The frequency-domain tag has no wiki summary.
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adaptive filter does not converge for all inputs
I am trying to make a frequency domain adaptive filter in matlab. It uses matlab adaptfilt.fdaf to create the filter parameters like step size and initializing initial filter weight values. Then I ...
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1answer
84 views
frequency domain phase shift
While going through FFT I came to know that, shifting of phase in frequency domain results on shifting of time in time domain.
According to this, in wireless communications, from the transmitter side ...
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1answer
37 views
Square of Frequency characteristic of the system
What does $|H(j\omega)|^2$ in $20 \log_{10}|H(j\omega)|$ mean?
Is it some ratio of energy or power? And why? How to derive it?
I'm sorry for curtness of my questin.
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3answers
100 views
How to compute fundamental frequency from a list of overtones?
Given a list of overtones (F1, F2, F3, etc), how do I compute the fundamental frequency? Can I do something like F2/F1=F1/F0? Is it the correct method to use?
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2answers
99 views
What is the basic concept of Fourier transform
I use discrete Fourier transform for digital image processing purposes , but I don't understand basic concept behind it. For example :
What information exists in frequency domain?
What is ...
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2answers
67 views
Fourier series - time and frequency domain confusion
I am computing the fourier series of the following function between $[-0.5, 0.5]$
$$\displaystyle f(t) = \frac{1}{2} - |t|$$
According to the definition of Fourier Series the coefficients are given by
...
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1answer
85 views
How to do image reconstruction from array data?
i have 15 set of data which is the s-parameter, consist of 2 column (1001x2) each set. The first column is frequency and the second column is magnitude in dB. I have transform the magnitude from (dB) ...
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1answer
106 views
Performing classification based on FFT results
It is perhaps important to start with the fact that I am a complete beginner in DSP.
I have got a number of audio recordings (of sampling rate 22 kHz) - of bird songs - which I have been trying to ...
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0answers
42 views
Keep the exact frequency content - Multidimensional fft
In Matlab I've got to generate a Gaussian process embodying a certain frequency content. Not to go multidimensional, I have used reshape function. I explain better ...
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1answer
49 views
What features to use for multilayer perceptron model of an EEG signal?
I have an EEG signal that I want to extract features to apply multilayer perceptron (MLP). What I should use, Fourier or wavelet coefficients?
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2answers
129 views
Extract frequencies from PCM signal
I have an PCM (pulse-code modulation) signal. If I want to work out the frequency of a sample $ x $ long, I count the number of peaks/troughs of the sample, and divide by $ x $. The equivent dB of ...
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2answers
221 views
Determining the noise floor of a signal in the frequency domain
Is there an accepted way of determining the noise floor of a signal by looking at it in the frequency domain? Is it a matter of averaging all the bins, or median, or some more complex calculation ...
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3answers
134 views
Chop out frequencies outside human hearing range
I have a bunch of audio files all sampled at 44100 Hz sample frequency. I am trying to remove all the frequencies which are outside the human hearing range (I use the following as reference: Frequency ...
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1answer
212 views
Time -Domain to Frequency Domain
I am constructing a MFCC and come to a section which is kind of confusing me.
It is:
Step 4: Fast Fourier Transform
and has this equation:
Now I understand that FFT needs to be carried out, I ...
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1answer
94 views
Fractional Frequency and negative Frequencies
So, when we Sampled any signal at the rate lower than Nyquist Frequency we get aliasing,
for instance,
If the frequency of Cosine wave is 5Hertz and I had to make 5cycles in a second and if the ...
2
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2answers
946 views
Amplitude of the Signal in Frequency Domain different from Time Domain
How does the Amplitude of the Signal is changed when taking the FFT of a Signal,
Have a look,
The amplitude had changed from 2 to 30,
and Here is my code for generating the above output,
...
