共查询到17条相似文献,搜索用时 62 毫秒
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时频平面分析非平稳信号的研究进展 总被引:1,自引:0,他引:1
时频平面是研究非平稳信号的有力工具,早期采用的主要是短时傅氏变换(STFT)和Wingner-Vill分布(WVD)等。近年来,非平稳信号研究受到广泛关注,在时频平面分析方面取得了新进展,本文简单介绍了时频分布的特点,指在时频分布研究中存在的问题与发展趋势。 相似文献
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广义指数分布是Cohen类二次时频表示的一种,同传统的短时傅立叶变换和wigner-Ville分布相比,它具有更加优良的时频分析特性.本文利用广义指数分布GED分析了地磁脉动信号的时频分布特征,高分辨率地再现了地磁信号的频谱随时间的演变过程,同时本文还探讨了GED分布中参数选取的方法.本文结果表明,在参数M,N,ξ1,τ1选取适当的情况下,GED可以达到既压缩多分量信号中的交叉干扰而同时又不损失自项时频分辨率的良好效果,是分析地球物理信号的有力工具. 相似文献
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提出了一种基于时频分布迭代的跳频信号参数估计新算法,利用时频平面最大值,通过计算跳频信号与最优原子时频分布的残差逐次迭代获取匹配于跳频信号分量的时频参数,进而实现跳频信号参数估计.理论分析和仿真结果表明,与基于匹配追踪和粒子群优化的跳频信号参数估计相比,基于时频分布迭代的参数估计算法在保证算法精度的情况下,有效地降低了算法的计算复杂度,为跳频信号盲接收的实时实现提供了一种新方法. 相似文献
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基于时频子空间分解的宽带线性调频信号DOA估计 总被引:2,自引:0,他引:2
针对具有时变方向向量的宽带线性调频信号,该文建立了基于短时Wigner-Ville分布(WVD)的空间时频分布矩阵,通过对各个空间时频矩阵的特征分解获得对应的信号子空间和噪声子空间,给出了基于时频子空间投影实现多个时频点综合估计信号DOA的算法。利用空间时频分布的前后向平滑解决了具有相同时频特性信号的均匀线阵DOA估计问题。算法不需要聚汇和插值等复杂的矩阵变换,精度较高,计算简便.仿真实验显示该算法性能显著优越于基于矩阵插值的宽带调频信号DOA估计算法. 相似文献
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A kernel based on the first kind Bessel function of order one is proposed to compute the time-frequency distributions of nonstationary signals. This kernel can suppress the cross terms of the distribution effectively. It is shown that the Bessel distribution (the time-frequency distribution using Bessel kernel) meets most of the desirable properties with high time-frequency resolution. A numerical alias-free implementation of the distribution is presented. Examples of applications in time-frequency analysis of the heart's sound and Doppler blood flow signals are given to show that the Bessel distribution can be easily adapted to two very different signals for cardiovascular signal processing. By controlling a kernel parameter, this distribution can be used to compute the time-frequency representations of transient deterministic and random signals. The study confirms the potentials of the proposed distribution in nonstationary signal analysis 相似文献
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提出一种可用于分离不同时频分布的非平稳信号的盲信号辨识算法。采用Wigner-Ville分布(WVD)进行盲源分离时,合成信号有交叉项存在,其分离性能不理想。而Cohen 类时频分布可以抑制交叉项,并且保持时频聚集性。因此,在TFBSS 中,Cohen 类时频分布可以取得更好的分离性能。分析了Cohen 类时频分布对交叉项的抑制性能,以及对盲源分离性能的影响,结果表明:采用盲辨识算法进行电磁干扰信号分离,其效果明显优于采用WVD进行分离的效果。 相似文献
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According to the performance degradation problem of the carrier frequency estimation method of time-frequency overlapped BPSK signals in Alpha-stable distribution noise,a novel carrier frequency estimation algorithm of the time-frequency overlapped BPSK signals based on the cyclic correntropy spectrum was proposed.The relationship between cyclic frequency and carrier frequency on the zero frequency section of the cyclic correntropy spectrum was deduced,which could be utilized for carrier frequency estimation.The proposed method can suppress the impulse noise and has better estimation performance than that of the contrastive methods.Simulation results are presented to demonstrate the effectiveness and robustness of the proposed method. 相似文献
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提出了一种基于排序时频特性的雷达脉内调制信号识别算法.该算法可分为三步:首先,通过检验信号时频曲线的互易回归特性,识别出线性调频信号;然后,通过检验信号时频RANKIT图的正态性,识别出常规信号;最后,检验信号平方后时频RANKIT图的正态性,用以区分二相编码与四相编码信号.仿真结果表明,该算法无需接收信号的任何先验知识,在较低信噪比条件下可实现对常用雷达脉内调制方式的有效识别. 相似文献
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In this article, a novel method is proposed to measure the separation qualities of statistically instantaneous audio signals with mixed Gaussian probability distributions. This study evaluates the impact of the Probability Distribution Function (PDF) of the mixed signals on the outcomes of both sub- and super-Gaussian distributions. Different Gaussian measures are evaluated by using various spectral-distortion measures. It aims to compare the different audio mixtures from both super-Gaussian and sub-Gaussian perspectives. Extensive computer simulation confirms that the separated sources always have super-Gaussian characteristics irrespective of the PDF of the signals or mixtures. The result based on the objective measures demonstrates the effectiveness of source separation in improving the quality of the separated audio sources. 相似文献