FFT for long waveform

1. What is the limitation of FFT?
2. What is length of signal in FFT?
3. What is 64 point FFT?
4. How many periods do I need for FFT?

What is the limitation of FFT?

A disadvantage associated with the FFT is the restricted range of waveform data that can be transformed and the need to apply a window weighting function (to be defined) to the waveform to compensate for spectral leakage (also to be defined). An alternative to the FFT is the discrete Fourier transform (DFT).

What is length of signal in FFT?

The correct size of the FFT lengths for a linear convolution, is Nfft=Lx+Ly−1, where obviously those lengths correspond to the length of your signals x and y.

What is 64 point FFT?

The 64-point FFT is realized by decomposing it into a two-dimensional structure of 8-point FFTs. This approach reduces the number of required complex multiplications compared to the conventional radix-2 64-point FFT algorithm. The complex multiplication operations are realized using shift-and-add operations.

How many periods do I need for FFT?

Number of periods of signal required when doing an FFT: 1

yup.