Is spectral leakage due to windowing 'different' for the DTFT and DFT?

1. What is the key difference between the DFT and DTFT?
2. How does windowing reduce spectral leakage?
3. What is spectral leakage in DFT?
4. What is spectral leakage caused by?

What is the key difference between the DFT and DTFT?

original sequence spans all the non-zero values of a function, its DTFT is continuous (and periodic), and the DFT provides discrete samples of one cycle. If the original sequence is one cycle of a periodic Page 2 function, the DFT provides all the non-zero values of one DTFT cycle.

How does windowing reduce spectral leakage?

Spectral leakage is caused by discontinuities in the original, noninteger number of periods in a signal and can be improved using windowing. Windowing reduces the amplitude of the discontinuities at the boundaries of each finite sequence acquired by the digitizer.

What is spectral leakage in DFT?

Spectral leakage occurs when a non-integer number of periods of a signal is sent to the DFT. Spectral leakage lets a single-tone signal be spread among several frequencies after the DFT operation. This makes it hard to find the actual frequency 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.