Questions tagged [signal-analysis]
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1,998
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Expressing mathematically the number of real addition operation for a vector after dividing it
I assume I have the length of such vector $y$ is $N$. In the first time I divide that vector into two columns and then sum them point-wise summation. The second time, I divide the same vector $y$ ...
- 593
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What is the complexity of multiplication a real matrix with real vector
I have a real matrix $Z$ which is following the form as following:
$Z = \begin{bmatrix}
x_1& 0& 0& 0& 0& 0& 0& 0\\
0& x_2& 0& 0& 0 & 0&...
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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'...
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In radar pulse analysis, why is the PRF of pulse not calculated using Fourier transform?
So, I am fairly new to this, but when going through books on Radar pulses, I noticed that quite often, a formula describing the frequency of the waveform is given. For example, the frequency of a ...
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Fourier transform of a top-hat function in the Faraday Measurement synthesis context
I'm currently trying to calculate the Fourier transform of a top-hat function in the context of Faraday Measurement Synthesis. This is pretty straightforward, however, I cannot understand why I cannot ...
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Allan variance and the bias
I was reading about the Allan-variance method and I have a question and I need some help to understand it. Since the Allan is about analyzing the frequency stability and it can characterize the IMU ...
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31
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IMU data using ble protocol is in a weird format
I am working on IMU data, this data was collected using wrist watch under the protocol BLE the reading are non-interpretable for me:
...
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46
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How to choose correctly oversampling ratio?
As many of us have noticed, last two months I am working on GMSK modulation and demodulation design. Before continuing my research, I want to be sure I chose the correct oversampling ratio ( how many ...
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Multiplication of Fourier repeated matrix with a higher dimensional matrix
I have a square Fourier matrix $F_{2\times 2}$ with size of $2 \times 2$. It’s repeated twice following this way: $F_r = F \bigotimes I_{2 \times 2}$, where $\bigotimes$ is the Kronecker tensor ...
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Envelope of a series of pulsed signals [duplicate]
I need to record a series of pulse waves for an experiment. The recording is done via Software Defined Radio (GNU Radio). The pulse waves are modulated in such a way that the amplitudes of each single ...
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Examples & Applications of Quadratic Phase Coupling
Quadratic phase coupling is defined as follows:
Consider the signal $$ x(t) = A_{1} \cos(\omega_{1}t+ \phi_{1}) +
> A_{2}\cos(\omega_{2}t + \phi_{2}) $$ which is passed through the
quadratic ...
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Analysis of two audio signal by autocorrelation
I have recorded my audio by two hardware, PC and Microcontroller, I know the PC result are correct but my signal have some deficit. I have recorded by my PC and MCU my voice 6s 7812Hz and ...
- 246
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Frequency repartition and transformation in channelizer and synthesizer
I am trying to get my head around channelizers and synthesis filterbanks. I stumbled across this thread, with its attached paper. In the explanation of the synthesis filter bank, the following ...
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localization based on TDOA
To locate a transmitter, I use a localization based on TDOA(Chan's method) with 3 receivers. The results obtained are not effective. What is a possible solution to improve the localization accuracy ...
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839
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Signal processing in Python vs C++ (band-pass filter)
I have implemented Python signal processing code using a butter bandpass filter and order 3. It is working pretty well.
I am required to implement the same signal ...
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What make sample rate affect QspectrumAnalyzer output?
Use QspectrumAnalyzer to analyze signal,set sample rate as 8M and 32M.
I get different output as below,32M sample rate cause ...
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49
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Interpreting sensor noise data
Introduction :I am trying to create an EKF for an autonomous vehicle, and i need to model the error of the sensors. (I am a mechanical engineer so my knowledge on electric signals is limited).
The ...
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Does tsa function in matlab assume constant rpm in the same rotation?
I just ran the example code, stepped into the tsa function, and saw the line 139:
By looking at the code in the red box, it seems that MATLAB assumes constant rpm in the same rotation and evenly ...
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49
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How to interpret arg min in the the following equation?
I am studying the following equation:
$$\hat{s}_m(n) = \arg \min_{s_m(n)\in A_s}\left| \frac{\psi_m^H}{||\psi_m^H||^2}y_m(n)-s_m(n)\right|^2\tag{1}$$
here $A_s$ is 1x$N$ vector of QPSK symbols, $s_m(n)...
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108
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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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Standardizing signals from the same experiment setup with different recording tools
I've been looking to merge two datasets I have, that capture instances of the same phenomenon using two different recording tools. Both are multichannel electrical signals, but the recording tools ...
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Converting 2 variables (obtained by ICA decomposition) named A_ffdiag and W_ffdiag into mixing/unmixing matrix
I have two variables as a result of an ICA (Independent Component analysis) decomposition (decomposed using joint diagonalization algorithm which uses frobenius norm formulation) named A_ffdiag and ...
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Optimal methodology for analysis of noisy 3-dimensional (x,y,z) vibrations data
Details
I have x, y and z data of some vibrations and a timeline of corresponding events that caused these vibrations.
I want to analyze how events and vibrations are related, so that it can be stated ...
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gnuradio: eCPRI link implementation for LTE
Need to build eCPRI link in xRAN network between eRE and eREC devices.
In eRE I'm capturing via osmocom source (SDR device) and I have a stream of float32 complex IQ numbers as usual output. Now I am ...
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What is the way in which an audio signal is "cleaned"?
I was studying how signals can be "decompose" with the Frequency domain analysis and Fourier transforms; I have also read that through these actions it is possible to clean the signals from ...
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25
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What can I do to improve the sound of a signal?
I want to improve the sound of my signal, I know I can do it by increasing or decreasing the amplitude of the signal itself. Are there any other ways to do this? How can I apply the Fourier transform ...
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75
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When is the Fourier transform of a periodic discrete signal $\mathcal{F}x[k]$ the same as $x[k]$ up to a diagonal matrix
I am looking for all pairs $(x[n],q)$ where $x[n]$ is a periodic discrete signal with period $N$ and $q$ is a rational number satisfying the following identity:
$$\mathcal{F}x[k]=e^{i(q-\frac{\pi k}{...
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Are there any order analysis functions in Python?
I would like to perform the following order related tasks in Python:
Convert tachometer pulse signal to RPM signal (tachorpm)
Convert RPM signal to even-angle signal (orderwaveform)
Time synchronous ...
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What happens if I register my entry?
Taking as an example that I want to record my voice. How does it appear in the frequency spectrum? Can I also view it on other spectra?
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Laplace transform of derivative
Here is a short proof that Laplace Transform of $x'(t)$ is laplace transform of $x(t)$ multipled by s:
On the other hand, the proof that I know uses integration by parts:
One condition is that $x(t)...
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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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Calculate the probability of error of two vectors
I am trying to calculate the probability of error of two vectors, for example the first one is transmitting a modulated data $x$ with modulation order $M$ as following $y_1 = [x \ \ 0]^T$ while the ...
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Confusion Understanding the mathematical expression of duality property of dft?
Duality Property for DFT
Above dsp.se question provides good understanding about dft duality property but i am having difficulty understanding its mathematical expression because on Google when i try ...
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Transformation of the independent variable of signals
I am struggling to understand the concept of transformation of the independent variable of signals.
Let $x[n]$ be a DT time signal.
As per my understanding, $x$ is a function of $n$, so it is not ...
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Bandwidth of a given function
Suppose the signal given is $x(t)=(cos(5t)+e^{-2t})u(t)$ and the goal is to find the bandwidth of this signal. We know the bandwidth, $B$, is just $f_{max}-f_{min}$.
Our first step is taking the ...
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Find maximum of a square wave with variable frequency
I have an experimental signal (measure) that looks like a pwm signal:
I want to find the x coordinate (time) of the maximum, i.e., the x coordinate where there is more density of the high values (255)...
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70
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Shift of the signal spectrum to the desired frequency
I have a task to select only the area I need from the signal and shift its spectrum.
I am digitizing the signal at 48kHz. A useful signal for me is in the region of 5500-5995Hz and 6005-6500Hz. In ...
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The Amplitude of the Correlation Function Peaks After Matched Filtering
I have 2 signals: $s_1(t)$ and $s_2(t)$. The autocorrelation functions are given by $R_{s_1}(\tau)$ and $R_{s_2}(\tau)$ with $|R_{s_2}(\tau)|<|R_{s_1}(\tau)|$.
I would like to know if the previous ...
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About the process to convert basedband signal into passband
Theoretically, the passband $y(t)$ signal equivalent into baseband signal $x(t)$ is given by:
$y(t) = \Re \begin{bmatrix}
x(t) e^{(-i2 \pi f_ct )}
\end{bmatrix}$
where $\Re$ represents the real part.
...
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Recalculating signal of acceleration
I have an acceleration vibration signal (m/s^2)
and I need to calculate displacement from this signal, as I know first I have to integrate acceleration I will get vibration velocity [mm/s]
after ...
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Removing sawtooth wave from DFT transform [duplicate]
We have samples $x_n$ and sawtooth wave $s_n$ with period N (especially if N=$2^k$)
$s_n = c \cdot n$ for n=0...N-1 where c is constant.
What is formula for coefficients of DFT this wave?
I want ...
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Plot the Power Spectral Density for a signal in Matlab
I have an OFDM signal x, generated using QAM modulation, I first use the command in matlab y1 = ifft(x); to generate the time-...
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Negative SDR result for evaluating audio source separation
I'm trying to use eval_mus_track function of the museval package to evaluate my audio source separation model. The model I'm evaluating was trained to predict vocals and the results are similar to the ...
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What is the magnitude response and phase of this function?
Given the system/filter $H(\omega)=\frac{1}{5-j\omega}$, find $h(t)$, it's magnitude response and phase and identify what type of filter it is.
Now clearly given it's form, $h(t)=e^{5t}u(-t)$, but I'm ...
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Why there is a difference from amplitude calculated from PSD and the real one? [duplicate]
I make a script in python to extract amplitude from power spectral density.
I try to verif it but I have a difference between the real amplitude and the amplitude extracted from PSD.
To calculate the ...
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How to take amplitude and frequency from the power spectral density?
I try to take the amplitude and the frequency from the power spectral density.
So I make a time series with a 5 component waves, then I draw the PSD with the welch method.
Now I need to take the ...
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How to obtain the wave height "H" /wave period T from the spectral density S(f)
I have the equation of the power spectral density $S(f)$.
I seek $(H,f)$ of each sinusoid which $H$ is the magnitude and $f$ is the frequency.
How to calculate $H$ from $S(f)$?
$S(f)$ is the spectral ...
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36
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Communications Security
To secure a communication, quantum cryptography can be used. The principle is to use an optical channel which allows the emission of photons in 2 simultaneous states and a radio channel which makes it ...
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43
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what the difference between spectral density and the power spectral density?
What is the difference between the spectral density and the power spectral density,
Or they are the same thing?
In fact, I find this term in the book of GODA 2000.