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The concise fractional Fourier transform and its application in detection and parameter estimation of the linear frequency-modulated signal 认领 引用 被引量：13
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作者 CHEN Yanli GUO Lianghao GONG Zaixiao 《Chinese Journal of Acoustics》 CSCD 2017年第1期70-86,共17页
A concise fractional Fourier transform （CFRFT） is proposed to detect the linear frequency-modulated （LFM） signal with low signal to noise ratio （SNR）. The frequency axis in time-frequency plane of the CFRFT is r... A concise fractional Fourier transform （CFRFT） is proposed to detect the linear frequency-modulated （LFM） signal with low signal to noise ratio （SNR）. The frequency axis in time-frequency plane of the CFRFT is rotated to get the spectrum of the signal in different an- gles using chirp multiplication and Fourier transform （FT）. For LFM signal which distributes as a straight line in time-frequency plane, the CFRFT can gather the energy in the corresponding angle as a peak and improve the detection SNR, thus the LFM signal of low SNR can be de- tected. Meanwhile, the location of the peak value relates to the parameters of the LFM signal. Numerical simulations and experimental results show that, the proposed method can be used to efficiently detect the LFM signal masked by noise and to estimate the signal＇s parameters accurately. Compared with the conventional fractional Fourier transform （FRFT）, the CFRFT reduces the transform complexity and improves the real-time detection performance of LFM signal. 展开更多
关键词 LFM FRFT The concise fractional Fourier transform and its application in detection and parameter estimation of the linear frequency-modulated signal
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A TECHNIQUE FOR MEASURING THE LINEARITY OF A LINEARLY FREQUENCY-MODULATED SIGNAL 认领 引用
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作者 宋景唯 《Journal of Electronics(China)》 1995年第1期66-72,共7页
A technique for measuring the linearity of a linearly frequency-modulated continuous wave (LFM-CW) signal is presented. It uses a delay-line and a mixer to sense the slope of the output of a sweep oscillator, so that ... A technique for measuring the linearity of a linearly frequency-modulated continuous wave (LFM-CW) signal is presented. It uses a delay-line and a mixer to sense the slope of the output of a sweep oscillator, so that the original form of frequency function deviated from idealized linear slope is retrieved by means of spectrum analysis. Consequently,the linearity of the LFM signal is determined. The formulation is performed based on the principle that an angle-modulated signal can be approximated by an amplitude-modulated signal if the modulation coefficient is sufficiently small. To examine the validity of the procedure and to study the effect of each parameter on the accuracy of measurement, a number of computer simulations has been made. The results of simulation show that the error of the measurement is less than 2%. 展开更多
关键词 Linearity Linearly frequency-modulated continuous wave Frequency deviation function
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Parameter estimation method for a linear frequency modulation signal with a Duffing oscillator based on frequency periodicity 认领 引用
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作者 张宁哲 闫晓鹏 +2 位作者 吕明慧 陈秀梅 黄鼎琨 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第8期237-246,共10页
In view of the complexity of existing linear frequency modulation(LFM)signal parameter estimation methods and the poor antinoise performance and estimation accuracy under a low signal-to-noise ratio(SNR),a parameter e... In view of the complexity of existing linear frequency modulation(LFM)signal parameter estimation methods and the poor antinoise performance and estimation accuracy under a low signal-to-noise ratio(SNR),a parameter estimation method for LFM signals with a Duffing oscillator based on frequency periodicity is proposed in this paper.This method utilizes the characteristic that the output signal of the Duffing oscillator excited by the LFM signal changes periodically with frequency,and the modulation period of the LFM signal is estimated by autocorrelation processing of the output signal of the Duffing oscillator.On this basis,the corresponding relationship between the reference frequency of the frequencyaligned Duffing oscillator and the frequency range of the LFM signal is analyzed by the periodic power spectrum method,and the frequency information of the LFM signal is determined.Simulation results show that this method can achieve high-accuracy parameter estimation for LFM signals at an SNR of-25 dB. 展开更多
关键词 linear frequency modulation(LFM)signal Duffing oscillator frequency periodicity parameter estimation
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Effect of inertial mass on a linear system driven by dichotomous noise and a periodic signal 认领 引用 被引量：1
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作者 李鹏 聂林如 +1 位作者 吕秀敏 张启波 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第10期123-131,共9页
A linear system driven by dichotomous noise and a periodic signal is investigated in the underdamped case. The exact expressions of output signal amplitude and signal-to-noise ratio （SNR） of the system are derived. ... A linear system driven by dichotomous noise and a periodic signal is investigated in the underdamped case. The exact expressions of output signal amplitude and signal-to-noise ratio （SNR） of the system are derived. By means of numerical calculation, the results indicate that （i） at some fixed noise intensities, the output signal amplitude with inertial mass exhibits the structure of a single peak and single valley, or even two peaks if the dichotomous noise is asymmetric; （ii） in the case of asymmetric dichotomous noise, the inertial mass can cause non-monotonic behaviour of the output signal amplitude with respect to noise intensity; （iii） the curve of SNR versus inertial mass displays a maximum in the case of asymmetric dichotomous noise, i.e., a resonance-like phenomenon, while it decreases monotonically in the case of symmetric dichotomous noise; （iv） if the noise is symmetric, the inertial mass can induce stochastic resonance in the system. 展开更多
关键词 underdamped linear system dichotomous noise inertial mass output signal amplitude,signal-to-noise ratio
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WIDELY LINEAR RLS CONSTANT MODULUS ALGORITHM FOR COMPLEX-VALUED NONCIRCULAR SIGNALS 认领 引用 被引量：1
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作者 Zhang Ting Wang Bin Liu Shigang 《Journal of Electronics(China)》 2014年第5期416-426,共11页
Based on the constant modulus criterion, a new Widely Linear(WL) blind equalizer and a novel widely linear recursive least square constant modulus algorithm are proposed to improve the blind equalization performance f... Based on the constant modulus criterion, a new Widely Linear(WL) blind equalizer and a novel widely linear recursive least square constant modulus algorithm are proposed to improve the blind equalization performance for complex-valued noncircular signals. The new algorithm takes advantage of the WL filtering theory by taking full use of second-order statistical information of the complex-valued noncircular signals. Therefore, the weight vector contains the complete second-order information of the real and imaginary parts to decrease the residual inter-symbol interference effectively. Theoretical analysis and simulation results show that the proposed scheme can significantly improve the equalization performance for complex-valued noncircular signals compared with traditional blind equalization algorithms. 展开更多
关键词 Complex-valued noncircular signals Blind equalization Widely Linear(WL) filtering Constant modulus
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Early detection of sudden cardiac death by using classical linear techniques and time-frequency methods on electrocardiogram signals 认领 引用 被引量：2
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作者 Elias Ebrahimzadeh Mohammad Pooyan 《Journal of Biomedical Science and Engineering》 2011年第11期699-706,共8页
Early detection of sudden cardiac death may be used for surviving the life of cardiac patients. In this paper we have investigated an algorithm to detect and predict sudden cardiac death, by processing of heart rate v... Early detection of sudden cardiac death may be used for surviving the life of cardiac patients. In this paper we have investigated an algorithm to detect and predict sudden cardiac death, by processing of heart rate variability signal through the classical and time-frequency methods. At first, one minute of ECG signals, just before the cardiac death event are extracted and used to compute heart rate variability (HRV) signal. Five features in time domain and four features in frequency domain are extracted from the HRV signal and used as classical linear features. Then the Wigner Ville transform is applied to the HRV signal, and 11 extra features in the time-frequency (TF) domain are obtained. In order to improve the performance of classification, the principal component analysis (PCA) is applied to the obtained features vector. Finally a neural network classifier is applied to the reduced features. The obtained results show that the TF method can classify normal and SCD subjects, more efficiently than the classical methods. A MIT-BIH ECG database was used to evaluate the proposed method. The proposed method was implemented using MLP classifier and had 74.36% and 99.16% correct detection rate (accuracy) for classical features and TF method, respectively. Also, the accuracy of the KNN classifier were 73.87% and 96.04%. 展开更多
关键词 Sudden Cardiac Death Heart Rate Variability Time-Frequency Transform Electrocardiogram Signal Linear Processing
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UNCERTAINTY PRINCIPLES AND SIGNAL RECOVERY RELATED TO THE CANONICAL FOURIER-BESSEL TRANSFORM 认领 引用
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作者 Jihed SAHBANI Lazhar DHAOUADI 《Acta Mathematica Scientia》 SCIE CSCD 2025年第5期2190-2207,共18页
The aim of this paper is to prove another variation on the Heisenberg uncertainty principle,we generalize the quantitative uncertainty relations in n different(time-frequency)domains and we will give an algorithm for ... The aim of this paper is to prove another variation on the Heisenberg uncertainty principle,we generalize the quantitative uncertainty relations in n different(time-frequency)domains and we will give an algorithm for the signal recovery related to the canonical Fourier-Bessel transform. 展开更多
关键词 Fourier Bessel transform linear canonical transform quantitative uncertainty principles Heisenberg uncertainty principle signal recovery
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Intelligent Estimation of ESR and C in AECs for Buck Converters Using Signal Processing and ML Regression 认领 引用
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作者 Acácio M.R.Amaral 《Computers, Materials & Continua》 SCIE EI 2025年第11期3825-3859,共35页
Power converters are essential components in modern life,being widely used in industry,automation,transportation,and household appliances.In many critical applications,their failure can lead not only to financial loss... Power converters are essential components in modern life,being widely used in industry,automation,transportation,and household appliances.In many critical applications,their failure can lead not only to financial losses due to operational downtime but also to serious risks to human safety.The capacitors forming the output filter,typically aluminumelectrolytic capacitors(AECs),are among the most critical and susceptible components in power converters.The electrolyte in AECs often evaporates over time,causing the internal resistance to rise and the capacitance to drop,ultimately leading to component failure.Detecting this fault requires measuring the current in the capacitor,rendering the method invasive and frequently impractical due to spatial constraints or operational limitations imposed by the integration of a current sensor in the capacitor branch.This article proposes the implementation of an online noninvasive fault diagnosis technique for estimating the Equivalent Series Resistance(ESR)and Capacitance(C)values of the capacitor,employing a combination of signal processing techniques(SPT)and machine learning(ML)algorithms.This solution relies solely on the converter’s input and output signals,therefore making it a non-invasive approach.The ML algorithm used was linear regression,applied to 27 attributes,21 of which were generated through feature engineering to enhance the model’s performance.The proposed solution demonstrates an R2 score greater than 0.99 in the estimation of both ESR and C. 展开更多
关键词 Buck converter boost converter AECs fault detection predictive maintenance signal processing techniques feature engineering linear regression and K-nearest neighbors
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Design and commissioning of a multiharmonic bunching system for the high‑intensity heavy‑ion accelerator facility 认领 引用
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作者 Zheng‑Rong Wu Long‑Bo Shi +7 位作者 Zheng‑Long Zhu Ke‑An Jin Guo‑Dong Jiang Zhen Gao Feng Qiu Yao Yang Gui‑Rong Huang Lie‑Peng Sun 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2026年第8期68-81,共14页
The high-intensity heavy ion accelerator facility(HIAF)is currently under construction in China for multidiscipline research.The front-end section has been completed and is currently undergoing commissioning.To optimi... The high-intensity heavy ion accelerator facility(HIAF)is currently under construction in China for multidiscipline research.The front-end section has been completed and is currently undergoing commissioning.To optimize beam quality,an external multiharmonic buncher(MHB)that reduces longitudinal emittance has been installed before the radio frequency quadrupole.The MHB system includes both cavity and low-level radio frequency(LLRF)system designs.The cavity consists of a quarter-wave resonator and a half-wave resonator,with a single grid-less gap,capable of providing the required voltage of 1.5 kV.With the newly developed multiharmonic LLRF control system,precise individual control of the four-harmonic components can be achieved,enabling flexible synthesis of various waveform configurations.The buncher can generate a 1st+2nd+3rd+4th harmonic bunching electric field with a fundamental frequency of 40.625 MHz,or a 1st+2nd harmonic bunching electric field with a fundamental frequency of 81.25 MHz.In addition,the first O6+beam commissioning results of front-end accelerator are presented herein,providing insights into the contribution of the MHB. 展开更多
关键词 Heavy-ion Buncher Linear accelerator Multiharmonic signal
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基于声信号多特征时频谱图的供水管网漏损检测 认领 引用 被引量：1
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作者 孙庆帅 张英杰 +1 位作者 刘华亮 李述杰 《控制与决策》 EI CSCD 北大核心 2026年第5期1381-1391,共11页
基于声信号的漏损检测方法在人工巡检中具有重要应用价值,正逐步发展为一种新兴的远程监测手段.传统基于深度学习的漏损声信号识别方法往往受到信号预处理流程繁琐以及环境噪声干扰的限制,难以在其他供水管网中实现良好的泛化性能,漏损... 基于声信号的漏损检测方法在人工巡检中具有重要应用价值,正逐步发展为一种新兴的远程监测手段.传统基于深度学习的漏损声信号识别方法往往受到信号预处理流程繁琐以及环境噪声干扰的限制,难以在其他供水管网中实现良好的泛化性能,漏损检测的准确率亦有待进一步提升.鉴于此,首先,针对供水管网声信号构建高时间分辨率和高频率分辨率下的线性谱图和对数梅尔谱图,兼顾声信号的高频与低频特征,突出短时动态变化以及微弱频率特征,并以并行方式输入至卷积神经网络;然后,引入并行机制的时-频注意力卷积块进行特征提取,增强对时间和频率维度的细粒度特征捕捉能力;最后,利用真实供水管网声信号数据和物理仿真数据对所提出方法进行漏损检测性能实验验证,实验结果表明,所提出方法显著提高了对漏损事件的识别率,具有良好的鲁棒性和泛化能力. 展开更多
关键词 供水管网 漏损检测 声信号分析 时频谱图 线性谱图 对数梅尔谱图 注意力机制
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基于信噪比改进预测的金融建模方法与实证研究 认领 引用
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作者 林艳艳 朱顺伟 吴冲锋 《管理科学学报》 CSSCI CSCD 北大核心 2026年第1期18-38,共21页
在经典的线性回归模型基础上,考虑拟合模型参数估计的随机性因素后,应该对经典的线性回归模型给予一定的修正才能更好地预测未来.因此,本文提出基于信息噪声比修正的L乘子模型,它架起拟合最优模型与预测最优模型的关系.文中给出了最优L... 在经典的线性回归模型基础上,考虑拟合模型参数估计的随机性因素后,应该对经典的线性回归模型给予一定的修正才能更好地预测未来.因此,本文提出基于信息噪声比修正的L乘子模型,它架起拟合最优模型与预测最优模型的关系.文中给出了最优L乘子的显式解,并在考虑预测变量存在自相关性的情况下,给出了L的改进表达式.然后,本文探讨了L乘子的两种估计方法.实证上,通过将L乘子模型应用于股票收益率的预测问题验证了本文理论有效性.结果表明:1)相较于基准的线性回归模型,L乘子模型具有更高的预测精度;2)噪声较高、历史样本量较小或预测变量的信息含量较低时,L乘子的修正力度较大,带来的预测改进效果越明显;3)对于均值-方差效用的投资者而言,这种预测性能的改进可以为其带来投资绩效提升.这些结论也满足一系列的稳健性检验. 展开更多
关键词 线性回归 噪声 信息噪声比 股票收益率 预测
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基于线性阵列公式的MRLA高效构造策略 认领 引用
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作者 唐保祥 任韩 《深圳大学学报（理工版）》 CAS CSCD 北大核心 2026年第1期118-126,I0006-I0009,共9页
针对雷达、微波辐射计及无线通信系统中大阵元最小冗余线性阵列(minimum redundancy linear array,MRLA)的获取难题——计算机长时间运算仅得有限解、易遗漏适配应用的最优阵列,通过分析L上元素最少的受限差基、最大连续基线长为L的MRL... 针对雷达、微波辐射计及无线通信系统中大阵元最小冗余线性阵列(minimum redundancy linear array,MRLA)的获取难题——计算机长时间运算仅得有限解、易遗漏适配应用的最优阵列,通过分析L上元素最少的受限差基、最大连续基线长为L的MRLA、长度是L的完美稀疏尺的刻度值、L条边的极小优美图顶点标号各自定义的条件,经循环论证,证明四者数学等价;证明得到:线性阵列成对存在;线性阵列的冗余度≥1,阵元数超过4时冗余度>1;若MRLA最大连续基线长度为L且阵元数为n,则最大连续基线长度为L+1的MRLA阵元数不超过n+1.基于大规模MRLA数据分析,提出假设:冗余度≤1.5的线性阵列可视为MRLA.研究还发现了两类新型线性阵列解析公式,能高效筛选出无穷多的MRLA配置模式(即均为完美稀疏尺的刻度数值),并可根据实际需求灵活设定线性阵列冗余度的筛选阈值,为MRLA的应用和完美稀疏尺的设计提供了理论支撑. 展开更多
关键词 无线通信技术 阵列信号处理 线性阵列 最小冗余线性阵列 受限差基 完美稀疏尺 极小优美图
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面向大规模新型电力系统小干扰稳定分析的特征值计算技术综述及展望 认领 引用
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作者 王渝红 苏苗红 +2 位作者 高仕林 叶华 陈颖 《电力自动化设备》 EI CSCD 北大核心 2026年第8期175-185,共11页
新型电力系统“双高”特征愈发明显,电力电子设备主导的新型电力系统小干扰稳定问题突出,传统机电暂态小干扰稳定分析方法难以适用,需采用电磁暂态小干扰稳定分析方法来评估新型电力系统的稳定性。在电磁暂态小干扰稳定分析方法中,特征... 新型电力系统“双高”特征愈发明显,电力电子设备主导的新型电力系统小干扰稳定问题突出,传统机电暂态小干扰稳定分析方法难以适用,需采用电磁暂态小干扰稳定分析方法来评估新型电力系统的稳定性。在电磁暂态小干扰稳定分析方法中,特征值分析法理论基础完备、应用广泛,但在应用于大规模系统时,存在电磁暂态线性化状态空间方程构建困难、高阶状态矩阵特征值求解困难等问题。首先分析了大规模新型电力系统电磁暂态模型特征值分析技术的迫切需求。然后分别从新型电力系统电磁暂态模型平衡点建模、线性化状态空间建模及关键特征值高效计算三方面,总结了电磁暂态模型特征值分析方法的研究现状和存在的挑战。最后对未来的研究方向进行了展望。 展开更多
关键词 新型电力系统 电磁暂态模型 平衡点建模 线性化状态空间建模 小干扰稳定分析 特征值计算
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交叉口车道布局与信号控制方案快速协同优化 认领 引用
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作者 杨震 许逸超 +1 位作者 王宝杰 李根 《科学技术与工程》 EI 北大核心 2026年第2期832-840,共9页
为实现交叉口时空资源的高效利用,对交叉口车道布局与信号控制协同优化问题进行了研究。首先,基于美国国家电气制造商协会(National Electric Manufacturers Association,NEMA)的双环标准相位,考虑饱和流量随车道数增加的递减效应,以信... 为实现交叉口时空资源的高效利用,对交叉口车道布局与信号控制协同优化问题进行了研究。首先,基于美国国家电气制造商协会(National Electric Manufacturers Association,NEMA)的双环标准相位,考虑饱和流量随车道数增加的递减效应,以信号周期最小化为模型的目标,以车道布局、相位时长、饱和流量、交通流量、流量比、饱和度为模型的约束条件,建立了交叉口车道布局与信号控制方案协同优化的0-1混合整数线性规划(binary-mix-integer-linear-program,BMILP)模型。其次,使用分支定界法,快速得到模型的全局最优解。最后,选取南京市的北京东路-丹凤街交叉口,设定了3组不同的流量组合,对模型进行了实例验证。结果表明:模型可根据交叉口交通流量的分布特征,生成相应的车道布局和信号配时方案,无须预设特定的车道布局模式,且能灵活配置共享车道和右转相位;同时,对模型的最大可接受饱和度参数进行了敏感性分析,讨论了该参数和信号周期、相位饱和度等优化结果的关系。 展开更多
关键词 信号控制 车道布局 双环相位 协同优化 0-1混合整数线性规划
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Chirp-Rate Resolution of Fractional Fourier Transform in Multi-component LFM Signal 认领 引用 被引量：13
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作者 刘锋 黄宇 +1 位作者 陶然 王越 《Journal of Beijing Institute of Technology》 EI CAS 2009年第1期74-78,共5页
Distinguishing close chirp-rates of different linear frequency modulation （LFM） signals under concentrated and complicated signal environment was studied. Firstly, detection and parameter estimation of multi-compone... Distinguishing close chirp-rates of different linear frequency modulation （LFM） signals under concentrated and complicated signal environment was studied. Firstly, detection and parameter estimation of multi-component LFM signal were used by discrete fast fractional Fourier transform （FrFT）. Then the expression of chirp-rate resolution in fractional Fourier domain （FrFD） was deduced from discrete normalize time-frequency distribution, when multi-component LFM signal had only one center frequency. Furthermore, the detail influence of the sampling time, sampling frequency and chirp-rate upon the resolution was analyzed by partial differential equation. Simulation results and analysis indicate that increasing the sampling time can enhance the resolution, but the influence of the sampling frequency can he omitted. What＇s more, in multi-component LFM signal, the chirp-rate resolution of FrFT is no less than a minimal value, and it mainly dependent on the biggest value of chirp-rates, with which it has an approximately positive exponential relationship. 展开更多
关键词 fractional Fourier transform（FrFT） resolution linear frequency modulation（LFM） signal chirp-rate
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Wigner-Hough transform based on slice's entropy and its application to multi-LFM signal detection 认领 引用 被引量：6
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作者 Hongwei Wang Xiangyu Fan +1 位作者 You Chen Yuanzhi Yang 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2017年第4期634-642,共9页
To enhance the capacity of the radar-reconnaissance interception receiver recognizing linear frequency modulated (LFM) at a low signal-noise ratio, this paper presents WignerHough transform (WHT) of the LFM signal and... To enhance the capacity of the radar-reconnaissance interception receiver recognizing linear frequency modulated (LFM) at a low signal-noise ratio, this paper presents WignerHough transform (WHT) of the LFM signal and its corresponding characteristics, derives the probability density functions of the LFM signal and Gaussian white noise within WHT based on entropy (WHTE), dimension under different assumptions and puts forward a WHT algorithm based on entropy of slice to improve the capacity of detecting the LFM signal. Entropy of the WHT domain slice is adopted to assess the information size of polar radius or angle slice, which is converted into the weight factor to weight every slice. Double-deck weight is used to weaken the influences of noise and disturbance terms and WHTE treatment and signal detection procedure are also summarized. The rationality of the algorithm is demonstrated through theoretical analysis and formula derivation, the efficiency of the algorithm is verified by simulation comparison between WHT, fractional Fourier transform and periodic WHT, and it is highlighted that the WHTE algorithm has better detection accuracy and range of application against strong noise background. 展开更多
关键词 low signal-to-noise ratio linear frequency modulated signal probability density function Wigner-Hough transform (WHT) signal detection entropy of slice
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Direct position determination using single moving rotating linear array: Noncoherent and coherent processing 认领 引用 被引量：10
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作者 Guizhou WU Min ZHANG +1 位作者 Chaoxin HE Fucheng GUO 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2020年第2期688-700,共13页
To improve the resolution and accuracy of Direct Position Determination(DPD),this paper investigates the problem of positioning multiple emitters directly with a single moving Rotating Linear Array(RLA).Firstly,the ge... To improve the resolution and accuracy of Direct Position Determination(DPD),this paper investigates the problem of positioning multiple emitters directly with a single moving Rotating Linear Array(RLA).Firstly,the geometry of the RLA is formulated and analysed.According to its geometry,the intercepted noncoherent signals in multiple interception intervals are modeled.Correspondingly,the Multiple SIgnal Classification(MUSIC)based noncoherent DPD approach is proposed.Secondly,the synchronous coherent pulse signals are individually considered and formulated.And the coherent DPD approach which aims for localizing this special type of signal is presented by stacking all array responses at different interception intervals.Besides,we also derive the constrained Cramer-Rao Lower Bound(CRLB)expression for both noncoherent and coherent DPD with RLA under the constraint that the altitudes of the emitters are known.At last,computer simulations are included to examine the performance of the proposed approach.The results demonstrate that the localization accuracy and resolution of DPD with single moving linear array can be significantly improved by the array rotation.In addition,coherent DPD with RLA further improves the resolution and increases the maximum emitter number that can be localized compared with the noncoherent DPD with RLA. 展开更多
关键词 Coherent signal processing Constrained Cramer-Rao lower bound Direct position determination Multiple signal classification Resolution Rotating linear array
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Vector tracking loops in GNSS receivers for dynamic weak signals 认领 引用 被引量：7
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作者 Jing Liu Xiaowei Cui +1 位作者 Mingquan Lu Zhenming Feng 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2013年第3期349-364,共16页
Vehicle positioning with the global navigation satellite system （GNSS） in urban environments faces two problems which are attenuation and dynamic. For traditional GNSS receivers hardly able to track dynamic weak sig... Vehicle positioning with the global navigation satellite system （GNSS） in urban environments faces two problems which are attenuation and dynamic. For traditional GNSS receivers hardly able to track dynamic weak signals, the coupling between all visible satellite signals is ignored in the absence of navigation state feedback, and thermal noise error and dynamic stress threshold are contradictory due to non-coherent discriminators. The vector delay/frequency locked loop （VDFLL） with navigation state feedback and the joint vector tracking loop （JVTL） with coherent discriminator which is a synchronization parameter tracking loop based on maximum likelihood estimation （MLE） are proposed to improve the tracking sensitivity of GNSS receiver in dynamic weak signal environments. A joint vector position tracking loop （JVPTL） directly tracking user position and velocity is proposed to further improve tracking sensitivity. The coherent navigation parameter discriminator of JVPTL, being able to ease the contradiction between thermal noise error and dynamic stress threshold, is based on MLE according to the navigation parameter based linear model of received baseband signals. Simulation results show that JVPTL, which combines the advantages of both VDFLL and JVTL, performs better than both VDFLL and JVTL in dynamic weak signal environments. 展开更多
关键词 dynamic weak signal maximum likelihood estimation （MLE） linear model navigation state feedback coherent discriminator
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基于奇偶性的四元数线性正则变换分解及仿真 认领 引用
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作者 姬锦仪 冯子健 +2 位作者 郭子园 杨茜 冯强 《中山大学学报（自然科学版）（中英文）》 CAS CSCD 北大核心 2026年第3期170-178,共9页
在信号处理与代数分析领域,四元数及其变换理论因其独特的数学特性受到广泛关注.本文研究右侧四元数线性正则变换(QLCT).首先,介绍了四元代数的基本概念,包括四元数的表示、运算规则、共轭、范数等,并给出了QLCT的定义;其次,基于信号的... 在信号处理与代数分析领域,四元数及其变换理论因其独特的数学特性受到广泛关注.本文研究右侧四元数线性正则变换(QLCT).首先,介绍了四元代数的基本概念,包括四元数的表示、运算规则、共轭、范数等,并给出了QLCT的定义;其次,基于信号的奇偶性,提出了右侧QLCT的偶分量与奇分量分解方法,深入探讨了该变换的相关性质并给出证明.最后,以高斯信号为例进行仿真实验,验证了理论推导,并展示了四元数值信号及其QLCT变换后各分量的特性. 展开更多
关键词 四元数 四元数线性正则变换 高斯信号
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Widely linear UKF constant modulus algorithm for blind adaptive beamforming 认领 引用 被引量：1
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作者 Huaming Qian Ke Liu +2 位作者 Long Li Linchen Qian Junda Ma 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2017年第3期413-423,共11页
Based on a uniform linear array, a new widely linear unscented Kalman filter-based constant modulus algorithm (WL-UKF-CMA) for blind adaptive beamforming is proposed. The new algorithm is designed according to the con... Based on a uniform linear array, a new widely linear unscented Kalman filter-based constant modulus algorithm (WL-UKF-CMA) for blind adaptive beamforming is proposed. The new algorithm is designed according to the constant modulus criterion and takes full advantage of the noncircular property of the signal of interest (SOI), significantly increasing the output signal-to interference-plus-noise ratio (SINR), enhancing the convergence speed and decreasing the steady-state misadjustment. Since it requires no known training data, the proposed algorithm saves a large amount of the available spectrum. Theoretical analysis and simulation results are presented to demonstrate its superiority over the conventional linear least mean square-based CMA (L-LMS-CMA), the conventional linear recursive least square-based CMA (L-RLS-CMA), WL-LMS-CMA, WL-RLS-CMA and L-UKF-CMA. 展开更多
关键词 widely linear filtering blind beamforming noncircular signals constant modulus algorithm unscented Kalman filtering
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