Denoise Noisy Doppler Signal

Use Signal Analyzer to denoise the noisy Doppler signal and display its scalogram. This example requires a Wavelet Toolbox™ license.

Load the noisy Doppler signal.

load noisdopp

Open Signal Analyzer and drag the signal from the Workspace Browser to the Signal table. Duplicate the signal. Rename the duplicate noisdoppDenoise. Click Display Grid to create a one-by-two grid of displays. Plot noisdopp in the left display and noisdoppDenoise in the right display.

Select the right display and highlight the name noisdoppDenoise in the Signal table. Select the Analyzer tab and choose Denoise from the list of preprocessing options.

The Denoise tab appears. You can use this toolstrip to adjust and apply denoising parameters to the selected signal. For more information, see Wavelet Signal Denoiser (Wavelet Toolbox). Click the Denoise button to denoise the signal with the default settings. The denoised signal is smoother than the original signal.

To denoise the signal with a different set of parameters, first click Undo Preprocessing. In the Denoise tab, select Universal Threshold from the Method dropdown list and Hard from the Rule dropdown list. Click the Denoise button.

To see the effects of denoising on the scalogram, click Time-Frequency on the Display tab and select Scalogram. Click on the left display and repeat the steps.