Two-dimensional chirp z-transform and its application to zoom Wigner bispectrum

In this paper, we present the 2-D chirp z-transform as an extension of the 1-D chirp z-transform. It can be used as a powerful analytic tool to emphasize any region in either the (t-f)- or the (f₁-f₂) planes, covering a wide variety of multidimensional distributions ranging from two-dimensional filters to higher order moment spectra (HOMS) including the Wigner distribution and Wigner bispectrum. In this paper we apply this technique to the Wigner bispectrum for high resolution analysis. It is shown to possess the capability to zoom onto any region of frequencies of interest in the 2-D (f₁-f₁) plane. Different zoomings along the two axes are also possible