# Questions tagged [frequency-domain]

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### cascade and summation process in frequency domain using overlap and save method

hello i'm doing signal processing like this S : FFT of input signal from microphone Exp : just gain 1/(Q*J) : include frequency component, I convert this equation to frequency domain digital filter ...
1answer
1k views

### Image 2D Real Cepstrum with DFT, Is ifftshift Needed?

This is my testing image, it is taken from the paper Image Restoration for Linear Local Motion-Blur Based on Cepstrum: I tried to transform it into its real cepstrum domain with this simple MATLAB ...
1answer
236 views

### Filter by 2D Gaussian Kernel in MATLAB

I have written a function that implements a gaussian filter. I use fft2 to transform my image and my filter to 2d fourier transform. Then I multiply them and then ...
2answers
63 views

### 2D Spatial Fourier Tranform on a pressure field

I'm doing some research on Fourier Near-field Acoustic Holography (NAH). The basic theory behind Fouerir NAH is that you take a sound pressure field measurement in a 2d plane p(x,y), 2d spatial ...
1answer
168 views

### LP to BP transformation steps

Considering the following problem, What i know to convert from LP signal to BP signal is to: Draw the FD of the LP equation From it I can draw the FD for BP From this graph I can deduce the equation ...
1answer
490 views

### The Proper Way to Do Sinc Downsampling (DFT Downsampling) for Uniformly Sampled Discrete Signals with Finite Number of Samples

Given a discrete signal $\left\{ x [ 0 ], x [ 1 ], \ldots, x [ N - 1 ] \right\}$ what would be the correct way to downsample it in the frequency domain (Sinc interpolation)?
2answers
8k views

### Understanding the frequency domain [duplicate]

I'm trying to understand what frequency domain is. I found general explanations on the Internet, for example: frequency-domain graph shows how much of the signal lies within each given frequency band ...
1answer
180 views

### Why does this transfer function estimation not work? System identification

Goal: I have an unknow dynmical system $G(s)$ and I want to find it from measurement data, output $y(t)$ and input $u(t)$. The data is frequency responses. Method: I begun first with creating the ...
1answer
364 views

### Is it right to talk about dynamic range on frequency domain?

I'm comparing three frequency response's plots from simulations and experiments and I observed that two of them look like clamped to a DC component, where the max dB value is i.e. 100 and the min is ...
2answers
112 views

### Frequency response of an ideal low pass filter

I have an ideal low pass filter having unity gain and cutoff frequency 100Hz. If I provide an input having single frequency component at 100Hz(E.g.- cos(200pi t), will the low pass filter block the ...
1answer
95 views

### Yet another fft question - a vocoder

Lets assume a pipeline X: ...
1answer
977 views

### When listening in to an AM signals of various frequencies, how do we exactly tune in?

Alright, so I read on AM and Double Sideband AM, but I don't the more fundamental idea - the frequencies. Frequency is just: $\frac{1}{T}$, where T is period So difference between 5 Hz and 30 Hz ...
1answer
222 views

### Break a signal into segments, add them together and then perform an FFT on the result

If you break a 4 second signal into 0.5 second segments, add them together and then perform an FFT on the resultant 0.5 second data. Will the FFT / frequency spectrum be the simlar to an FFT on the ...
2answers
67 views

### Relation of zero-padding and frequency resolution

Consider simple rectangular pulse and FFT of it in Python: ...
1answer
60 views

### Frequencies calculation of discrete signal in frequency domain

I have some misunderstanding in definition of frequency resolution of the signal. Here it is assumed that the resolution is: $$\hat{f_k}=f_{signal}\cdot T_{sampling}$$ (which is just relation of ...
2answers
215 views

1answer
72 views

### Train of impulses in frequency domain

Why compressing a train of impulses in time domain produce a wide-spaced train of impulses in frequency domain and vice versa? i want to know the intuition behind that.
1answer
139 views

### Frequency-domain deconvolution: "Direct" filtering vs "Wiener" filtering

Can someone help with clarifying the difference between two approaches to frequency domain "deconvolution: For the frequency domain problem: We want to find a filter $F(\omega)$ which will ...
1answer
89 views

### Measuring frequency response with white noise signal

I need to measure a frequency response of an eleсtric circuit (simple like an RC-filter). I suppose that I can generate an input signal that has spectrum like white noise (for example, m-sequence ...
1answer
69 views

### How to do sliding window multiplication in frequency domain

I want to perform the following computations with the impulse response of length L of a LTI system: Multiply the impulse response with a window w(n) of length M << L. Take the FFT of the result ...
4answers
320 views

### Estimation of Amplitude, Frequency and Phase of Linear Combination of Harmonic Signal Beyond the Leakage Resolution of DFT

How can I find a rough ( as accurate as possible) Amplitude of each frequency when there is spectral leakage. Currently, I am dealing with a system that contains special leakage which seems ...
7answers
235 views

### Where do harmonics come from?

At first, I thought harmonics come from the signal being periodic. However, we know a sine wave is also periodic but contains a single frequency and no harmonics. A harmonic for me is a component (...
1answer
34 views

### Names of system functions in frequency domain

I was just trying to refresh my systems theory known from long ago, and I realized that I had forgetten the name of the basic functions. Specifically, what are the names of these functions ...
1answer
132 views

### Estimating the SNR of 2-FSK

I have some iq data recordings of a 2-FSK waveform that I've created periodograms from. How do you estimate the SNR of this waveform in the frequency domain? I've heard two opinions: One: Integrate ...