Noise Reduction for Doppler Ultrasound Signal Based on Matching Pursuits with Different Time-Frequency Dictionaries

The spectral analysis of the Doppler ultrasound signal has been widely used in medical diagnosis. To remove noise effectively, matching pursuits with three different time-frequency dictionaries including Gabor atoms (GMP), cosine packets (CMP), and wavelet packets (WMP) are proposed to remove noise from the Doppler ultrasound signal in this paper. The simulation results have shown that the GMP method can be best adapted to approximate the Doppler ultrasound signal with fewer atoms compared with the CMP and WMP methods. In contrast to the translation-invariant adapted local cosine transform, although the GMP method has only achieved approximate performance improvements with higher computation intensity, it offers the potential advantages in pulsed Doppler ultrasound application because it has no requirement for the signal over-sample, which is needed in the traditional transform-based denoising methods to obtain a more precise noise level estimate.