Questions tagged [signal-analysis]
The processing of signals for the purpose of extracting a parameter or property embedded in a signal. Signal goes in and far fewer numbers come out.
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How Can I Detect Peaks and Regions of Highest Variance in a 1D Signal?
I'm not a signal processing person at all so hopefully I'm not asking an obvious question (if I am, I'd appreciate any resources that would help give more context).
I have a 1D vector where the ...
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How to avoid the edge effects that may occur when applying the Hilbert transform (by mirroring)?
How to avoid the edge effects that may occur when applying the Hilbert transform (by mirroring) for image or image series signal?
Code is appreciated (in python) please.
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Compare two Fourier series to depict the signal smoothness
I have several signals, that I am trying to find a metric to compare the signal smoothness.
By signal smoothness I mean, the signal that the distance between the peak to trough become smaller (getting ...
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How to be sure that we chose the correct sampling rate in practice?
Let say I perform an experiment and I record data at a given frequency sampling $F_s$ and then I perform FFT analysis on these results.
As I do not know the characteristics of the perturbation that I ...
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Power Spectral Density and Total Power Calculation for Signal
I am currently working on analyzing a signal with the autocorrelation function given by:
$$R(\tau) = 100 \cos( 10000\pi\tau) (Λ(2000\tau))^2$$
I need assistance in plotting the power spectral density ...
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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 ...
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Calculation of response of continuous-time LTI system [closed]
Consider an LTI system defined by the following impulse response $S_{1}$
$$ h \left( t \right) = u \left(t - 6 \right) - u \left( t \right) \tag{1} \label{1} $$
Assuming $x \left( t \right) = 5 \left[ ...
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Allan variance plot does not match with the true plot
I am trying to simulate an Inertial Measurement Unit (IMU) by generating sample noisy gyroscope and accelerometer data. Currently I am analyzing the simulated gyroscope( gyro)
data. Using the noise ...
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Best signal processing method for recognising changes in accelerometer results?
I am new to signal processing and trying to build a gadget that hits an object and recognizes fractures and weaknesses in it using an accelerometer attached to a hammer. I have some initial results ...
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DSP programming in C/C++
I have exposure to MATLAB and have some basic exposure to signal processing and plotting in MATLAB... but I am more comfortable with C/C++ than MATLAB because I have been working in Image processing ...
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Signal Processing of Long Term Behavior in Stochastic Systems
I am quite new to techniques of signal processing. I have a fairly generic problem and wish to find information about topics and/or techniques that may help me address this problem.
Let $x(t)$ and $y(...
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How to know which type of sensing matrix would do the job?
Compressed sensing refers to the recovery of a high-dimensional but sparse vector $x\in\mathbb{R}^n$ from its linear measurement $y = Ax+\eta$, where $A\in\mathbb{R}^{m\times n}$ $(m<<n)$ is a ...
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Calculating the main lobe width of Dirichlet kernel
The Dirichlet kernel of order $N$ is defined as:
$$
D(\theta,N)=\frac{\sin(N\theta /2)}{\sin(\theta /2)}
$$
We know that the main lobe widths between zero crossings is: $4\pi/N$
I was wondering if ...
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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 ...
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Determine reflections from received signal
I have a reference signal $r(t)$ and the correlation between that reference signal and the received signal : $C_{XR}(\tau)$. The signal I receive contains reflections on walls. I have to build a ...
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Calculating the settling time of lowpass and bandpass SOS filters constructured using SciPy
I have constructed a high pass filter using scipy:
...
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Fourier Transform and Music Analysis
I am a senior in high-school and am currently trying to conduct an exploration on Fourier Analysis, specifically using the Discrete Fourier Transform to analyze a chord played on my piano. Basically, ...
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CFO Estimation in LoRa Chirp Signal (Preamble part)
I am trying to estimate CFO in LoRa chirp signal (preamble part). I have seen the discussion about CFO on this forum but it is mainly related to CFO estimation in OFDM.
I want to estimate the CFO in a ...
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Analysis of impulse response in downsampling problem
Hey everyone, I'm stuck on this problem and I've got an exam in a few days. I think the filter H is used here so as to avoid aliasing artifacts, and afterwards went on to the second question.
I've got ...
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Determine Noise Level by Convolving N Signals
I using a microphone to determine (air) leakage characteristics. The signals need to be filtered to reduce the noise level and i thought of using the Spectral Subtraction Technique. Since im having 4 ...
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Integral of product of two shifted Dirac impulses
In this question the multiplication of two impulse functions is discussed
However, what if I have two shifted impulses say:
$z(t) = \delta(t-\tau)\cdot \delta(t-\beta)$
Now if I want to integrate $z(t)...
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Clipping detection algorithm for a sinusoidal signal with noise and unknown amplitude in an online fashion
My problem is the following:
I am sampling data from a sine signal
Samples come in a online fashion (more and more data incoming through time).
The device does not have a lot of memory so it is ...
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Practical Implications of DFT Eigenvector Formulations
Different sets of eigenvectors for the Discrete Fourier Transform (DFT) are well-established.
Are there any potential practical implications associated with deriving explicit formulations for these ...
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Relationship between signal rate, data rate, minimum bandwidth
I need to understand the relationship between bit rate, signal rate and minimum bandwidth. I read in a textbook that
We define three cases for relationship between bit rate and signal rate for ...
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How to determine the nature (real or complex valued) of a signal?
A signal X(t) is a real valued time domain signal and Y(t) is a signal that only contains the non-negative spectral components of X(t). How do I determine whether Y(t) is real-valued or complex?
I ...
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jumps in spectrogram of frequency ramping
I create spectrogram of a sine wave that changes its frequency from 60 MHz to 70 MHz over a period of 1 millisecond.
can someone help me understand why I see those jumps? how can I make it smoother?
<...
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Cannot understand a simple example in Phased Array System Toolbox (MATLAB), regarding FREE SPACE
I am learning about radar and signal processing. I try to run a simple code snippet provided on Mathwork's official website
It is just about FREE SPACE, which I think you know very well, but I am new ...
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Fixed sine using HP 35665A signal analyzer
I would like to perform a fixed sine test at my DUT's natural frequency after finding the nat. freq. from a sine sweep test. I can see from "fixed sine" softkey under "Source" that ...
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Why is numpy.angle returning values on real numbers?
This question is a follow up on previous. As I am analyzing the sampled data I need to know if it is complex or real. This is important for me since I want to transform my two-sided to a one-sided PSD....
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Calculate a signal of brightness
I am new to signal processing. Currently, I am reading a paper regarding musical expression. The paper calculates brightness, and I want to reproduce their way of computing it. I was wondering if ...
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Sampled data plot doesnt make sense
I've measured an accoustic signal for approx. 90 seconds with a sample frequency of 192 kHz (Note: the used device can sample data with maximaly 192 kHz, therefore i am not 100% certain, what sample ...
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SAR Doppler centroid estimation
I read book Comming Wong Digital Processing of Synthetic apperture, where they describe in detail various metods for estimation doppler centroid. Fractional part and resolve ambiguous.
But in tne ...
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How to identify the middle of the first trough in a waveform?
(Asked on CrossValidated before I found this community)
I have audio files and timestamped fragment transcriptions that I have force-aligned with third party software.
Unfortunately the software ...
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Displaying and analyzing an audio file in MATLAB
I was given the following problem at my university:
We are given an audio file which we have to download. Following that we have to create a MATLAB code that can create a discrete-time graph of the ...
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Calculating RMS/Crest Factor for a Stereo Signal
I'm doing some MIR related work with stereo audio and am a little unsure on how to proceed with some basic tasks. All my academic work prior to this has involved forcing audio to "mono" to perform ...
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How to express random signal in MATLAB which is transmitted from transmitter to receiver
I am trying to model a random transmitted signal between transmitter (source) to receiver.
Specifically, the transmitter has $N_s = 1$ antenna and receiver has $N_r = 2$ antennas.
My query is that I ...
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Why a windowed signal is considered to evaluate the Power Spectral Density?
Let's consider a real function of time $x(t)$ being a Fourier-transformable signal. The synthesis equation states that:
$$x(t)=∫_{-∞}^{+∞}X(f)⋅e^{2πjft} df $$
Meaning: $x(t)$ can be seen as the sum of ...
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Smooth signal with Hanning
I have an acceleration record and i want to smooth it's spectrum by using a hanning window with Bandwidth=0.5 Hz.
How could i do that?
Example in python/matlab will be appreciated!
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How to determine number of observations based on measurement frequency?
So I'm working on a problem where I'm measuring a signal with two different instruments -- one is a low frequency measurement system (1 Hz), and the other is a high frequency measurement system (200 ...
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Why are convolutions between those functions equivalent (signal processing for theoretical neuroscience)?
I'm reading a book on theoretical neuroscience [1], in which the following definitions are given:
$\rho(t)=\sum_{i=1}^n \delta(t-t_i)$
where $\delta$ is Dirac's delta and the $t_i$ are timestamps at ...
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What am i doing wrong?
How do I remove the noise (long vertical lines) from signal? I am applying AC voltage via function generator which is amplified by the power amplifier to a 6mm thick steel specimen. The signals are ...
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How to check if a signal is power signal or energy signal?
What is the procedure to check the signal type?
example:
$ x(t) = A \sin (\omega t) $
$ y(t) = A e^ {-\lambda |t|} $
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How to extract the oscillation frequency from the following signals?
Signals contain both transient and stabilizing processes.
In the transient process, the signal exhibits oscillatory behavior with damping. Is there some efficient algorithms to extract the frequency? ...
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Sinus Pattern analysis
i have 1000 data which range between 50 and 180 ( heart BPM data in a day) how can i measure its similarity to a Sinus pattern?
for example, for 20th recorded data (for example it is 60BPM), evaluate ...
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Order analysis on sample vibration data to detect unbalance in python
My main goal is to figure out how to do an order analysis in Python. For this I'm trying to do an order analysis in python to some sample vibration data I found here (with and without unbalance).
I ...
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Demodulation + LPF gives derivative of modulated signal
I'm new in this community and I hope it is the right place to post my question. Unfortunately, signal processing and electronics in general are not my fields, so I'm sorry if the question is trivial.
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Why is bandwidth inversely proportional to mulitpath interference?
I have a project related to Signals of Opportunity and during my research on the communication signals that can be used for navigation purpose I saw that as references are given below signals that ...
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What effect causes this Pattern?
I've conducted a measurement of underwater noise in a laboratory experiment.
Therefore i am using a sweep signal.
Sometimes -I guess when the signal is much more louder- I get this fascinating ...
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Plotting a Manually made Spectrogram with python
I'm following a guide about signal processing, but since I'm a fresher to the domain, the guide just stops at a point where only a function that could return the spectrogram values is written. So, my ...
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Integer multiples of fundamental period in sine wave
I have a simple question.
Suppose I have a signal : $f(t)=\sin(2\pi \, 25t)$
We know that it's CTFT(continuous time fourier transform) will result in 2 delta's at +- $2\pi\,25$ [rad/sec].
Or ...
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