Howtosignalprocessing
- What is DFT spectral leakage?
- Is DFT a convolution?
- What is frequency leakage?
- What is leakage and windowing?
What is DFT spectral leakage?
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.
Is DFT a convolution?
Convolution is cyclic in the time domain for the DFT and FS cases (i.e., whenever the time domain has a finite length), and acyclic for the DTFT and FT cases. That is, convolution in the time domain corresponds to pointwise multiplication in the frequency domain.
What is frequency leakage?
Leakage is the smearing of energy from the true frequency of the signal into adjacent frequencies. Leakage also causes the amplitude representation of the signal to be less than the true amplitude of the signal.
What is leakage and windowing?
Windowing of a simple waveform like cos(ωt) causes its Fourier transform to develop non-zero values (commonly called spectral leakage) at frequencies other than ω. The leakage tends to be worst (highest) near ω and least at frequencies farthest from ω.
