expressions in the high SNR regime depending on the quality of the main and wiretap links. It is shown from the asymptotic SOP expressions under both single-relay and multirelay scenarios that the secrecy diversity order reduces to zero in the high SNR regime, regardless of number of antennas, number of users, and number of relays. Our results also reveal that the SOP performance diminishes with an increased number of eavesdropper antennas. Numerical and simulation results verify our derived analytical findings.Trans Emerging Tel Tech. 2019;30:e3639.wileyonlinelibrary.com/journal/ett

Secure mm‐Wave communications with imperfect hardware and uncertain eavesdropper location

“…It should also be remarked here that, and are independent because and and . Remark 2: (High-SNR Regime): To gain deeper insights, we consider ( 6) and (7) in the high transmit SNR regime. When the transmit power is sufficiently large, we find that approaches a constant ceiling which only depends on the EVMs at the nodes, while the information leaked towards significantly depends on the power allocation factor .…”

“…Comparing ( 8), ( 9) with ( 6), (7), it can be clearly seen that the terms and in ( 6) and ( 7), respectively, contribute to a more complicated expression for the non-ideal hardware SNDRs. Based on ( 6), (7), we see that the distortion noises emitted by results in interference at both and , while the self-distortion noise at only degrades the received SNDR at the legitimate destination. Thus, even though hardware imperfection can intrinsically confuse passive eavesdroppers, the secrecy performance is still degraded.…”

“…Also, PLS of a UAV network for transmission of confidential information from a base station to multiple receivers utilizing a UAV jammer in presence of multiple eavesdroppers (Eves) was studied in [5]. PLS of overlay device-to-device untrusted relaying in the presence or absence of a friendly jammer was comprehensively analyzed in [6] and secrecy performance of cellular multi-user decode-and-forward based two-way relaying networks was investigated in [7] where a multi-antenna base station communicates bidirectionally with several users by the aid of decode-and-forward relay(s) under the existence of a multiantenna passive eavesdropper. In recent years, massive multiple-input multiple-output (MIMO) systems have come into prominence due to the significant performance gains in terms of security, spectral efficiency and energy saving [8], [9].…”

Security and Reliability Analysis of a Two-Way Half-Duplex Wireless Relaying Network Using Partial Relay Selection and Hybrid TPSR Energy Harvesting at Relay Nodes

“…During the last decade, PLS has experienced a resurgence of interest from a lot of scientists [4] due to its potential to enhance the quality of communication to satisfy the vast demand of mobile users. PLS has been applied in relay networks [5], cellular networks [6], [7], cognitive radio networks [8], IoT networks [9], and massive multipleinput multiple-output (MIMO) networks [10]. In multi-user networks, physical layer security can be improved by node cooperation.…”

“…These two network coding techniques have been the main focus of TWRC for last decade. With the advance research of TWRC, the PLS in spectrally-efficient TWR networks has been extensively researched in the literature [6], [7], [14]- [16], [43]. In particular, Shukla [7] and Pandey [6] investigated the secrecy outage performance of a full-duplex cellular multiuser two-way amplify-and-forward relay network, where a multiantenna base station using transmit antennas selection communicates with one of the several users by the assistance of a relay in the presence of a passive eavesdropper that employs maximal ratio combining.…”