Efficient FFT (or SFFT) for adjacent parts of signal with overlap?

1. Why do we use overlap in FFT?
2. What is FFT overlap?
3. What is a 50% overlapping technique?
4. Why FFT is efficient?

Why do we use overlap in FFT?

FFT processing can be particularly problematic when the signal consists of randomly occurring transients superimposed on a more continuous signal. Overlap processing is commonly used in this situation to improve the estimates.

What is FFT overlap?

FFT convolution uses the overlap-add method together with the Fast Fourier Transform, allowing signals to be convolved by multiplying their frequency spectra. For filter kernels longer than about 64 points, FFT convolution is faster than standard convolution, while producing exactly the same result.

What is a 50% overlapping technique?

A technique utilized while applying a polish or protection where each pass overlaps the previous pass by 50% to ensure thorough application.

Why FFT is efficient?

In an FFT, D and E come entirely from the twiddle factors, so they can be precomputed and stored in a look-up table. This reduces the cost of the complex twiddle-factor multiply to 3 real multiplies and 3 real adds, or one less and one more, respectively, than the conventional 4/2 computation.