Questions tagged [frequency]
Frequency in signal processing is the number of cycles (of the signal) per second.
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What is a speaker behaviour for out of range frequencies?
I was watching this video. The experiment is to create a square signal and record what is outputted by a speaker. We see two diracs signal (+ and -) that looks like the derivative of the signal. Can ...
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3answers
255 views
Why does dot product return zero at non-harmonic frequency
If I understand correctly, dot product between two sinusoids should return zero if they are orthogonal. Since dot product is at the heart of the DFT, we can only clearly compare the frequencies that ...
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1answer
46 views
Frequency Domain Distribution
I have a complex signal in the time domain normally distributed. What will be its distribution in the frequency domain?
I assumed since the frequency domain is a linear transformation the distribution ...
4
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1answer
66 views
How to do Frequency Scaling on an Audio File
Please excuse me if my terminology is wrong. I'm from a music production background and have no experience in signal processing.
I was wondering if it was possible to stretch out the overtones (...
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1answer
33 views
What's the relation between frequency band of $X(j\omega)$ and $\Phi_{xx}(j\omega)$?
in which:
$x_{c}(t)$ is a continuous-time signal
$X(j\Omega)$ is the Fourier Transform of $x_{c}(t)$
$\Phi_{xx}(j\Omega)$ is the Power Spectrum Density of $x_{c}(t)$ which defined as Fourier ...
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20 views
Fundamental frequency in DFT [duplicate]
I was looking into the fundamental frequency in DFT and I noticed many sources mention that the fundamental frequency is $1/N$, where $N$ is the number of samples. (When doing the DFT, we have $k/N$, ...
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1answer
35 views
Match an Equalizer Curve
I’ve passed a sine sweep wave file into an equalizer plugin I have, now I want to model it in matlab so that I can ‘copy’ the equalizer setting sound. I’ve both in.wav and out.wav audio files and ...
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1answer
34 views
Why does toning up a piano make it sound similar to that a string instrument
I have a .wav file of a piano being played at 220 hertz. When I tone this up to 880 hertz, it begins to sound "stringy". However, if I were to use the piano plugin in fl studio and play it ...
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2answers
59 views
Coding an LFO in C
I want to know how I could implement a Low Frequency Oscilator on a simple synth I've coded in C. First in order to understand how to make this happen I would like just to modulate a sine wave by a ...
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4answers
13k views
Simple and efficient algorithm to detect frequency and phase of a sine signal
I need an algorithm to detect frequency and phase of a pure sine signal. The frequency of the input signal changes between 0 and 100 Hz.
The value of the signal gets captured with a frequency of 20 ...
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0answers
10 views
Which equation for analyzing mixed mode sparameters?
I am reading about converting single ended sparameters to mixed mode here.
"As shown by Equation 43, single-ended S-parameters can be converted into mixed-mode S-parameters with the [M]-matrix (...
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1answer
32 views
Accelerometer sensor's data analysis [closed]
Here is a sample data that I got from the accelerometer sensor:
The first selected area shows the acceleration of the IMU device to right side and the second shows the movement to left side.
I am ...
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19 views
Interpretation of Complex modes in Frequency Domain Decomposition
When I do a Frequency Domain Decomposition (FDD) I always get mode shapes with significant imaginary components.
Let's say I see a strong modal response. Still have strong complex nature.
When I do a ...
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2answers
180 views
How do I remove “jitter” when detecting frequency of Sine Wave
Input: Sine wave of any frequency centred at 1.66V
Output: Square wave with a frequency equal to input
I have been working on implementing a common DSP problem -- Detect the frequency of a Sine Wave. ...
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1answer
50 views
How does one interpret an element of the “transfer matrix” used to calculate frequency domain granger causality (via VAR models)?
I am attempting to gain a better mathematical understanding for how autoregressive models can be used to infer frequency-domain granger causality. All freq. domain measures of causality that utilize ...
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1answer
52 views
Is pitch detection for bass instruments a solved theme?
I would like to know if pitch detection is a solved theme for an instrument like a bass (bass tones).
Is it, or there is always a percentage of error rate on the detection?
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23 views
modulation depth
When a value for the power dissipated by an AM signal is given, and the depth of modulation is also given. Then you are told to find the modulation depth required to increase the power to a higher ...
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2answers
50 views
Continuous frequency vs discrete frequency? [closed]
I have understood idea of discrete time and continuous time but I am feeling difficult to comprehend this idea in regard to frequency.
As for example the DFT output is discrete and the DTFT output ...
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1answer
19 views
A-GPS frequency (fd) search ranges
A-GPS is able to reduce the fd search range from several kHz (GPS search range) to several hundred Hz (a-GPS search range). I know the GPS search range has a center at 0 Hz. What is the center ...
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1answer
10 views
What is role of BW and frequency in internet speeds?
First the bandwidth (BW):
It is the amount of data that can be transferred simultaneously.just like more no. of highway lanes so that many cars can travel side by side simultaneously.
Frequency
It ...
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1answer
60 views
Group delay of non differentiable unwrapped phase
As we know group delay as a function of frequency, computed as differentiation of unwrapped phase, but what happen at those frequencies where unwrapped phase is non differentiable?how to calculate ...
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21 views
Does it make sense to apply convolution in the frequency dimension of a fourier transformed signal?
What I have is more likely a theoretical question. Since I am not from a signal processing background it is hard for me to grasp the issue in using convolution in the frequency dimension of a Fourier ...
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14 views
Perceptual Based Adversarial Audio Attacks
I am reading this paper Perceptual Based Adversarial Audio Attacks I have a doubt what is meant by weighting in the frequency domain and what does Section 3.4-equation-4 wants to convey .Please refer ...
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1answer
873 views
How to find PSD (Power spectral density) of spatial data
I have profiled a surface, measuring the height of peaks and troughs at 0.02mm intervals. I have 1501 data points, the below listed as an example:
$$\begin{align}
x &= 0\,\mu\text m & y &...
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1answer
23 views
Is it possible to prove that dither VS PWM can result the same output?
Assume that we have a SISO transfer function model $G(s)$ and we want to look how the output looks like when we have a input signal $u(t)$ that looks like this:
$$u_1(t) = \left\{\begin{matrix}
50 + ...
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9 views
Frequency response Test (Bode Diagramm) on system controlled with a PLC
i have to perform frequency response test on a pump system with servo Motor controlled by a PLC von ALlen Bradley (Logix 5156). I not sur how to proceed and will like to know if someone did such work ...
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9 views
What is the Effect of Multiplying a Function by the Unit Impulse Function in the Frequency Domain? [duplicate]
I know about the the shifting property of the impulse function in the time domain as can be seen in the picture.
But what is the effect of multiplication of a function by the impulse function in the ...
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26 views
Existence of finite output of a system [closed]
1.If frequently response of a LTI system exist and finite then can we say that, for a periodic or non periodic input signal, output is also finite?
2.if responses(output) of LTI
system for ...
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0answers
16 views
Error in measuring wavelength/frequency using autocorrelation
I am currently using these two fonctions to compute to autocorrelation of a signal in order to measure the wavelength:
...
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1answer
26 views
Why is the frequency measured in radians in filter design?
This is my first time posting a question, so sorry if my articulation is not proper.
I'v just started out with FIR filter design and I see the domain being -$\pi$ to $\pi$. Now I understand that ...
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1answer
55 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 ...
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1answer
25 views
RF Downconversion using Heterodyne Principle
after a RF down-conversion using heterodyning principle, will there be an information loss?
If we translate to a fixed IF frequency, is there is an intuitive way of explain that the information can be ...
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3answers
431 views
How do I find a 50Hz sin/cos signal in a measurement among other frequencies and noise?
I measure magnetic fields with high precision, in a gradiometer setup with fluxgate magnetometers, sampling at 2000Hz. I can have big data sets if I want to - one is 600000+ samples long. I need to ...
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3answers
71k views
time in Sine Wave equation
According to Wikipedia,
The sine wave or sinusoid is a mathematical function that describes a
smooth repetitive oscillation.
The formula for the Sine wave is,
A = Amplitude of the Wave
ω = the ...
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3answers
821 views
Distribution of energy in frequency bands
On my wav-file (music), I do a short-time Fourier transform (STFT). I have spectrum, which spans from $0\textrm{ Hz}$ to $f_s/2$. I took out the range between $1$ and $1000\textrm{ Hz}$, which I ...
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33 views
frequencies in frequency spectrum with no correlation together
I have a lack of understanding of the following questions:
If I have a signal from a motor that is recorded with an accelerometer. And the rotating speed of the motor is 150Hz(rpm 9000 ), I can see in ...
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1answer
74 views
DFT and integer valued basis functions'sf requencies
In Matlab the function
W=dftmtx(N)
gives the DFT matrix of size N.
Each row is computed for an integer frequency k. $W_{k,n} = e^{-i2\pi kn/N}$, k-th frequency, ...
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3answers
27k views
What is the Gabor filter? And what are its main uses?
I'm doing research on the Gabor filter. When I Googled it, I found very long and complicated articles. Can anyone help me to find a simple explanation about it, or recommend a website or article to ...
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1answer
928 views
Chebyshev I or Chebyshev II?
I am new to DSP, and I am trying to recreate some analysis of a signal,
They use a chebyshev I filter to go from a 100Hz signal to a 50Hz signal. Whereas I am currently using a chebyshev II filter, ...
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4answers
15k views
What does “frequency” mean for various kinds of signals?
I've been involved in Signal processing for quiet a time but I'm still so confused of what frequency could possibly is, as it has different meanings in different scenarios, for example,
According to ...
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2answers
23 views
What does following statement mean: “ Simulation was done at the rate of 12 samples per cycle of 50Hz a.c.”
I am very new to the signal processing world and i am currently doing a project of studying frequency components in electrical machines. I am simulating the system in PSCAD. But i need to simulate the ...
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1answer
667 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 ...
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3answers
3k views
What is the difference between phase noise and frequency noise?
I'm reading Audoin and Guinot's The Measurement of Time: Time, Frequency and the Atomic Clock, and ran across a confusing an interesting passage (Section 5.2.5, pp 72-73):
The physical origins of ...
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1answer
116 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 ...
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0answers
25 views
Signal is not audible after frequency re-sampling
I'm trying to change the frequency of an audio signal from 22050hz to 500hz. I'm using librosa to read the wav audio and pass the custom sampling rate as 500. Once read, I'm saving it back to audio ...
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2answers
119 views
Difference between OFDM and FDM
In Frequency Division Multiplexing we provide one channel to one user.
Example like BandWidth of user1's voice is 200Khz. I provide one channel of 200KHz in FDM for uplink as shown in the figure.
...
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52 views
Increasing parameter $\omega$ in $x[n] = e^{j\omega n }$
Suppose $x[n] = e^{j\omega n }$. I've seen following statement many times in the different sources:
For the discrete-time sinusoidal signal $x[n]$, as $\omega$ increases from $\omega = 0$ toward $\...
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4answers
266 views
How to see the amplitude of each frequency?
do you know software that exports spectrograms to images of 500x22000 pixels?
all the spectrograms that I know show diffused frequencies and it does not look very good
I just want to see the amplitude ...
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3answers
54 views
Is it better to use sampling rates which are a power of 2? 32-64-128-256-512Hz? instead of using for example 30- 60-100-250-500Hz?
I am recently working with a sensor that I its sampling frequency can only be configured to either 32hz- 64hz- 128hz-256hz... and I was wondering whether using such sampling frequencies have any ...
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1answer
26 views
Possibilities to get the amplitude of a signal at specific frequency from IQ
I'm newbie to the dsp topic and my understanding of math symbols is limited.
So at the moment I'm little bit lost to find the right resources.
I receive an IQ stream from a SDR.
Sample rate: 250k/s
...
