Questions tagged [fast-convolution]
Fast convolution is using the FFT, multiplication in the frequency domain, and inverse FFT to perform convolution of a long signal with a long FIR.
62 questions
0 votes
1 answer
68 views
Generating the Filter segment coefficients for uniformly partitioned convoluter from an arbitrary frequency domain signal
I'm implementing an Eq which uses a uniformly partitioned convoluter in the backend. I'm following wefers pg 106.. . I'm using overlap save with 50% overlap. I have 8 filter parts with each size of (...
1 vote
2 answers
364 views
Linear convolution of a 100 sample time series and a 20 tap filter in the frequency domain
I came across this question on an internship application. For context, I'm three years into my bachelor's for electrical engineering right now. I have learned continuous and discreet convolutions, so ...
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1 vote
1 answer
191 views
Non-uniformly partitioned convolution in real time
I am implementing a real-time convolution reverb. I currently have a working implementation, doing frequency-domain multiplication after FFT, using uniformly partitioned block sizes. This answer on ...
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2 votes
0 answers
137 views
cyclic convolution: still have problems in understanding it correctly
I have the following scenario where there are 9 input boxes $S_{m\prime}$ and each box contain $L$ samples. I transfer the input samples of $S_{m\prime}$ to $G_m$ by multiplying and summing each ...
- 679
1 vote
1 answer
357 views
Convolution of two functions using FFTW
I'm trying to perform a discrete convolution of two functions, $f(x) = 1$ and $g(x) = \exp(-x)$ of length nsize using FFTW. I have followed the procedure for zero-...
- 11
2 votes
1 answer
1k views
Convolving Image with Kernel with Fourier
I am trying to convolve an image with the code above using Convolution Theory and numpy's Fourier transform. However, my output seems to be slightly different than the result from scipy. I am not sure ...
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7 votes
1 answer
504 views
Avoid circular convolution aliasing in weighted overlap-add (WOLA) method
This link gives the procedure of implementing the WOLA method. It can be summarized briefly as windowing the extractd data frame, FFT, modify the spectrum, IFFT and overlap-add the windowed IFFT ...
- 429
9 votes
2 answers
3k views
FFT-based fast convolution vs IIR filtering
I'm doing an multichannel audio equalizer system on a chip, which is parametric EQ, usually implemented in cascaded biquad IIR filters. My problem is that I use a lot of IIR filters due to multiple ...
- 527
5 votes
3 answers
1k views
Why is sweeping in convolution so confusing
From this formula, I thought that time constant (m or tau) is the variable sweeping from -infinity to infinity. But in this visualisation https://lpsa.swarthmore.edu/Convolution/CI.html, it is t the ...
0 votes
3 answers
150 views
Signature for the kernels in fast-convolution
Continuing the discussion from Convolution kernel in Bluestein's algorithm it has a very specific signature of the kernel ...
- 679
0 votes
1 answer
114 views
How to zero pad a 3d data and apply fast convolution?
I have two sequences, Let $A$ be the first sequence whose dimensions are $(5, 5, 3)$ takes complex values Let $B$ be the second sequence whose dimensions are $(5, 5, 1)$ also takes complex values I ...
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0 votes
1 answer
332 views
What means `crop` in FFT calculation?
In soapy power manual: Crop: -o PERCENT, --overlap PERCENT percent of overlap when frequency hopping (incompatible with -k) -k PERCENT, --crop PERCENT percent of crop when frequency hopping (...
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1 vote
3 answers
1k views
Are there any reasons to use overlap algorithm when one could do ifft(X * Y) from the complete signal as well in similiar time complexity
We learned that overlap add and overlap save are used as fast convolution methods, because they can be applied with fft due to the formula $x[n] * y[n] = \text{IFFT}(X[k] Y[k])$ So now I was wondering ...
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1 vote
1 answer
637 views
Convolve audio signal with filter with different sampling rates
I would like to convolve two signals: Room impulse response that was obtained by deconvolution, measured at 48 kHz. Truncated to 8192 samples. Anechoic recording (.wav) recorded at 41.1 kHz If I ...
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0 votes
1 answer
149 views
Result of convolution using FFT method not accurate in time
I am trying to implement fast convolution between a signal and complex Morlet wavelets. To make the result equivalent to a linear convolution, I let the MATLAB fft function zero-pad both the signal ...
