Non-Orthogonal Multiple Access and Artificial-Noise Aided Secure Transmission in FD Relay Networks

In this paper, we investigate an artificial-noise (AN) aided secure transmission for non-orthogonal multiple access (NOMA) full-duplex (FD) relay network. We propose a novel joint NOMA and AN-aided full-duplex relay (NOMA-ANFDR) scheme to enhance the physical security. In this scheme, the optimal power allocation between the information and the AN signal is determined such that the capacity of the two end-to-end (i.e., two source-relay-destination pairs) channel are maximized to ensure the highest quality of cooperative transmission. To fully examine the benefits of the NOMA-ANFDR scheme, we derive a new closed-form expression for the secrecy outage probability. We show that the NOMA-ANFDR scheme significantly outperforms the joint NOMA and AN in half-duplex relay (NOMA-ANHDR) scheme as well as the NOMA-HDR scheme in terms of minimum secrecy outage probability and effect secrecy throughout. This result indicates that adopting the joint of FD and AN technique at relays can effectively enhance the physical layer secrecy performance in the NOMA cooperative network.ARC Discovery Projects Grant DP150103905

Physical layer security enhancement in multi-user multi-full-duplex-relay networks

We propose a novel joint user and full-duplex (FD) relay selection (JUFDRS) scheme to enhance physical layer security in a multi-user multi-relay network. In this scheme, the user and the FD decode-and-forward relay are selected such that the capacity of the end-to-end channel (i.e., the user-relaydestination channel) is maximized to ensure the highest quality of cooperative transmission. In order to fully examine the benefits of the JUFDRS scheme, we derive a new closed-form expression for the secrecy outage probability. We show that the JUFDRS scheme significantly outperforms the joint user and half-duplex relay selection (JUHDRS) scheme when the self-interference at the FD relay can be reasonably suppressed. This result indicates that adopting the FD technique at relays can effectively enhance the physical layer secrecy performance in the multi-user multirelay network.ARC Discovery Projects Grant DP150103905

TAS-Based Incremental Hybrid Decode–Amplify–Forward Relaying for Physical Layer Security Enhancement

In this paper, a transmit antenna selection (TAS)- based incremental hybrid decode-amplify-forward (IHDAF) scheme is proposed to enhance physical layer security in cooperative relay networks. Specifically, TAS is adopted at the source in order to reduce the feedback overhead. In the proposed TAS-based IHDAF scheme, the network transmits signals to the destination adaptive select direction transmission mode, AF mode or DF mode depending on the capacity of the source-relay link and source-relay link. In order to fully examine the benefits of the proposed TAS-based IHDAF scheme, we first derive its secrecy outage probability (SOP) in a closed-form expression. We then conduct asymptotic analysis on the SOP, which reveals the secrecy performance floor of the proposed TAS-based IHDAF scheme when no channel state information is available at the source. Theoretical analysis and simulation results demonstrate that the proposed TAS-based IHDAF scheme outperforms the selective decode-and-forward (SDF), the incremental decodeand-forward (IDF), and the noncooperative direction transmission (DT) schemes in terms of the SOP and effective secrecy throughout, especially when the relay is close to the destination. Furthermore, the proposed TAS-based IHDAF scheme offer a good trade-off between complexity and performance compare with using all antennas at the source.ARC Discovery Projects Grant DP150103905

Aggregation-induced emission fluorogens as biomarkers to assess the viability of microalgae in aquatic ecosystems

Open Access Article. This article is licensed under a Creative Commons Attribution 3.0 Unported Licence.Microalgae can be a valuable indicator for monitoring water pollution due to their sensitivity to the changes induced by pollutants in the environment. In this study, an aggregation-induced emission fluorogen was used as a novel tool to differentiate dead and live microalgae and quantify the link between live algal concentration and fluorogen intensity. Protein in the cell protoplasm is the key component contributing to fluorescence emission in algae

Vortex-Induced Vibration of a Marine Riser: Numerical Simulation and Mechanism Understanding

Marine riser is a key equipment connecting a floating platform and a seabed wellhead. Vortex-induced vibration (VIV) is the main cause of the fatigue damage of the riser. The prediction of marine riser VIV is very difficult because of its strong non-linearity, instability and uncertainty. In recent years, many numerical models of VIV of marine riser have been developed to explore the mechanism of marine riser VIV, providing scientific theoretical basis and practical engineering methods for vibration control and engineering design of marine riser. Combined with the authors’ own recent research, this chapter discusses the research progress on marine riser VIV in the ocean engineering, including phenomenon mechanism analysis and different numerical research methods

Aggregation-Induced Emission (AIE), Life and Health

Light has profoundly impacted modern medicine and healthcare, with numerous luminescent agents and imaging techniques currently being used to assess health and treat diseases. As an emerging concept in luminescence, aggregation-induced emission (AIE) has shown great potential in biological applications due to its advantages in terms of brightness, biocompatibility, photostability, and positive correlation with concentration. This review provides a comprehensive summary of AIE luminogens applied in imaging of biological structure and dynamic physiological processes, disease diagnosis and treatment, and detection and monitoring of specific analytes, followed by representative works. Discussions on critical issues and perspectives on future directions are also included. This review aims to stimulate the interest of researchers from different fields, including chemistry, biology, materials science, medicine, etc., thus promoting the development of AIE in the fields of life and health

A leakage‐based hybrid beamforming design for multi‐user mmWave massive MIMO systems

Abstract In massive multiple‐input multiple‐output systems, hybrid beamforming (HBF) is an attractive technique due to its excellent tradeoff between system performance and hardware implementation cost. In this paper, the signal‐to‐leakage‐plus‐noise ratio is considered as the optimization criterion and investigate the HBF design for multi‐user millimetre‐wave massive multiple‐input multiple‐output systems. To overcome the difficulty of solving the multi‐variable design problem, a novel two‐stage HBF scheme to optimize the analogue and digital beamformers are proposed. In particular, an orthogonal matching pursuit‐based method and a joint design method are introduced respectively to find the solution in the analogue stage. Then, in the digital stage, the digital precoder and combiner are designed to suppress the inter‐user interference plus noise, aiming at maximizing the sum‐signal‐to‐leakage‐plus‐noise ratio of multi‐user systems. Simulation results show that the proposed HBF scheme with lower complexity can achieve superior performance over the existing HBF schemes. Moreover, it is also indicated that the performance of the HBF scheme remains strong even with the imperfect channel state information