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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questions with no upvoted or accepted answers
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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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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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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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Practically Calculating Cramer-Rao Lower Bound
What is the method to compute Cramer-Rao lower bound for a particular application. For example I have an application in which FFT of an incoming signal is performed to get a Coarse estimate and then ...
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Finding the parameters and endpoints of a sinusoid
Suppose I have some signal
$$
s(t) = n(t) + \left\{\begin{aligned}
&0 &&: t < t_0\\
&A e^{i (2 \pi f t + \theta_0)} &&: t_0 \le t \le t_1\\
&0 &&: t > t_1
\...
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Linear Frequency Cepstral Coefficients, is Filter bank needed?
I am working on my master thesis on acoustic pattern recognition and have a question to the calculation of cepstral coefficients.
I understand the step with a filter bank in MFCC calculation, it is ...
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Can we detect WiFi from Spectrograms using signal processing?
I'm looking for some suggestions on detecting wifi using spectrograms (abs magnitude only) . My project involves a wifi driver which outputs a spectrogram whenever it scans the channel .
Can we use ...
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OFDM channel estimation using the transmitted signal multiplied with a matrix
I have OFDM system, where the modulated signal $x$ with length $N$, and $N$ is the number of subcarriers in OFDM symbol. $x$ is multiplied with a well-known unitary matrix $G \in N \times N$ before ...
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Difference between AoA and DoA
I noticed a mixed usage of AoA (Angle Of Arrival) and DoA (Direction Of Arrival) and was quite confused about the exact distinction between AoA and DoA with respect to wireless signals. Reference to ...
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How can I explain the result of of multiplications by matrices
I have a vector $x$ with size $N \times 1$, it's multiplied with a $Z$ matrix $N \times N$, the resulted $N \times 1$ vector is $y = Zx$. I know that each value of $y_i$, where $i = 0, 1, 2, .., N-1$ ...
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How to compute (in non adaptative way based on MMSE FIR) the feedback and feedword filter for DFE equalization?
System Model
Consider the single-input single-output (SISO) communication system in the figure below:
where the information bit stream is encoded and mapped such that the output of the encoder is a ...
user47976
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Power spectral density vs. Fourier Transform
I am trying to understand the difference between the Power Spectral Density and the Fourier transform. Specifically, I am trying to understand why the power spectral density is useful and in what ...
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How to visualize the autocorrelation matrix and it's properties
Having a hard time wrapping my head around autocorrelation matrix as it applies to a spectral estimation problem like MUSIC or ESPRIT. If the signal vector contains a summation of sinusoids in noise, ...
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Connections between quantum field theory and signal processing
I've been working with quantum field theory on the basis of it being a stochastic signal processing formalism for a number of years. The projection to fourier components within the forward light-cone ...
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Preserve scale during PCA
I have two signals, I've done a Principal Component Analysis and separated my signals, I get one with noise and one with signal. .
...
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Segment/Idenfication of signal from a spectrogram
I have the following Spectrogram of a signal:
Essentially, in this signal, I know there is one point of interest (between 60-80) and between the the particular frequencies.
I could, potentially ...
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understanding discrete wavelets
I was reading section 4.3.3 from chapter 4 of "A Wavelet Tour of Signal Processing",
"...Let $\bar{f}(t)$ be a continuous time signal defined over $[0,1]$. Let $f[n]$ be the discrete signal obtained ...
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How to convert raw pulse sensor data into actual pulse?
I've built a simple device, which sends readings from a pulse sensor to a PC.
I get these data:
What technique or algorithm can I use in order to calculate the pulse rate (beats per minute) from ...
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Intuition of Location on the Conic Axis TDOA solution
In an old paper "A New Approach to Geometry of Range Difference Location", there is a mathematical derivation that does not include any mention of the relationship to the underlying problem. In the ...
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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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MUSIC Algorithm for 2D Power Spectrum
I am trying to use Frequency-wavenumber analysis for estimating speed of sound using two-dimensional data obtained via channel of arrays. The traditional technique is to use FFT to transform the data ...
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Synchronization of two noisy sinusoidals signals
I have two noisy sinusoidal signals and I am currently investigating solutions to synchronize them using python. Here is an example I made to illustrate my goal, supposing that I generate these two ...
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Condition for these sequences to be stationary correlated (tipp for integration of exponential functions)
I have two sequences $s$ and $r$ defined as :
$s = \{s_n\}_{n \in \mathbb{Z}}$ where $s_n(t) = (M_{\beta}^n s)(t) = s(t) e^{int}$ with arbitrary $s \in L^2(\mathbb{R})$ and $\beta > 0$
$r = \{r_n\}...
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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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Advantages of Chan's method over the Kalman filter
For a 3-receiver tracking system. Chan's positioning method gives an exact solution to the location problem. However in the literature, I saw that one could use the extended Kalman filter which is ...
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Deterministic, stochastic and chaotic components of a signal ; their combined effect
If a signal contains deterministic, stochastic as well as chaotic components, does this generally represent a problem in the analysis of the signal? By a problem, I mean that a signal containing all ...
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Ideal low pass filter with cut-off B does not affect a band-limited baseband signal with maximum frequency B
Let $x(t)$ be a band-limited signal with spectrum (fourier transform) lying between -B and +B. Such a signal is not warped by an ideal low-pass filter with cut-off frequency equal or higher than +B.
...
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White noise does not contradicts Wide Sense Stationarity?
I am studying White Noise. But I am really beginner level, so I have a confusion with its construction.
White Noise is usually defined as a Wide Sense Stationary process $N=\{N_t\}_{t\in T}$ (for $T$ ...
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Welch Method FFT Python - Scaling factor?
I've been implementing a Welch method FFT and I am trying to work out the correct scaling factor that should be applied to the output of the function so the PSD is accurate because at the moment it's ...
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What does the sample entropy of a digital signal mean?
What sample entropy signifies about a signal and how it used to analyse a signal?
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What is the physical significance of statistical quantities like mean, variance, skewness and kurtosis of a digital signal?
I understood the mathematical meanings of the mean, variance, skewness and kurtosis. But when we calculate these quantities for a signal (say a digital audio signal), what physical meaning do they ...
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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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GPS CDMA signal acquisition (BPSK modulation)
Sorry, this may be a rookie question: I have a CDMA gps communication in BPSK. Codes have a duration equal to $1\ \text{ms}$ and their length is 1023. At the carrier frequency ($f_c = 1.57524\ \text{...
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How to remove varying noise from strain data in MATLAB
I'm very new to signal processing. I have some data measured over time at 800 Hz. I'm interested in the high frequency signals. You can easily identify them in the image below (in this case, 3 signals)...
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Basics of Normalizing Cross-Correlation with a View to Comparing Signals
I'm trying to understand how cross-correlation is used determine the similarity of two signals. This tutorial offers a very clear explanation of the basics, but I still don't understand how to use ...
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ESPRIT signal subspace and rotational invariance
so in ESPRIT[1,2] we have some signal of the form:
$$y[n] = \sum_{k=1}^{K} a_i(k) e^{j\omega_k n} + N[n]$$
where N is noise, then we get the autocovariance matrix
$$R_{yy}=E[y[n]y[n]^*]$$
take the ...
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Is there in signal processing similar method than Otsu's method in image processing?
I'm just wondering that is there any similar method for separate signal and signal+noise in signal processing like otsu's method set threshold to valley of image histogram? And if there is how can I ...
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Auto correlation properties of window functions in pulse compression application
It is known that different window functions perform differently and users pick a window function (in amplitude modulation) based on their application or requirement.
I am trying to pick a window ...
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Distinguish between chords and single notes
I am implementing a pitch detection system where I detect pitch in single notes (guitar).
I recently found this library, that detects chords in an audio signal.
When there are chords in the signal, ...
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Is there a way to extract the difference between the 2 signals? Fitting?
I'm very new to signal processing and have been struggling this far.
I have a device that measures the signal due to the magnetization of iron particles.
In order to calculate the response of the ...
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Help detecting target in pulsed radar signal
This signal is from the Pasternack $2.4\textrm{ GHz}$ development kit. The saved signal appears to be the pulsed waveform. It is sampled at $20\textrm{ kHz}$ for $4130$ points. I recorded a ...
user19960
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Vibration signal analysis of non-stationary movement
my task is to develop a condition monitoring system of a machine module. For that I am using the vibration sensors placed on the machine housing. I want to focus on only one module of the machine, a ...
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how to design wavelets from splines
Can any one tell me how to design wavelets from splines using matlab. whether we can make wavelets from higher order splines or only with B splines
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Audio transient characterization of instrumental music
Some time ago, I seem to recall hearing or reading of an audio experiment where the very short initial transients of one musical instrument (A) were spliced in front of the much longer steady state or ...
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Peak detection techniques
I'm using a cell-averaging constant false-alarm rate (CA-CFAR) detector to detect peaks like the first one in the following plot:
The magenta line is the adaptive threshold, which is the local ...
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Analyzing accelerometer data: appropriate use of rotation matrices?
I'm working on a project in which a rod is attached at one end to a rotating shaft. So, as the shaft rotates from 0 to ~100 degrees back-and-forth (in the xy plane), so does the rod. I mounted a 3-...
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Signal conjugation detected on RF recording samples, why?
I collected spread spectrum signals at 400 MHz at low elevation angles using Software Defined Radio complex sampling over the seasons. I noticed that over watery, icy surfaces, the RF samples are ...
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Determining the point in a temporal signal when a periodic behavior begins to occur
I'm a newcomer to digital signal processing, so I'm looking for some general advice and direction on this problem I have. I have a signal like that shown below. Starting around x=40000, you can see a ...
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Extracting the phase of a jittering sine wave using python
The background:
I conducted an experiment where I rotated an object (with three-fold symmetry) many times and recorded the projection of the object. I should be able to tomographically reconstruct ...
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Can ICA be applied to solve BSS problem in frequency domain?
I'm recently doing research on EMI, and I want to seperate the mixing signals. However, the data given is in frequency domain. As I have used ICA to solve blind source separation problem in time ...
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