Viet-Thanh Le

This paper investigates physical layer security (PLS) in a half duplex (HD) relay network with radio frequency energy harvesting (EH). We consider an amplify and forward (AF) protocol in which both the source and the relay harvest energy from a dedicated power beacon, while a passive eavesdropper attempts to intercept the confidential message. Unlike prior studies that rely on asymptotic analysis or numerical integration, we derive exact closed form expressions for the outage probability (OP) and the intercept probability (IP). The proposed expressions characterize the reliability and secrecy trade-off in energy limited cooperative relaying and enable efficient performance evaluation. Monte Carlo simulations validate the analysis and match the theoretical results. Moreover, the closed form results reveal how channel conditions and harvesting duration jointly shape outage and interception behaviors. We further quantify the impacts of normalized transmit power, the time allocation factor between harvesting and information transmission, and the EH efficiency. The results provide practical guidance for selecting system parameters to meet target reliability and secrecy levels, and they show that the time allocation factor must be carefully chosen to balance harvested energy and transmission time.

In this paper, a novel framework to enhance the reliability of wireless sensor networks (WSNs) by addressing the high probability of outage (OP) resulting from limited energy resources and unreliable channels. The framework integrates three techniques: half-duplex two-way relaying (HD-TWR), digital network coding (DNC), and rateless codes. Although these techniques have been extensively studied in isolation, a comprehensive analysis of their joint performance is provided as the main contribution. The proposed scheme leverages the energy efficiency of HD-TWR, the transmission reduction capability of DNC, and the retransmission-free resilience of rateless codes. Simulation results show that the integrated framework significantly reduces OP, offering a robust and practical solution to enhance the reliability enhancement. Furthermore, the impact of optimal relay node placement is investigated through parameter adjustments in the simulation stage to maximize performance gains.

In the era of 6G, addressing the issues of constrained-resource and non-chargeable devices in Internet of things (IoT)-enabled wireless sensor networks (WSN) is an urgent need due to the exponential increase in data traffic generated by numerous applications and services. This paper proposes a distance, energy, and density-aware self-organizing map (SOM) clustering-based routing (DEDSCR) scheme to improve the performance of low-power IoT-enabled WSN. The DEDSCR scheme utilizes the total sum of squared distance-based elbow (SDE) method, SOM, fuzzy logic, and ant colony optimization (ACO) to identify the number of clusters, organize the sensor nodes into the clusters, select the cluster heads (CH), and determine the optimal path from the CHs to the base station (BS). In this scheme, the fuzzy model plays an important role in selecting the proper CHs and generating the best heuristic values for clustering and routing based on the inputs from the distance towards the BS and the remaining energy and density of sensor nodes. Simulation results are presented to demonstrate the advantages of the proposed DEDSCR scheme in terms of lifespan and energy consumption compared to other methods. The impacts of SDE, SOM, fuzzy, and ACO on the performance metrics are also discussed and analyzed to provide valuable insights into the design of clustering and routing for low-power IoT-enabled WSN.

Intelligent Reflective Surfaces (IRSs) are recognized as fundamental technology in the context of the forthcoming sixth-generation (6G) communication systems. Non-Orthogonal Multiple Access (NOMA) can augment fifth-generation (5G) wireless networks’ spectral efficiency. This manuscript investigates a NOMA-based downlink configuration that integrates IRS and functions in a physical layer security (PLS) scenario, accounting for self-interference (SI) inherent to full-duplex (FD) operation. The examination also considers the utilization of Fountain Codes (FCs) when faced with a potential eavesdropper exhibiting malicious intentions. This paper is evident in the development of accurate mathematical expressions for the outage probability (OP), throughput, energy efficiency (EE), and intercept probability (IP). Moreover, a Deep Neural Network (DNN) model is formulated to assess OP and IP. Subsequent Monte Carlo simulations were conducted to validate the theoretical results. More research is done on the relationship between base station (BS)-IRS-Users when the Nakagami-m fading scenario is present. The outcomes of the simulations offer the following insights: i) Their primary aim is to corroborate the analytical expressions. ii) This investigation substantially enhances our understanding of IRS-NOMA systems, setting a foundation for prospective explorations into practical realizations. The OP’s optimal performance is given. Furthermore, we have expanded our research by examining the performance of two more scenarios: one IRS without a relay and a two-IRS setup without a relay. iii) Furthermore, the results demonstrate the superior performance of IRS-NOMA compared to the traditional IRS-Orthogonal Multiple Access (OMA) approach.

Wireless sensor networks (WSNs) have been one of the fields that have attracted a lot of attentions from many scientific researchers in recent years. The sensor nodes of the network are fixed or moved to detect the environment and impart the data accumulated from the remote monitored regions via wireless connections. It is indicated in complex environments such as forests, deep seas, urban areas, etc., the sensor nodes in WSNs are usually tiny and battery-driven devices. Thus, energy-effective data accumulation methods required to improve the network’s lifetime are very necessary. In this paper, we propose a joint technique of fuzzy clustering and heuristic ant routing (FCHAR) to save the energy for low-power WSNs. Simulation results are shown to demonstrate the benefits of the proposed FCHAR compared to other conventional ones.