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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Decoding Packet preamble success percent
I have a radio that stays on a channel for 500 milliseconds to listen to the packets and increment the detection_counter if packet is found( by correlating the preamble which is about 48us)
For some ...
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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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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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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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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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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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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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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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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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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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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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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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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 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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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 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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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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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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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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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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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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Why do complex signals and their real world equivalents have different measurements of power?
My understanding is that the relationship between complex signals and real signals is such that for some complex signal $f(t) = s(t) \cdot e^{j2\pi f_c}$, the actual broadcast signal sent through the ...
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How to compute the direction/bearing of a vector time series in the frequency domain (i.e. as a function of frequency)?
I have a time-domain magnetic field, $\mathbf{b}(t)$, with components $b_x(t)$ and $b_y(t)$ where $x$ and $y$ denote orthogonal coordinate directions (i.e north and east, respectively). At each time, ...
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How to Show Signals That Can Be Isolated
What would be the best way to plot or graph a mixed signal that contains other signals that can be isolated?
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Overall spectrum computation from Short-Time-Fourier-Transform
I am trying to computing the overall spectrum of a given signal from its Short-Time-Fourier-Transform. I am using python to do this and I wrote my function to compute the STFT:
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Cfar Algorithm Implementation
I am trying to implementation Cfar algorithm to our radar signal processing algorithm. I obtained some output but I want to be sure that is right. Cfar algorithm's output below like, I'm interpreting ...
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Transfer Function Estimate
This is related to this post: https://engineering.stackexchange.com/questions/56050/obtaining-the-open-loop-gain-estiamte-the-gain-and-phase-frequency-response
Using python, I would like to write a ...
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How to normalize FIR filter gain from the amplitude response in frequency domain?
I've got a set of measured data (amplitude and phase responses) of a filter. And I want to normalize its gain to be unit (equal to 1) for further processing. I know that we can convert to time-domain ...
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Is there a quadratic version of exponential smoothing?
I have a time series - let's say I'm given one new sample (a real value) every second.
I could take a moving average of the last 50
samples or I could use exponential smoothing of the samples with a ...
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producing sine signal with few samples
I need to produce a signal of $\sin(2\pi\cdot 60\cdot10^6 t)$, where $t$ in sec, with sample rate of $2^{28}$ Hz.
Since the signal has period of $\frac{1}{60\cdot 10^6}$ sec can I somehow sample only ...
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Abnormal Y-axis value after performing FFT
I have an UFF file which consists of Vibration data. The objective is to convert the timewaveform signal to frequency domain.
I have written a python script to convert the timewave form signal to ...
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Onset time determination of fast pulse
I am looking for the most precise way to determine the onset time of a
very fast pulse sampled at 5 GHz coming from a physics detector.
Here is an example of my signals:
I already tried different ...
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Processing of Channel State Information from WiFi for Generalizability
For my master's thesis I collected CSI with 4 WiFi network cards (Intel AX210) for three different persons for 102 positions (spaced roughly 30cm apart).
The covered area was around 10m x 7m and in ...
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Why are analytical wavelets said to have no negative frequency?
I have been reading about analytical wavelets and came across this definition:
An analytic wavelet is a complex wavelet such that its Fourier
transform is null for negative frequency.
If it is a ...
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Average of a set of transfer functions: how should I treat the phase?
I have a set of transfer functions obtained by impacting an instrumentation hammer against a mass, measuring the acceleration on a set of accelerometers; the result is shown below. I want to get a ...
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Show a grid with specifications and hide the horizontal and vertical ticks label [closed]
This is a code I made for cleaning and visualizing raw ECG data from physioNet. I want to make some enhancements to the output and can't figure out how so I am asking if someone could help or give me ...
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How can we prove using matlab that after each level of decomposition of a signal using DWT the frequency content is halved?
I was trying to decompose an EMG signal, which was sampled at 200 Hz, into 7 levels of decomposition using DWT.
And the result is shown in the figure( only up to level 3 is shown here)
However, I ...
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Phase rotation compensation in AOA
We are using $4 \times 4$ corehw antenna array with nrf52833 mcu as the receiver and nrf52833 as transmitter. When working on AOA Direction Finding, we found that each element in the antenna array has ...
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