Questions tagged [frequency]
Frequency in signal processing is the number of cycles (of the signal) per second.
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Plot amplitude vs freqency in DB
I have C++ App which wich plot 3 plot
amplituede vs sample
amplitude vs frequncey(used FFT for calculation)
amplitude(in dB) vs frequncey
I want plot 2 with y axis lable represent in DB, without ...
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How to convert the phase noise spectrum density to frequency spectrum density?
Following the answer in this post: Phase noise and frequency noise relationship, I can calculate the phase noise spectrum density with the unit from $\frac{dB_{c}}{Hz}$ to $\frac{rad}{\sqrt{Hz}}$. ...
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Real part of signal
A little story. At the university, I did laboratory work on expanding functions into the Fourier series. I have this drawing. My teacher told me he is faithful. But he asked me this question: "...
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Collecting average frequency data of a song/audio recording
I'm a university student, and for one of our classes we have to use TouchDesigner to make some sort of dynamic visualizers. I know how to do this already, but to make the process more scientific I ...
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How to find Gain when i have frequency of input and output signal
I need to find the bandwidth of an filter, for this im generating frequency of 1Hz to 200 hz in step of 1hz from a function generator Im expecting -3db point anywhere between 1 and 200
The output of ...
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How to extract the oscillation frequency from the following signals?
Signals contain both transient and stabilizing processes.
In the transient process, the signal exhibits oscillatory behavior with damping. Is there some efficient algorithms to extract the frequency? ...
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Does analytic signal have positive instantaneous frequency?
The Analytic representation of a signal has no negative frequencies.
Does this mean that everywhere, it's instantaneous frequency is positive?
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Why does FFTPack 5.1 not give the same complex numbers as Matlab's FFT2 command does?
I'm doing FFT2 with FFTPack 5.1 and it's working great. But it does not give the same result as Matlab's FFT2 command.
Turning Time domain -> Frequency domain -> Time Domain give the same result ...
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How to do FFT with complex numbers - Ansi C code
I have a small issue.
I'm going to do FFT2 onto a matrix $X$, and the only library I have is FFTPack. FFTPack is the oldest FFT library, but it's one of the fastest and 100% portable too.
The problem ...
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Separating an audio file into "N" frequencies
I'm working on an audio visualizer using Blender, and I'm wanting to separate input audio files into their respective frequencies to allow my models to react based on the amplitude at different ...
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Separating an audio file into "N" frequencies
I'm working on an audio visualizer using Blender, and I'm wanting to separate input audio files into their respective frequencies to allow my models to react based on the amplitude at different ...
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Sampling a pulse train with a controllable square wave
I have an issue regarding a sampling process of a pulse train in an image sensor based on events. Basically, these are a family of image sensors in which each pixel outputs a train of pulses, and the ...
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Replicating SDR transmitter and receiver (shifting of a quadrature signal)
I am trying to implement an SDR transmitter and receiver based on the description here.
...
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Central frequencies of band filters with cut-offs at 0 and the sampling rate
I'm trying to configure AutoEq for SuperEQ. The latter was originally a Winamp DSP, but now it's used in foobar2000 and DeaDBeeF.
AutoEq requires a list of central frequencies and Q-factors for ...
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Paul Kellet Resonant Filter: freq from/to hz?
I was working/studing a basic Resonant Filter, using the Paul Kellet one as test case: https://www.musicdsp.org/en/latest/Filters/29-resonant-filter.html
The freq is feed in normalized value 0..1.
So ...
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Frequency response measurements by audio signal FFT
I am trying to measure the frequency response of different audio canals, e.g. tubes, hollow pipes etc.
My experimental setup looks like this: I generate an audio signal with a loudspeaker (Visaton WS ...
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How to remove phase shift for a baseband signal given an estimated CFO (Bluetooth)
I am working with Bluetooth specification 5.1 where the advertisement packets can send a constant tone extension (CTE) over the baseband signal to estimate the angle of arrival with an antenna array.
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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 ...
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Why does spectrum magnitude decay away from DC for positive signals?
I would like to understand why the second frequency component usually has the greater magnitude within the range [1, (N/2)], i.e why (I remove the DC component and ...
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How to modulate a signal to a certain frequency in time domain
I have a root-raised cosine pulse signal of bandwidth $500$ MHz.
If the signal is modulated at the frequency $6$ GHz, the result should apparently look like this :
If I understand well, to modulate ...
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Is there a way to get this reverb effect working on something else than 44.1 kHz?
I have successfully implemented the Sony PlayStation 1 reverb effect, until I realized that it strictly works at a sample of 44.1 kHz.
A quick web search shown that (as far as I understand), an IIR ...
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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 ...
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Block Diagram 2nd Butterworth Low-pass
I would like to represent a second-order butterworth low-pass filter in a block diagram, how can I get started?
As per the attached image
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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 ...
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Sampling Frequency of a Rotational Sensor
In the picture above you can see a sensor I've been dealing with, called a "Caliper". This sensor arm simply passes over the pits or bumps on a disk rotating with a constant angular velocity ...
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How to find sampling frequency in aperiodic signal?
I have a signal that is $x(t)=e^{-3/t^2}+2\cos(3\pi t^3)$ and I'm trying to find its proper value for fs. But I couldn't find a way on how to do it. I'm working on an interval $0<=t<=2$ and $x(t)...
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Aliasing problem with pressure data
I have done some pressure measurements of flowing air with transducers that had a frequency response of 5 kHz.
The data from these transducer was sampled also with 5 kHz and this is where my problem ...
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Laplacian Filter kernel size meaning
I'm using laplacian filter in opencv.
I usually use laplacian filter with kernel size 3 which is default setting in opencv.
I'm just curious what happen(intuitively) when I choose bigger size kernel?
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Frequency shifting with complex exponential
I'm trying to frequency shift a sine wave at 50kHz by using a complex exponential at 15kHz. I should be getting an FFT with a peak at 65kHz.
Instead I'm getting a strange looking peak at 52.4kHz. ...
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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):
$$X[k]=\sum_{n=0}^{N-1}x[n]e^{-...
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Representation of Sampling Frequency in the Fast Fourier transform
I have 21600 data in the time domain. What Sampling frequency should I use? can someone explain the effect of showing the result by selecting different sapling frequencies?
Cheers
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Bode Plot - Why we add dB value in some situations?
Question: Specify the straight -line approximation of the Bode magnitude plot: $$H(j\omega) = 0.04 \cdot \frac{jw+50}{jw+0.2}$$
I don't understand that in the plotting part we add 6dB for two ...
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How does slow-time FFT detect velocity?
The signal processing steps for a pulsed radar are: Fast time matched filter -> Slow time FFT.
I cannot understand how is the second step able to detect frequency,
because the results after the ...
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Is the maximum possible bandwidth of a radar system dependent (or related) to its center frequency?
One of the core parameters of any radar system is its center frequency. Another core parameter is its bandwidth, which is the reciprocal of its ranging resolution. I am wondering: Is there some sort ...
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Phase vocoder has crackling artifact
I built a phase vocoder in JavaScript based on this paper. It works great, except for a crackling artifact that is present in the rebuilt signal.
I recorded this clip if you want to hear what it ...
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How is the Goertzel algorithm useful when it lacks information about relative magnitudes?
I am trying to understand how the Goertzel algorithm can be useful. I know it provides efficient evaluation of individual terms of a DFT, and I read that it can be used for pitch detection by ...
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Implement a simple Continuous Wavelet Transform for specifics frequency
I have a question. I am worked with the Wavelet Transform, Continuous and Discrete. With the Discrete Wavelet I implemented a noise reduction in a signal, using Python library.
Now i have a signal ...
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How can I determine the frequency of a sine wave signal with gradually increasing frequency?
I have been trying to solve the following problem. I have a DSP algorithm where these variables occur:
$$x(k) = \cos[\theta(k)],\quad y(k) = \sin[\theta(k)]$$
I have recorded both of them and I would ...
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Sweep length and FFT time
I'm trying to figure out what length of linear sine sweep I need to cover 100Hz to 9KHz at 1Hz frequency resolution. The max sweep length of my software is 160s, so for this bandwidth it sweeps 55....
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What is "modified frequency slice wavelet transform"?
What is "modified frequency slice wavelet transform"? It was written in an article but It's not been described on the web.
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Finding the maximum frequency deviation and phase deviation
I'm trying to solve a problem regarding communication and I'm stuck. The questions asked me to find the maximum frequency deviation are usually written in cos or sin wave. But this question isn't, so ...
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Effect of sample frequency on deconvolution
I am a chemical engineer so I'm not very familiar with the methods of signal processing. Nevertheless I need to apply them now on my thesis work. Most recently a question occurred to me, that is ...
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Adding two sine waves results in a low buzz
I'm working on a little audio/embedded systems project, and I'm using synthesis to generate waveforms and feeding them into DAC and speakers. Currently, I am able to produce sine waves of individual ...
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Pitch successfully changes with Phase Vocoder, but there's an issue
I've been working on a phase vocoder program. The goal is to change the pitch of a recording of my voice. While doing research on how to change pitch, I came across this from a paper on phase vocoders ...
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Implement Quinn’s second estimator for frequency estimation
I am trying to get the estimation frequency from the FFT output in unity, I have read that Quinn's second estimator method is the most accurate method, and I found the algorithm for how to implement ...
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Why complex signal doesn't remove "beatings" while sampling?
My motivation to this post has arisen from the accepted answer to Amplitude modulation vs sampling rate?
Sampling the signal with the frequency close to $f_s/2$ can lead to some kind of "beatings&...
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Calculate a signal of brightness
I am new to signal processing. Currently, I am reading a paper regarding musical expression. The paper calculates brightness, and I want to reproduce their way of computing it. I was wondering if ...
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How to find the phase difference between two signals with and without noise?
I need to find the phase difference between two sinusoidal signals with the same frequency (23.5MHz) but not in same phase.
Test case:
Generate two sinusoidal signals of length 8 with different ...
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When I am acquiring the DFT on collected data, do I need to normalize the sampling frequency?
I have collected data from an oscillating system where angle values change over time and I am interested in identifying frequencies in my oscillations.
Given that my sampling frequency is $f_s = 1$ ...
