Questions tagged [array-signal-processing]
Signal processing for data collected with an array of sensors.
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Scipy.signal.find_peaks in c/c++
Hi guys I am trying to find a peak in waveform 1-d array data until I can find peaks in Python using scipy.signal find_peaks reference for that https://docs.scipy.org/doc/scipy/reference/generated/...
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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 compensate for rotational offset for Steering vector of a phased antenna array
I am working with antenna phased arrays for direction finding. According to the manufacturer of the antenna some elements of the uniformed rectangular array (URA) have a rotational difference. This ...
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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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How to modulate a signal to a certain frequency in time domain
I have a root-raised cosine pulse signal of bandwidth $500$ MHz.
If the signal is modulated at the frequency $6$ GHz, the result should apparently look like this :
If I understand well, to modulate ...
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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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how to log phase of NWC Australia 19.8KHz in a file in python
First I am very new in this field,and i am doing a college project and i stuck at determining phase of msk signal which is transmitted from a radio stations called NWC Australia 19.8Khz , so let me ...
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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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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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localization comparison with AOA and TDOA
I have 3 base stations. Each base station is equipped with several antennas such that the distance between antenna is smaller than the distance between base station and target. We then have the ...
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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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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 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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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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Is the beamforming result described by this matlab code useful?
A narrow-band beamformer for $0$ degree in the frequency domain is created for $8$ sensors and compared with a usual delay and sum beamformer. The question can also be expressed as : can we have ...
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FFT channelising for DF
I have a 25 MHz IBW real time signal analyser throwing out 25 MHz wide complex data at 50 MHz sampling frequency.
I want the frequency resolution to be 12.5 kHz (width of a vhf channel) so need 2000 (...
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How can I find a transfer function between two signals in python?
If we call one signal $x$ and the other signal $y$.
I want to find a transfer function that takes $x$ as input and gives $y$ as output. I have recorded data of signal $x$ and $y$.
$$x(t) \overset{H}\...
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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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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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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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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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How to calculate Diffential Entropy (DE) in Python?
I am working with a data which 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 official dataset website: https://www.eecs....
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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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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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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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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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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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What is going wrong with the plot of 2D spatial spectrum at a specific frequency?
I've a set of 09 sensors in the following arrangement and the script for the sensor positions as follows:
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How do I make a graph of pseudo frequency vs. time. in ssqueezepy?
How do I make the y axis in psuedo-frequency?
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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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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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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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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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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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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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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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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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pattern recognition with some features in time series data
I am trying to capture peaks in a time series data which has some predefined feature.
Here is a snapshot of time-series data (Time series data with peaks)
In this time-series I want to detect peaks ...
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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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I have two signals, recorded from the same device. How do I standardize/normalise them?
I essentially have two signals X and Y, recorded with PPG devices. These have been filtered already. I want to standardize(z-score) or min-max scale them but I don't know if I should do this on each ...
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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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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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Can FFT tells us existance of same frequencies with different phases?
So I know that applying FFT on a time-domain signal, shows which frequency components exists and what amplitudes each frequency signal has.
My question is, suppose the signal contains same frequency ...
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Extracting different frequency bands (alpha, beta, gamma) from MEG source estimated data
I have a dataset that consists of source estimated data of MEG brain signals.
I need to extract the different frequency band features (i.e., alpha, beta, gamma, etc) from them.
What steps/procedure ...
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Calculating power of brain signals
I have a dataset that contains EEG (or MEG) recordings of brain signals during some cognitive tasks.
Each row, shows the source estimates of neurons in a particular region.
source estimate contains ...
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Why does my amplitude change upon inverse Fourier Transform when I am only randomizing the phase of the fourier transform using Python numpy?
I am trying to make a surrogate time series of a discrete data series using python, basically I wish to keep the amplitude same and change the frequency
I take a Fourier Transform of the data
I ...
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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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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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