Overlap-save convolution

1. Which convolution is used in overlap save method?
2. How do you overlap a save method?
3. Why do we use overlap save method?
4. Why we go for overlap-add and overlap save method rather than direct convolution?

Which convolution is used in overlap save method?

Two methods that make linear convolution look like circular convolution are overlap-save and overlap-add. The overlap-save procedure cuts the signal up into equal length segments with some overlap. Then it takes the DFT of the segments and saves the parts of the convolution that correspond to the circular convolution.

How do you overlap a save method?

Overlap Save Method

Let the length of input data block = N = L+M-1. Therefore, DFT and IDFT length = N. Each data block carries M-1 data points of previous block followed by L new data points to form a data sequence of length N = L+M-1. First, N-point DFT is computed for each data block.

Why do we use overlap save method?

The overlap–save algorithm can be extended to include other common operations of a system: additional IFFT channels can be processed more cheaply than the first by reusing the forward FFT. sampling rates can be changed by using different sized forward and inverse FFTs.

Why we go for overlap-add and overlap save method rather than direct convolution?

The overlap-add method is used to break long signals into smaller segments for easier processing. FFT convolution uses the overlap-add method together with the Fast Fourier Transform, allowing signals to be convolved by multiplying their frequency spectra.