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In functional analysis, a Shannon wavelet may be either of real or complex type. Signal analysis by ideal bandpass filters defines a decomposition known as Shannon wavelets (or sinc wavelets). The Haar and sinc systems are Fourier duals of each other. == Real Shannon wavelet == The Fourier transform of the Shannon mother wavelet is given by: : where the (normalised) gate function is defined by : The analytical expression of the real Shannon wavelet can be found by taking the inverse Fourier transform: : or alternatively as : where : is the usual sinc function that appears in Shannon sampling theorem. This wavelet belongs to the -class of differentiability, but it decreases slowly at infinity and has no bounded support, since band-limited signals cannot be time-limited. The scaling function for the Shannon MRA (or ''Sinc''-MRA) is given by the sample function: : 抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)』 ■ウィキペディアで「Shannon wavelet」の詳細全文を読む スポンサード リンク
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