DFT - zero padding avoids aliasing?

  • Thread starter Thread starter LM741
  • Start date Start date
  • Tags Tags
    Dft Zero
AI Thread Summary
Zero padding a signal before applying the Discrete Fourier Transform (DFT) increases the frequency resolution by creating a larger gap between frequency points, which can help reduce aliasing. However, this approach alters the original signal, resulting in a different DFT outcome. The discussion emphasizes that while zero padding can improve frequency representation, it does not maintain the same signal characteristics. Thus, comparing the DFT of the original and zero-padded signals is not valid, as they represent different signals. Understanding the implications of zero padding is crucial for accurate signal analysis.
LM741
Messages
130
Reaction score
0
hey guys - i can't seem to find find this statement anywhere - but it makes sense to me - could someone please verify.
When you find the DFT of a signal say: x[0]=2, x[1]=4, x[2]=6, x[3]=8 - you will get four discrete points in frequency (per period) now if you zero pad the time signal such that you get x[0]=2, x[1]=4, x[2]=6, x[3]=8 x[4]=0, x[5]=0, x[6]=0, x[7]=0 - you will once agin get four discrete frequency points but now the gap between each period will be larger (thus decreasing any chances of aliasing)


thnks
 
Engineering news on Phys.org
Sure, but that is a completely different signal with a different DFT. It is an apples/oranges comparison.
 
Thread 'Weird near-field phenomenon I get in my EM simulation'

Thread 'Weird near-field phenomenon I get in my EM simulation'

I recently made a basic simulation of wire antennas and I am not sure if the near field in my simulation is modeled correctly. One of the things that worry me is the fact that sometimes I see in my simulation "movements" in the near field that seems to be faster than the speed of wave propagation I defined (the speed of light in the simulation). Specifically I see "nodes" of low amplitude in the E field that are quickly "emitted" from the antenna and then slow down as they approach the far...
View full post »

Thread 'EMF (Electromagnetic Field) & EHS (Electromagnetic Hyper Sensitivity)'

Hello dear reader, a brief introduction: Some 4 years ago someone started developing health related issues, apparently due to exposure to RF & ELF related frequencies and/or fields (Magnetic). This is currently becoming known as EHS. (Electromagnetic hypersensitivity is a claimed sensitivity to electromagnetic fields, to which adverse symptoms are attributed.) She experiences a deep burning sensation throughout her entire body, leaving her in pain and exhausted after a pulse has occurred...
View full post »

Similar threads

Is my understanding of the Nyquist theorem correct?
Replies
4
Views
2K
Understanding N-Stages of FFT & DFT Formula for Frequency Domain
Replies
4
Views
2K
Discrete Fourier Transform (DFT) Matching
Replies
5
Views
6K
Aliasing, Continuous sinusoids and discrete sinusoids....
Replies
3
Views
1K
Why can't a critical point of a system of DEs be complex?
Replies
27
Views
2K
DFT vs. DTFT: Understanding the Difference
Replies
1
Views
4K
I Please discuss discrete Fourier analysis
Replies
12
Views
2K
Find integer points on this equation
Replies
8
Views
1K
Digital Electronics: Image Frequencies & Nyquist/Shannon Theorems
Replies
7
Views
4K
Basic 2d DFT - interpreting the coefficients
Replies
4
Views
3K

Hot Threads

Recent Insights

Back
Top