Linked Questions

0
votes
1answer
175 views

What Is the Point of Doing the Zero Padding? [duplicate]

What are the advantages and disadvantages of doing Zero-padding, in particular the case of speech signals?
0
votes
1answer
331 views

What does it mean when you zero pad data and why does one do it? [duplicate]

I am struggling to understand what effect zero padding data would have on EMG data. How does it improve the signals? Any help in simple terms that's not too mathematical would be greatly appreciated!
0
votes
2answers
535 views

What proportion of a padded FFT should be actual values

For a given signal, I've been told that you can pad the vector with $0$s at the end to get a larger DFT, and as a result get more precision in frequency bins. What are the limits to this approach? ...
4
votes
1answer
3k views

What happens when N increases in N-point DFT [duplicate]

I am curious about DFT, and I wrote a simple MATLAB code to test what happens when $N$ increases. I took a rectangular signal with length $L=15$, an then found th DFT of 16, 32 and 64 points. I looked ...
-1
votes
1answer
530 views

Digital signal and frequency analysis

I am generating a digital signal with software. I have defined the vector $$[0,1,1,1,0,1,0,1,0,1,0,0,0,0,0,0,0,0,0,0] $$ and my sampling rate is 8 million per second. The frequency spectrum is ...
-1
votes
2answers
575 views

Bin spacing in FFTs

I have a signal that I sample at some frequency (currently 100Hz), and want to extract low frequency information (between 0.8 and 3 Hz) I have three constraints on this: I would prefer to compute ...
1
vote
2answers
641 views

Mathematical justification for zero padding?

This question asks what's the point of zero padding. The accepted answer is certainly very insightful, but I don't understand a big chunk of it: Zero padding allows one to use a longer FFT, which ...
3
votes
2answers
938 views

The frequency response function (FRF) fails to detect the antiresonance of a system

I am trying to identify a vibrational systems by computing the frequency response function (FRF) of the system when a chirp signal is applied to its input. After comparing the FRF computed and the ...
0
votes
2answers
181 views

Beginner question on aperiodic samples and DFT behavior

I have a strongly aperiodic signal and I get weird artifacts after running a fft, using a low-pass filter, and then doing an inverse fft. I believe the artifacts are due to the way the signal is ...
5
votes
3answers
8k views

Advantages/disadvantage of zero padding

I would like to know what are the advantages/disadvantage of zero padding with respect to frequency measurement and amplitude measurement
0
votes
0answers
978 views

Autocorrelation and FFT : avoid zero-padding

Some posts evocate the computation of convolution or cross-correlation using FFT and zero-padding the temporal signal. I want to compute the autocorrelation of a 3D array using FFTW (2 dimensions are ...
3
votes
3answers
3k views

disadvantages of FFT, it can not extract enough frequencies without enough samples

Let's say sampling rate is $Fs = 44\mathtt{kHz}$, now I have $N = 2048$ samples, then I can get $N/2 + 1 = 1025$ frequencies. I'm confused by Matlab's FFT documentation that says the frequencies are ...
3
votes
3answers
5k views

Zero-pad before or after windowing for FFT

What's the correct way. Should I zero-pad a signal before or after applying a windowing function?
2
votes
0answers
249 views

Is there any problem with my FFT method?

I am trying to analysis a system by Fourier Transform. my system has 3 dominant modes. (1,0.05) (0.51,0.01),(0.46,0.01) the pairs are defined as (freq,damping_ratio) I've got those result with ...
5
votes
3answers
4k views

Zero Padding in FFT

whats is the effect of pading zeroes to a sequence in FFT? for eg: x[n]=[2 3 4 5] corresponds to X[K]=[14 -2+2i -2 -2-2i] while x[n]=[2 3 4 5 0 0 0 0] corresponds to X[K]=[14 0.58-9.65i -2+2i -3.414+...

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