Inverse ShortTime FFT
Recover timedomain signals by performing inverse shorttime fast Fourier transform (FFT)
Libraries:
DSP System Toolbox /
Transforms /
Matrix Operations
Description
The Inverse ShortTime FFT block reconstructs the timedomain signal from the frequencydomain output of the ShortTime FFT block using a twostep process. First, the block implements the overlapadd algorithm.
$$x\left[n\right]=\frac{L}{W(0)}{\displaystyle \sum _{p=\infty}^{\infty}\left[\frac{1}{N}{\displaystyle \sum _{k=0}^{N1}X\left[pL,k\right]{e}^{j2\pi kn/N}}\right]}$$
Then, the block rebuffers the signal in order to reconstruct the timedomain signal. Depending on the analysis window used by the ShortTime FFT block, the Inverse ShortTime FFT block might or might not achieve perfect reconstruction of the timedomain signal.
Ports
Input
Output
Parameters
Block Characteristics
Data Types 

Direct Feedthrough 

Multidimensional Signals 

VariableSize Signals 

ZeroCrossing Detection 

References
[1] Quatieri, Thomas E. DiscreteTime Speech Signal Processing. Englewood Cliffs, NJ: PrenticeHall, 2001.
Extended Capabilities
Version History
Introduced before R2006a
See Also
Objects
Blocks
 ShortTime FFT  Spectrum Estimator  Burg Method  Magnitude FFT  Periodogram  Spectrum Analyzer  Window Function  YuleWalker Method