Wireless Systems Research Articles

Hybrid selection combining scheme for correlated cooperative communication over [formula omitted]-[formula omitted] fading channels

Due to poor (limited) scattering, a correlation among channels is inevitable, resulting in performance degradation of wireless communication systems. In this paper, we propose a hybrid selection combining (SC), also known as switched scaled - SC for correlated cooperative communication over κ-μ fading channel. By using paired error analysis, we derive the end-to-end symbol error probability of this system over bivariate κ-μ channel fading with M-ary phase shift keying (MPSK) modulation. In addition, we obtain significant parameters of hybrid SS-SC, such as the optimum scaling factor and optimum threshold by using the second derivative test. For every signal to noise ratio (SNR), we obtain different optimum thresholds and scaling factors. Our analytical results were found to overlap significantly with those of the simulation results. They were also compared with the variants of SC and switched diversity techniques. Our study demonstrates that the proposed hybrid technique performs better than the other SC and switched diversity schemes over correlated and uncorrelated fading channels. Furthermore, we derive an asymptotic symbol error probability for the proposed system, and the asymptotic results are in agreement with the analytical results at higher SNRs. Our study also shows that the diversity order of the system depends on the mutually exclusive events of the proposed technique.

Memristor Equivalent Model of an Inductive Wireless Power Transfer System Based on the Sigmoid Function

Memristor Equivalent Model of an Inductive Wireless Power Transfer System Based on the Sigmoid Function

Predicted position-driven deep learning channel estimation for massive MIMO systems

Multiple-input multiple-output (MIMO) can significantly improve the energy efficiency and spectral efficiency of wireless communication systems, and obtaining accurate channel state information is a key prerequisite. However, traditional channel estimation techniques often have high computational complexity, poor channel estimation performance, and do not fully utilize the information in the communication scene. In this paper, a channel estimator (PrePD-CNN) with convolutional neural network (CNN) driven by predicted position information is proposed based on high-precision localization technology for 6G. The channel estimation performance is improved by rationally transforming the sensing information and accurately reconstructing the quasi-channel state as auxiliary information. Simulation results show that the BER performance and MSE performance of PrePD-CNN are significantly lower than that of traditional channel estimation algorithms. Therefore, the proposed scheme combines stronger robustness and good generalization, which not only reduces the complexity of the algorithm but also improves the performance.

Modeling and analysis of magnetic resonance wireless transmission coil

Wireless transmission technology is a new type of power transmission technology with electric and magnetic fields as the medium. It has more advantages in transmission direction, transmission characteristics, security, and penetration. The model of a magnetically coupled resonant radio energy transmission system is designed. The main parameters such as resonance frequency and mutual inductance are considered comprehensively. The model is designed using the equivalent topological circuit structure of mutual inductance coupling. The equivalent parameters in the circuit topology can be affected by setting the size of the coil, the distance between the coils, the excitation size, and the high frequency. The structure parameters of the whole system are modeled and calculated by the Ansoft Maxwell software. At the same time, the influence on the power and efficiency of wireless power transmission is explored by several factors such as the coil diameter, the distance between the transmitting end and the receiving end, and the resonance frequency of the system, so as to achieve the purpose of verifying the technical characteristics of wireless power transmission. The key factors that may affect the transmission efficiency and power of the system are analyzed in detail by deriving the calculation model of transmission efficiency and power.

Aider: Artificial Intelligent-Based Deep Receiver for Wireless Communication Systems

Aider: Artificial Intelligent-Based Deep Receiver for Wireless Communication Systems

Patterning Techniques Based on Metallized Electrospun Nanofibers for Advanced Stretchable Electronics.

Stretchable electronics have experienced remarkable progress, especially in sensors and wireless communication systems, attributed to their ability to conformably contact with rough or uneven surfaces. However, the development of complex, multifunctional, and high-precision stretchable electronics faces substantial challenges, including instability at rigid-soft interfaces and incompatibility with traditional high-precision patterning technologies. Metallized electrospun nanofibers emerge as a promising conductive filler, offering exceptional stretchability, electrical conductivity, transparency, and compatibility with existing patterning technologies. Here, this review focuses on the fundamental properties, preparation processes, patterning technologies, and application scenarios of conductive stretchable composites based on metallized nanofibers. Initially, it introduces the fabrication processes of metallized electrospun nanofibers and their advantages over alternative materials. It then highlights recent progress in patterning technologies, including collector collection, vapor deposition with masks, and lithography, emphasizing their role in enhancing precision and integration. Furthermore, the review shows the broad applicability and potential influence of metallized electrospun nanofibers in various fields through their use in sensors, wireless systems, semiconductor devices, and intelligent healthcare solutions. Ultimately, this review seeks to spark further innovation and address the prevailing challenges in stretchable electronics, paving the way for future breakthroughs in this dynamic field.

Unlocking Security Risks: Exploring Vulnerabilities in Software-Defined Radio with RTL-SDR

Abstract: This study illustrates potential avenues for exploitation by utilizing RTL-SDR dongles to reveal Software-Defined Radio's (SDR) vulnerabilities. Using replay attacks, the study reveals the weakness of car key unlocking techniques, concentrating on static codes. The study also shows how RTL-SDR, in conjunction with SDR++ software, may use to intercept communications, posing major privacy concerns and enabling one to listen in on walkie-talkietalks. These findings demonstrate how urgently security measures are required to reduce the risks associated with RTL-SDR exploitation in a variety of industries. As the field of technology advances, the study advances our knowledge of potential threats in wireless communication systems and it emphasizes the security implementations to safeguard against unauthorized access and misuse.

Self-Switching Wireless Power Transfer System Design with Constant Current/Constant Voltage Output Features Based on LCC-LCL/S Topology

To meet the demand for constant current and constant voltage charging of batteries and to increase the system output power, the LCC-LCL/S-type self-switching wireless power transfer system is proposed. The system does not require communication between the primary and secondary circuits, and its output mode is controlled by simply changing the status of two switches on the secondary side. Notably, the system satisfies the zero phase angle characteristic before and after mode switching. The parameter design method is proposed based on the circuit topology and the maximum safe current constraint. To make the output voltage fluctuation as small as possible, the optimum load switching point for the system has been designed, and its optimality has been validated by simulation. Furthermore, the switching control strategy is proposed, considering the effects of the system no-load and load short-circuit in real situations. Finally, an experimental platform was built to achieve the high efficiency output of the system with the maximum output voltage of 46.21 V, the maximum output power of 180 W, and the maximum efficiency of 93.4%, which verified the applicability of the proposed method.

An Ultra-Selective OLR – based Microstrip Diplexer with Minimal Insertion Loss for Wireless Communication System

An Ultra-Selective OLR – based Microstrip Diplexer with Minimal Insertion Loss for Wireless Communication System

Wireless Patient Monitoring System with LoRa Communication for Remote Healthcare

This study presents a novel approach to remote healthcare through a wireless patient monitoring system using LoRa communication. The system consists of two main parts: a transmitter and receiver. The transmitter collects vital health data, such as body temperature, SpO2, accelerometer and gyroscope measurements, electrocardiogram (ECG) signals, air quality and heart rate. This information will be transmitted wirelessly using LoRa technology to the receiver section, which will transmit the data to the IoT cloud server. In addition, the receiver section is equipped with a GSM module to send an SMS alert in the event of abnormal health parameters. The aim of this system is to provide real-time monitoring of patients in remote areas, enabling timely interventions and improving accessibility to healthcare. The efficiency and reliability of the system make it a promising solution for remote patient monitoring in challenging environments.

Wireless Power Transfer System in Electric Vehicle Application

Abstract: As an alternate form in the road transportation system, electric vehicle (EV) can help reduce the fossil-fuel consumption. However, the usage of EVs is constrained by the limited capacity of battery. Wireless Power Transfer (WPT) can increase the driving range of EVs by charging EVs in motion when they drive through a wireless charging lane embedded in a road. The amount of power that can be supplied by a charging lane at a time is limited. A problem here is when a large number of EVs pass a charging lane, how to efficiently distribute the power among different penetrations levels of EVs? However, there has been no previous research devoted to tackling this challenge. To handle this challenge, we propose a system to balance the State of Charge (called BSoC) among the EVs. It consists of three components: i) fog-based power distribution architecture, ii) power scheduling model, and iii) efficient vehicle-to-fog communication protocol. The fog computing center collects information from EVs and schedules the power distribution. We use fog closer to vehicles rather than cloud in order to reduce the communication latency. The power scheduling model schedules the power allocated to each EV. In order to avoid network congestion between EVs and the fog, we let vehicles choose their own communication channel to communicate with local controllers.

Wireless Charging of Electric Vehicle on Highways in Running Mode by Solar Energy

Abstract: The adoption of electric vehicles (EVs) is on the rise globally, driven by the need for sustainable transportation solutions to mitigate climate change and reduce dependence on fossil fuels. However, the infrastructure for charging EVs remains a significant challenge, hindering widespread adoption. In response, innovative approaches such as wireless charging technology, coupled with solar energy, have emerged to address these challenges. This paper presents an overview of wireless charging systems for electric vehicles, integrated with solar energy, aiming to provide a sustainable and convenient solution for EV owners. The integration of wireless charging and solar energy offers numerous benefits, including convenience, efficiency, and environmental sustainability. By eliminating the need for physical connections and harnessing the power of the sun, electric vehicles can be charged seamlessly and sustainably, reducing reliance on the grid and lowering carbon emissions. This paper discusses the principles behind wireless charging technology, the design considerations for integrating solar energy, and the potential impact on the future of sustainable transportation. Additionally, it addresses the challenges and opportunities associated with this innovative approach, highlighting the need for further research and development to realize its full potential. Overall, the convergence of wireless charging technology with solar energy represents a promising solution to the challenges facing the widespread adoption of electric vehicles, contributing to a cleaner and greener transportation ecosystem.

Iot Based Electric Meter Tampering Detector

Abstract: IoT based smart and multifunctional energy meter reading of automatic meter using ATmegha kit. It has the ability to connect to the public database maintained by the energy supplier through computing and energy meter tamper detection. It can prevent theft detection for unregistered users and save losses as a result. A unique feature of this meter is its Internet of Things based functionality. Metmegha. In this case, the system will use the wireless system communication protocol. Wireless is used because the application requires high data rate, low power consumption and low cost. This article shows the ATmegha remote meter reading system. This is to solve the shortcomings of traditional ATmega Meter Reading technology by combining the features of wireless technology with Microcontroller ATMega16. The hardware design was implemented and then the usage of the ATmegha meter was analyzed. There are many opportunities for errors, processing delays, meter confusion, and misuse of electricity and other resources. More than one worker is needed; One group of workers must record the readings, and others must reduce electricity if payment is not made on time.

Smart Water Quality Monitoring with IoT Wireless Sensor Networks.

Traditional laboratory-based water quality monitoring and testing approaches are soon to be outdated, mainly because of the need for real-time feedback and immediate responses to emergencies. The more recent wireless sensor network (WSN)-based techniques are evolving to alleviate the problems of monitoring, coverage, and energy management, among others. The inclusion of the Internet of Things (IoT) in WSN techniques can further lead to their improvement in delivering, in real time, effective and efficient water-monitoring systems, reaping from the benefits of IoT wireless systems. However, they still suffer from the inability to deliver accurate real-time data, a lack of reconfigurability, the need to be deployed in ad hoc harsh environments, and their limited acceptability within industry. Electronic sensors are required for them to be effectively incorporated into the IoT WSN water-quality-monitoring system. Very few electronic sensors exist for parameter measurement. This necessitates the incorporation of artificial intelligence (AI) sensory techniques for smart water-quality-monitoring systems for indicators without actual electronic sensors by relating with available sensor data. This approach is in its infancy and is still not yet accepted nor standardized by the industry. This work presents a smart water-quality-monitoring framework featuring an intelligent IoT WSN monitoring system. The system uses AI sensors for indicators without electronic sensors, as the design of electronic sensors is lagging behind monitoring systems. In particular, machine learning algorithms are used to predict E. coli concentrations in water. Six different machine learning models (ridge regression, random forest regressor, stochastic gradient boosting, support vector machine, k-nearest neighbors, and AdaBoost regressor) are used on a sourced dataset. From the results, the best-performing model on average during testing was the AdaBoost regressor (a MAE¯ of 14.37 counts/100 mL), and the worst-performing model was stochastic gradient boosting (a MAE¯ of 42.27 counts/100 mL). The development and application of such a system is not trivial. The best-performing water parameter set (Set A) contained pH, conductivity, chloride, turbidity, nitrates, and chlorophyll.

Wireless Communication: Applications Security and Reliability—Present and Future

Information security is of great importance nowadays. This is related to the widespread use of new technologies in the development of long-distance communications and the use of increasingly “faster” signals. Information security can be considered in many areas of information processing, including wireless systems and wired systems that are based on electronic devices. Each of such devices is a source of electromagnetic disturbances but may also be sensitive to such disturbances. This Special Issue titled “Wireless Communication: Applications, Security, and Reliability” covers a broad spectrum of information security related to cybersecurity, cryptography, and electromagnetic protection. In each case, the information protection solutions used must keep up with the development of technologies used in information processing. The broad thematic area of this Special Issue was intended to encourage scientists and researchers to present their research results and the goals that this research was intended to serve. At the same time, it could allow for the exchange of knowledge and experience gained during the work on information security.

Optimized wireless communication for 6G signal processing using memory‐augmented deep unfolding network

SummaryIn this manuscript, optimized wireless communication for 6G signals processing using memory‐augmented deep unfolding network (WC‐6G‐SP‐MADUN) is proposed. The aim of this work is to give a memory‐augmented deep unfolding network approach with a focus on belief propagation decoding of error correction codes and multiple‐input multiple‐output (MIMO) wireless systems. In contrast, compares and tabulates the performance of memory‐augmented deep unfolding methodologies with classic principled procedures, which could potentially enable 6G. Here, the wireless communication for 6G signal processing methods was used for a variety of receiver functions, including self‐interference cancelation, signal estimation and detection using memory‐augmented deep unfolding Network (MADUN), and advanced error correction by clouded leopard optimization algorithm (CLOA). Furthermore, outline the general framework of memory‐augmented deep unfolding method for any kind of signal processing application and talk about cutting edge research paths that will make it possible to build communication networks in the future. The proposed approach is implemented in MATLAB; the performance is analyzed with performance metrics such as reliability, complexity, SNR gain, convergence rate, hardware efficiency, and quantization bit width. The proposed approach attains higher SNR gain 17.96%, 24.75%, and 30.09%; lower complexity 17.92%, 23.41%, and 30.13%; and higher convergence 18.01%, 25.41%, and 31.39% when analyzed with existing techniques such as redefined wireless communication for 6G: signal processing meets deep learning and deep unfolding (RWC‐6G‐SP‐DU), lower complication deep unfolded neural network receiver for MIMO under probability data association detector (LC‐DUNN‐MIMO‐PDAD), and deep learning in physical layer communications: evolution with prospects on 5G and 6G networks (DL‐PLC‐6G), respectively.

Hybrid electromagnetic Halbach array for wireless power transfer (WPT) system using variable and uniform pitch coils

AbstractThe electromagnetic Halbach array (EHA) for wireless power transfer (WPT), designed to improve the transferred power and power transfer distance, has been proven to be effective and can be applied in various consumer applications. This paper presents a hybrid form of the EHA, aimed at improving the quality of power generated and transmitted. The expression for the determination of the magnetic field of a variable pitch flat coil for wireless power transfer and other uses has been derived. The average magnetic field, magnetic flux, and power transfer efficiency are investigated. The power transfer efficiency and the average magnetic field generated by four different design considerations were compared. The hybrid electromagnetic Halbach array wireless power transfer system (HEHA‐WPTS) has also been studied and results are compared with the conventional arrangements. Simulations and experiments were carried out to verify the analytical results obtained. According to the results obtained, the HEHA‐WPTS, with a base coil with variable pitches and uniform side coils, produces a more uniform average magnetic field and a better average power transfer efficiency over a longer power transfer distance.

3D-Printed Conformal Meta-Lens with Multiple Beam-Shaping Functionalities for Mm-Wave Sensing Applications.

In this paper, a 3D conformal meta-lens designed for manipulating electromagnetic beams via height-to-phase control is proposed. The structure consists of a 40 × 20 array of tunable unit cells fabricated using 3D printing, enabling full 360° phase compensation. A novel automatic synthesizing method (ASM) with an integrated optimization process based on genetic algorithm (GA) is adopted here to create the meta-lens. Simulation using CST Microwave Studio and MATLAB reveals the antenna's beam deflection capability by adjusting phase compensations for each unit cell. Various beam scanning techniques are demonstrated, including single-beam, dual-beam generation, and orbital angular momentum (OAM) beam deflection at different angles of 0°, 10°, 15°, 25°, 30°, and 45°. A 3D-printed prototype of the dual-beam feature has been fabricated and measured for validation purposes, with good agreement between both simulation and measurement results, with small discrepancies due to 3D printing's low resolution and fabrication errors. This meta-lens shows promise for low-cost, high-gain beam deflection in mm-wave wireless communication systems, especially for sensing applications, with potential for wider 2D beam scanning and independent beam deflection enhancements.

Design and fabrication of optically transparent transmitarrays using inkjet-printing technology

Abstract This paper explores the use of inkjet-printing technology for transparent transmitarrays, presenting a viable alternative to traditional copper microwire counterparts. The study focuses on achieving high-gain performance crucial for wireless communication systems, with a particular emphasis on the fifth-generation (5G) millimeter-wave communication. Transparent transmitarrays leverage transparent conducting films and conductive mesh structures, overcoming opacity limitations and seamlessly integrating with urban architecture. In this paper, the inkjet-printing process is detailed for fabricating transmitarray apertures, highlighting the flexibility and precision in depositing nanosilver particles onto a glass substrate. The design intricacies involve optimizing feeding characteristics, determining unit cell structures, and constructing transmitarrays of various sizes. To validate the proposed technique, three different apertures (15 × 15, 20 × 20, and 25 × 25 unit cells) are constructed. The antenna performances are evaluated in terms of reflection coefficients, radiation efficiency, realized gain, and patterns, demonstrating the effectiveness of inkjet-printed transmitarrays. Comparative analysis with copper microwire counterparts is also conducted, validating the inkjet-printing technology for similar gain performance with added advantages of flexibility, compatibility with transparent substrates, and cost-effective manufacturing.

SMART WIRELESS BATTERY CHARGER WITH CHARGING MONITER

Smart wearables for health monitoring are new technologies that enable customers to monitor and track their health. However, as the number of sensors in a wearable device grows, along with continuous monitoring and wireless communications, battery lifetime and charge length become a big concern. This issue is especially relevant for health monitoring of workers in hazardous environments such as emergency response responders, mining, and construction. In this research, we describe a wireless charging system for a health monitoring smart-wear application for workers, taking into account the power consumption needs of sensory hardware, communication technology, and realistic charging scenarios. We also show a functional prototype of a 5-watt wireless charging device utilized in our health monitoring wearable. Our paper describes the design, analysis of the needs, and important components of a 'wireless charging bin' that we are currently prototyping for our application.