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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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1 answer
27 views

Beat Frequency Test for ADC

I'm trying to do beat frequency testing to test the dynamic parameters of the ADC. I am doing what is written in TI's Application Note Dynamic Tests For A/D Converter Performance. I add a frequency to ...
0 votes
1 answer
33 views

CPM Modulation and Demodulation, How to determine the values for normalized bandwidth?

See table related to CPM Modulation which specifies $L$, $h$, $B_{norm}$ and sampling rate $f_s$. $B_{norm}$ and the sampling rate $f_s$ are directly related and I understand that relationship. What I ...
0 votes
1 answer
65 views

Difference Data Collected and Reference Sinus

I have a signal generator with 40 MHz bandwidth and 1.2 GSa/s features. I generate a 9.7 MHz sine on this generator. I sample using ADC demo board at 100 MHz. I generate a reference signal in MATLAB ...
1 vote
1 answer
94 views

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 ...
1 vote
1 answer
58 views

Removing rotational frequencies from a signal

I have a torque signal from an experimental adapter which measures based on strain gauges. Turns out that my signal presents very strong oscillations at the same frequency of rotation, which very like ...
0 votes
1 answer
50 views

Cross-correlation function between discrete and continuous random signals [closed]

What does it like the desired cross-correlation function? Does it take a psudo periodic shape? or a random one?
3 votes
1 answer
82 views

Difference Artifacts of Quantization and Spur

I saw a graph like the one in the picture and frankly I could not fully understand the difference between quantization artifact and spur. (ref. The Data Conversion Handbook Walt Kester (Editor) page ...
0 votes
0 answers
71 views

How to get a reliable envelope of a signal with clipped peaks?

I'm trying to compute the power per minute in the time domain of some seismic signals. I deal with signals sampled at 5 kHz characterized by random amplitude peaks emerging from low background noise ...
3 votes
6 answers
20k views

Interpreting the amplitude of signals in fourier transform

I totally understand the concept of fourier transform, but one thing thats bothering me is the amplitude that we plot in the frequency domain. What does that amplitude of each frequency signifies? Is ...
2 votes
1 answer
457 views

Two Sinus Multiply and Add

I'm trying to understand the difference between the sums and products of two sine signals. I also wonder where and how these two situations are used in practice. ...
11 votes
2 answers
1k views

DSP Puzzle: Advanced Signal Forensics - Complex Time Domain Signal

Signal Forensics is the art of detecting likely culprits from the time and frequency spectrum of signals. I made that up, but whatever you want to call it, this is an extremely useful skill, ...
0 votes
1 answer
54 views

Signal processing of dominant components in exponential modes

I am doing theoretical computer science (TCS) research, where I encountered this problem of signal processing as a subroutine in my algorithm design. The problem can be understood as given a threshold ...
0 votes
2 answers
30 views

Measurement to compare the width of the autocorrelation peak

I would like to know if there is a metric to compare the autocorrelation peak width of one signal with the peak width of another signal. Additionally, what does it mean to have a broad autocorrelation ...
0 votes
1 answer
264 views

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 ...
0 votes
0 answers
45 views

Please solve this problem from Signals & Systems , u(t) is step signal?

Please solve this problem from Signals & Systems , u(t) is step signal
0 votes
2 answers
43 views

TCP vs UDP for signal consumption

I understand the difference between TCP and UDP when it comes to reliability and packet ordering. In all my testing, I have been using a TCP test server, but it has come to my attention that most SDRs ...
0 votes
0 answers
31 views

How to relate a section of a PSD plot back to the original complex numbers IQ or remove part of a signal from a spectrum with python-signal excision?

I have data coming off an software defined radio, I want to remove a certain signal(interference) from a spectrum new to DSP. I am using python. the signal comes in as an array of complex numbers (...
0 votes
1 answer
114 views

Simulation of Doppler shift in C/A code

I am trying to simulate C/A code under the effect of a doppler shift. Let's say the doppler shift is 5000Hz. I am assuming an ideal scenario where I can down convert the GPS to its baseband of 1....
1 vote
2 answers
57 views

High PAPR (Peak-to-Average Power Ratio)

I have a signal $s(t)$ which has $PAPR=26$ dB. In the literature, the highest PAPR I have seen is OFDM with $PAPR_{ofdm} \simeq 12$ dB. I would like to know if the PAPR (Peak-to-Average Power Ratio) ...
1 vote
0 answers
47 views

How to utilize product graphs in graph signal processing?

I'm working with dynamic graph signal processing. How to plot time variation and spatial variation separately and take the cartesian product of those two graphs?
2 votes
2 answers
279 views

Detect and Localize Abrupt Changes on a Noisy Non Periodic Signal

I have a set of some 5000 x,y datapoints. They plot a smooth curve with large gradient and curvature at the right. There is high-freq noise that varies in amplitude from dataset to dataset, but the ...
0 votes
2 answers
68 views

Can Autocorrelation be used to Differentiate Signal Quality (High, Medium, Low, Very Low) for Periodic Signals?

I'm working on a project to classify the quality of periodic signals into four categories: high, medium, low, and very low (noisy). I was initially exploring autocorrelation as a potential feature for ...
0 votes
0 answers
29 views

Power spectrum: $uV^2$ scale

I was reading a paper and found this figure: The paper defines slow wave activity as the mean power in the slow wave frequency band (0.4 to 5 Hz). I'm used to seeing power measured in "raw power&...
0 votes
1 answer
57 views

why are the coefficients different when I design an IIR bandpass filter using butter compared to using the Filter Design Toolbox?

In matlab, for the same parameters, why are the coefficients different when I design an IIR bandpass filter using butter compared to using the Filter Design Toolbox? When I run a command in matlab <...
0 votes
1 answer
273 views

Can someone explain me how the phase spectrum of trigonometric fourier series is related to phase spectrum of exponential fourier series of a signal?

Suppose we take a periodic signal and perform fourier analysis over it . Now we have two ways of representing the fourier series of this particular signal , one is trigonometric fourier series and ...
6 votes
2 answers
4k views

How to measure the smoothness of a signal

so how can i determine if a signal is smooth or not ? And if its possible to get something indicating the level of the smoothness of my signal. I looked at the r-squared and hurst exponent but i ...
1 vote
1 answer
41 views

Will open, edit, store from/to lossy audio format significantly degrade quality?

Say I have files only available as "ogg vorbis", 44.1kHz at 128 kbps vbr - which are meant for archival, but not much storage for lossless was available at the time. These are to be kept for ...
1 vote
1 answer
2k views

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 ...
-1 votes
1 answer
32 views

Statement on detectability based on relative height of abs max of spectrum

I have $2$ signals $s(t)$, $z(t)$ with the same energy $E(|s(t)|^2)=E(|z(t)|^2)=1$. However, the maxima of the signal spectra obtained with Fourier transforms verify: $\max(|S(f)|^2) \leq \max(|Z(f)|^...
0 votes
0 answers
23 views

I want to generate a real time fft of vibration data from a triaxial MEMS accelerometer

I have been trying to generate a real-time FFT plot for my final year project on Condition Monitoring using a MEMS accelerometer (an MPU 6050) and an Arduino UNO. My goal is to generate a real-time ...
0 votes
1 answer
61 views

Is the analytical fourier transform of an exponential decay the same as the FFT of a time series of the same signal?

Analytical Fourier Transform of $e^{-t/2}$: FFT of a time series representation of $e^{-t/2}$: I'm trying to find the decay coefficiencts in tri-eponential decay signals, and as a logical starting ...
0 votes
1 answer
46 views

How single-tap equalization can be performed in OFDM for perfect channel estimation?

If I have for example IFFT length of 3 with cyclic prefix length of 2 and 3 channel taps, how can I illustrate the frequency domain equalization in OFDM? For example as far as I know, it's elementwise ...
1 vote
0 answers
46 views

How to improve quality of the recovered image in compressed sensing technology?

I was trying to use compressed sensing technology in image processing. Basically, I did a code in Python(Spyder IDE) which takes an image, compress the image and reconstructs it. I tried with the ...
1 vote
0 answers
53 views

ML-Classification of Motor Imagery EEG data only at 50% in MatLab

I'm trying to do ML-classification on some Motor Imagery EEG data and for a long time now I've been stuck at ~50% being correctly classified. This is my first time working with EEG data and signal-...
1 vote
1 answer
90 views

Removing DC bias

I have a signal that I have recorded from a AirSpyHF and want to remove a unwanted narrow signal with a notch filter (see figure). The spike in the image below appears to be a center spike, however it ...
0 votes
0 answers
40 views

Generating a whitening filter using MATLAB cceps() function

I have a few thousand realisations of a discrete stochastic process. I am trying to generate a whitening filter from these realisations. I am expected to use the MATLAB cceps() function to generate ...
2 votes
4 answers
2k views

Sawtooth wave Fourier coefficients

I have to calculate the Fourier coefficients of this signal. I found that signal equation is $$ y = \frac {A(2t-T)}{T} $$ To find Fourier coefficients I wrote $$ x_k = \frac{2A}{T} \int_{0}^{T/2} \...
5 votes
5 answers
2k views

Is it possible to find the FFT of a 1024-point signal by taking 8-input points at a time and calculating the FFT of those 8-points until the end?

Suppose the input signal has 1024 samples, and I want to take a 1024-point FFT. Can I instead take the 8-point FFT of the first 8 input samples then another 8 samples and continue this till the end? ...
0 votes
1 answer
87 views

Based on the eigen structure, What applications of discrete sine/cosine transformations can be found?

I am a PH.D in mathematics. I am interested in finding some applications of discrete Sine/Cosine transformations (DTTs) that are based on the eigenvectors. I have found some results concerning ...
0 votes
2 answers
105 views

How to remove known noise from acquired signals

what is the question: I have some time sequences(sampled at 0.5s and 3kHz which means every one of them has 1,500 points) from my force sensor. But I find the signal fluctuates wildly under no load, ...
0 votes
2 answers
540 views

Improvement of SNR by sampling different number of cycles using FFT of a fixed length singal

My question relates to Fourier transform of signals with different lengths in time but the same fixed length of the digitized signal with different sampling rates. Specifically, how does the number ...
0 votes
1 answer
251 views

Compute SNR of a signal with not clear fundamental frequency in PSD

I'm trying to compute SNR from a signal in which by visual inspection I can guess the SNR but I cannot compute it because I cannot find the fundamental frequency of the signal as I should be. On the ...
0 votes
1 answer
155 views

How to find frequency , location and phase of two sinusoid signal buried in noise?

There is a data set which has two different sinusoids buried in noise. Data record has following properties: A data records with a total data length of 2048 points. The sampling frequency is 100 Hz. ...
0 votes
0 answers
33 views

Getting amplitude from messy signal

I'm working on analyzing some data from a grain boundary in an atomic simulation. I've got a lot of similar data to go through and am trying to determine a reliable way to get the amplitude of my ...
3 votes
2 answers
89 views

Maximum of the sum of different sinusoids

How to find the maximum sum of several (more than two) harmonic sinusoidal oscillations of the form $$y_n(t) = A_n\sin(2\pi f_nt+\phi_n)$$ with different amplitudes $A_n$, frequencies $f_n$ and phase ...
0 votes
0 answers
34 views

Can I get a resonance frequency from FFT power spectrum result?

I'm going through vibration analysis of cantilever by using FFT device but impact hammer input data isn't showing for some reason. So instead, I'm trying to get the resonance frequency by acceleration ...
0 votes
3 answers
82 views

very basic confusion about the bandwidth of constant signal function

I have a very basic question about bandwidth of constant function $f(t) = K$. As the Fourier transform of a constant pulse is a delta-function centered at zero frequency, the bandwidth (maximum value ...
0 votes
1 answer
102 views

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 ...
2 votes
1 answer
75 views

Frequency components in graph signal processing

As a mathematics researcher, I've delved into the intriguing realm of graph signal processing, yet I often find myself tangled in mental conflicts about certain aspects of this field. Any insights you ...
0 votes
0 answers
24 views

Spectral Theory: A Key to Unlocking Efficient Insights in Network Datasets

In the context of directed or undirected graphs, matrices such as adjacency and Laplacian matrices are commonly used. The eigenbasis of these matrices addresses some practical implications, such as ...

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