© 2026 Aqora Quantum S.A.S.

Terms Privacy Legal Notice

Transactions on Emerging Telecommunications Technologies

Achievable secrecy rate analysis of OFDM‐based multi‐user untrusted relay networks with imperfect CSI

Volkan Özduran, Νικόλαος Νομικός, Imran Shafique Ansari

Published Jun 1, 2024• 3 citations

Abstract

Abstract This study investigates the impact of imperfect channel state information (CSI), caused by channel estimation errors and feedback delays, on the physical‐layer security performance of multi‐user relay networks. More specifically, a multi‐user untrusted half/full‐duplex (HD/FD) uni/bi‐directional wireless amplify‐and‐forward (AF) relay network is studied, adopting orthogonal frequency division multiplexing (OFDM). In order to minimize the information leakage, it is considered that a limited number of friendly jammers affect the untrusted relay. In this context, the achievable secrecy rate of the relay network is theoretically analyzed and optimization problems are formulated and solved for the untrusted relay's location and power allocation. Monte Carlo simulations are conducted to validate the theoretical findings, revealing that channel estimation errors cause coding gain losses for low signal‐to noise ratio (SNR) while their impact becomes negligible for high SNR. Also, a large number of user‐pairs achieves higher secrecy rate while FD relaying further improves the secrecy performance. Finally, bi‐directional relaying provides higher achievable secrecy rate over uni‐directional relaying.

DOI: 10.1002/ett.5005

Related papers

Impact of channel estimation error on physical layer security in dual-hop half/full-duplex two-way wireless relaying networks

Volkan Özduran, Binboğa Sıddık Yarman, J.M. Cioffi

This paper investigates the impact of the imperfect channel state information that is caused by the channel estimation errors on physical layer security. The investigation considers a dual-hop single amplify-and-forward (AF) based untrustworthy half/full-duplex bi-directional relay with a finite number of friendly jammers in the system model. According to Monte-Carlo simulation results, the channel estimation error causes system coding gain losses at low signal-to-noise ratio (SNR) regimes both for half and full-duplex cases. Results also show that the CEE effects turn out to be at negligible levels in high SNR regimes. Results also show that friendly jammer, besides improving the secrecy performance of the system model, also degrades the curves and causes system coding gain losses at high SNR regimes. Results also show that better secrecy performance can be achieved when the relay terminal operates in full-duplex mode.

IEEE Conference on Computer Communications Workshops (INFOCOM WKSHPS)•Apr 1, 2016•14 citations

Secrecy Analysis of Multi-user Half/Full-Duplex Wireless Bi-directional Relaying Network

Volkan Özduran

This paper investigates the physical layer security of orthogonal frequency division multiplexing technique. The investigation considers a multi-user untrustworthy half/full-duplex based two-way wireless relay with a finite number of friendly jammers in the system model. According to Monte-Carlo simulation results, the system model that operates in full-duplex mode achieves slightly better secrecy outage performance than the system model that operates in half-duplex mode. The results also show that friendly jammers, besides minimizing the information leakage, degrade the system performance severely and cause system coding gain losses in high signal-to-noise ratios.

Balkan Journal of Electrical and Computer Engineering•Jul 29, 2019•3 citations

Physical Layer Security of Multi-user Full-Duplex One-Way Wireless Relaying Network

Volkan Özduran

This paper investigates the physical layer security of the orthogonal frequency division multiplexing based wireless relaying network. The investigation considers a multi-user untrustworthy amplify-and-forward based one-way full-duplex wireless relaying network in the system model. According to the Monte-Carlo simulation results, the friendly jammers severely affect the system achievable secrecy outage probability performance and degrade the system performance curves in high signal-to-noise ratio regimes. Results also show that the system model that contains a large number of user-pairs achieves better secrecy performance in comparison to a small number of user-pairs.

Advances in Wireless and Optical Communications (RTUWO)•Nov 1, 2018•10 citations

Feedback Delay Effects on Physical Layer Security in a Dual-Hop Half/Full-Duplex Bi-Directional Wireless Relaying Networks

Volkan Özduran, Binboğa Sıddık Yarman, J.M. Cioffi

This paper investigates the feedback delay effects on physical layer security. The investigation considers a dual-hop single amplify-and-forward based untrustworthy half/full-duplex two-way relay with a finite number of friendly jammers in the system model. According to the Monte-Carlo simulation results, the feedback delay degrades the system secrecy achievable rate and causes system coding gain losses in high signal-to-noise regimes. Results also show that if the number of friendly jammers in the system model increases then system secrecy achievable rate tends to degrade and causes system coding gain losses. Results also show that better system secrecy achievable rate can be achieved when the relay terminal operates in full-duplex mode.

IEEE Globecom Workshops (GC Wkshps)•Dec 1, 2016•8 citations

Optimal power allocation for achievable secrecy rate in an untrusted relay network with bounded channel estimation error

Tamer Mekkawy, Rugui Yao, Fei Xu +1 more

The objective of this paper is to maximize the secrecy rate in an untrusted relay network with imperfect channel state information (CSI). Considering bounded channel estimation error in cooperative jamming network, we optimize the power allocation for confidential and jamming signals to maximize the instantaneous secrecy rate. The upper and lower bounds of achievable secrecy rate are analyzed. The ergodic secrecy rate (ESR) is further derived to evaluate the maximum average secrecy rate. And the optimal power allocation is also studied based on ESR. Numerical results show optimal power allocation can increase both instantaneous secrecy rate and ESR, and at higher SNR, the impact of channel estimation error can be neglected for the maximum ESR, which is asymptotically approaches to the upper bound.

Wireless and Optical Communications Conference•Apr 1, 2017•14 citations

Subcarrier‐pair based joint resource allocation for secure cooperative OFDM system with multiple untrusted AF relays

Yifeng Jin, Xunan Li, Guocheng Lv +2 more

Abstract In this paper, a cooperative orthogonal frequency division multiplexing system with multiple untrusted amplify‐and‐forward relays is considered. Since there exists no direct link between source and user because of the shadowing effect, a positive system secrecy rate cannot be obtained. Addressing this issue, a cooperative user‐aided jamming technique to improve the secrecy performance is employed. With the aim of maximising the system secrecy rate, a joint resource allocation problem of power allocation, relay assignment and subcarrier pairing is formulated. By using the signal‐to‐noise ratio based approach and the Lagrange dual method, this nonconvex problem is solved efficiently. To reduce the calculation complexity, a suboptimal algorithm, which decouples the power allocation with the relay assignment and subcarrier pairing is further proposed. Numerical results are presented to demonstrate the advantage of the two proposed algorithms and the impact of relays' location and number of subcarriers on the secrecy performance. Moreover, it is shown that the secrecy performance of the proposed scheme is decreased with respect to the number of untrusted relays.

IET Communications•Apr 19, 2022•3 citations

Abstract This study investigates the impact of imperfect channel state information (CSI), caused by channel estimation errors and feedback delays, on the physical‐layer security performance of multi‐user relay networks. More specifically, a multi‐user untrusted half/full‐duplex (HD/FD) uni/bi‐directional wireless amplify‐and‐forward (AF) relay network is studied, adopting orthogonal frequency division multiplexing (OFDM). In order to minimize the information leakage, it is considered that a limited number of friendly jammers affect the untrusted relay. In this context, the achievable secrecy rate of the relay network is theoretically analyzed and optimization problems are formulated and solved for the untrusted relay's location and power allocation. Monte Carlo simulations are conducted to validate the theoretical findings, revealing that channel estimation errors cause coding gain losses for low signal‐to noise ratio (SNR) while their impact becomes negligible for high SNR. Also, a large number of user‐pairs achieves higher secrecy rate while FD relaying further improves the secrecy performance. Finally, bi‐directional relaying provides higher achievable secrecy rate over uni‐directional relaying.

This paper investigates the impact of the imperfect channel state information that is caused by the channel estimation errors on physical layer security. The investigation considers a dual-hop single amplify-and-forward (AF) based untrustworthy half/full-duplex bi-directional relay with a finite number of friendly jammers in the system model. According to Monte-Carlo simulation results, the channel estimation error causes system coding gain losses at low signal-to-noise ratio (SNR) regimes both for half and full-duplex cases. Results also show that the CEE effects turn out to be at negligible levels in high SNR regimes. Results also show that friendly jammer, besides improving the secrecy performance of the system model, also degrades the curves and causes system coding gain losses at high SNR regimes. Results also show that better secrecy performance can be achieved when the relay terminal operates in full-duplex mode.

This paper investigates the physical layer security of orthogonal frequency division multiplexing technique. The investigation considers a multi-user untrustworthy half/full-duplex based two-way wireless relay with a finite number of friendly jammers in the system model. According to Monte-Carlo simulation results, the system model that operates in full-duplex mode achieves slightly better secrecy outage performance than the system model that operates in half-duplex mode. The results also show that friendly jammers, besides minimizing the information leakage, degrade the system performance severely and cause system coding gain losses in high signal-to-noise ratios.

This paper investigates the physical layer security of the orthogonal frequency division multiplexing based wireless relaying network. The investigation considers a multi-user untrustworthy amplify-and-forward based one-way full-duplex wireless relaying network in the system model. According to the Monte-Carlo simulation results, the friendly jammers severely affect the system achievable secrecy outage probability performance and degrade the system performance curves in high signal-to-noise ratio regimes. Results also show that the system model that contains a large number of user-pairs achieves better secrecy performance in comparison to a small number of user-pairs.

This paper investigates the feedback delay effects on physical layer security. The investigation considers a dual-hop single amplify-and-forward based untrustworthy half/full-duplex two-way relay with a finite number of friendly jammers in the system model. According to the Monte-Carlo simulation results, the feedback delay degrades the system secrecy achievable rate and causes system coding gain losses in high signal-to-noise regimes. Results also show that if the number of friendly jammers in the system model increases then system secrecy achievable rate tends to degrade and causes system coding gain losses. Results also show that better system secrecy achievable rate can be achieved when the relay terminal operates in full-duplex mode.

The objective of this paper is to maximize the secrecy rate in an untrusted relay network with imperfect channel state information (CSI). Considering bounded channel estimation error in cooperative jamming network, we optimize the power allocation for confidential and jamming signals to maximize the instantaneous secrecy rate. The upper and lower bounds of achievable secrecy rate are analyzed. The ergodic secrecy rate (ESR) is further derived to evaluate the maximum average secrecy rate. And the optimal power allocation is also studied based on ESR. Numerical results show optimal power allocation can increase both instantaneous secrecy rate and ESR, and at higher SNR, the impact of channel estimation error can be neglected for the maximum ESR, which is asymptotically approaches to the upper bound.

Abstract In this paper, a cooperative orthogonal frequency division multiplexing system with multiple untrusted amplify‐and‐forward relays is considered. Since there exists no direct link between source and user because of the shadowing effect, a positive system secrecy rate cannot be obtained. Addressing this issue, a cooperative user‐aided jamming technique to improve the secrecy performance is employed. With the aim of maximising the system secrecy rate, a joint resource allocation problem of power allocation, relay assignment and subcarrier pairing is formulated. By using the signal‐to‐noise ratio based approach and the Lagrange dual method, this nonconvex problem is solved efficiently. To reduce the calculation complexity, a suboptimal algorithm, which decouples the power allocation with the relay assignment and subcarrier pairing is further proposed. Numerical results are presented to demonstrate the advantage of the two proposed algorithms and the impact of relays' location and number of subcarriers on the secrecy performance. Moreover, it is shown that the secrecy performance of the proposed scheme is decreased with respect to the number of untrusted relays.