How to reduce spectral leakage?

We have seen that spectral leakage is reduced by tapering the digital signal by a window function before the DFT takes place. A generalization of this technique is the short-time discrete Fourier transform (STDFT).

1. What is spectral leakage and how it can be reduced?
2. How do you prevent spectral leakage in FFT?
3. What is spectral leakage caused by?
4. What is meant by spectral leakage?

What is spectral leakage and how it can be reduced?

--> This phenomenon of leaking energy from peak value to other samples is called Spectral leakage. --> This reduction in energy from main lobe is called scalloping loss. Spectral leakage cannot be eliminated but it can be reduced by using proper windowing technique before applying FFT. Cite.

How do you prevent spectral leakage in FFT?

By increasing the side lobe roll-off rate, you can reduce spectral leakage. Selecting a window function is not a simple task. Each window function has its own characteristics and suitability for different applications. To choose a window function, you must estimate the frequency content of the signal.

What is spectral leakage caused by?

Spectral leakage results from an assumption in the fast Fourier transform (FFT) and discrete Fourier transform (DFT) algorithms that the time record exactly repeats throughout all time. Thus, signals in a time record are periodic at intervals that correspond to the length of the time record.

What is meant by spectral leakage?

Leakage, more explicitly called spectral leakage, is a smearing of power across a frequency spectrum that occurs when the signal being measured is not periodic in the sample interval.