摘要
维格纳分布（ＷｉｇｎｅｒＤｉｓｔｒｉｂｕｔｉｏｎ）是８０年代中发展起来的对非平稳信号进行时间一频率联合分析的有效工具。应用中的主要困难是交叉项引起的干扰。由于交叉项在时间－频率平面上表现为高频起伏，而模糊函数与维格纳分布是二维富氏变换对，因此本文提出直接对前者进行“低通滤波”来抑制交叉项的方法。仿真试验证实了方法的有效性。文中还进一步对实际心音信号进行了初步分析，取得了一些有益的结果。
Wigner
distribution is an effective joint time -frequency representation of signals whichshows many
prominent proproperties for nonstationary signal analysis. The main obstacle for
itswidespread application is the interference caused by crossterms,because it is not a linear
transform. Basing on the fact that Wigner Distribution WD(t,w)and Ambiguity Function AF(ξ,
τ)are a two -dimensional Fourier Transform pair and that the crosssterms appear in the t-w
plane as high spatialfrequency fluctuations, it is proposed in this paper that the crossterm may
be suppressed by ‘ low passfiltering’ the Ambiguity Function in(ξ,τ)plane and then
inverse transformed to the (t,w)plane. The validity of the proposed method was verified by
computer simulation,It was also applied to theanalysis of heart sound and some interesting
initial results were obtained.
出处
《航天医学与医学工程》
CAS
CSCD
1995年第1期15-22,共8页
Space Medicine & Medical Engineering
基金
国家自然科学基金
关键词
心电图
心音
信号分析
模糊函数
维格纳分布
heart sound signal analysis ambiguity function wigner
distribution time一frequen-cy analysisAddress reprint requests to:ZHENG Ling.Dept of
Electrical Tsinghua University,Bei-jing 100084,China
