Questions tagged [array-signal-processing]
Signal processing for data collected with an array of sensors.
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Practical wideband digital beamforming for large arrays in radar applications
I do understand the mathematics behind digital beamforming but I am not sure how such systems are practically implemented. For example, in a typical wideband FMCW radar operating in S-band, the (...
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Multi-channel audio upsampling interpolation
I have a four-channel audio signal from a microphone tetrahedral array. I wish to upsample it from 48 kHz to 240 kHz.
Is there a preferred interpolation method for audio? Does cubic ...
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MUSIC Algorithm for Direction of Arrival (DOA) in Acoustic Signals
I have seen multiple reviews of the MUSIC algorithm for the estimation of DOA. Most of those reviews consider a complex signal input with a complex steering vector. So, how do I implement this ...
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Noise leakage problem with least square estimation in the frequency-distance domain
I have data $d$ recorded from an antenna of sensors. These data are composed of a Gaussian noise $n$ and a signal $s$ which I try to estimate. This signal propagates on the antenna with frequency ...
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Radar signal processing flow chart
I'm new to Radar in general, and I'm studying RADAR using online resources. I came across the following slide which shows the process flow of the Radar signal processing.
The thing I don't get in ...
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What wavelength do we use when calculating the array manifold vector when transmitting LFM waveforms?
We know that the array manifold vector, also called the steering vector, for an M element array is given by:
$$ \mathbf{a}(\theta, \phi) = [e^{-j \omega \tau_{1}(\theta, \phi)}, e^{-j \omega \tau_{2}(\...
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MUSIC Algorithm in LabView not Working Well
I am working on performing the MUSIC Algorithm in LabView. The hardware testbed includes four phase-locked receiving channels and a coherent single-channel transmitter (first I will verify the MUSIC ...
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Phase Difference Calculation in Frequency Domain
I am currently working on an application in which I have a Linear acoustic array, the audio of which is analyzed using FFT. Now I also want to perform phase difference calculation and have also learnt ...
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How does SciPy's Welch function change the shape of the data?
I am working with some time series data with a shape of 8064. The data is actually the popular EEG data called DEAP. It basically is a 3D array of size (40, 40, 8064) and here is the link to the ...
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Estimation of the attenuation of two waves on a linear sensor array
Context and objective
I am trying to estimate the attenuation coefficients ($\alpha_u$ and $\alpha_v$) of two waves ($\overrightarrow{u}$ and $\overrightarrow{v}$). These waves propagate on a linear ...
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Determining location of moved sensor in near field array processing
I have a situation where a linear array of sensors monitoring near field sources has had one of the sensors bumped so that the sensor position is off by a smallish amount and is not in its original ...
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Can one use MUSIC algorithm to estimate DOA for a circular microphone array with a small radius?
I am trying to locate the sound source using MUSIC algorithm in a circular microphone array. The array that I am using is "ReSpeaker Mic Array - Far-field w/7 PDM Microphones", and the ...
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Why do we need to estimate eigenvalues?
I am not working in signal processing field, but recently I happen to read a paper which estimates source numbers using Gerschgorin radii, and I feel kind of confused about why we need to estimate ...
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Plotting beam pattern of uniform linear array
I am trying to reproduce Fig. 2.17 from the book 'Optimum Array Processing' by Van Trees.
The figure is a polar plot of the beam pattern $B_{\theta}(\theta)$ given by
$$B_{\theta}(\theta) = \frac{1}{...
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MUSIC implementation in Pyroomacoustics library
I am currently using the multiple signal classification (MUSIC) algorithm provided by the Pyroomacoustics library in order to estimate direction of arrival angles and it works pretty well for both ...
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Crash course on Sonar
I have some experience in Signal processing and a lot more in solving numerically the electromagnetic field integral equations using Matlab and C++.
Now I am curious about the Sonar (e.g., underwater) ...
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MUltiple SIgnal Classification (MUSIC) Implementation
I have a linear 4 element antenna array currently in my design, I am able to obtain the I/Q data from each antenna. Now I am trying to implement the MUSIC algorithm to obtain the AoA (Angle of Arrival)...
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Understanding Implementation of ULA Array Response and Beamforming Techniques in MATLAB
I am currently working on a MATLAB project where I aim to replicate the functionality of certain Phased Array System Toolbox functions (phased.ULA() and ...
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Tetrahedral microphone array beamforming
I have a microphone array of 4 channels taken as channels [6,10,22,26] from Eigenmike spherical microphone array. I wish to do 3D beamforming and create $8\times 4$ beams, 4-elevations with 8 ...
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How to extract human voice from cluttered signal?
I have a signal which has human speech, background voice and noise as it can be seen in below figure.
I have calculated its power spectral density (PSD) using many different methods which can be seen ...
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Direction-of-Arrival estimates clustered at specific angles
I am having an issue which I cannot understand completely. I am working on a simple project where I am testing various algorithms from the family of the Generalised Cross Correlation [GCC] for ...
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How to compare imaginary coherence values?
High, I am currently writing my Master's thesis on susceptibility for hypnosis. I am comparing EGG signals of lowly and highly susceptible individuals.
The imaginary coherence is given by:
$$ \...
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Finding the mode of propagation of a progressive wave and the velocity of that mode
Injecting a sinusoid say, $Z = A \sin(k_x X + k_y Y - \omega t)$, $K = 2 \pi f/c$,
for example, assume $f = 10$ Hz or $50$ Hz, and $c = 50$ m/s, now if I draw the 2D K-space plot with the following ...
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Having problems with GMSK modulation
I'm trying to modulate array of bits with GMSK modulation with BT=0.3 . What I'm doing is making O-QPSK modulation for given bits, then applying Gaussian filter on I and Q arrays and after that ...
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1
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pan-tompkins algorithm
The difference equation of the differentiator used in pan-tompkins algorithm is as follows : ( a five-point derivative)
$$ y \left( n T \right) = \frac{1}{8} T \left[-x \left(nT - 2 T \right) - 2x \...
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Grating lobe in ULA exhibits a jump
The beam pattern of a uniform linear array is
$$B(\theta) = \frac{1}{N} \frac{\sin(\frac{N}{2} \frac{2\pi d}{\lambda} \cos(\theta))}{\sin(\frac{1}{2} \frac{2\pi d}{\lambda} \cos(\theta))}$$
where $N$ ...
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How to find the pattern of a signal or main cycle of a signal?
I have a dataset where a certain pattern is repeatating in different time interval. The repetation of data pattern can come with slight change. I want first find the pattern (or cycle) and later by ...
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1
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Basis Pursuit Denoising (BPDN) algorithm for Direction of Arrival Estimation
I am working on Compressive sensing algorithms for DOA estimation. Can i get any references for writing BPDN code in MATLAB.
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What does the intensity values on wavelet transform mean? Amplitude or power?
So when applying wavelet transform, we get a 2d plot. Each point in that 2d plot has a color, showing intensity of something. But I cannot understand if it is an amplitude or power?
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How do I create a polar plot from a multi-channel sound file?
I have a multi-channel sound file from a microphone array. I want to get the polar plot in Matlab in order to get the directivity patter of the sound source. How do I do this? I did the FFT on the ...
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By using array antenna and a MUSIC algorithm, how many targets could be detected?
By using an array antenna which has N receivers, How many targets could be detected and classified when we use the MUSIC(MUltiple SIgnal Classification) algorithm?
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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-...
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How to reconstruct the signal using overlapping frames in MATLAB
I understand that we can use the buffer function in matlab to split a long signal into overlapping frames. But is there any functions that we can use to put the ...
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Effect of down-sampling to PSD from auto-correlation?
I have a problem to evaluate the PSD from auto-correlation.
As you know, PSD is the Fourier Transform of the auto-correlation.
But I observe the spur at PSD when I calculate the auto-correlation with ...
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Source Localization with the BLUE Estimator
I'm trying to implement BLUE estimator in MATLAB for source localization and after my research I've come up with a theoretical example in Steven Kay's "Fundamentals of Statistical Signal Processing: ...
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Cross-correlation of two signals
I want to find the direction of a sound source in 2D space. I use two microphones and one sound source for that. I have recorded audio data into two arrays. When a sound is detected, it starts to ...
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magnitude spectrum
I have an ECQ signal of 360 Hz sampling frequency. I used an FFT to extract the frequency spectrum of my signal. Now I don't know exactly how to interpret this plot. How can I know the noise from ...
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1
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a neural network approach for FIR filter
I am trying to write a code for a neural network to do the digital filtering on some signals. Is there any neural network model for digital filtering?
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error on angle of arrival
I have $2$ sensors allowing me to measure angles of arrival. These sensors are a distance $d$ ($d \simeq 10$ m) apart and the target to be located is at a distance $R$ with $d<<R$. In the ...
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How to get a single point of the rising edge of a square wave in relation to its time?
I am trying to get data from only 1 point of each rising edge and trying to relate it to 1 point of the sin wave at the same time. Ideally, the middle of the rising edge is where I want the sin wave ...
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2
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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-...
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DSP based phase shifting in Phased Array systems
Is there a downside to doing phase shifting at basedband in the DSP section of phased Array systems?
I suppose you trade off analog components for digital which may be more costly but I suspect modern ...
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How to perform the 2d Vector Antenna in LabView for MUSIC Algroithm
I have 1 transmitted channel and 4 receiving channels on Uniform Linear Array (ULA) and I am using the MUSIC algorithm to determine the AoA of the incoming signals in LabView. Now I want to use the 2D ...
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Convert a list of values and times into an audio file
I have two pandas dataframe, one with time in seconds and one with the actual audio data (values from -1 to 1).
The audio data points are not equidistant, this why I need the list of time in seconds.
...
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Number of microphone limitation for Spherical Harmonics based DOA estimation
I am following this book "Theory and Applications of Spherical Microphone Array Processing", as well as this paper on DOA estimation "Eigenbeam-ESPRIT for DOA-Vector Estimation".
My dataset is ...
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Determining system clock frequency for a given sampling rate and number of channels
I am designing a multielectrode application on fpga. I am recording from multiple electrodes at a sampling rate of 2KHz. Lets say I want to create 60 channels for reading from 60 electrodes. My ...
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Time of arrival
The definition for the time of arrival is:
$TOA=\frac{d}{c}+t_e$ where $c$ the wave speed, $d$ the range between the transmitter and the receiver and $t_e$ the transmission time of the signal to the ...
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What is the difference between array gain and diversity gain?
In a multi-antenna system, we often mention diversity gain in fading channels. I am doing simulations with multiple antenna settings at the receiver considering TDLC channel, for example, 1rx, 2rx, ...
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Simulation of Discrete Inverse Fourier Transform of an array in Python
So I have a simulation to get Fourier Transform of an given array.
This is my Python code to get Fourier Transform
...
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2
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Discrete Wavelet Transform (DWT) and wavelet family
I have just started reading about wavelets for a data compression problem that I want to perform. I am reading about Discrete Wavelet Transform (DWT) but I can't understand where the wavelet family ...
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