Could anybody explian how to use Wiener filter to revocer the audio signal from low-pass filter in Matlab? I filtered the signal, after that I used simple deconvolution by dividing filtered signal with frequency response of the LPF, but it didnt give me any result. I didnt get restoration at all. I have checked the LPF, it works correct. I need some information about using Wiener filter for audio files, but there are only answers about deblurring images. Thank you in Advance!
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I will attempt to provide some help. You should study the normal equations as per section 11.11
This set of equations will appear in every literature on the Wiener filter. The objective regardless of the application is to compute from a noisy observation signal a clean - but reconstructed - version of the clean input signal. Since this is a mathematical model, the quality of the reconstruction is based on how good are the computed statistics and characteristics of the "noise". Noise in audio is always uncorrelated statistically to the clean signal. This is the principle upon which the Wiener filter works.
Figure 11.3 gives an example of deconvolution in block diagram form that should suffice to solve your application in audio. A real Wiener filter minimizes the MMSE ratio as defined in 11.37. That is the difference in expectation of the square of the e(t) process.
