Questions tagged [algorithms]
Algorithm is a method expressed in a finite list of steps of well-defined instructions to process a signal.
432
questions
1
vote
0
answers
17
views
implement gradient descent with sparsification algorithm
I am trying to implement the algorithm in this paper for finding a sparse vector x that minimizes the square error $\lVert y − \Phi x\rVert_2^2$ where $\Phi$ need to satisfy the restricted isometry ...
- 145
1
vote
0
answers
49
views
Is `fft` always the best choice?
I hope this is the right place to ask this question since it is partially a note which might help others. Until recently, I always used the fft-algorithm ...
- 111
0
votes
2
answers
101
views
What is the name of this FFT technique for carrier recovery?
https://dsp.stackexchange.com/a/67221/69442
What is the name of this FFT-based technique whose code is given in the answer and whose link I added above? Can I find information about this in any paper?
- 21
10
votes
2
answers
1k
views
What is the name of a low-pass filter that tracks rate of change?
When applying a low-pass filter to a constantly changing signal, there will be a lag between the actual value and the filtered value. For example, if f(x) = x, the ...
- 683
0
votes
0
answers
71
views
Cfar Algorithm Implementation
I am trying to implementation Cfar algorithm to our radar signal processing algorithm. I obtained some output but I want to be sure that is right. Cfar algorithm's output below like, I'm interpreting ...
- 1
0
votes
0
answers
44
views
How to detect known audio samples within a stream of audio
If I've got a bunch of short .wav files, 16 bit linear pcm, and an incoming stream of audio that's been run through a voice codec (g.722, g.711, or others) and then converted back to pcm, what's the ...
- 101
1
vote
1
answer
60
views
Measure of how well sounds fit together in a composition
Are there any approaches to gauge how well a sound may sit together with other sounds in a mix?
I’m thinking about something similar to picking instruments that might go well together in a band. ...
1
vote
1
answer
62
views
How should I go about calculating sines or cosines without the errors introduced solely by the transcendence of pi?
This may be irrelevant for many people but I'm asking this question because I don't need to do these things in real time, I don't care if modifying a 1-minute sound recording takes 5 minutes to ...
- 23
3
votes
4
answers
298
views
What is the equation I can use to create the inverse expoential graph?
I am seeking an equation I can apply to provide a score based on a measurable ability rating.
It would be great to understand how the equation works so I can alter the curvature of this flexibly based ...
- 31
1
vote
2
answers
201
views
How to use MUltiple SIgnal Classification (MUSIC) algorithm to detect the wavenumber of a received signal at array of sensors?
I am working on analyzing data obtained from Fiber Optic - Distributed Acoustic Sensor (DAS) to estimate the properties of acoustic waves that impinge FO cable, such as velocity of acoustic waves. FO-...
- 153
0
votes
1
answer
183
views
MUltiple SIgnal Classification (MUSIC) for Frequency Estimation
I am trying to use MUSIC algorithm to detect individual frequencies of an incident signal. I read the original paper and some interesting books that explain the algorithm. I used the following ...
- 153
2
votes
0
answers
168
views
MUSIC Algorithm for 2D Power Spectrum
I am trying to use Frequency-wavenumber analysis for estimating speed of sound using two-dimensional data obtained via channel of arrays. The traditional technique is to use FFT to transform the data ...
- 153
0
votes
0
answers
22
views
Model validation- comparing signals
Let's say I am trying to validate a model. I have a signal from measurement and a signal from the simulation of the model. Simulation was done with the same initial and boundary conditions as ...
1
vote
1
answer
167
views
DSP function used by musical distortion plugins
In short: what kind of mathematical function was applied to this sine WAVE?
I am trying to implement my own distortion plugins. Amongst other things I have read several chapters of Will Pirkle's book (...
- 113
5
votes
2
answers
780
views
How to measure aliasing?
Aliasing is bad, and we want good filters when downsampling. While what qualifies as aliasing is well-defined mathematically, and we can manually design filters with various tradeoffs, how do we ...
- 8,805
0
votes
0
answers
40
views
model of a quasi static block fading channel in MIMO system
can I know what is the model of a quasi static block fading channel in a MIMO system, in function of angle of departure and arrival?
0
votes
0
answers
15
views
Is there any method to incorporate boundary periodic conditions into the kernel summation over unstructured data points?
Supposing that there are $N$ particles distributed inside a periodic cubic box of volume $V=L^3$, I want to divide the cube into a regular mesh and calculate the following summation at each grid point ...
- 124
1
vote
3
answers
138
views
Measures of "coincidence"?
Assuming I have two sensor feeds, is there an algorithm that gives an estimate of how likely it is that they point at/derive data from the same scene (possibly from different angles, with different ...
- 69
9
votes
5
answers
779
views
Identify abrupt changes in an audio waveform
I have an audio file which was created by substituting multiple speech segments into an original utterance.
I want to find the timestamps where such substitutions happened, so I guess that one thing I ...
- 143
1
vote
1
answer
1k
views
What are the step by step actions taken in order to convert PDM data to PCM data?
I would like to convert PDM (Pulse Density Modulation) microphone data into PCM (Pulse Code Modulation) data. I understand that ...
- 125
1
vote
0
answers
39
views
Different kinds of beeps and tones
I have heard many different types of beeps, chimes, and other tones. Audacity allows me to generate simple waveforms like sine waves and square waves, as well as DTMF tones.
But I want to generate ...
- 159
2
votes
3
answers
113
views
Finding start point of a curve
I'm currently working on a project where I have to measure the latency of a given system.
Below you can see a exemplary image which shows the input pulse (green) and the response (blue).
In order to ...
- 21
2
votes
1
answer
116
views
Choosing the scaling parameters for a modem implementation
I have succesfully modeled a modem using floating-point data and with the following scheme, where the SRRC filter has gain G=6dB.
...
- 123
1
vote
0
answers
63
views
Algorithm for Hue correction behind HSL sliders in image processing software
I have a project where i need to recreate hue specific hue adjustment sliders like in Lightroom/Capture One/DxO photolab.
Initial image.
Image after hue adjustment (Orange hue range) in DxO Photolab....
- 11
1
vote
1
answer
66
views
Steering Vectors and Bluetooth Low Energy for computing Angle of Arrival
I am new to signal processing, but I have background in mathematics. I am trying to use Bluetooth Low Energy (BLE) on three mobile devices, where one device is being tracked and the other two act as ...
- 11
0
votes
0
answers
38
views
What is the point of using this derived PID controller?
Previously, I answer for this PID controller that I want to understand completly.
This is used for control the opening $U_n$ of a valve let gas pass and reach a certain pressure (SetPoint).
There is ...
0
votes
1
answer
64
views
Conceptual doubt about PID algorithm in PLC
I have to use the PID algorithm that I describe below, obtained from a PLC in the company where I work, so I want to understand it. This is used for control a valve that opens to let gas pass and ...
4
votes
1
answer
260
views
Is there an analogue to the 2D DFT that is rotation equivariant?
I'd like to know if there is some general Fourier transform or other signal processing algorithm, such as a discrete wavelet transform, that is rotation equivariant.
Rotational equivariance of a ...
- 77
0
votes
2
answers
171
views
How to detect signal in spectrum without empirical data
Let's say, I have got a spectrum of a signal with noise using fft:
For a human it's pretty obvious that there is a signal with a frequency of about 51Hz. But what is the mathematical apparatus behind ...
- 1
3
votes
1
answer
175
views
How do I do a point response FMCW SAR simulation?
I am trying to simulate and focus the point response for an FMCW stripmap SAR system. I have specified my target coordinates as
targets = [100,100,0;400,100,0] and ...
- 173
3
votes
0
answers
116
views
Are there algorithms to compare changes in signal amplitudes?
I am working on a project to reduce resonances caused by motors.
The vibrations in the material are measured and sampled by ADCs. The measuring works as intended and the next step is to reduce the ...
- 31
0
votes
0
answers
214
views
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 ...
1
vote
1
answer
187
views
Weird Noise arises on the small scales: one question about the fast CWT algorithm implemented in real space
Background:
I am learning an interesting Fast CWT algorithm(PPCWT) by reading this paper published in 2019. The algorithm is summarized as below. The continuous wavelet transform of a signal can be ...
- 124
0
votes
1
answer
64
views
Spectrogram of a shock event
I have measured data of a vibration with chirp input were I suspect unwanted shock events occurred.
I therefore thought about computing the spectrogram of my time histories to check the frequency ...
- 413
1
vote
0
answers
32
views
TDoA self-calibration with a single calibration emitter
I've recently asked a similar question aiming at the same problem on
Math.SE, for which I've set a bounty.
Problem.
I have a radio calibration transmitter with known fixed location $\langle t_x, t_y, ...
- 123
1
vote
1
answer
234
views
Problem with "Topological Structural Analysis of Digitized Binary Images by Border Following" by Suzuki Abe
I have a Problem with the Paper "Topological Structural Analysis of Digitized Binary Images by Border Following" by Suzuki and Abe.
In the Chapter "Appendix I: The Formal Description of ...
- 11
0
votes
1
answer
302
views
Finding rectangle corners by using point cloud
I have a rectangle in the 3D scene, which I know its width and height. It is placed in the 3D scene like the image below. I can manually select all points on the rectangle by mouse click.
Given the ...
- 103
0
votes
1
answer
74
views
convert from binary to hexadecimal according to the algorithm "keeloq"
Good afternoon. I have the key to my gate. I received its recording in the form of a PWM pulse train. Instead, I converted the impulses into binary code. Now I should get the hex numbers but it doesn'...
- 113
1
vote
2
answers
66
views
Which of an array's contiguous subarrays is an algorithm best applied to?
A function $f$ accepts two equally-long arrays $A$ and $B$ as input, and returns a real number $s$ such that the root mean square of $A-sB$ is minimal.
I'm hoping to come up with a better-than-brute-...
- 23
0
votes
0
answers
56
views
How to decided the score threshold in speaker recognition?
I am new to speaker recognition and now starting from the GMM-UBM algorithm.
Say I have a pre-trained UBM and speech from target speakers ...
- 21
1
vote
0
answers
69
views
Why some implementation of Wavelet transform use reconstruction filter instead of decomposition filter?
I'm using MODWT (Maximal Overlap DWT) to extract features from a signal. Matlab implementation is using reconstruction filter instead of decomposition filter. In the first level of modwt decomposition,...
0
votes
1
answer
189
views
What difference AoA algorithm between 4x4 URA and 12 elements square shaped?
I'm reading a paper from Lund University. They show the measurement and compare the accuracy of 3 types of arrays.
The interest and question I got are two types, 4x4 URA and 12 elements square-shaped.
...
- 3
0
votes
0
answers
76
views
What is a good algorithm for filtering data from a sensor that occasionally malfunctioned?
I was in a lab and recorded some data from 2 pressure sensors. One worked perfectly (red line), the other one would send random data occasionally (blue line.) All of my values are supposed to be ...
0
votes
0
answers
62
views
How is the 'difference' of two audio tracks best computed, in order to maximise instrument isolation?
I'm hoping to improve the results of a simple application I've been working on, which aims to isolate as fully as possible the electric guitar heard (along with drums/bass/vocals) on a single track of ...
- 23
1
vote
3
answers
4k
views
range-doppler map to range-velocity map conversion
UPDATE 2.0
I think I've managed to produce the correct range-velocity map. I'm struggling with analytically calculating the range which I expect to see on the range-velocity map. Could someone please ...
- 113
1
vote
0
answers
52
views
Do CQT, FFT, and NNLS provide different "perspectives" on the original signal?
From a bird's-eye perspective, do CQT, FFT, and NNLS algorithms provide different "perspectives" on the original signal? Does each preference some features of the original signal?
I'm using ...
- 111
4
votes
3
answers
116
views
Algorithm for finding best matching sin wave to input signal
Question
Suppose I take a signal $y(t) = \cos(2\pi \cdot 4.1t + 2)$ and I sample it uniformly up to 2 seconds.
Given only these time samples, how would I design an algorithm that finds the pair of ...
-1
votes
1
answer
111
views
Convolution of a discrete continuous function for reconstruction
From chapter 9 page 198 of https://github.com/t4world/Computer-Graphics/blob/master/Fundamentals-of-Computer-Graphics-Fourth-Edition.pdf
I am confused as to what this book's description is saying ...
0
votes
1
answer
70
views
Identifying a signal by its power spectrum
Background: There is a method in optics for determining the electric field of light (both intensity and phase) via a three step process:
Add a known phase shift to the light (called the "...
- 101
1
vote
1
answer
239
views
When if an FFT more efficient than Goertzel?
Given a block, $x[n]$, of M samples.
Calculating abs(fft(x)).^2 returns the power spectrum of that block through the use of a $M$-point FFT.
I can calculate the same using Goertzel's algorithm.
At ...
- 319