- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Polarization attack on continuous-variable quantum key distribution
摘要： The shot-noise unit (SNU) is a crucial factor for the practical security of a continuous-variable quantum key distribution system. In the most widely used experimental scheme, the SNU should be calibrated first and acts as a constant during the key distribution. However, the SNU of a practical system is dependent on the various parameters of the local oscillator (LO), which can be controlled by the eavesdropper in the open channel. In this paper, we report a quantum hacking method to control the practical SNU by using the limited compensation rate of the polarization compensation. Since the compensation is only based on of the polarization measurement results of part of LO pulses, the polarization of other unmeasured pulses may not be compensated correctly, which can be utilized by the eavesdropper to control the practical SNU. The simulation and experiment results indicate that the practical SNU can be controlled by the eavesdropper. Thus, the eavesdropper can use the fact that the practical SNU is no longer equals to the calibrated one to control the excess noise and final key rate.
关键词： shot noise unit,polarization compensation,continuous-variable quantum key distribution,quantum hacking
更新于2025-09-23 15:23:52
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Achievable noise performance of spectroscopic prototype DEPFET detectors
摘要： A new generation of spectroscopic X-ray DEPFET detectors has been produced in the course of the detector development for the Wide Field Imager (WFI) of Athena. These devices served to perform a detailed analysis of the noise composition, which was enabled by the development of appropriate test algorithms. A result of the analysis is the distinction of different components, which sum up to the total noise. In particular the contribution of shot noise, white noise and 1/f noise to the readout noise is determined as well as the signal noise caused by the generation of charge carriers. The resulting parametrization enables the adaptation and optimization of operation modes to given purposes. The studied prototype detectors included 64×64 pixels with a linear gate design and provided an excellent noise, below 1.6 e?ENC at a readout time faster than 10 μs/pixel and a temperature of -80 ?C in rolling-shutter operation. This performance is enabled by an extended signal integration time. A further noise reduction is prevented by the signal noise, caused by charge carrier generation. In order to demonstrate the low noise properties of the DEPFET transistor, the measurement conditions were adapted and a noise of 0.95 e?ENC was measured at the expense of the sensor size — by operating only parts of the sensor in window mode — and dynamic range — by using the Al Kα line at about 1.49 keV for calibration.
关键词： Imaging spectroscopy,Solid state detectors,Instrumental noise,X-ray detectors and telescopes
更新于2025-09-23 15:23:52
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[IEEE 2018 International Carnahan Conference on Security Technology (ICCST) - Montreal, QC, Canada (2018.10.22-2018.10.25)] 2018 International Carnahan Conference on Security Technology (ICCST) - Microwave Quantum Radar: An Experimental Validation
摘要： We describe an experiment which comes very close to implementing a quantum radar based on entangled microwaves. A pair of entangled microwave beams are generated using a Josephson parametric amplifier (JPA) and measured by a pair of digitizers after amplification. We present a receiver operating characteristic (ROC) curve for the case where the signal power at the digitizers is ?83.84 dBm (corresponding to a JPA power output, before amplification, of ?148.26 dBm), as well as for a classically correlated source which attempts to approximate the covariance structure of the entangled JPA signals. The entangled signals are seen to be clearly superior to the classically correlated signals. Although the latter is still interesting from a noise radar perspective, this demonstrates that attempting to simulate entanglement with classical signals causes a measurable decrease in correlation. Our experiment validates the feasibility and desirability of a microwave quantum radar.
关键词： entanglement,Quantum radar,microwave,noise radar,correlation
更新于2025-09-23 15:23:52
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[IEEE 2018 IEEE 7th Data Driven Control and Learning Systems Conference (DDCLS) - Enshi (2018.5.25-2018.5.27)] 2018 IEEE 7th Data Driven Control and Learning Systems Conference (DDCLS) - Quantum Noise Protection via Weak Measurement for Quantum Mixed States
摘要： Due to the interaction with the environment, a quantum state is often affected by the different types of noises which becomes to one of the biggest problems for practical quantum computation. We study the possibility of protecting the mixed state of a quantum system that goes through noise by weak measurements and control operations. The aim is to find the optimal measurement strength and control operations and make the input and output states as close as possible. We show that our scheme can effectively protect arbitrary mixed states against typical types of noise sources: amplitude damping, phase damping and amplitude-phase damping. The optimal measurement and control operators are deduced in different bases of the Bloch sphere to find the best control scheme for each type of noise. The effectiveness of our control scheme is demonstrated by simulation results.
关键词： quantum system control,Open quantum system,optimal noise protection,weak measurement
更新于2025-09-23 15:23:52
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[IEEE 2018 International Symposium on Electromagnetic Compatibility (EMC EUROPE) - Amsterdam (2018.8.27-2018.8.30)] 2018 International Symposium on Electromagnetic Compatibility (EMC EUROPE) - Investigation on Degradation of Common Mode Noise Suppression with Electrostatic Discharge Protection Array
摘要： In this paper, it is proposed that the electrostatic discharge protection devices may degrade the common-mode noise suppression. The mode conversion of ESD protection devices for single and multiple differential transmission lines are investigated. Experiments are set up to measure the scattering parameters and common-mode current of common-mode filter cascading different ESD protection devices. From the experimental results, the cases with four-line ESD protection array perform worse mode conversion and common-mode noise suppression.
关键词： mode conversion,common-mode noise suppression,high-speed input/output interface,electrostatic discharge
更新于2025-09-23 15:23:52
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Noise Estimation for Image Sensor Based on Local Entropy and Median Absolute Deviation
摘要： Noise estimation for image sensor is a key technique in many image pre-processing applications such as blind de-noising. The existing noise estimation methods for additive white Gaussian noise (AWGN) and Poisson-Gaussian noise (PGN) may underestimate or overestimate the noise level in the situation of a heavy textured scene image. To cope with this problem, a novel homogenous block-based noise estimation method is proposed to calculate these noises in this paper. Initially, the noisy image is transformed into the map of local gray statistic entropy (LGSE), and the weakly textured image blocks can be selected with several biggest LGSE values in a descending order. Then, the Haar wavelet-based local median absolute deviation (HLMAD) is presented to compute the local variance of these selected homogenous blocks. After that, the noise parameters can be estimated accurately by applying the maximum likelihood estimation (MLE) to analyze the local mean and variance of selected blocks. Extensive experiments on synthesized noised images are induced and the experimental results show that the proposed method could not only more accurately estimate the noise of various scene images with different noise levels than the compared state-of-the-art methods, but also promote the performance of the blind de-noising algorithm.
关键词： additive white Gaussian noise,local gray statistic entropy,image sensor,Poisson-Gaussian noise,noise estimation,local median absolute deviation
更新于2025-09-23 15:22:29
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[IEEE 2018 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - Chengdu, China (2018.5.7-2018.5.11)] 2018 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - A Broadband 1-dB Noise Figure GaAs Low-Noise Amplifier for Millimeter-Wave 5G Base-Stations
摘要： A broadband low-noise amplifier (LNA) with sub-1 dB noise figure (NF), intended for use in millimeter-wave 5G base-stations, have been fabricated in 0.1-μm InGaAs pHEMT technology. Common-source topology with inductive source degeneration is utilized for simultaneous noise and input match. Measurement results show this LNA achieves a gain of 7.9 dB at 24-GHz and a -1 dB bandwidth of 5-GHz, while consuming 13 mW from a 1-V supply. The noise figure is below 1.5 dB from 21-GHz to 27-GHz, with a lowest noise figure of 0.7 dB at 26-GHz.
关键词： millimeter-wave,noise figure,pHEMT,5G,low-noise amplifier,GaAs
更新于2025-09-23 15:22:29
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Digital Circuit Methods to Correct and Filter Noise of Nonlinear CMOS Image Sensors
摘要： Nonlinear complementary metal-oxide semiconductor (CMOS) image sensors (CISs), such as logarithmic (log) and linear–logarithmic (linlog) sensors, achieve high/wide dynamic ranges in single exposures at video frame rates. As with linear CISs, fixed pattern noise (FPN) correction and salt-and-pepper noise (SPN) filtering are required to achieve high image quality. This paper presents a method to generate digital integrated circuits, suitable for any monotonic nonlinear CIS, to correct FPN in hard real time. It also presents a method to generate digital integrated circuits, suitable for any monochromatic nonlinear CIS, to filter SPN in hard real time. The methods are validated by implementing and testing generated circuits using field-programmable gate array (FPGA) tools from both Xilinx and Altera. Generated circuits are shown to be efficient, in terms of logic elements, memory bits, and power consumption. Scalability of the methods to full high-definition (FHD) video processing is also demonstrated. In particular, FPN correction and SPN filtering of over 140 megapixels per second are feasible, in hard real time, irrespective of the degree of nonlinearity.
关键词： FPGA,salt-and-pepper noise,digital circuits,real-time processing,fixed pattern noise,CMOS image sensors
更新于2025-09-23 15:22:29
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[IEEE 2018 OCEANS - MTS/IEEE Kobe Techno-Ocean (OTO) - Kobe, Japan (2018.5.28-2018.5.31)] 2018 OCEANS - MTS/IEEE Kobe Techno-Oceans (OTO) - A Speed Measurement Method Using AUV Radiated Noise Spectrum
摘要： The noise produced by a motor can be easily controlled because its speed is from 0 to 1000 rpm. The noise of a motor is mainly caused by the interaction between the stator and rotor, and the noise can be reduced by controlling the speed of the motor. In this paper, we use a motor to produce noise and control it by a computer. The motor is driven by a computer and the noise is measured by a microphone. The computer controls the speed of the motor and the noise is reduced.
关键词： noise reduction,motor noise,speed control,computer control
更新于2025-09-23 15:22:29
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Ultra-Low Noise Amplifier for X-Band SiGe BiCMOS Phased Array Applications
摘要： This paper presents a low noise amplifier (LNA) with sub-1dB noise figure (NF) at X-Band. Different than generally known noise-and-power match technique, the presented LNA is designed by considering impedance between the base-collector terminals of an HBT in CE configuration. The presented amplifier stage can achieve sub-1dB NF performance with ~10 dB gain. The LNA dissipates 19.8 mW of dc power and has 0.77 dB NF while occupying 0.4 mm2. It succeeds 1.5 dBm of input-referred compression point. To the best of authors' knowledge, the presented work achieves the best NF performance in the literature of any LNA that utilizes SiGe technology.
关键词： noise,transceivers.,low-noise amplifier,BiCMOS integrated circuits
更新于2025-09-23 15:22:29