随机噪声信号的功率谱估计的仿真

在通讯与电子信息工程行业及领域中,大部分问题的解决需要进行估计一个随机信号在频率域上的功率谱分布,诸如此类的问题有很多,比如：设计滤波器消除噪声信号,振动随机信号的回波抵消,随机信号的特征抽取与表示等等。功率谱估计的分类：一般分为两大类,一类是参数法功率谱估计,一类是非参数法功率谱估计。参数法功率谱估计通常对数据进行一种建模,比如把数据建模成滑动平均模型（Moving Average）,或者自回归（Autoregressive）模型,而非参数法功率谱估计。除了要求信号满足广义平稳之外,不需要其它的统计假设。与非参数法相比较,参数法的优点是在一个给定的数据集合上能够有较少的误差、偏差与方差。     

基于双核技术的数字涡街流量计信号处理系统

介绍一套数字信号处理器 (DSP)和 16位单片机 (MSP4 30 )相结合的双核结构的数字涡街信号处理系统 ,采用松弛陷波周期图法计算涡街流量计信号的频率。实验结果表明 ,该双核式数字涡街流量信号处理系统可以有效地扩大涡街的量程比 ,滤除各种噪声及干扰 ,实现整机数据处理的实时性 ,具有很好的发展前景     

Spectral estimation using modified Daniell method

In this article, a new spectral estimation method is proposed based on modifying the Daniell method. This modification is done by decomposing the periodogram before windowing it. It reduces the variance of estimation without removing the details.     

LFM signal detection using LPP-Hough transform

This paper presents a new method to detect linear frequency modulated (LFM) signals by jointly using the local polynomial periodogram (LPP) and the Hough transform. Theoretical comparison is made on the 3 dB signal-to-noise ratios (SNRs), achieved by the pseudo-Wigner-Ville distribution (PWVD) and the LPP, to show that the latter is important to achieve significant increase of noise margins in the Hough transform domain. The results of computer simulations are presented for the detection of mono- and multi-component LFM signals corrupted by additive white Gaussian noise and impulsive noise. It is also found that by using the time-frequency filtering, the computational complexity of the detection can be substantially reduced. Both the theoretical analysis and the simulation results show that the proposed method achieves significant performance improvement on detecting the LFM signals in very low signal-to-noise ratio environments.     

基于a参数平均的AR谱估计在心率变异性研究中的应用

利用α参数平均的AR估计法分析研究心率变异性信号的AR谱。分析结果表明，这种方法（特别是在低信噪比场合）能够明显改善了HRV信号AR谱的测频性能。     

基于局域线性法和卡尔曼滤波的强混沌背景下正弦信号恢复的混合算法

本文提出一种局域线性-周期图检测-卡尔曼滤波混合算法LL-P-KF,用来恢复强混沌背景下正弦信号.首先,建立混沌信号的一步预测模型;然后,利用周期图检测潜在周期;最后,应用卡尔曼滤波从误差中恢复正弦信号.仿真实验表明该混合算法具有较好的恢复效果.     

环境激励下输电塔动力特性参数识别

输电塔的动力参数是进行抗风设计的重要依据,其中阻尼比的取值对输电塔风振系数的计算影响显著.以一基110 kV输电塔为背景,分别采用环境随机激振和牵引绳激振对输电塔施加激振作用,采用修正平均周期图法消除环境噪声对真实信号的干扰,在考察峰值频率相干度在95％以上的基础上,采用半功率带宽法识别输电塔的频率和阻尼比等动力参数....     

Hidden Frequency Estimation with Data Tapers

The detection and estimation of hidden frequencies has long been recognized as an important problem in time series. In this paper we study the asymptotic theory for two methods of high-precision estimation of hidden frequencies (the secondary analysis method and the maximum periodogram method) using a data taper. In ordinary situations, a data taper may reduce the estimation precision slightly. However, when there are high peaks in the spectral density of the noise or other strong hidden periodicities with frequencies close to the hidden frequency of interest, the procedures for detection of the existence of and estimation of the hidden frequency of interest fail if data are nontapered whereas they may work well if the data are tapered. The theoretical results are verified by some simulated examples.     

经典功率谱估计Welch法的MATLAB仿真分析

周期图法是经典功率谱估计中的一种基本方法,但是在实际应用中难以同时保证良好的分辨力和方差性能.因此本文以周期图法原理为切入点,对改进后的Welch算法进行研究,并借助MATLAB软件强大的信号处理与数值分析能力,对Welch算法的谱估计分辨力、方差等性能进行仿真分析.讨论了不同数据分段长度、不同窗函数类型等因素对算法性...     

基于功率谱估计的管道超声测厚研究

管壁厚度的测量是长输管道无损检测的主要内容之一,对于超声探头接收的回波信号,若采用经典谱估计法处理,则其分辨率较低.笔者采用Burg最大熵法,对超声波回波信号进行了处理,以提高谱的分辨率.模拟结果证明了该方法的正确性和实用性.