摘要
针对血流多普勒信号的谱估计问题 ,将经典的短时傅立叶变换谱图和现代小波尺度图进行了比较 ,从时 -频分布的观点 ,分析认为 ,STFT谱图和小波尺度图是Wigner-Ville分布的一种特殊情形 ,STFT谱图是平滑的伪Wigner-Ville分布 ,小波尺度图是一种仿射平滑的Wigner-Ville分布 ,对于实际仿真的多普勒信号 ,计算得到的STFT谱图和小波尺度图表明 ,小波尺度图的低频效果较好 ,但是交叉项干扰也较大。
On the basis of ultrasonic blood flow Doppler signal, the comparison of classical short time fourier transform spectrogram and wavelet scalogram are made in this paper. On the point of time-frequency representation, STFT spectrogram and wavelet scalogram are all one of the Wigner-Ville transform, the former is a smooth pesudo Wigner-Ville transform and the latter is an affine smooth Wigner-Ville transform. Wavelet scalogram for the simulating blood flow ultrasonic signal has a higher distinguishability in the high frequency than STFT spectrogram, but has poorer decussation terms than spectrogram.
出处
《系统工程与电子技术》
EI
CSCD
2000年第6期18-21,共4页
Systems Engineering and Electronics
