Wireless Techniques Research Articles

Wireless Power Transfer Module Design using Discontinuous Direct Electromagnetic Field

In this paper, a new way of wireless power transmission has been described. By using this method, very simple and low cost general purpose wireless power transfer module is possible to design. All the components which will be required in this design are available in any locality. General Terms This method of wireless power transfer module is very simple. This particular way of transferring power wirelessly, has been found by applying many different technics with available local components in some practical experiments. This paper describes mostly on wireless power transmission technique. So, anyone will be able to design their own wireless power transfer module with their available components using this method. That means, there are no bindings about choosing components to design a wireless power transfer module while using this method. Anyone can choose any components which are available from their position.

Wireless technique uses nanoparticles to stimulate brain

Wireless technique uses nanoparticles to stimulate brain

A prototype of wireless power and data acquisition system for large detectors

We have developed a prototype detector and data acquisition module that incorporates wireless power and wireless data transmission techniques. The module has no electrical connections. It receives power using photovoltaic devices, and communicates control, timing, trigger, and data using the 802.11n wireless communication standard. The work is part of a study for building a large detector having many readout channels, where it is desirable to reduce the cable plant and infrastructure. The system could also be deployed in smaller detectors that require mobility or are difficult to cable due to extreme conditions. We describe the design and operation of the prototype module, including benchmark performance measurements, and discuss aspect and issues in extrapolating to a large detector system.

A Mathematical Model for Wideband Ranging

Wideband ranging is essential for numerous emerging applications that rely on accurate location awareness. The quality of range information, which depends on network intrinsic properties and signal processing techniques, affects the localization accuracy. A popular class of ranging techniques is based on energy detection owing to its low-complexity implementation. This paper establishes a tractable model for the range information as a function of wireless environment, signal features, and energy detection techniques. Such a model serves as a cornerstone for the design and analysis of wideband ranging systems. Based on the proposed model, we develop practical soft-decision and hard-decision algorithms. A case study for ranging and localization systems operating in a wireless environment is presented. Sample-level simulations validate our theoretical results.

Optimization of Generalized Predictive Control (GPC) Tuning Parameters By Response Surface Methodology (RSM)

Response Surface Methodology(RSM) was successfully applied to a process simulator for optimization of Generalized Predictive Control(GPC) tuning parameters. Wireless experimental input/output data obtained from process simulator. GPC algorithm which is written in MATLAB is utilized to wireless temperature control experiments achieved by using MATLAB/Simulink program.The efficiency of the GPC is observed by calculating the integral of the square of the error (ISE) and the integral of the absolute value of the error (IAE) from experimental results which was optimized by the application of RSM. The three independent variables, which had been found the most effective variables on the GPC by screening experiments, were determined as NU, N2 and λ as minimum prediction horizon, maximum prediction horizon and control weighting, respectively. The quadratic models were developed through RSM in terms of related independent variables to describe the ISE and IAE as the two response. Based on statistic analysis, optimum GPC tuning parameters of NU (X1), N2 (X2) and λ (X3) for minimize the ISE were determined to be 1.7922, 1.9453 and 0.0642 and for minimize the IAE were determined to be 1.8880, 1.9752 and 0.0612, respectively. Calculated optimum points of GPC tuning parameters are close to based on ISE and IAE results. The data evaluated from the quadratic model were good agreement with those measured experimentally. The wireless temperature control is successfully applied to the process simulator and wireless control technique is proposed for various application areas.

Clinical applications of correlational vestibular autorotation test

Conclusion: The correlational vestibular autorotation test (VAT) system has the advantages of good test–retest reliability and calibrations of absolute degrees of eye movement are unnecessary when acquiring a cross correlation coefficient (CCC). The approach is able to efficiently detect peripheral vestibulopathies. Objective: A VAT has some drawbacks including poor test–retest reliability and slippage of sensor. This study aimed to develop a correlational VAT system and to evaluate the reliability and applicability of this system. Methods: Twenty healthy participants and 10 vertiginous patients were enrolled. Vertical and horizontal autorotations from 0 to 3 Hz with either closed or open eyes were performed. A small sensor and a wireless transmission technique were used to acquire the electro-ocular graph and head velocity signals. The two signals were analyzed using CCCs to assess the functioning of the vestibular ocular reflex (VOR). Results: The results showed a significantly greater CCC for open-eye versus closed-eye of head autorotations. The CCCs also increased significantly with head rotational frequencies. Moreover, the CCCs significantly correlated with the VOR gains at autorotation frequencies ≥1.0 Hz. The test–retest reliability was good (intraclass correlation coefficients ≥0.85). The vertiginous participants had significantly lower individual CCCs and overall average CCC than age- and-gender matched controls.

Performance improvement of rectifiers for WPT exploiting thermal energy harvesting

This paper proposes a combined harvesting system to improve the efficiency and flexibility of autonomous wireless network nodes, supplied by means of wireless power transfer technique. In particular, a mixed system for electromagnetic (EM) and thermal energy harvesting (EH), conceived for passive nodes of wireless sensor networks and radio frequency (RF) identification tags, is described. The proposed system aims at increasing the effectiveness and the efficiency of the EH system by integrating an antenna and a rectifier with a thermo-electric generator (TEG) able to perform thermal EH. The energy provided by the thermal harvester is exploited twice: to increase the rectifier efficiency by providing a voltage usable to improve the bias condition of the rectifying diode, and to provide additional dc energy, harvested for free. Ultimately, a great efficiency improvement, especially at low incident RF power, has been observed. The design methodology and the EM performance of a quarter-wavelength patch antenna, integrated with the TEG are resumed. Then, a test campaign to evaluate the thermal EH performance has been carried out. Afterward, a rectifier with variable bias voltage, operating at the same frequency of the antenna, has been opportunely designed to exploit the harvested thermal energy to bias the diode. A measurement campaign has been then carried out to test the efficiency increment obtained and to validate the proposed solution.

A Survey of Recent Trends in Wireless Communication Standards, Routing Protocols, and Energy Harvesting Techniques in E-Health Applications

One of the most rapidly growing technology areas is the advances in sensing, networking, and miniaturization in medical domain, which enables innovative new applications. This is especially apparent in e-Health and telemedicine. There is an enormous demand for innovation in wireless sensor networking, body area networks, network security and routing, and many other areas, attracting the attention of numerous researchers. With all the advances it can be challenging to identify trends and areas with opportunities for research engagement. In this paper, the authors therefore review the state-of-the-art in wireless communication used in telemedicine and e-Health applications – ranging from the Wide Area Networks to Body Area Networks – and discuss the studies and literature that employ these technologies for e-Health applications. Moreover, recent routing protocols and techniques that are used for Body Area Networks are investigated. One key challenge for e-Health applications, particularly for mobile or patient-worn devices, is energy consumption and supply. One possible solution is found in energy harvesting, and our survey encompasses current challenges and accomplishments in its application to e-Health and discuss various promising techniques.

Single-Phase Zero Reactive Power Wireless Power Transfer Topologies Based on Boucherot Bridge Circuit Concept

High reliability and cost effectiveness of power electronic components have resulted in high level of interest in wireless power transfer techniques among academic and industrial professionals. Since the major interest is directed toward automotive and rail industries for electromagnetically coupled fast battery charging systems, a special transformer with a large gap and relatively large leakage inductance is used. To achieve desired voltage and power levels with a reasonable compact-sized transformer, high frequencies in the order of 20-100 kHz are preferred, producing high levels of reactive power, which limit the amount of transferred power and efficiency if not compensated. There are four basic transformer compensation topologies reported in the literature, each being the combination of series and/or parallel compensations. This paper presents all four topologies and the associated input-to-output dependence based on a Boucherot bridge model of a transformer. Analytical modeling predictions are supported by finite-element analysis results to provide the proof of conceptual finding of this technology. Design procedures for each of the four configurations are presented in detail. A comparison study that highlights the merits and demerits of each configuration is given to help determine the appropriateness of each transformer configuration to a particular application.

Heterogeneous Vehicular Networking: A Survey on Architecture, Challenges, and Solutions

With the rapid development of the Intelligent Transportation System (ITS), vehicular communication networks have been widely studied in recent years. Dedicated Short Range Communication (DSRC) can provide efficient real-time information exchange among vehicles without the need of pervasive roadside communication infrastructure. Although mobile cellular networks are capable of providing wide coverage for vehicular users, the requirements of services that require stringent real-time safety cannot always be guaranteed by cellular networks. Therefore, the Heterogeneous Vehicular NETwork (HetVNET), which integrates cellular networks with DSRC, is a potential solution for meeting the communication requirements of the ITS. Although there are a plethora of reported studies on either DSRC or cellular networks, joint research of these two areas is still at its infancy. This paper provides a comprehensive survey on recent wireless networks techniques applied to HetVNETs. Firstly, the requirements and use cases of safety and non-safety services are summarized and compared. Consequently, a HetVNET framework that utilizes a variety of wireless networking techniques is presented, followed by the descriptions of various applications for some typical scenarios. Building such HetVNETs requires a deep understanding of heterogeneity and its associated challenges. Thus, major challenges and solutions that are related to both the Medium Access Control (MAC) and network layers in HetVNETs are studied and discussed in detail. Finally, we outline open issues that help to identify new research directions in HetVNETs.

基于315 Mhz无线射频技术的全向遥控小夜灯

21世纪的人口老龄化浪潮已经成为了全球发展的趋势。自从2000年以来，我国逐渐步入了老龄化国家行列。老年人的健康问题、老年人人口数量的发展趋势等问题，现在已经受到很大的重视。老年人由于身体机能下降，夜间起夜、吃药、喝水等活动的频率增加，在黑暗中发生摔倒和撞伤的几率也增大。尤其对于独居老人，夜间发生意外伤害不易得到救助。本文针对老年人夜间活动不便设计了一种小夜灯，采用无线射频遥控技术，可以远程对小夜灯开关进行控制，且无需对准灯头，减少老年人夜间寻找灯泡开关的不便。按键设计简单大方，便于老年人夜间轻松稳定地按下。采用LED灯头和电路结构、亮度的优化设计，控制小夜灯成本，降低功耗和节约电能，解决部分老年人对于用经济成本方面的顾虑。 Aged tendency of population has become a worldwide trend in 21th century. Since the year of 2000, our country has gradually stepped into ageing country camp. Health issue, population development tendency of the aged has been attached more importance. As somatic function of the aged drops, the frequency of the aged getting up at night to wash, medicine, drink increases, the odds of falling and crushing in the darkness also increases. Especially for the aged who live alone, if accident happens at night, they will not get help easily. This paper designed a night-light aiming at reducing the aged inconvenience during their night activities. The night-light adopts wireless RF remote control technique, and the old can control night-light on and off remotely without remote aiming at the night-light, reducing the inconvenience of finding light switch at night. The key is designed simply and apparently, easy to press stably at night for the aged. LED lamp cap is ado- pted and circuit configuration and lamp luminance are optimized to control the night-light’s cost, reduce power dissipation and save electricity, which solve the scruple of economic issue of some aged people.

Recharging RFID Tags for Environmental Monitoring Using UAVs: A Feasibility Analysis

RFID tags are used for different purposes. One of the major problems to be addressed, particularly for monitoring purposes, is their limited power autonomy. Tags must perform different tasks with limited power consumption and their batteries capacities are often too low, even if low power consumption techniques are implemented. In these operational situations tags should be kept in operation for long periods of time and the common solution is to go directly where they are installed and recharge them manually or change their batteries; alternatively, when possible, small photovoltaic (PV) panels may be adopted. This paper proposes a feasibility analysis of how it is possible to recharge a multipurpose RFID tag using a UAV (Unmanned Aerial Vehicle), which is programmed to go above the tags and recharge them. This possibility is analyzed from an energetic point of view assuming to recharge a Wireless Sensor Network (WSN) using a common commercial UAV adequately instrumented using the wireless power transfer technique.

Data Collection with Probabilistic Guarantees in Opportunistic Wireless Networks

Sensors can be embedded in many mobile devices/objects such as smart phones, vehicles and animals to collect data from the surrounding environment. These mobile devices can communicate with each other by wireless techniques to form opportunistic wireless networks (OWNs). OWNs have volatile network topology and loose connectivity. Data collection from mobile devices is very challenging. This paper proposes a data collection protocol named DCPG with probabilistic guarantees in OWNs. DCPG consists of four parts: broadcasting sink's position periodically, electing collectors by partitioning a network into grids, direct transmission from general nodes to collectors, and directional transmission from collectors to the sink. The theoretical analysis shows that DCPG can adjust the parameters to guarantee that the average data collection ratio is greater than the user-specified data collection ratio. The simulation results show that DCPG outperforms the existing best protocol SMITE on the aspects of data collection ratio and communication overhead.

Wireless System for Sleeper Vibrations Measurement

This paper describes testing of a wireless technique for measuring the actual sleeper vibrations and determination of their dynamic deflection based on the experimentally acquired acceleration data. Practical measurements of sleeper vibrations and calculation of displacements (deflections) along the track provide insight into the actual condition of layers below sleepers. The main goal was to develop the equipment for structural health monitoring as a basis for the track maintenance management.

A synergetic formed quantitative model for users' selections in different network service providers

Multiple heterogeneous wireless techniques, possibly administered by different entities, are coexisted in the rapidly-expanding communications market. In order to understand the complex interactions among different network service providers (NSPs), it is important to study the factors taken into consideration by users during their selections of the NSPs. The article focuses on interactions between macro-level dynamics of user subscription and the factors causing such dynamics. The key factor was discussed on the interactions between different subpopulations rather than the general factors such as quality of service (QoS). Guided by synergetic theory, a general mathematical description model was built. The influence of key factors on users' selections was considered and analyzed. Some examples were presented to validate capabilities of the proposed model.

Hassle-Free Vitals: BioWireleSS for a Patient-Centric Health-Care Paradigm

Continuous monitoring of vital information via a wireless medium has become an integral part of next-generation health-care technologies. The benefits of a wireless monitoring technique include facilitating in-home care services, reduction of the cost of frequent visits to hospitals, and lightening of the burden to the elderly persons. The development of miniature, lightweight, and energy-efficient circuit solutions for biomedical sensor applications has been made possible by the tremendous recent advancements in health-care monitoring technologies, micro- and nanofabrication processes, and wireless communications. Exuberant growth of the wireless sensor networks has opened up a new and innovative application of wireless technology in health care. The advancement of wireless technology has led to the development of the recently proposed comprehensive patient monitoring systems such as wireless body area network (WBAN) and body sensor network (BSN). Implantable and wearable sensors are integral components of these networks and are employed for monitoring various levels of physiological activities. Wireless sensor technology provides an effective tool for instant access to patient data, laboratory test results, and clinical histories as well as insurance information, thereby ensuring immediate health care in case of emergency, eliminating the lengthy clinical decision. This biomedical wireless technology has resulted in a new health-care concept known as telemedicine, which facilitates the monitoring of in-home patient care by incorporating smart medical devices and WBANs. In this scheme, implantable and wearable sensors are placed within the vicinity of the patient's body and various physiological parameters are monitored and transmitted wirelessly to a nearby hub station and subsequently to the remote health-care provider via a secure wireless communication network. The telemedicine platform can also be configured for identification of the object location, medicine reminder, or emergency alert in case of any sign of fatal disease. As a result of the recent developments in biomedical wireless technologies, the traditional clinic-centric health care is giving way to a patient-care centric health-care concept. This translational health-care concept facilitates the multidirectional integration of basic research, patient-oriented research, and population-based research, with the long-term aim of improving the health of the public. However, the successful integration of this new health-care paradigm hinges on the proper interpretation, storage, and dissemination of the large data sets generated by the all implantable and wearable devices within the wireless network.

Heterogeneous statistical QoS provisioning over 5G mobile wireless networks

As a critical step towards the next new era of mobile wireless networks, recently 5G mobile wireless networks have received significant research attention and efforts from both academia and industry. The 5G mobile wireless networks are expected to provide different delay-bounded QoS guarantees for a wide spectrum of services, applications, and users with extremely diverse requirements. Since the time-sensitive services in 5G multimedia wireless networks may vary dramatically in both a large range from milliseconds to a few seconds and diversity from uniform/ constant delay-bound to different/variable delay-bound guarantees among different wireless links, the delay-bound QoS requirements for different types of services promote the newly emerging heterogeneous statistical delay-bounded QoS provisioning over 5G mobile wireless networks, which, however, imposes many new challenging issues not encountered before in 4G wireless networks. To overcome these new challenges, in this article we propose a novel heterogeneous statistical QoS provisioning architecture for 5G mobile wireless networks. First, we develop and analyze the new heterogeneous statistical QoS system model by applying and extending the effective capacity theory. Then, through the wireless coupling channels, we apply our proposed heterogeneous statistical QoS architecture to efficiently implement the following powerful 5G-candidate wireless techniques: 1) device-to-device networks; 2) full-duplex networks; and 3) cognitive radio networks, respectively, for providing heterogeneous statistical delay-bounded QoS guarantees. Finally, using the simulation experiments we show that our proposed architecture and schemes significantly outperform the existing traditional statistical delay-bounded QoS provisioning schemes in terms of satisfying the heterogeneous delay-bounded QoS requirements while maximizing the aggregate system throughput over 5G mobile wireless networks.

TDOA Wireless Localization Comparison Influence of Network Topology

The interest to wireless positioning techniques has been increasing in recent decades due to wide spread of location-based services as well as constraints imposed by regulator on cellular operator to achieve an accepted level of cellular accuracy regardless of availability of GPS signals. Nevertheless, failure of some base stations cannot be fully avoided, yielding various cellular topologies, which, in turn would likely influence the accuracy of the positioning. This paper explores four types of cellular topologies: balanced, circular, U-shape and linear, which can be inferred from balanced topology structure. Assuming time difference of arrival technology and, up to some extent, time of arrival technology were employed, least square like methods are contrasted with maximum likelihood, Taylor, Chan and hybrid approaches in a simulation platform

Wireless Telemetric Data Acquisition and Real-Time Control for a High Measurement-Density Internal Heat Transfer Experiment

This paper describes a wireless data transmission system for a large-scale rotating experiment to investigate the heat transfer in a three-passage serpentine test section. Patterned after the NASA HOST program, the current experiment extends the data set to larger aspect ratios including 1:2, 1:4, and 1:6. As with HOST, heat transfer is measured using the heated segments technique, and the serpentine test section spins at rotation numbers representative of engine conditions. Rotating experiments are essential for capturing the representative operating conditions and complicated flow physics that must be understood to advance internal cooling technology for high aspect ratio configurations. There are challenges associated with controlling the operating parameters and collecting accurate data for high measurement-density rotating experiments. This experiment requires that 140 copper panels be held at a constant temperature by independently controlling and recording the power supplied to a separate heater on each panel. This means there must be 140 temperature measurements, 140 pairs of heater power leads, enough power to drive all of these heaters, and data recording capacity left over to measure fluid temperatures and pressures. Traditional methods of transferring rotating signals to the stationary frame of reference (like slip rings) are widely implemented but have practical limitations in the quantity of transferrable signals and the electrical current capacity of the individual channels. Alternatively, wireless transmission techniques were first developed decades ago, but their practical use has been limited by onboard power delivery requirements and cost. This paper describes the development of a new data transmission and control system that takes advantage of improvements in inexpensive electronics to create a battery-powered and microprocessor controlled system for acquisition, storage, control, and wireless communication. These components are assembled as an integral part of the rotating mechanical hardware. By handling high-fidelity microcircuit signal conditioning, data acquisition, feedback control, and data storage in the rotating frame and transmitting the results wirelessly, this system provides high measurement density and active feedback control that would have been impractical with a conventional slip-ring approach. The design and construction of the wireless control system for one full sidewall of the three-serpentine passage is described in detail. Its capability and functionality is demonstrated with operational data. It will be demonstrated that while all of the components in this system are readily available, the unique combination of this technology opens up a new world of measurement capabilities.

Lightweight Robust Device-Free Localization in Wireless Networks

Due to its ability of realizing localization without the need of equipping the target with a wireless device, the device-free wireless localization technique has become a crucial technique for many security and military applications. However, there still lacks an efficient scheme which could achieve robust location estimation performance with low computational cost. To solve this problem, we propose a lightweight robust Bayesian grid approach (BGA) in this paper. The BGA utilizes not only the observation information of the shadowed links, but also the prior information involved in the previous estimations and the constraint information involved in the non-shadowed links, which ensure its robust performance. Meanwhile, the BGA can be carried out with a series of lightweight grid multiplication and addition operations, which eliminates the complex matrix inversion computation involved in the traditional algorithm. The experimental results demonstrate that BGA could achieve a mean tracking error of 0.155 m with a running time of only 1.5 ms.