Hirley Alves

Performance of Transmit Antenna Selection Physical Layer Security Schemes

We analyze the physical layer (PHY) security of a communication scheme consisting of a multiple antenna transmitter with a single radio frequency (RF) chain using transmit antenna selection (TAS) and a single antenna receiver, in the presence of a sophisticated multiple antenna eavesdropper. We develop closed-form expressions for the analysis of the secrecy outage probability, and we show that the PHY security can be considerably enhanced when multiple antennas are available at the legitimate transmitter. Moreover, a single RF chain multiple antenna transmitter reduces cost, complexity, size and power consumption at the expense of a slight loss in performance with respect to a multiple RF chain transmitter.

Performance of Block-Markov Full Duplex Relaying with Self Interference in Nakagami-m Fading

This paper investigates the performance of a Full-Duplex Block Markov (FD-BM) relaying scheme with self interference at the relay under independent non-identically distributed Nakagami-m fading. Relying on efficient approximations proposed elsewhere in the literature for the sum of Gamma random variables (RVs), and based on a new, accurate approximation for the product of two Nakagami-m RVs, tight closed-form approximate expressions for the outage probability and throughput are derived. Representative numerical results show the accuracy of the proposed approximations.

Performance analysis of full duplex and selective and incremental half duplex relaying schemes

In this work we compare full-duplex (FD) and half-duplex (HD) relaying in terms of outage probability and throughput. We consider a practical FD relay model where the loop interference between transmitted and received signals is taken into account. We analyze two modes for FD transmission, block Markov encoding and multi-hop transmission without interference cancellation, and two different modes for HD transmission, which are based on selective and incremental decode-and-forward protocols. Results show that there is a tradeoff between SNR and information rate in which each scheme becomes more suitable.

Exploiting the Direct Link in Full-Duplex Amplify-and-Forward Relaying Networks

This letter investigates the outage probability of a variable-gain amplify-and-forward full-duplex relaying network in which not only the relaying link but also the direct link is used to convey information, thus improving the system reliability. We consider a basic three-node relaying system composed of a source, a destination, and a two-antenna relay-one antenna for transmission, one antenna for reception. Also, we consider that the full-duplex relay undergoes some residual self interference, modeled as a fading channel, and that maximal-ratio combining is employed at the destination to merge the signals from the source and relay. We derive an exact integral-form expression for the outage probability and validate this via Monte Carlo simulation. In addition, we propose a highly-accurate closed-form approximation to the outage probability, as well as a simple asymptotic expression at high signal-to-noise ratio. The use of the direct link is shown to overcome the zero diversity order inherent to full-duplex relaying.

On the Performance of Secure Full-Duplex Relaying under Composite Fading Channels

We assume a full-duplex (FD) cooperative network subject to hostile attacks and undergoing composite fading channels. We focus on two scenarios: a) the transmitter has full CSI, for which we derive closed-form expressions for the average secrecy rate; and b) the transmitter only knows the CSI of the legitimate nodes, for which we obtain closed-form expressions for the secrecy outage probability. We show that secure FD relaying is feasible, even under strong self-interference and in the presence of sophisticated multiple antenna eavesdropper.

Outage, throughput and energy efficiency analysis of some half and full duplex cooperative relaying schemes

In this paper, we compare cooperative full-duplex FD and incremental cooperative half-duplex HD relaying, in terms of outage probability, throughput and energy efficiency. We consider a practical model for the FD relay, where self-interference between transmitted and received signals is taken into account. The FD transmission is based on the well-known block Markov encoding scheme. For the HD transmission, incremental space-time cooperation and selection combining based on the cooperative decode-and-forward protocol are considered. Our results show that incremental cooperative HD relaying can outperform cooperative FD relaying, specially if the self-interference is non-negligible, achieving a better trade-off between throughput and energy consumption. Copyright

On the performance of two-way half-duplex and one-way full-duplex relaying

In this paper, assuming a bidirectional network, the performance of two-way half-duplex (HD) relaying systems based on physical-layer network coding is compared with one-way full-duplex (FD) relaying schemes. Specifically, the outage probability and system throughput of the considered schemes are investigated. Our results show that unidirectional FD relaying can outperform bidirectional HD relaying, even in the presence of self-interference at the FD relay.

Brief survey on full-duplex relaying and its applications on 5G

This paper gives an brief survey on full-duplex relaying. First, we discuss the importance of full-duplex communications and its major drawback, known as self-interference. We provide a overview of the state-of-the-art on self-interference cancellation techniques from antenna design to digital cancellation. Then, we assess current developments in full-duplex relaying, some promising protocols and we discuss some of the performance analysis carried out so far. Finally, we discuss the importance of full-duplex, more specifically full-duplex relaying, on 5G networks.

On the performance of full-duplex relaying under phy security constraints

In this paper we investigate the performance of a cooperative network in the presence of an eavesdropper (Eve). Alice and Bob communicate with the help of a relay, which can operate either in half-duplex (HD) or full-duplex (FD) mode. We account for the self interference at the relay when operating under FD mode. Our analysis focus in the case that the CSI of Eve is not available at Alice. Thus, we derive closed-form expressions for secrecy outage probability. Our results allow us to compare the performance of FD and HD cooperative scenarios under secrecy constraints and, despite the additional interference at the relay, show the advantages of FD relaying over HD. In addition, we also show that a cooperative network is more vulnerable if Eve is closer to Alice than to the relay.

An Adaptive Transmission Scheme for Cognitive Decode-and-Forward Relaying Networks: Half Duplex, Full Duplex, or No Cooperation

We propose an adaptive transmission scheme for cognitive decode-and-forward relaying networks, whereby, before each communication process, one out of three transmission modes is dynamically selected in order to maximize the instantaneous capacity of the system, namely, half-duplex (HD) relaying, full-duplex (FD) relaying, or direct transmission with no cooperation. The following key issues, relevant to underlay spectrum sharing and cooperative relaying, are considered: 1) the overall transmit power at the secondary network is constrained by both the maximum tolerable interference at the primary receiver and the maximum transmit power available at the secondary nodes; 2) under FD operation, the secondary relay is subject to residual self-interference, which is modeled as a fading channel; and 3) the signals coming from the secondary source and relay are handled at the secondary destination via maximal-ratio combining, in the HD relaying mode, and via a joint-decoding technique, in the FD relaying mode. We derive an exact analytical expression for the outage probability of the proposed scheme. Then, an approximate closed-form expression is proposed, and a corresponding asymptotic expression is derived. Monte Carlo simulations are run to validate the accuracy of the presented mathematical analysis and to showcase the tightness of the proposed approximation.