Questions tagged [algorithms]
Algorithm is a method expressed in a finite list of steps of well-defined instructions to process a signal.
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Space-Time coding uses large amount of block codes to acheive maximum spectral efficiency
Assume I have a MIMO system with $M=8$ transmit antennas, and an arbitrary number of receive antennas.
This MIMO systems uses space-time coding. the block codes (matrices) transmitted are part of a ...
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Understanding Fourier Transforms in abstract math terms
I am having a hard time implementing a method that computes Fourier transform coefficients for the complex form using the trapezoid rule.
I have floated questions in the math and stackoverflow ...
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Fuse two sources of linear acceleration with a Kalman filter
How would I fuse two different sources of linear acceleration with a Kalman filter (perhaps linear acceleration readings from an IMU and from a dedicated accelerometer)?
My state is defined by ...
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Range Migration Algorithm in FMCW MIMO RADAR
I’m using a FMCW MIMO radar [77-79 GHz] with a virtual linear array made of 48 channels.
I’m wondering if the adaptation of the range migration algorithm (typically used in SAR processing) is ...
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State of the art for automatic rhythm analysis
What are the currently most used and less error prone algorithms in the field of music information retrieval for beat detection and tracking?
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Idea for Noise Level Estimation / Automatic Thresholding in the Presence of Peaks
I have the fft of some signal, and want a rough estimate of the noise level in order to choose an appropriate threshold for our peak detection algorithm. In general, the fft contains mostly noise with ...
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Understanding a lowpass - comb filter implementation
I try to understand the implementation of the low-pass comb filter of the Freeverb reverberation algorithm:
https://ccrma.stanford.edu/~jos/pasp/Lowpass_Feedback_Comb_Filter.html
The original ...
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Need Help with Time-Stretching WSOLA Algorithm
I’m having problems implementing time-stretching using the Wave Similarity Overlap Add (WSOLA) algorithm. I got the basic OLA algorithm working first and then added wave alignment using cross-...
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Baseband signal processing algorithms [closed]
What is one exactly referring to when you say "baseband signal processing algorithms"?
Can anyone give a few (common) examples.
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Is it possible to estimate the DOA from real samples only?
I'm sampling a ULA with a scope after transmitting a CW.
I'm wondering if I can estimate the DOA assuming I'm interested only
in the range [0,90] [deg] and not the full [-90,90] [deg].
The first issue ...
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How to automatically identify a surge in a periodic signal
Say I have a periodic signal i.e. Sine wave, which sometimes can have spikes that are 100% larger than the peak value. These spikes can be periodic as well. I'm trying to find an algorithm that could ...
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Extracting 'structure' post permutation
I have particle activity as shown in the left pane of animation below. The activity is clustered and it moves slowly. Sometimes these clusters merges together. On the right side of it, its shuffled ...
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What do these values in the freeverb diagram mean?
I am implementing a reverb based on the Freeverb implementation detailed here. There is also a more in-depth description of the LBCF in question here, but I am not able to find the information I want ...
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Goertzel derivation
Referring to this link, about Goertzel,I am confused about the final equation after N iterations
Where does
real = (q1 - q2 * cosine)
and
...
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Are there any efficient algorithm to detect circular shape of arbitrary size in an image?
I have images that are 1278 by 1024. They are pictures of a certain product that is rectangular in shape and are about 25mm by 20mm. As a part of a quality inspection process using computer vision, ...
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Robust peak detection taylored for spectroscopy
i need a algorithm for peak detection in raman spectroscopy. I tried this one, but it did not give me satisfying results.
Spectrums may look like this:
In professional software, i think they use the ...
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Partitioning data for minima detection
I am working with signals that consist of consecutive equidistant dips. I am trying to write an algorithm that finds the absolute lowest (minimum) point in each of the dips.
We don't know the ...
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Is it possible to do better than Cramér Rao lower bound for different estimation methods
I’m new to learning about the Cramér Rao lower bound. Does the calculation of the CRLB imply that only particular estimation algorithms can be used (e.g. estimating delay and Doppler from a complex ...
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Maximum likelihood estimation complexity computation
I have a basic question about maximum likelihood (ML) estimator and its implementation.
I am trying to simulate a communication system, while using ML at the receiver side to find the transmit ...
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How can I specify the distance between values in such row
I have a question, about verifying the value which are near to each other in such row, Is there any algorithm which can determine that ?
Suppose I have a vector $z_i =$ {$z_1 , z_2, z_3, . . . ., ...
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Detecting similar behaviour in audio files
Can anyone help, I'm trying to find a solution that would allow me the ability to look at a batch of .WAV files and detect ones which share a similar behaviour in the recording like the image attached....
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Algorithm to convert a GeoTIFF file to PNG image format
I have a bunch of GeoTIFF files that I am processing into a TFrecords format for machine learning. Now I can't put tiffs directly into a TFRecords format and so I ...
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How to change the shape of a function generator keeping the rate?
I'm making a sort of Envelope Function Generator. At the moment, I'm calculating only the the "rise" stage, which goes from 0 to 10 V; than, brutally, I back it to ...
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Is there an algorithm for computing auto-correlation in a frame-based manner?
I am trying to find out if an algorithm similar to the Overlap-And-Add method that enables frame-based computation of convolution and cross-correlation exists.
When I say frame-based computation I am ...
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Method for the Localisation of Impulsive Noise in Speech Signal
I'm sorry if this question has already been answered, but I couldn't find anything.
I'm working on a program for noise detection and need to locate the position of impulsive noise. The following image ...
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What language or framework would you use to develop and test natively algorithms meant to be ported on an embedded hardware later?
I am trying to find a nice clean solution to this problem since some days now, and couldn't make myself to stick to a solution.
I need to develop some stream and block processing for audio, including ...
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Berlekamp–Massey algorithm verification
I'm implementing Berlekamp–Massey algorithm for BCH codes, but I have some troubles with it: I don't realize how to verify this algorithm. Is there any methods to prove, that code works correctly or ...
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90 Degree Phase Shift / Rotation Algorithm for SDR
I'm working on a library to preform frequency demodulation from an SDR signal. I'm using https://github.com/sysrun/rtl-sdr/blob/master/src/rtl_fm.c as a crib for this. The algorithm starts by taking ...
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Convolution of signals sampled on a logarithmic grid
Is there a practical accelerated algorithm or a theoretical discrete (Fourier) transform based method to convolve discrete-time signals sampled on a logarithmic grid? What I mean is representing a ...
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Extending Goertzel algorithm to 24 kHz, 32 kHz and 48 kHz
I'm learning to implement Goertzel's algorithm to detect DTMF tones from recorded wave files. I got one implemented in python from here. It supports audio sampled at 8 kHz and 16 kHz. I would like to ...
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How do audiobook players manage to quickly speedup/slowdown playback speed without using more memory?
Many audiobook player apps on Android have a reading speed slider which lets us choose the reading speed e.g. 0.5x 0.75x 1.00x 1.25x 1.50x. This is time-stretching ...
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What's wrong with my implementation of the Matching Pursuit algorithm?
I have recently attempted to implement a simple version of the Matching Pursuit algorithm, following the description detailed on Wikipedia. Although the algorithm itself seems dead simple, my ...
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FM synthesis algorithm is not very efficient
I have very little knowledge of DSP, I'm trying to implement an FM synthesis algorithm in code / software.
So far I've successfully implemented a FM algorithm using the following:
...
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Is there an intensity estimation algorithm working solely in time domain
Given a second of sampled sound pressure signal, speed of sound and medium density, can the average sound intensity be estimated without performing DFT, that is in linear time by simply traversing all ...
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Determine 3 most dominant frequencies in a signal, PSD or just the absolute value of a Fourier transform?
I have a noisy ECG signal recorded for 5 minutes. My goal is to determine heart rate every 2 seconds. To find out 3 most dominant heart rates (Beats per minute) in a 2s-signal should I calculate its ...
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Ways to parallelize Sifting in EMD (Empirical Mode Decomposition)
Sifting process, which is recursive in nature, is used in EMD (Empirical Mode Decomposition) to decompose the signal (x(t)) into Intrinsic Mode Functions (IMFs) and residue, which is a monotonic ...
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Improve NMF for data with partial overlaps in multiple groups?
I want to use NMF to separate true sources from data. My data is in group structure with overlap elements. For example (in the smaller version)
group1: contains A,B,C,D,E,F,G patterns
group2: ...
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Message-round probability in SCCC graph
I am reading the paper Interleaver Design for Serial Concatenated
Convolutional Codes by Yu et al., and it states the concept of message-round probability as $F(l_1)F(l_2)$ where $F(l)$ refers to the ...
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Fast Morphological Erosion / Dilation with Variable Window Size
I want to perform the following operation on an image: consider a square window around every pixel, find the maximum value in this window, and replace the central pixel value with this maximum value. ...
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Frequency detection in audio and what parameter or set of parameters help/limit frequency detection
I'm trying to learn audio and voice/speech processing techniques out of interest. I intend to learn, experiment with algorithms and design, implementation of such systems, frameworks using programming ...
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How can I evaluate the complexity of two solutions when both additions and multiplications are present?
I am evaluating FFTs algorithms radix-2/4 and split radix. (although this talk can be applied to any algorithm).
Each of them has a certain amount of complex additions and multiplications.
That can ...
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Efficient calculation of exact frequency from a broad frequency range (1 Hz - 1000 Hz)
I have some input signal sampled at 1-10 MS/s. Let's assume that it contains one strong frequency component (with frequency anywhere in the range from 1 Hz to 1000 Hz or even higher, changing over ...
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Do you recognize this filter?
I'm trying to decipher the uncommented source code of SoundBox which is a little music tracker written in javascript.
There is an included synthesizer, which applies a filter on the output samples. I'...
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High / Low Pass Filters from Zero
I everyone,
I'm a computer scientist but not from the signal processing community. I want to implement a real time digital low pass filter (to begin with) for a sound processing application. I've ...
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Simple question about HS algorithm's formul(Optical flow)
In the below pic, I can not understand what U vector is? It says flow field but I can not imagie what really is the flow field?
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FFT for distance-limited sum of pairwise products
I have a sequence of fixed length $N$ input arrays ($x_0$, $x_1$, ..., $x_{n-1}$), and my goal is to compute output arrays as such:
$$d_{00}[l] = \sum_{i = 0}^{N - l} x_0[i]x_0[i + l]$$
$$d_{01}[l] = ...
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Using the Kalman filter given acceleration to estimate position and velocity
I am reading data from an accelerometer. I want to use this data to estimate velocity and position. Originally, I performed a double integration of acceleration to read this data, and as confirmed by ...
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What are some efficient algorithms for real-time calculation of eigenvalues?
I need to calculate eigenvalues of a square matrix for a real-time implementation using microcontrollers or dSPACE. Obviously, I can find the eigenvalues of a 2by2 matrix analytically. I am wondering ...
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Multilateration of Sound in 3D Space
TL:DR - How can you find the 3D coordinates of a emitter than transmits an impulse signal?
STORY:
I'm working on something to improve my bird-watching. I've got a camera that can take pictures of ...
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Does this Signal Smoothing algorithm have a name?
We are reverse engineering some 20 year old software. Original developers were laid off years ago, and cannot be found.
In this code, there is a signal that is getting smoothed as follows:
$P_{new} ...
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