- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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SNR analysis and estimation for efficient phase noise mitigation in millimetre-wave SC-FDE systems
摘要： This study demonstrates a signal-to-noise ratio (SNR) analysis and estimation algorithm for efficient phase noise mitigation that can be practically applied to single-carrier frequency-domain-equalisation (SC-FDE) systems that operate in millimetre-wave bands. First, the effect of phase noise in SC-FDE systems is investigated on each of the packet reception processes, namely, channel estimation, SNR estimation, and data-field reception. According to the analysis, an SNR estimation algorithm is proposed. The performance of minimum-mean-square-error equalisation and conventional phase noise mitigation algorithm can be enhanced using the proposed SNR estimation. The effectiveness of the proposed analysis and SNR estimation algorithm is verified through the link-level simulation. Compared with the conventional SNR estimation and the iterative phase noise mitigation algorithms, the proposed algorithm provides a lower packet-error rate without any iterative decoding process.
关键词： SNR analysis,phase noise mitigation,millimetre-wave,channel estimation,SC-FDE systems,packet-error rate
更新于2025-09-23 15:23:52
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Wavelet Denoising of High-Bandwidth Nanopore and Ion-Channel Signals
摘要： Recent work has pushed the noise-limited bandwidths of solid-state nanopore conductance recordings to more than 5 MHz and of ion channel conductance recordings to more than 500 kHz through the use of integrated complementary metal-oxide-semiconductor (CMOS) integrated circuits. Despite the spectral spread of the pulse-like signals that characterize these recordings when a sinusoidal basis is employed, Bessel filters are commonly used to denoise these signals to acceptable signal-to-noise ratios (SNRs) at the cost of losing many of the faster temporal features. Here, we report improvements to the SNR that can be achieved using wavelet denoising instead of Bessel filtering. When combined with state-of-the-art high-bandwidth CMOS recording instrumentation, we can reduce baseline noise levels by over a factor of four compared to a 2.5-MHz Bessel filter while retaining transient properties in the signal comparable to this filter bandwidth. Similarly, for ion channel recordings, we achieve a temporal response better than a 100-kHz Bessel filter with a noise level comparable to that achievable with a 25-kHz Bessel filter. Improvements in SNR can be used to achieve robust statistical analyses of these recordings, which may provide important insights into nanopore translocation dynamics and mechanisms of ion channel function.
关键词： ion channel,Nanopore,CMOS,wavelet,denoise.,SNR
更新于2025-09-23 15:23:52
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[IEEE 2018 International Conference on Communication and Signal Processing (ICCSP) - Chennai (2018.4.3-2018.4.5)] 2018 International Conference on Communication and Signal Processing (ICCSP) - A Comparative Analysis of Total Variation and Least Square Based Hyperspectral Image Denoising Methods
摘要： Hyperspectral image (HSI) with high spectral resolution will be always degraded by the noise accumulation. Therefore, image denoising is a fundamental preprocessing technique which improves the precision of successive processes like image classification, unmixing etc. In this paper, we compare least square (LS) weighted regularization in spectral domain with spatial least square and total variation (TV) denoising techniques. These methods are experimented on real, and noise simulated hyperspectral image datasets. The contrast and edges of the image are well preserved in the spectral LS. The image contrast varies in spatial LS, and edge informations are lost in TV. The experimental results show that, the spectral LS is superior to other two techniques in terms of visual interpretation, Signal-to-Noise Ratio (SNR) and Structural Similarity (SSIM) Index.
关键词： IBBC,SNR,Least Square,Hyperspectral Image,Denoising,Spectral domain,Total Variation,SSIM
更新于2025-09-23 15:22:29
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[IEEE 2018 International Conference on Radar (RADAR) - Brisbane, Australia (2018.8.27-2018.8.31)] 2018 International Conference on Radar (RADAR) - Fast Direction-of-Arrival Estimation in Coprime Arrays
摘要： We present a fast direction-of-arrival (DOA) estimation algorithm for coprime array structures. In many practical applications of radar signals processing, reducing the redundancy inherent in linear arrays is advantageous. Arrays employing a coprime-pair configuration offer an increased number of degrees of freedom and permit the detection of more sources than sensors. Traditionally, this is achieved using conventional subspace-based methods. While these methods, such as MUltiple Signal Classification (MUSIC), are capable of high-resolution, the computational complexity of these algorithms is a significant hindrance to their practical implementation as the number of sensors increases. Furthermore, they must resort to spatial smoothing in order to calculate the covariance matrix. We, on the other hand, propose a fast iterative interpolated beamforming algorithm that has a computational complexity of the same order as the fast Fourier transform (FFT). The proposed approach is capable of delivering high fidelity DOA estimates that outperform the traditional high resolution methods. Simulation results demonstrate the DOA estimation performance of the technique.
关键词： SNR,coprime arrays,FIIB,DOA estimation,MUSIC
更新于2025-09-23 15:22:29
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Applications of Cell-Ratio Constant False-Alarm Rate Method in Coherent Doppler Wind Lidar
摘要： A cell-ratio constant false-alarm rate (CR-CFAR) method for detecting the Doppler frequency shift is proposed to improve the accuracy of velocity measured by coherent Doppler wind lidar (CWL) in low signal-to-noise ratio (SNR) environments. The method analyzes the spectrum to solve issues of weak signal submergence in noise encountered in the widely used periodogram method. This characteristic is that the signal region slope is larger than the noise region slope in the frequency spectrum. We combined the ratio and CFAR to propose the CR-CFAR method. The peak area is discriminated from the spectrum using this method. By removing background noise, the peak signal is obtained along with the Doppler shift. To verify the CR-CFAR method, a campaign experiment using both CWL and a commercial Doppler lidar was performed in Hami, China (42°32' N, 94°03' E) during 1–7 June 2016. The results showed that the proposed method significantly improved the reliability of CWL data under low SNR conditions. The height—at which both horizontal wind speed correlativity and horizontal wind direction correlativity exceeded 0.99—increased by 65 m. The relative deviation of the horizontal wind speed at 120 m decreased from 40.37% to 11.04%. We used the CR-CFAR method to analyze continuous data. A greater number of wind field characteristics were obtained during observation compared to those obtained using the common wind field inversion method.
关键词： coherent Doppler wind lidar,cell-ratio constant false alarm rate (CR-CFAR),signal-to-noise ratio (SNR)
更新于2025-09-23 15:22:29
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A Novel Flexible Electro-textile 3T MRI RF Coil Array for Carotid Artery Imaging: Design, Characterization and Prototyping
摘要： Magnetic Resonance Imaging (MRI) is one of the most powerful imaging modality in clinics and is essential for the diagnosis of strokes through carotid artery imaging. The limiting factor for high quality MR imaging is the Signal to Noise Ratio (SNR) performance of the Radio Frequency (RF) coils. The current RF surface coils, however, are made of rigid materials or semi-flexible materials with very limited bending properties. As a result, their SNR is limited because they cannot be placed very close to the imaging area thus receiving noises from parts of the human body that are not intended to be imaged. Taking advantage of the computerized embroidery and laser cutting technology, in this work, we utilize electro-textile to design, fabricate and measure multi-layer RF coil array system for 3T MRI to improve the SNR performance. The proposed RF coil array system provides an ergonomic and high performance solution to the 3T MRI systems. A roadmap to systematically design electro-textile RF coil arrays is proposed. RF coil array is characterized to have the accurate resonant frequency, good impedance matching, and low mutual coupling. Additionally, magnetic field distribution, bending effects, human body effects are also discussed. A systematic method to characterize the performance of the electro-textile pattern is studied and used to assist the development and performance characterization. Finally the high resolution and high SNR images of various kinds of phantoms are obtained using the UCLA Antenna Lab electro-textile coil array after its integration with the 3T MRI scanners at UCLA David Geffen School of Medicine Translational Research Imaging Center (TRIC). Compared with the conventional surface coil, more than 10 dB SNR increase is observed at the depth of 0.5 cm and 3 dB increase at the depth of 3 cm.
关键词： coil,SNR,flexible antenna,MRI,embroidered,RF,e-textile
更新于2025-09-23 15:22:29
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[IEEE 2020 IEEE Radio and Wireless Symposium (RWS) - San Antonio, TX, USA (2020.1.26-2020.1.29)] 2020 IEEE Radio and Wireless Symposium (RWS) - Optimized LEDs Positions for Channel Analysis Performance of an Intra-Vehicle Visible Light Communication System
摘要： This paper investigates the effect of light emitting diodes (LEDs) positioning and allocation in the channel analysis performance for an indoor intra-vehicle visible light communication (VLC) system. The MATLAB simulation results focus on the received power and the signal to noise ratio (SNR) within a sports utility vehicle. Furthermore, this work aims to validate by investigating two different scenarios, one utilizing two sources of power and the other using three sources of power with various locations, how LED's spatial positioning affects the VLC system and the probability of error. Proving the demand for considering LEDs layout positioning while designing a VLC system.
关键词： SNR,LEDs positioning,Intra-vehicle,Visible light communication (VLC)
更新于2025-09-23 15:21:01
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[IEEE 2019 Chinese Automation Congress (CAC) - Hangzhou, China (2019.11.22-2019.11.24)] 2019 Chinese Automation Congress (CAC) - Temperature Compensation of Laser Triangular Displacement Sensor
摘要： This paper focuses on the end-to-end signal-to-noise ratio (SNR) maximization for full-duplex massive multiple-input multiple-output (MIMO) amplify-and-forward (AF) relay systems in the presence of direct link. First, we rigorously prove the asymptotic optimality of the maximum-ratio combining/maximum-ratio transmission (MRC/MRT) relaying strategy by taking into account the massive MIMO setup. Then, concerning the equivalent optimization problem with respect to source beamformer, we advocate a two-tier iterative algorithm relying on bi-section search, which guarantees a globally optimal solution. As a byproduct of this approach, we show that the optimal source beamformer has an interesting generalized channel matching structure associated with both source-relay and source-destination links. In addition to the optimal design, we devise a high SNR approximation-based suboptimal scheme, which admits a closed-form solution. Simulation results verify the advantage of our full-duplex relaying designs, and also demonstrate a negligible performance gap between the proposed optimal and suboptimal methods.
关键词： signal-to-noise ratio (SNR) maximization,massive multiple-input multiple-output (MIMO),Full-duplex amplify-and-forward (AF) relaying,direct link
更新于2025-09-23 15:19:57
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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) - Radiation Effects in Thinned GaAs Photovoltaics Incorporating DBRs for Improved Radiation Tolerance of Multijunctions
摘要： Blind interference alignment (BIA) can greatly improve the degree of freedom with the infinite signal-to-noise ratio (SNR) assumption. Under the finite SNR condition, noise accumulation can have a significantly negative impact on SNR, inducing severe performance deterioration. In particular, in multi-cell networks, the transmitter to which a user connects can further affect its received SNR and the BIA design. To address such problem, we present a user grouping scheme for reducing noise accumulation in a single cell and analyze the impact of transmitter connections on the user grouping scheme. SNR BIA in a multi-cell network is further proposed, which jointly optimizes the transmitter connection and the user grouping scheme. Extensive simulations demonstrate that the achievable sum rate of SNR BIA is 1.36 times, 1.66 times, and 2.68 times that of data shared BIA, standard BIA, and extended BIA reported in the literature, respectively, and SNR BIA is more robust to user mobility.
关键词： SNR reduced factor,effective degree of freedom,Blind interference alignment,transmitter connection
更新于2025-09-23 15:19:57
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Performance studies of MIMO based DCO-OFDM in underwater wireless optical communication systems
摘要： The research in underwater communication system is focused towards wireless networks in view of recent developments in wireless technology and increasing need for deep sea data mining. The underwater wireless optical communication (UWOC) have more advantages for short-range wireless links due to very high bandwidth and data rate than acoustic communication. Although UWOC offers high capacity links at low latencies, they suffer from limited communication range due to various distinctive characteristics of underwater channel. A major degrading effect associated with the underwater channel is turbulence-induced fading. To mitigate this fading and to extend the viable communication range, spatial multipath diversity techniques can be adopted over UWOC links. The proposed work evaluates the performance of a multicarrier modulation scheme, i.e., MIMO based DC biased Optical Orthogonal Frequency Division Multiplexing (DCO-OFDM) for underwater wireless optical channel. The simulation of MIMO-DC biased optical OFDM technique employing spatial diversity in underwater optical communication is a novel approach towards the determination of an optimal modulation technique for underwater optical wireless channels. The performance is evaluated based on the various parameters such as Signal to Interference plus Noise Ratio (SINR), Throughput and Bit Error Rate (BER). A simple experiment is conducted to demonstrate the BER performance assessment for different link distance of 0.45 m and 1.5 m with different transmitter and receiver configurations (SIMO and MIMO) for both clear water and coastal water using MIMO DCO OFDM technique.
关键词： SNR,BER,MIMO,DCO-OFDM,QAM,Underwater wireless optical communication
更新于2025-09-23 15:19:57