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[IEEE 2018 9th International Conference on Ultrawideband and Ultrashort Impulse Signals (UWBUSIS) - Odessa, Ukraine (2018.9.4-2018.9.7)] 2018 9th International Conference on Ultrawideband and Ultrashort Impulse Signals (UWBUSIS) - Features of Millimeter-Wave Ultra-Wideband Signals Application in Telecommunications
摘要： In the paper, the features of millimeter-wave ultra-wideband signals application, related to photon methods of generation and transmission of millimeter-wave signals, as well as the quasi-optical approach for modeling signal loss (amplification) are considered. It is proposed to use more accurate models of millimeter-wave ultra-wideband radio systems, which should correspond to the fundamental physical features of the propagation of millimeter waves, especially in urban conditions. It is shown that when calculating such systems it is necessary to take into account the noise associated with the method of generating millimeter waves.
关键词： energy budget,wireless communications,noise regime,ultra-wideband signal,millimeter-wave,radio-over-fiber
更新于2025-09-23 15:21:21
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[IEEE 2018 9th International Conference on Ultrawideband and Ultrashort Impulse Signals (UWBUSIS) - Odessa, Ukraine (2018.9.4-2018.9.7)] 2018 9th International Conference on Ultrawideband and Ultrashort Impulse Signals (UWBUSIS) - Graded Band Diode for Noise Generation in Terahertz Range
摘要： The noise signal sources at subterahertz(sub- in many terahertz(THz) region are useful THz) and applications such as tomographic imaging, spectroscopy, radars and other. The GaInAs-based diodes for noise generation in the sub-THz and THz region are proposed. The diodes based on the mechanism of impact ionization in graded- gap region and static high field domain formation near cathode. Ensemble Monte Carlo technique was used for diodes analyze. The spectral noise density power is calculated for difference profiles of spatial Ga distribution in GaInAs. It is found that the spectral noise density power of the proposed diodes exceeds the one of GaAs-based diodes by at least an order of magnitude.
关键词： spectral noise density power,impact ionization,compound,static cathode domain,graded band
更新于2025-09-23 15:21:21
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Optimized entanglement for quantum parameter estimation from noisy qubits
摘要： For parameter estimation from an N-component composite quantum system, it is known that a separable preparation leads to a mean-squared estimation error scaling as 1/N while an entangled preparation can in some conditions afford a smaller error with 1/N^2 scaling. This quantum superefficiency is however very fragile to noise or decoherence, and typically disappears with any small amount of random noise asymptotically at large N. To complement this asymptotic characterization, here we characterize how the estimation efficiency evolves as a function of the size N of the entangled system and its degree of entanglement. We address a generic situation of qubit phase estimation, also meaningful for frequency estimation. Decoherence is represented by the broad class of noises commuting with the phase rotation, which includes depolarizing, phase-flip and thermal quantum noises. In these general conditions, explicit expressions are derived for the quantum Fisher information quantifying the ultimate achievable efficiency for estimation. We confront at any size N the efficiency of the optimal separable preparation to that of an entangled preparation with arbitrary degree of entanglement. We exhibit the 1/N^2 superefficiency with no noise, and prove its asymptotic disappearance at large N for any nonvanishing noise configuration. For maximizing the estimation efficiency, we characterize the existence of an optimum Nopt of the size of the entangled system along with an optimal degree of entanglement. For nonunital noises, maximum efficiency is usually obtained at partial entanglement. Grouping the N qubits into independent blocks formed of Nopt entangled qubits restores at large N a nonvanishing efficiency that can improve over that of N independent qubits optimally prepared. Also, one inactive qubit included in the entangled probe sometimes stands as the most efficient setting for estimation. The results further attest with new characterizations the subtlety of entanglement for quantum information in the presence of noise, showing that when entanglement is beneficial, maximum efficiency is not necessarily obtained by maximum entanglement but instead by a controlled degree and finite optimal amount of it.
关键词： entanglement,quantum noise,Quantum estimation,quantum information
更新于2025-09-23 15:21:21
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8-GHz Locking Range and 0.4-pJ Low-Energy Differential Dual-Modulus 10/11 Prescaler
摘要： In this paper, we present a differential dual-modulus prescaler based on an injection-locked frequency divider (ILFD) for satellite low-noise block (LNB) down-converters. We fabricated three-stage differential latches using an ILFD and a cascaded differential divider in a 130-nm CMOS process. The prototype chip core area occupies 40 μm × 20 μm. The proposed prescaler achieved the locking range of 2.1–10 GHz with both divide-by-10 and divide-by-11 operations at a supply voltage of 1.4 V. Normalized energy consumptions are 0.4 pJ (= mW/GHz) at a 1.4-V supply voltage and 0.24 pJ at a 1.2-V supply voltage. To evaluate the tolerance of phase-difference deviation of the input differential pair from the perfect differential phase-difference, 180 degrees, we measured the operational frequencies for various phase-difference inputs. The proposed prescaler achieved the operational frequency range of 2.1–10 GHz with an input phase-difference deviation of less than 90 degrees. However, the range of operational frequency decreases as the phase-difference deviation increases beyond 90 degrees and reaches 3.9–7.9 GHz for the phase-difference deviation of 180 degrees (i.e. no phase difference). In addition, to confirm the fully locking operation, we measured the spurious noise and the phase noise degradation while reducing the supply voltage. The sensitivity analysis of the prescaler for various supply voltages can explain the above degradation of spectral purity. Spurious noise arises and the phase noise degrades with decreasing supply voltage due to the quasi- and non-locking operations. We verified the fully-locking operation for the LNB down-converter at a 1.4-V supply voltage.
关键词： CMOS,prescaler,ILFD,phase noise,phase difference
更新于2025-09-23 15:21:21
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Noise mitigation methods for ion detectors operating with a direct view of high temperature plasmas
摘要： We have developed an ion current measurement instrument with a direct view of a plasma that reduces the particle and radiation-induced noise current it detects by over three orders of magnitude, from tens of microamps to tens of nanoamps. This is accomplished using electric ?elds, magnetic ?elds, and physical shielding that limit the ?ux of particles and radiation into the instrument and suppress the secondary electrons produced within it by particle and radiation impact. Operation of this detector in various con?gurations, without an ion beam, has allowed identi?cation of the sources of noise current. In our experimental setup, the largest noise contributors were found to be plasma ions and photoelectric emission due to UV radiation.
关键词： high temperature plasmas,magnetic fields,electric fields,ion detectors,physical shielding,noise mitigation
更新于2025-09-23 15:21:21
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A new design on image processing scheme for smart car
摘要： As a product of comprehensive discipline, smart car involve artificial intelligence, computer vision, mechanical design, control science and vehicle engineering, etc. In this study, we take the NXP smart car competition as the background and put forward a new image processing scheme for smart car. The purpose of the image processing is to identify the different types of track from continuously transformed video images, to filter out noise and interference in the images, to identify the obstacles and extract the available left and right edges of the track. The proposed new scheme can effectively extract and classify the image features of different road types and give corresponding image processing algorithms. Experiments show that this scheme can efficiently deal with the probe images and provide accurate image information for smart car. Thus, the proposed scheme has a high practical value in applications, such as smart car contests and self-driving car industry.
关键词： noise filtering,NXP smart car competition,smart car,image processing,track identification,obstacle identification
更新于2025-09-23 15:21:21
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Sequential quantum secret sharing in noisy environments
摘要： Sequential quantum secret sharing (QSS) schemes do not use entangled states for secret sharing, rather they rely on sequential operations of the players on a single state which is circulated between the players. In order to check the viability of these schemes under imperfect operations and noise in the channels, we consider one such scheme in detail and show that under moderate conditions it is still possible to extract viable secure shared keys in this scheme. Although we specifically consider only one type of sequential scheme and three different noise models, our method is fairly general to be applied to other QSS schemes and noise models as well.
关键词： Noise,Sequential,Quantum secret sharing
更新于2025-09-23 15:21:21
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Transition kinetics of impurity doped quantum dots under time-dependent confinement potential: role of noise
摘要： Present study endeavors to analyze the role of Gaussian white noise and fluctuating confinement potential on time-average excitation rate (TAER) of impurity doped quantum dot (QD). The TAER profiles are exhaustively monitored as a number of physical quantities are varied over a range with and without noise. Application of noise to the system takes place in two different pathways known as ‘additive’ and ‘multiplicative’. And the fluctuation of the confinement potential has been considered to be cosinusoidal and random which induces the excitation of ground state electronic population to the higher states. The TAER profiles comprise of features like steady increase/decrease, maximization, minimization and saturation. However, the specific characteristics of a particular profile depend on presence/absence of noise, the noise mode, the nature of fluctuating confinement potential and the identity of the physical quantity being varied. Production of large TAER of doped QD depends on noise-mode and nature of fluctuating confinement potential based on which the noise strength is required to be maintained in the vicinity of some typical values.
关键词： additive noise,Gaussian white noise,time-average excitation rate,impurity doped quantum dot,multiplicative noise,fluctuating confinement potential
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) - Spectrally-selective Photovoltaics via Photonic Band Engineering in Absorbing Media
摘要： Partial discharge (PD) detection has been proved as an effective tool for insulation condition monitoring of power equipment. The energy of PD pulses is valuable for studying the characteristics of PD activities. This paper proposes a method for estimating the energy of PD pulses in the presence of white noise and narrowband noise. First, a maximum likelihood (ML) estimator of the pulse energy is derived from the probability distribution of the energy spectral coefficients. To implement the ML method, the sampled data are divided into signal frames and noise frames. The noise frames are then utilized for extracting noise parameters using the 3F-C method. Eventually, these noise parameters are applied to the signal frames to find the ML estimate of the pulse energy. To verify the effectiveness of the proposed method, both simulated data and measured data have been processed using the proposed method and the conventional wavelet packet (WP) denoising method. Compared with the WP denoising method, the proposed method has a higher accuracy and is less susceptible to the lengths of the sampling time windows. The advantage of the method is more significant in unfavorable conditions where the signal-to-noise ratio is low and the accurate lengths of the PD pulses are difficult to determine.
关键词： white noise,maximum likelihood (ML) estimation,3F-C method,Partial discharge (PD),narrowband noise,energy estimation
更新于2025-09-23 15:21:01
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Research and Modeling of Photovoltaic Array Channel Noise Characteristics
摘要： The photovoltaic array can be used as a medium for carrier communication to realize monitoring of photovoltaic components. Photovoltaic array channel noise, especially the pulse-type noise therein, seriously interferes carrier communication, so it is necessary to grasp the characteristics of the photovoltaic array channel noise. Photovoltaic array channel noise modeling is a key process when conducting anti-noise immunity tests of monitoring equipment. Based on the time-domain waveform of photovoltaic series channel noise which is measured in a photovoltaic power station, this paper proposes a photovoltaic array noise modeling method of Wavelet Peak-Type Markov chain, and studies the in?uence on modeling accuracy when different mother wavelets are adopted for modeling. From the simulation results, root mean square errors of the predicted output for Haar, Biorthogonal and Daubechies wavelet-based function modeling case are 0.9614 V, 1.4915 V and 0.7928 V, respectively, validating that Daubechies wavelet-based function is the best wavelet-based function of modeling. In the case that the peak of original noise reaches 20 V, the predicted mean absolute error of this model is only 0.4926 V, which not only veri?es the applicability of the Wavelet Peak-Type Markov chain model to the photovoltaic array channel noise, but also veri?es the applicability to the pulse-type noise.
关键词： photovoltaic array channel noise,noise characteristics and modeling,wavelet packet decomposition and recombination,Peak-Type Markov chain
更新于2025-09-23 15:21:01