针对减少多普勒信号时频分布斑点的研究(英文)  

Research on Reducing Doppler Signal Time-frequency Distributed Speckles

作　　者：余炜[1] 张榆锋[1] 章克信[2] 施心陵[1] 陈建华[1] 

机构地区：[1]云南大学信息学院,云南昆明650091 [2]昆明医学院第二附属医院,云南昆明650031

出　　处：《昆明理工大学学报（理工版）》2003年第4期67-72,共6页Journal of Kunming University of Science and Technology(Natural Science Edition)

基　　金：ThisworkissupportedbytheYunnanNaturalScienceFoundationunderGrant 2 0 0 2C0 0 0 2ZandtheInternationalCooperationProjectunderGrant 2 0 0 1GH0 2 .

摘　　要：基于短时傅立叶变换 (STFT)的商用多普勒分析仪所得出的多普勒信号谱存在较大的随机噪声和随机抖动 (形成多普勒斑点 ) ;为了减少或抑制这些多普勒斑点 ,我们利用维纳辛钦定理先对信号进行自相关 ,消除其电噪声 ,然后再对去噪后的信号加上一个高斯窗函数做傅立叶变换抑制其谱的随机抖动 ,最终得出了较好的信号谱形 。Bigger noises and random fluctuations (forming Doppler speckles) are found in the Doppler signal spectra obtained from Short-time Fourier Transform (STFT) based on commercial Doppler analyzers. In order to reduce or inhibit these Doppler speckles, Wiener-Khintchine theorem is used to perform an auto correlation on the signal, reducing its electric noises and then conducting an Fourier Transform on the resulted signal with a Gaussian window function added to prevent the random fluctuations of spectrum. Finally better signal spectra are generated to reduce Doppler speckles.

关 键 词：多普勒信号 短时傅立叶变换 维纳辛钦定理 电噪声 高斯窗函数 谱形 自相关 时频分布斑点 

分 类 号：TN911.7[电子电信—通信与信息系统]