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Influences of user's posture and contact conditions of electrodes on the transmission characteristics of human body communication (HBC) were studied. A subject wore a transmitter on the left wrist and touched the receiver electrode with his right or left index finger. User's postures were selected from possible scenarios in practical applications. Electrodes of the transmitter and/or the receiver...
A fast 3-D ray tracing method based on image theory is presented. The proposed method defines reflection tubes and organizes them in a tree structure to treat images efficiently in a complex 3-D environment. The method can account for all possible rays undergoing multiple reflections and transmissions, and its predictions agree well with the measurements.
In this paper, a method of recording food intake using intra-body communication technology and estimating food sizes by measuring its electrical properties is described. The method uses high-frequency signals to detect contact and estimate food sizes when the food makes contact with the cutlery before consumption. Previous studies have addressed detection of food contact and identification of food...
Power consumption is a key issue for wireless network design. Cooperative routing, an efficient scheme for saving transmission power in wireless networks, combines the advantage of the cooperative communication in the physical layer and the routing technology in the network layer. In this paper, we propose a distributed minimum power cooperative routing algorithm based on optimal power allocation,...
This paper evaluates the use of an intermediate coupler in a series-series resonant configuration under different magnetic coupler displacements via mathematical and simulation analysis. The circular design was selected and different intermediate coil arrangements were simulated using a 3D FEM software. A variable inductor (VI) is inserted in the transmitter circuit to compensate the extra reactance...
This paper proposes a new Inductive Power Transfer (IPT) transmitter configuration tolerant to displacements in the magnetic coupler and in the resonant capacitors. The new configuration uses a variable inductor in the transmitter side to regulate the power supply impedance and achieve zero voltage switch (ZVS) for different vertical and horizontal displacements in the magnetic coupler. The proposed...
The application of Wireless Power Transfer (WPT) systems is primarily limited by its energy transfer efficiency. For modern WPT that utilises Strongly Coupled Magnetic Resonances (SCMR), which transfers energy by using the mutual inductance between coils, a higher efficiency can be achieved compared with a conventional air-core transformer module. An SCMR normally works at a desired frequency which...
A method for detecting human motion in complex scenarios based on Channel State Information (CSI) is presented. First, the sensitivity of CSI phase information to human motion is explored, especially to the strenuous motion. Through a large number of experiments, the influence of human motion on CSI phase is found out, and the characteristics of signal changes are extracted. The One-class Support...
Respiration rate plays an important role in human health monitoring. Traditional respiration rate monitoring techniques usually require users to wear some special equipment, which is not convenient for the elderly and the baby. Recently, Wi-Fi based respiration detection technique has attracted much attention due to its device-free and low-deployment-cost. However, most existing studies focus on respiration...
The Doppler effect is typically an impairment for wireless communications in mobile-to-mobile environments. Multipath effects leading to delay dispersion at the receiver can create a challenging doubly selective time-frequency channel response. In Vehicle-to-Vehicle (V2V) communications, small-scale effects of the V2V channel over short durations are well understood. However, observing the Doppler...
In this paper we study and analyze the problem of self-interference in transceivers performing inter-band carrier aggregation, where separate power amplifiers (PAs) are used for each component carrier (CC). The self-interference stems from the nonlinear behaviour of the passive RF components at the transmitter, which results in passive intermodulation terms that in some cases fall onto the RX band...
The paper deals with an analytical model of the transmitter-blocking technique for mitigating short-time fades on free-space optical links. Due to the effect of atmospheric turbulence, the optical channel is characterized by received power fades in the order of tens of milliseconds, during which the transmitted data is lost. Under certain conditions, the propagation through turbulent channel is reciprocal,...
In the context of an impressive development of software defined networks and of internet technologies, this paper presents the aspects related to the implementation of an online wideband multimode radio receiver. The receiver was developed considering its main application in LEO satellite data reception, for frequencies up to 1.7 GHz. In additional to the hardware implementation description, the paper...
In this digest, a coupling coefficient estimation method for wireless charging system is proposed based on its transmitter and receiver current and voltage harmonics analysis. One of the main challenges of wireless charging in vehicular application is the significant variation of magnetic coupling coefficient between transmitter (Tx) and receiver (Rx) coils due to large air-gap and lateral misalignment...
Simultaneous non-contact energy transmission for multiple loads with separate receiving coils is a remarkable advantage of magnetically coupled resonant (MCR) wireless power transfer (WPT). Nevertheless, diverse energy requirements of different loads and efficiency quota make it considerably difficult to design and optimize the parameters of present single-frequency system. In this paper, a novel...
This paper presents a novel electric vehicle (EV) dynamic wireless charging (DWC) research platform solution. Conventional solution tends to build a low speed, space-occupying, power-derating system, which does not accurately reflect the dynamic process of on-board wireless charger at high travelling speed. Considering the receiver-side open circuit voltage equivalent, the proposed solution simulates...
Techniques of long-term in-vivo electrophysiological recording play important roles in brain research and neural rehabilitation. To avoid interruption of experiment and risk of infection, use of wireless power transfer (WPT) technique has recently been suggested to eliminate cumbersome wires and batteries attached to the animals in rodent electrophysiological applications. This paper presents a holistic...
In most loosely coupled inductive wireless power transfer systems, the air-gap magnetic flux density between coils is still far above safety limit, which is a potential threat to human beings and animals. In addition, less attention is paid to the air-gap electric field intensity, which increases significantly as the operating frequency increases. In this paper, a multi-kW inductive wireless power...
Wireless communication technology is spreading rapidly to all areas of our lives. The technology, which has a wide range of applications from radios, intelligent home systems, automation applications to GPS units, was used in monitoring the workers working in mines in this study. Most of the mining area underground mining is risky and the possibility of accident (gas jams, the explosion and dents,...
With the extensive use of smartphones, technology improving secure communication between smartphones is a growing field of research. As a form of Visible Light Communication, a color video barcode system creates a smartphone-tosmartphone communication channel. This color video barcode system, effectively an evolved form of QR codes, provides a secure alternative to WiFi, Bluetooth, and Near Field...
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