# Linked Questions

14 votes
7 answers
11k views

### The difference between DFT and DFS

In the literature, I've found that DFS and DFT are one and the same. If they are one and the same why to use two different names for them? If there is really a difference what is it and what is the ...
• 450
9 votes
5 answers
4k views

### Is a Fourier transform a sound way to analyse a transient signal?

I am currently working on a project that involves analysing transient signals from sensors. While not actually part of the analysis itself, I discussed it with the team, and they are using an fft to ...
• 271
5 votes
5 answers
9k views

### About Discrete Fourier Transform vs. Discrete Fourier Series

I am new to the field of signal processing. I am wondering what is the difference between DFS(Fourier Series) vs. DFT(Fourier Transform). For common applications, usually we get a segment(length <...
• 161
4 votes
2 answers
16k views

### Difference between CTFT and DTFT?

I have tried to read different articles but still confused in difference between continuous time Fourier transform and discrete time Fourier transform?
• 1,850
0 votes
2 answers
2k views

### derivation of discrete Fourier Transform

I'm learning DSP on my own. Found a free online book. Currently reading a chapter on Discrete Fourier Transform. Right out of the gate I can't understand several things. I'm pretty good with math and ...
• 195
2 votes
5 answers
709 views

### How is the DTFT of a periodic, sampled signal linked to the DFT?

I am trying to understand the connection between FT, DTFT and ultimately the DFT. But I am failing to link the DTFT to the DFT. This is how far I am getting: Say I have a function $f(t)$, and its ...
• 184
1 vote
3 answers
710 views

### Discrete Fourier Series - Time Index

I have been trying to understand Discrete Fourier Time Series (NOT Transform). It is defined as $$a_k = \sum_{n=0}^{N-1} x[n]e^{jk\frac{2\pi}{N}n}$$ where N is the Time period and an integer (by ...
• 137
1 vote
1 answer
1k views

### What is a periodic signal in image processing?

In the context of image processing (and computer vision), the concept of convolution comes up a lot. Convolution is quite related to the concept of Fourier transform and DFT. In the context of image ...
2 votes
2 answers
701 views

### Significance of modular arithmetic in DFT?

In what ways does modular arithmetic plays a part in DFT? Why is it a so integral part of DFT?
• 167
2 votes
1 answer
1k views

### Circular vs Linear Convolution

When deriving DFT from DTFT,we sample the frequency domain with uniformly spaced samples,hence adding periodicity to time domain. But DFT requires a limited support: we take only 1 period. Does that ...
0 votes
2 answers
418 views

### FFT of complex signal (I/Q), what do the bins N/2..N-1 represent?

I know it's a very basic question, but I've spent almost a full work day researching and still can't find a clear (or even just usable) answer. For the DFT of a real-valued signal the second half of ...