WVD pros and cons

[Pavan Kumar B]

Dear sir , 

Pic1 provies an excellent resolution(i.e perfectly localized in frequency and in time) of modulated chirp using Wigner ville distribution 

Pic2 Scalogram of same modulated chirp 

sir how Wignr-ville distribution  is philosophically different from spectogram(STFT)  and scalogram(wavelets) ?

& what are the pros and cons of wavelts and wigner ville distribution ...

[NOC16 March - May]

Hi Pavan,

The main Two issues with the Wigner Ville distribution are : 

Non-linearity of the Wigner Ville distribution and the presence of cross-terms also called as the "beats" in the literature. Although Wigner distribution provided a fascinating link between  time and frequency domain in signal analysis, its interference terms are seen by many as unwanted artifacts. One big appalling reason for the use of Wigner distribution is that  it can be computed very efficiently using the FFT algorithm.

There is a much more evolved framework for discretization - analysis and synthesis in wavelets, based on multirate filter banks. This is one of the major advantages that wavelets have got. I hope that this would resolve some of your doubts.

Thanks

TA