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Fourier transforms, cosine and wavelet transforms, wavelet scattering

DSP System Toolbox™ offers several System objects and blocks to transform streaming time-domain signals into frequency domain, and vice versa. Techniques such as fast Fourier transform (FFT), short-time Fourier transform, high-resolution FFT, wavelet transforms, and the corresponding inverse operations enable you to analyze the signal in either of the domains and have applications in several fields. For an example, see Analyze a Subband of Input Frequencies Using Zoom FFT. For a MathWorks® teaching curriculum module on this topic, see Fourier Analysis (MathWorks Teaching Resources).

DSP System Toolbox also offers the Wavelet Scattering block, which creates a framework for wavelet time scattering in the Simulink® environment. Use this block to derive low-variance features from real-valued data, and then use those features in machine learning and deep learning applications. For more information, see Wavelet Scattering (Wavelet Toolbox). The Wavelet Scattering block requires Wavelet Toolbox™.


dsp.FFTDiscrete Fourier transform
dsp.IFFTInverse discrete Fourier transform (IDFT)
dsp.ISTFTInverse short-time FFT
dsp.STFTShort-time FFT
dsp.ZoomFFT High-resolution FFT of a portion of a spectrum


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Complex CepstrumCompute complex cepstrum of input
FFTFast Fourier transform (FFT) of input
IFFTInverse fast Fourier transform (IFFT) of input
Inverse Short-Time FFTRecover time-domain signals by performing inverse short-time fast Fourier transform (FFT)
Magnitude FFTCompute nonparametric estimate of spectrum using periodogram method
Real CepstrumCompute real cepstrum of input
Short-Time FFTNonparametric estimate of spectrum using short-time fast Fourier transform (STFT) method
Zoom FFTHigh-resolution FFT of a portion of a spectrum
DCTDiscrete cosine transform (DCT) of input
DWTCompute discrete wavelet transform (DWT) of input or decompose signals into subbands with smaller bandwidths and slower sample rates
IDCTInverse discrete cosine transform (IDCT) of input
IDWTInverse discrete wavelet transform (IDWT) of input or reconstruct signals from subbands with smaller bandwidths and slower sample rates
Wavelet ScatteringModel wavelet scattering network in Simulink (Since R2022b)