- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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SparseCast: Hybrid Digital-Analog Wireless Image Transmission Exploiting Frequency Domain Sparsity
摘要： A hybrid digital-analog wireless image transmission scheme, called SparseCast, is introduced, which provides graceful degradation with channel quality. SparseCast achieves improved end-to-end reconstruction quality while reducing the bandwidth requirement by exploiting frequency domain sparsity through compressed sensing. The proposed algorithm produces a linear relationship between the channel signal-to-noise ratio (CSNR) and peak signal-to-noise ratio (PSNR), without requiring the channel state knowledge at the transmitter. This is particularly attractive when transmitting to multiple receivers or over unknown time-varying channels, as the receiver PSNR depends on the experienced channel quality, and is not bottlenecked by the worst channel. SparseCast is benchmarked against two alternative algorithms: SoftCast and BCS-SPL. Our findings show that the proposed algorithm outperforms SoftCast by approximately 3.1 dB and BCS-SPL by 14.8 dB.
关键词： hybrid digital-analog,compressed sensing,channel signal-to-noise ratio,frequency domain sparsity,peak signal-to-noise ratio,wireless image transmission
更新于2025-09-23 15:21:21
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A sensitive and selective triple-channel optical assay based on red-emissive carbon dots for the determination of PFOS
摘要： In this study, a simple, fast and cost-effective triple-channel optical assay for the determination of PFOS has been developed. The carbon quantum dots (CDs) were prepared by one-pot hydrothermal method and employed as probe for sensing PFOS. CDs react with PFOS to form ground-state complex, which brings about the intensity changes of three signals including fluorescence, UV–vis absorption and resonance light scattering (RLS). And the changes of the fluorescence and absorption signals can be used for the visual detection of PFOS. And there is a certain relationship between the three-signal changes with the concentration of PFOS, respectively. The proposed assay exhibits good selectivity and sensitivity with a limit of detection (LOD) of 18.27 nmol/L in the fluorescence signal. Fluorescence lifetime, transmission electron microscopy (TEM) images, Fourier transform infrared (FTIR) and zeta potential were investigated for the mechanism study. Furthermore, this promising approach was also successfully applied to PFOS sensing in real water samples with RSD ≤ 2.09%.
关键词： Perfluorooctane sulfonate (PFOS),Triple-channel,Visualization,Carbon dots
更新于2025-09-23 15:21:21
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Research on image de-disturbing algorithm based on dark channel prior and anisotropic Gaussian filtering
摘要： In order to solve the problem of serious degradation of images collected outdoors in dense fog weather, a defogging algorithm for dense fog images was proposed. The fog-day imaging physical model was simplified; the concept of fog concentration factor was proposed. The single image de-hazing algorithm based on dark channel priors solves the problem of estimating the transmittance of fog and sky scenes. The image recovered by the algorithm is clear and natural. The algorithm has high computational complexity. It takes a long time to meet real-time requirements. The principle of anisotropic Gaussian filtering is introduced. It combines with the dark channel. The value of the fog concentration coefficient is obtained by estimating the visibility value of a single fog image. It is then combined with an anisotropic Gaussian filter of the image to estimate the atmospheric light value. Defogging of the fog image is performed by using the repair function. It is necessary to perform effective de-hazing processing on smog images. Experiments show that the improved algorithm can greatly reduce the complexity of the algorithm while ensuring the defogging effect of the original algorithm.
关键词： anisotropy,Gaussian filter,foggy image removal,dark channel prior principle
更新于2025-09-23 15:21:21
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Transparent Electronics Using One Binary Oxide for All Transistor Layers
摘要： A novel process is developed in which thin film transistors (TFTs) comprising one binary oxide for all transistor layers (gate, source/drain, semiconductor channel, and dielectric) are fabricated in a single deposition system at low temperature. By simply changing the flow ratio of two chemical precursors, C8H24HfN4 and (C2H5)2 Zn, in an atomic layer deposition system, the electronic properties of the binary oxide (HfxZn1?xO2?δ or HZO) are tuned from conducting, to semiconducting, to insulating. Furthermore, by carefully optimizing the properties of the various transistor HZO layers, all-HZO thin film transistors are achieved with excellent performance on both glass and plastic substrates. Specifically, the optimized all-HZO TFTs show a saturation mobility of ≈17.9 cm2 V?1 s?1, low subthreshold swing of ≈480 mV dec?1, high Ion/Ioff ratio of >109, and excellent gate bias stability at elevated temperatures. In addition, all-HZO inverters with high DC voltage gain (≈470), and all-HZO ring oscillators with low stage delay (≈408 ns) and high oscillation frequency of 245 kHz are demonstrated. This approach presents a novel, simple, high performance, and cost-effective process for the fabrication of indium-free transparent electronics.
关键词： transparent multilayer semiconducting channel,transparent electronics,transparent oxide contacts,thin film,transistors,transparent dielectric oxides
更新于2025-09-23 15:21:21
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Disorder-tunable ZnGeP <sub/>2</sub> for epitaxial top cells on Si
摘要： In this paper, we evaluate the bit-error-rate (BER) performance of a turbo-coded, transmitter pre-processing-assisted spread spectrum technology-based multi-carrier (MC) system for the acoustic information transmission in underwater communication. Our primary goal is to improve the power ef?ciency of the system in terms of signal-to-noise ratio (SNR) while obtaining achievable BER in underwater communication. In underwater communication, inter-symbol-interference and acoustic interference are the two most important issues, which affect the system performance. We use spread spectrum technique to mitigate the effects of unwanted information in the presence of ambient noise. Multi-user transmitter pre-processing (MUTP) is the digital processing method, which is carried out at the transmitter side to offer the low complexity of the receiver. We formulate the singular value decomposition-based pre-processing matrix using noisy feedback of vector quantized (VQ) estimated channel information (CI). We consider the MC communication to mitigate the effects of multi-path propagations. We realize iterative style of decoding algorithm at the receiver to retrieve the acoustic information from the ambient noise contaminated acoustic signals. In particular, we evaluate the error-rate analysis of MC system for realistic channel model based on shallow water channel model, which consists of 11 tap delay. Simulation results emanating from this paper bring to surface the considered coded MC system with MUTP offering a better BER performance with power ef?ciency regarding SNR while retaining the low complexity of the receiver. Furthermore, we observe that there is an improvement in the system performance when perfect CI is utilized to frame the pre-processing matrix compared with noise contaminated VQ-CI.
关键词： Channel state information (CSI),vector quantization – channel information (VQ-CI),transmitter pre-processing (TP),Llyod’s algorithm
更新于2025-09-23 15:21:01
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Studies on Co-sputtered Al-Zn-Sn-O Films: A New TCO for Thin film Solar Cells
摘要： Hybrid analog/digital multiple-input multiple-output architectures were recently proposed as an alternative for fully digital-precoding in millimeter wave wireless communication systems. This is motivated by the possible reduction in the number of RF chains and analog-to-digital converters. In these architectures, the analog processing network is usually based on variable phase shifters. In this paper, we propose hybrid architectures based on switching networks to reduce the complexity and the power consumption of the structures based on phase shifters. We define a power consumption model and use it to evaluate the energy efficiency of both structures. To estimate the complete MIMO channel, we propose an open-loop compressive channel estimation technique that is independent of the hardware used in the analog processing stage. We analyze the performance of the new estimation algorithm for hybrid architectures based on phase shifters and switches. Using the estimate, we develop two algorithms for the design of the hybrid combiner based on switches and analyze the achieved spectral efficiency. Finally, we study the tradeoffs between power consumption, hardware complexity, and spectral efficiency for hybrid architectures based on phase shifting networks and switching networks. Numerical results show that architectures based on switches obtain equal or better channel estimation performance to that obtained using phase shifters, while reducing hardware complexity and power consumption. For equal power consumption, all the hybrid architectures provide similar spectral efficiencies.
关键词： channel estimation,precoding,Millimeter wave,hybrid architecture,switches
更新于2025-09-23 15:21:01
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - WDM Optical Steganography Based on Super-Continuum Light Source
摘要： In this paper, a 10 Gb/s stealth channel based on super-continuum light source in 120km SSMF transmission system is experimented, which can be hidden under the public WDM channel in both time and frequency domain.
关键词： optical steganography,super-continuum light source,WDM channel,optical stealth
更新于2025-09-23 15:21:01
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Improving the performance and economic analysis of photovoltaic panel using copper tubular-rectangular ducted heat exchanger
摘要： This research empirically and theoretically assessed the performance of a solar photovoltaic (PV) panel in five different cooling configurations under the weather conditions of Sanandaj, Iran in September 2018. The findings indicated that, compared to the simple PV mode, the increased mean electrical efficiencies over the whole experiment were 0.27%, 0.5%, 0.72%, 0.6, and 0.88% for the PV/w-XP, PV/w-XD, PV/w-2XDP, PV/a ,and PV/b-2XDP modes, respectively. Further, the highest electrical power for the PV/w-XP, PV/w-XD, PV/w-2XDP, PV/a, and PV/b-2XDP modes increased by 6.8, 12.17, 16.83, 13.17, and 18.92%, respectively compared to the simple PV mode. The monthly electrical output energy the PV/S, PV/w-XP, PV/w-XD, PV/w-2XDP, PV/a, and PV/b-2XDP modes were 28.24 kWh/A, 29.16 kWh/A, 30.34 kWh/A, 31.81 kWh/A, 31.15 kWh/A, and 32.9 kWh/A, respectively. Then, an economic analysis was carried out for the system with two adjustment coefficients. The results showed that although the payback period with an interest rate and an adjustment coefficient of 10% was 2.72 years longer in the PV/b-2XDP than in the PV/S, the annual worth over 20 years was State USD 3.32 (SANA USD 1.07) higher in the PV/b-2XDP mode than in the PV/S mode by considering merely the electrical section. Hence, considering the outlet hot water and air, PV/b-2XDP is more economical to use.
关键词： Water tubular and channel heat exchanger,Photovoltaic panel,Payback period,Thermoelectric
更新于2025-09-23 15:21:01
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[IEEE GLOBECOM 2019 - 2019 IEEE Global Communications Conference - Waikoloa, HI, USA (2019.12.9-2019.12.13)] 2019 IEEE Global Communications Conference (GLOBECOM) - Intelligent Reflecting Surfaces for Free Space Optical Communications
摘要： In this paper, we investigate the use of intelligent reflecting surfaces (IRSs) (i.e., smart mirrors) to relax the line-of-sight requirement of free space optical (FSO) systems. We characterize the impact of the physical parameters of the IRS, such as its size, position, and orientation, on the quality of the end-to-end FSO channel. In addition, we develop a statistical channel model for the geometric and the misalignment losses which accounts for the random movements of the IRS, transmitter, and receiver due to building sway. This model can be used for performance analysis of IRS-based FSO systems. Our analytical results shows that depending on the angle between the beam direction and the IRS plane, building sway for the IRS has either a smaller or larger impact on the quality of the end-to-end FSO channel than building sway for the transmitter and receiver. Furthermore, our simulation results validate the accuracy of the developed channel model and offer insight for system design.
关键词： Smart mirrors,Channel model,Free space optical communications,Intelligent reflecting surfaces,Building sway
更新于2025-09-23 15:21:01
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[IEEE 2019 IEEE International Conference on Electrical Engineering and Photonics (EExPolytech) - St. Petersburg, Russia (2019.10.17-2019.10.18)] 2019 IEEE International Conference on Electrical Engineering and Photonics (EExPolytech) - Determination of Noise Components in Laser Correlation Spectroscopic Devices for Signal-to-Noise Ratio Estimation
摘要： This paper concerns with a wireless-energy-transfer (WET)-enabled massive multiple-input-multiple-output (MIMO) system with superimposed pilot (SP)-aided channel estimation. Unlike the conventional WET-enabled frame transmission schemes, with the aid of SP, both the uplink (UL) channel estimation and wireless information transmission (WIT) that powered by the downlink (DL) WET can be operated simultaneously, and thus provide the potential for improving the UL achievable throughput. The impact that the SP has on the performance of such a WET-enabled massive MIMO system is mathematically characterized, and the optimal solution, including the SP power-allocation and the ratio of time-allocation between the duration of UL WIT and DL WET, is derived with regard to maximize the UL achievable throughput. Numerical results demonstrate the proposed SP-aided WET technique yields a superior performance than the conventional pilot-only-based schemes.
关键词： wireless information and power transfer,Energy harvesting,massive MIMO,throughput maximization,channel estimation
更新于2025-09-23 15:21:01