Questions tagged [frequency-domain]

The tag has no usage guidance.

Filter by
Sorted by
Tagged with
0 votes
2 answers
20 views

What does the frequency domain of bipolar Alternate Mark Inversion (AMI) look like?

Someone said to me that Bipolar AMI is not low-pass; it does not include the 0Hz in its frequency domain. I doubt that that is the case. However, at present I am unable to do Fourier transformations. ...
tryingtobeastoic's user avatar
0 votes
1 answer
57 views

Filtering in time domain vs filtering in frequency domain

The signal is an impulse repsonse. I am filtering the signal using a windowed sinc filter in both frequency and time domain. I am interested in knowing the differences between the two methods and ...
Tanmayee Pathre's user avatar
0 votes
0 answers
43 views

Bode plot phase shift equation when poles and zeros are not at the origin

Let $$H(s)=\frac{s^{n}}{s^{m}}$$ For $n \ne m$ the phase shift between output and input will be $\frac{\pi}{2}(n-m)$. For situations where the poles and zeros are not at the origin, I could find the ...
Cerise's user avatar
  • 143
0 votes
0 answers
92 views

Sampled data plot doesnt make sense

I've measured an accoustic signal for approx. 90 seconds with a sample frequency of 192 kHz (Note: the used device can sample data with maximaly 192 kHz, therefore i am not 100% certain, what sample ...
Tom's user avatar
  • 67
1 vote
1 answer
65 views

IFFT caused inverted phase

I've created ifft of signal: Wf=[0 zeros(1,19) conj(W) zeros(1,6000) flip((W)) zeros(1,19)]; w=real(ifft(Wf)); Now take a look ...
mohammadsdtmnd's user avatar
1 vote
1 answer
34 views

Mixer and control systems

A mixer in the time domain usually multiplies 2 signals of the time domain , however what does it do in the Laplace domain?Is there a equivalent block diagram of a mixer in the Laplace domain?The ...
Cerise's user avatar
  • 143
2 votes
2 answers
112 views

How can I convert a 1/3rd octave spectrum into a linear spectrum for use as a frequency response?

I have a one-third octave spectrum with 23 frequencies, and I want to use it as a frequency response to filter another spectrum, however that spectrum is specified linear with 2049 points. I know I ...
stix's user avatar
  • 133
1 vote
1 answer
972 views

Why is the convolution of two sine waves a sinc function?

Problem/Question After taking the convolution of two discrete sine waves of the same frequency and length the result appears to be a sinc function but I was expecting to get a sine wave since this ...
Usman Mutawakil's user avatar
0 votes
1 answer
38 views

Freq domain filtering in a sample by sample basis

Im simulating a system in code, the real system uses a 3Mhz sample rate on PDM, trying to simulate the feedback response, in the feedback path there is a system, this system has a impulse response of ~...
user2982010's user avatar
2 votes
1 answer
152 views

Frequency domain derivation of Hilbert transform of $\cos(\omega t)$

I'm reading "Understanding Digital Signal Processing, 3rd Edition" by Richard Lyons. Chapter 9 derives Hilbert transform impulse response by defining it in frequency domain first and then ...
Aleksander Alekseev's user avatar
1 vote
3 answers
139 views

FMCW Radar - What's wrong with the transmitted signal model?

I am new to FMCW radar and trying to plot the transmit signal over time. As you know, the transmitted signal is modelled as: $$s(t) = cos(2\pi f_c t + \pi S^2),$$ where $S = BW/T_{chirp}$ is the slope,...
pej's user avatar
  • 13
2 votes
1 answer
94 views

Does subtracting a phase from the frequency components of a DFT output result in rotation?

I'm currently reading a paper (Page 23 of the PDF) about the application of the Fourier transform to standardize some climatic data to easily compare them. I have the following text : 2.3 ...
Franck Might's user avatar
0 votes
2 answers
39 views

Routh's stability condition

Assume we have a LTI system which has poles in the half left plane of the s domain. Before I learnt Routh's stability condition I had imagined that this was enough to decide whether a LTI system was ...
Volpina's user avatar
  • 295
0 votes
1 answer
53 views

Can we do down sampling by taking fft, omitting samples on the ends of the spectrum, and then taking inverse fft?

Suppose that we have a signal with a length of 4096 and want to down sample it by a factor of 2 and obtain a signal with a length of 2048. Suppose that the the maximum frequency content of the signal ...
alireza's user avatar
  • 117
0 votes
1 answer
95 views

What is the symbol for angular frequency?

I am reading the book Signals and Systems Laboratory with Matlab Book by Alex Palamides and Anastasia Veloni I was going through chapter 6 (Fourier transform) and I came across a confusing thing ...
DSP_CS's user avatar
  • 1,850
0 votes
0 answers
52 views

Signal Spectrum Anomaly and Interference Detection

I am trying to detect anomalies (interferences for example) given signal spectrum data in discrete form (frequency vs power spectral density) in python or matlab. I am trying to do this in 2 scenarios....
Abdel's user avatar
  • 1
1 vote
1 answer
345 views

Removing zero frequency peak in fourier spectrum

I have been looking at the FFT (in python) of various simple functions. Everything was working as expected, except when I take the Fourier transform of the function: $$ f(t) = e^{-\gamma t}\cos^2\...
Angus's user avatar
  • 13
2 votes
1 answer
89 views

How to Solve a Composition of Convolutions from Regularized Least Squares Model in Frequency Domain

Assume we need to solve the model: $$ \arg \min_{\boldsymbol{x}} \frac{1}{2} {\left\| \boldsymbol{h} \ast \boldsymbol{x} - \boldsymbol{y} \right\|}_{2}^{2} + \frac{\lambda}{2} {\left\| \boldsymbol{g} \...
Royi's user avatar
  • 19.3k
1 vote
1 answer
78 views

What should be the size of my FFT values for speed,acceleration,..?

I am not from electrical eng. or physics background, so a layman explanation would be appreciated. I work with sensor data (accelerometer) from wearable device, collected for few hours. I take few ...
Amina Umar's user avatar
1 vote
0 answers
124 views

IFFT confusion, sampling frequency

I made a previous post about what I am trying to do Previous Post I have band-limited data in the frequency domain from a VNA and I am trying to convert it into the time domain. VNA data saved in .s2p ...
Frank's user avatar
  • 33
4 votes
1 answer
703 views

Why do we calculate the second half of frequencies in DFT?

As far as I know, for any signal the first $N/2$ frequency samples and second $N/2$ frequency samples are equal (by magnitude), so (sorry, if I made mistake in indices): $$X[k]=\sum_{n=0}^{N-1}x[n]e^{-...
Curious's user avatar
  • 355
3 votes
1 answer
831 views

Why does interpolation with zeros introduce frequency artifacts?

Consider the original signal (just a sine) and the same signal interpolated with zeros: The Fourier transform of them: In this example I inserted only one zero between the samples, as if I sampled ...
Curious's user avatar
  • 355
1 vote
1 answer
194 views

FIR filter design using DFT matrix inversion

In my previous question I use a system identification case as an example. Here I came across another question. I want to design a FIR filter of length $L$ to equalize an LTI system whose impulse ...
DSP novice's user avatar
0 votes
0 answers
61 views

How to remove PWM cycles present in a signal?

I have applied PWM across a DC motor. The voltage measured across the motor is shown above. I want to count the ripples present in the data. The ripples exist at a different frequency than the PWM ...
Nitin Singh's user avatar
0 votes
0 answers
25 views

How do I determine how many noise components are numerically contained in the Wavelet Transform Image?

How do I determine how many noise components are numerically contained in the Wavelet Transform Image? I used Matlab's DWT2 to convert the wavelet to check the vertical, horizontal, and diagonal noise ...
bsg's user avatar
  • 43
0 votes
2 answers
76 views

Causality of an estimated filter

Assume $\tilde{h}(f)$ is a filter estimated by an algorithm for (room) impulse response estimation working in the frequency domain. Is there a way to assert if such filter is causal? Specifically, ...
Chutlhu's user avatar
  • 113
2 votes
2 answers
201 views

Frequency-domain deconvolution

I want to estimate the impulse response of an LTI system using frequency-domain deconvolution. Suppose that the input signal $x[n]$ of length $N$, and the unknown system impulse repsonse $h[n]$ of ...
DSP novice's user avatar
0 votes
1 answer
459 views

Constellation Mapping In OFDM

If i am not mistaken, the two following hold : a. In OFDM Conceptualization, the constellation mapping at Tx (or de-mapping at Rx) is done in Frequency domain b. However the basic theory (Including ...
Vinayak Anant Karandikar's user avatar
1 vote
1 answer
224 views

Calculating SNR of one N-point DFT over another M-point DFT in frequency domain

Consider N-point sine signal mixed with a random noise (implemented in Python below): ...
Curious's user avatar
  • 355
4 votes
1 answer
85 views

Extract the Frequency from the Index of the Bin in 2D DFT

How can I find the distance from DC term (center) to the peak point of the frequency in the image Fourier transform? In the figure below, we know that the distance of the peak point goes to the edge ...
bsg's user avatar
  • 43
0 votes
1 answer
98 views

How can you get the mean wavelength/frequency of a Discrete Fourier Transform (DFT)?

I am very new to the concept of Fourier transforms and DFTs so please explain in as simple terms as possible. I am messing around with Fourier transforms in processing. I wanted to determine the ...
Alexander's user avatar
0 votes
2 answers
47 views

frequency Domain with bandlimit

May I ask why does the frequency Domain Picture of a signal look like that? Is the signal built with many different frequencies?
kidox's user avatar
  • 3
0 votes
1 answer
40 views

Frequency domain equivalent to center oriented rotated convolution?

I have a convolution kernel which I need to apply to an image. However, at each pixel in the image, I'm convolving using a rotated kernel, with respect to the center (think hands on a clock, with the ...
Krupip's user avatar
  • 111
1 vote
1 answer
54 views

Frequency difference measurements

I am trying to find the frequency difference ($\Delta f= f_1 - f_2$) between two complex sinusoidal signals using Matlab. The two signals are: $$r_1 (t)= A~ e^{j 2 \pi f_1 t}= A \cos(2 \pi f_1 t)+j A\...
wesam amiri's user avatar
1 vote
1 answer
2k views

Detecting and Removing Noise from Signal using Python

Through this platform, I want to ask that how can I remove unwanted noise from the signal when you do not have much information regarding the frequency at which they appear? Data is collected from an ...
Aisha Nasir's user avatar
1 vote
1 answer
123 views

Need help with DTFT problem

Prepping for exam and this is one of the practice problems: I just want some clarification on some of the steps my professor took. This is the answer in the answer sheet Only thing I dont understand ...
dnimatullo's user avatar
1 vote
2 answers
2k views

S domain vs frequency domain?

Laplace domain is also known as "s domain". Is there any difference between "s domain" and "frequency domain"? Can we use both terms interchangeably? If we want to ...
DSP_CS's user avatar
  • 1,850
0 votes
1 answer
262 views

Confusions understanding frequency spectrum?

I am trying to learn about frequency domain and I am using audacity software. I selected a small YouTube video (link below): https://www.youtube.com/watch?v=rGHrKkieqCY&ab_channel=PANKAJSAO I ...
kjl's user avatar
  • 9
0 votes
0 answers
68 views

Analytical derivation of convolution and multiplication implement of time-domain signal

I have a system model as shown in figure 1. I want to change the model to a new schematic as in figure 2. How to analytically derive the filter $H_2$ if all parameters are known? I guess that we will ...
user190055's user avatar
11 votes
2 answers
6k views

What is the maximum possible frequency of human voice/speech(That can be generated through human vocal cords)?

Human hearing range is commonly known to be 20 Hz to 20 KHz But what about speaking range? We know that speech Sounds are generated through our vocal cords. So What is the maximum value of frequency ...
DSP_CS's user avatar
  • 1,850
12 votes
5 answers
1k views

What is the frequency representation of nonuniform sampling?

Uniform sampling can be thought of as multiplication of a function $x(t)$ with a Dirac comb function: $$\text{III}_T(t) = \sum_{k=-\infty}^{\infty}\delta(t-kT)$$ Multiplication of $x(t)$ with $\text{...
Gillespie's user avatar
  • 1,662
0 votes
1 answer
436 views

Multiplication in frequency domain for a signal containing a whole frequency spectrum

Imagine we have two signals in the frequncy domain X(f) and H(f), for one of the signal H(f) I have the complex pair and the frequncy at which that complex pair exists. The second could be any random ...
Novice_Developer's user avatar
0 votes
2 answers
242 views

Does LPF limit the maximum sampling frequency of the input signal? [closed]

Consider the system where the signal passes through analog LPF with cutoff frequency of 50 Hz, so the maximum sampling frequency of the input signal could be 100 Hz (according to the theorem). But can ...
Curious's user avatar
  • 355
0 votes
1 answer
529 views

Phase extraction from Fourier transform

Is it possible in principle to correctly extract the phase from Fourier transform? I just tried to do so using Python, here some attempts: ...
Curious's user avatar
  • 355
0 votes
2 answers
711 views

Bandwidth visualization in frequency domain

Consider some signal in frequency domain: the maximum length of which corresponds to the half of the original signal ($N/2$), here $N=32$. It is known that the bandwidth of each sample is $2/N$, so ...
Curious's user avatar
  • 355
0 votes
0 answers
44 views

mp3 encoding in the frequency domain

Let's start with an arduino signal, which can be periodic over time. When this signal is converted from analog to digital it "turns" into a series of bits. At this point, is this signal in ...
Luca Leone's user avatar
2 votes
1 answer
512 views

FFT and spatial frequency basic knowledge

Using the following website: on how the Fourier transform works (Interested in the Basic Principle part). I found out that if you have 3 pixels closer in the spatial domain you'll get more spaced ...
Michael's user avatar
  • 75
0 votes
0 answers
273 views

Frequency filtering in the frequency domain vs. time domain

As a DSP newbie, I've stumbled into doing band pass filtering (of pre-recorded IQ data) in the frequency domain - which allows brick wall filtering (I'm just setting the IQ values of each consecutive ...
Rob's user avatar
  • 31
0 votes
2 answers
316 views

Power spectral density and auto correlation function: Frequency vs time representation

I have a time correlated periodic signal $a(t)$ with $t=0,1,...,T$ and $a(t+T) = a(t)$ that has been sampled at rate $\Delta t$ and I analyse the signal using the PSD via FFT and the ACF. As far as I ...
Lew Dawidowitsch's user avatar
1 vote
1 answer
120 views

Sinc Based Multi Dimension Signal Resampling on the Fourier Spectrum (DFT)

As a generalization of the following questions: The Proper Way to Do Sinc Downsampling (DFT Downsampling) for Uniformly Sampled Discrete Signals with Finite Number of Samples. The Proper Way to Do ...
Eric Johnson's user avatar

1
2 3 4 5
7