User-Pair Selection in Multiuser Cooperative Networks With an Untrusted Relay

Abstract

This paper investigates the physical-layer security of an amplify-and-forward wireless cooperative network where N source nodes communicate with their corresponding destination nodes under the help of an untrusted relay. In each slot only one user-pair is scheduled to transmit the information, and the destination aided cooperative jamming is adopted to protect information from being intercepted by the untrusted relay. Three user-pair selection schemes have been proposed for the considered system, namely opportunistic user-pair selection (OUS) scheme, greedy user-pair selection (GUS) scheme and genie-aided user-pair selection (GAUS) scheme. Both the secrecy outage probability and average secrecy rate have been studied to evaluate the performance of the OUS and GUS schemes, and the asymptotic analysis has also been obtained. It reveals that, the proposed schemes can improve the secrecy performance for the cooperative multiuser networks as the number of user-pairs increases. We also prove that the achievable diversity order of both OUS scheme and GUS scheme is N 2. Finally, numerical and simulation results are presented to validate the accuracy of the developed analytical results.

Secure Resource Allocation for Cooperative OFDMA System With Untrusted AF Relaying

“…2) Untrusted user case: all users are untrustworthy so each user receives data with considering all other users as the potential eavesdroppers [14]- [16]. 3) Untrusted relay case: when the source communicates with users by relay-assisted, there exists another research scenario of physical layer security, where the relay is assumed to be untrustworthy and act as an eavesdropper [17]- [27].…”

Security‐reliability tradeoff for multi‐terminal multi‐mode coexisting systems in the presence of multiple eavesdroppers

“…As an alternative, in [15], an extra user is selected to transmit artificial noise to reduce the secrecy outage probability of the chosen user. In [16], in order to protect wireless transmissions of scheduled user‐pair, the destination‐aided collaborative jamming is designed. In [17], a user having the maximal secrecy rate will be selected to access the AP, and the AP may utilise multiple antennas to transmit artificial noise to the illegal users.…”

“…Although extensive research efforts have been devoted to the PLS in the multi‐terminal wireless networks, less attention has been paid to multi‐terminal multi‐mode wireless scenarios. In this paper, differing from [15–21], we explore the PLS of a wireless network consisting of multiple smart terminals relying on coexisting between the licensed modes and the unlicensed modes, in the presence of an eavesdropper. The main contributions of this paper are summarised as follows.…”

Secure AF relaying with efficient partial relay selection scheme

“…In this scenario, the source and destination are equipped with large‐scale multiple antennas. He et al introduced the cooperative jamming technique into an untrusted network with N source‐destination pairs and presented user‐pair selection schemes. For Nakagami‐ m fading, the impact of eavesdropping on SOP performance for AF relaying with an untrusted relay was investigated in Ding et al…”