Cooperative Beamforming and User Selection for Improving the Security of Relay-Aided Systems

Abstract

Abstract-A relay network in which a source wishes to convey a confidential message to a legitimate destination with the assistance of trusted relays is considered. In particular, cooperative beamforming and user selection techniques are applied to protect the confidential message. The secrecy rate (SR) and secrecy outage probability (SOP) of the network are investigated first, and a tight upper bound for the SR and an exact formula for the SOP are derived. Next, asymptotic approximations for the SR and SOP in the high signal-to-noise ratio (SNR) regime are derived for two different schemes: i) cooperative beamforming and ii) multiuser selection. Further, a new concept of cooperative diversity gain, namely, adapted cooperative diversity gain (ACDG), which can be used to evaluate security level of a cooperative relaying network, is investigated. It is shown that the ACDG of cooperative beamforming is equal to the conventional cooperative diversity gain of traditional multiple-input single-output networks, while the ACDG of the multiuser scenario is equal to that of traditional single-input multiple-output networks.Index terms-Physical layer security, decode-and-forward relays, cooperative diversity, cooperative beamforming, large scale relaying.

Secure Massive MIMO Relaying Systems in a Poisson Field of Eavesdroppers

“…where c DF is a constant subject to the constraint (8). From (6), (8) and (14), we have c DF = √ N whereby (6) can be given by…”

“…Among recent works on the security for massive MIMO relaying systems [3]- [8], the authors in [3] and [4] considered cooperative relay systems and compared the security improvement for both amplify-and-forward (AF) and decodeand-forward (DF) relaying, while only the AF scheme (or the DF scheme) was considered in [5] and [6] (or in [7] and [8]). These works, however, did not consider any direct link between source and eavesdropper.…”

“…Note that in general, eavesdroppers may possibly receive two versions of transmitted messages from source and relay in cooperative relay networks. The lack of direct links in [3]- [8] leads to the fact that the way eavesdroppers benefit from the configuration of cooperative relay networks is not sufficiently interpreted. Meanwhile, the impact of a direct eavesdropping link on the secure performance was presented in [19], but there was no discussion on large antenna arrays.…”

Resource Allocation for Energy Efficiency in 5G Wireless Networks

“…To enhance the performance of communication systems, the combination of interference alignment [59], spectrum allocation and energy-efficient management should be necessarily considered and implemented simultaneously. This leads to the introduction of a hybrid resource management scheme for the emerging of 5G network architectures, i.e., cognitive relay networks [19,59], massive multiple-input multiple-output (MIMO), heterogeneous networks (HetNets), and cell-free. In this paper, we provide and analyse the novel of hybrid resource allocation approaches for improving EE performance in potential 5G network scenarios.…”

Robust beamforming and cooperative jamming for secure transmission in DF relay systems

“…Recently, the introduction of relay into physical layer security has attracted a lot of research interest as a promising solution to improve transmission security through cooperative diversity [4,5]. Similar to the traditional relay systems, amplify-and-forward (AF) [6] and decode-and-forward (DF) [7] are two commonly used schemes in secure relay systems.…”