This paper presents a design for a high-frequency single-input multiple-output (SIMO) wireless power transfer (WPT) system that incorporates the parasitic capacitance of coupled coils. Additionally, the effect of the ...
详细信息
ISBN:
(纸本)9798350375596;9798350375589
This paper presents a design for a high-frequency single-input multiple-output (SIMO) wireless power transfer (WPT) system that incorporates the parasitic capacitance of coupled coils. Additionally, the effect of the mutual inductance among the receiving coils is considered in the design. To evaluate the feasibility and effectiveness of the proposal, a SIMO WPT system using a class-E inverter as the transmitter and two resistive loads as receivers is designed and tested. The switch-voltage waveforms in both the numerical calculations and experiment meet the class-E Zero-Voltage-Switching / Zero-Derivative-Switching (ZVS/ZDS) conditions, enabling a high power-transmission efficiency at a high frequency. Furthermore, the calculated results are consistent with the experimental ones, validating the proposal. The results also highlight the significance of accounting for coil-coupled parasitic capacitance in the design of high-frequency SIMO WPT systems.
In single-input multiple-output (SIMO) underwater acoustic (UWA) communications, the receiver based on passive time reversal (PTR) combined with decision feedback equalizer (DFE) is widely used but has a limited perfo...
详细信息
In single-input multiple-output (SIMO) underwater acoustic (UWA) communications, the receiver based on passive time reversal (PTR) combined with decision feedback equalizer (DFE) is widely used but has a limited performance. A multi-channel joint estimation algorithm based on sparse Bayesian learning (MJSBL) is proposed in this paper to exploit the diverse gain from multi-channels, where reasonable prior distribution functions are selected for parameters in the probabilistic model. Afterwards, the algorithm is derived by the mean-field variational inference (VI), iteratively updating the estimation of symbols, channels and noise variation. As a result, the maximum likelihood estimation of the dictionary matrix, as well as the maximum posterior estimation of the channel vectors and noise variance, can be approximated. Simulation and experimental results verify that compared to typical single-channel and multi-channel algorithms, the systems always have lower bit error rates (BERs) and symbol error rates (SERs) with the MJSBL algorithm for different communications distances and symbol block lengths.
This paper analyzes a resonant inductive wireless power transfer link using a single transmitter and multiple receivers. The link is described as an (N+1)-port network and the problem of efficiency maximization is for...
详细信息
This paper analyzes a resonant inductive wireless power transfer link using a single transmitter and multiple receivers. The link is described as an (N+1)-port network and the problem of efficiency maximization is formulated as a generalized eigenvalue problem. It is shown that the desired solution can be derived through simple algebraic operations on the impedance matrix of the link. The analytical expressions of the loads and the generator impedances that maximize the efficiency are derived and discussed. It is demonstrated that the maximum realizable efficiency of the link does not depend on the coupling among the receivers that can be always compensated. Circuital simulation results validating the presented theory are reported and discussed.
The experiment is designed and taken to measure the link gain in a single-input multiple-output ultraviolet (UV) communication system with diversity reception, and the correlation of multichannel is also taken into ac...
详细信息
The experiment is designed and taken to measure the link gain in a single-input multiple-output ultraviolet (UV) communication system with diversity reception, and the correlation of multichannel is also taken into account. Theoretical and experimental research on the multireceiver UV communication system suggests that diversity reception is an effective way to gain high BER performance even if the link gain correlation is non-negligible (with normal level correlation coefficient). The link gain of diversity reception is compared particularly with the gain from expanding the detecting area to find its boundary for performance improvement and the distance limit between receivers. The experimental results provide more reliable guidelines for receiver design in UVC systems and other scattering wireless optical communication channels with diversity reception applied such as multiple-inputmultiple-output. (C) 2017 Society of Photo-Optical Instrumentation Engineers (SPIE)
This study presents a high-efficiency-isolated single-input multiple-output bidirectional (HISMB) converter for a power storage system. According to the power management, the proposed HISMB converter can operate at a ...
详细信息
This study presents a high-efficiency-isolated single-input multiple-output bidirectional (HISMB) converter for a power storage system. According to the power management, the proposed HISMB converter can operate at a step-up state (energy release) and a step-down state (energy storage). At the step-up state, it can boost the voltage of a low-voltage input power source to a high-voltage-side dc bus and middle-voltage terminals. When the high-voltage-side dc bus has excess energy, one can reversely transmit the energy. The high-voltage dc bus can take as the main power, and middle-voltage output terminals can supply powers for individual middle-voltage dc loads or to charge auxiliary power sources (e.g., battery modules). In this study, a coupled-inductor-based HISMB converter accomplishes the bidirectional power control with the properties of voltage clamping and soft switching, and the corresponding device specifications are adequately designed. As a result, the energy of the leakage inductor of the coupled inductor can be recycled and released to the high-voltage-side dc bus and auxiliary power sources, and the voltage stresses on power switches can be greatly reduced. Moreover, the switching losses can be significantly decreased because of all power switches with zero-voltage-switching features. Therefore, the objectives of high-efficiency power conversion, electric isolation, bidirectional energy transmission, and various output voltage with different levels can be obtained. The effectiveness of the proposed HISMB converter is verified by experimental results of a kW-level prototype in practical applications.
作者:
Su, WeiUS Army
Commun Elect Res Dev & Engn Ctr Aberdeen MD 21001 USA
This paper discusses the automatic modulation classification of weak communication signals using distributed low-cost sensors. The concept of a secondary user in sensor networks is presented and very high-order statis...
详细信息
This paper discusses the automatic modulation classification of weak communication signals using distributed low-cost sensors. The concept of a secondary user in sensor networks is presented and very high-order statistics are used as modulation features. Two feature-based methods, single-variable and multivariable modulation classifiers, are proposed for estimating unknown modulation schemes through single-input multiple-output signal sensing channels. The new approaches acquire multiple signal observations collected from distributed sensors and leverage the channel diversity to enhance signal power and reduce bias in estimation. The experiment demonstrates that the network centric modulation classifier achieves significantly improved performance in terms of probability of correct classification than the current state-of-the-art single sensor modulation classifier, and the multivariable modulation classifier is more robust to the channel parameter variations than the single-variable classifier.
In this paper, for a single-input multiple-output (SIMO) system aided by a passive reconfigurable intelligent surface (RIS), the joint transmission accomplished by the single transmit antenna and the RIS with multiple...
详细信息
In this paper, for a single-input multiple-output (SIMO) system aided by a passive reconfigurable intelligent surface (RIS), the joint transmission accomplished by the single transmit antenna and the RIS with multiple controllable reflective elements is considered. Relying on a general capacity upper bound derived by using a maximum-trace argument, we respectively characterize the capacity slope of low-signal-to-noise-ratio channels and the exact capacity of rank-one channels, in which the optimal configuration of the RIS is proved to be beamforming-only with carefully-chosen phase shifts. To exploit the potential of modulating extra information on the RIS, by leveraging a strategy named partially beamforming and partially information-carrying based on QR decomposition and successive interference cancellation, we propose a novel transceiver architecture with only a single RF front end at the transmitter, by which the considered channel can be regarded as a concatenation of a vector Gaussian channel and several phase-modulated channels. Especially, we investigate a class of vector Gaussian channels with a hypersphere input support constraint, and not only generalize the existing result to arbitrary-dimensional real spaces but also present its high-order capacity asymptotics, by which both capacities of hypersphere-constrained channels and achievable rates of the proposed transceiver with two different signaling schemes can be well-approximated. Information-theoretic analyses show that the transceiver architecture designed for the SIMO channel has a boosted multiplexing gain, rather than one for the conventionally-used optimized beamforming scheme. Numerical results verify our derived asymptotic results and show notable superiority of the proposed transceiver as compared with the beamforming and the receive spatial modulation schemes.
This paper presents the design of the near-field wireless power transfer (WPT) system capable of charging two independent loads simultaneously. It is imperative to note that it becomes possible by developing single-in...
详细信息
ISBN:
(纸本)9798350330991;9798350331004
This paper presents the design of the near-field wireless power transfer (WPT) system capable of charging two independent loads simultaneously. It is imperative to note that it becomes possible by developing single-inputmultiple -output WPT, i.e., a single transmitter (Tx) and two receivers (Rxs). The developed Tx and Rx resonators possess small areas of 30-by-30 sq. mm and 30-by-13 sq. mm, respectively. The concurrent powering is achieved by coupling Tx and two Rxs at 27 mm. As a consequence, the obtained measurement results demonstrate power transfer efficiencies of 50% and 25%.
For the development of accurate and reliable simulation models, the procedure of calibration and validation against measurement data is essential. In this paper, a finite element model and a waveguide finite element m...
详细信息
For the development of accurate and reliable simulation models, the procedure of calibration and validation against measurement data is essential. In this paper, a finite element model and a waveguide finite element model of a slab track are calibrated and validated against hammer impact measurement data from a full-scale test rig. The finite element model is three-dimensional, where the rails are modelled as Rayleigh?Timoshenko beams and the concrete slab and support layer are modelled using linear shell elements. In the waveguide finite element model, a constant track cross-section described by two-dimensional finite elements is assumed, and the vibration in the direction perpendicular to the cross-section is described by propagating waves that are decaying exponentially. Measured frequency response functions (FRFs) are compared with the corresponding calculated FRFs from the two modelling approaches. The calibration is conducted in two steps using (i) a parameter study and (ii) a genetic algorithm. For multiple excitation positions and sensor locations, both calibrated models capture the trend of the single-input multiple-output measurements with rather small deviations compared to the overall dynamic range. This implies that both models can successfully represent the dynamic response of the test rig and can be considered as validated.
Cephalopods can display variable body color/patterns upon environmental stimulation via bioelectricity-controlled muscle contraction/expansion of skin chromatophores. However, it remains challenging to produce artific...
详细信息
Cephalopods can display variable body color/patterns upon environmental stimulation via bioelectricity-controlled muscle contraction/expansion of skin chromatophores. However, it remains challenging to produce artificial display analogs that exhibit reversible and rapid switching between multiple expected luminescent patterns, although such systems are very appealing for many practical uses (e.g., data encryption). Inspired by the bioelectromechanical display tactic of cephalopods, in this work, a conceptually new photomechanically modulated fluorescent system that enables on-demand display of fluorescent patterns via a cascading stimulation-mechanical movement-optical output conduction mechanism is presented. Specifically, this biomimetic system comprises a customizable hollow display panel and a bottom-tethered photothermally responsive fluorescent actuator. Under NIR light, the photomechanically bending movements of the fluorescent actuator will immediately cover the hollow window of the display panel and synchronously manifest as the display of fluorescent patterns. Owing to its desirable time- and light-power-dependent actuating behaviors, diverse fluorescent patterns/information can be dynamically and reversibly displayed by facilely controlling this single remote NIR signal. This bioinspired strategy is universal and promising for fabricating on-demand fluorescent display platforms that combine a wide choice of fluorophores, remote control with high spatial/temporal precision, and especially single-input multiple-output features.
暂无评论