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Questions tagged [signal-analysis]

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1answer
28 views

Graph Fourier transform: the adjoint notation for the eigenbasis matrix

I already asked this question here but there is no response. I'd like to ask this question in signal processing domain. It is well-known that for a real symmetric matrix $L$ (here, graph ...
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0answers
23 views

Find LF component of AM signal

I'm trying to figure out how to find the low frequency component of an AM-signal when I have regained the carrier. So the signal is: $$U_{AM} = 2[3+0.4cos(2\pi\cdot2\cdot 10^3\cdot t)]\cdot sin(2\pi\...
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1answer
37 views

Beamforming but only for total power?

Is there a method to speed up beam-forming if you only care about the total power in a given direction, or total power in frequency groups? I've googled this, and can't find anything. My intuition ...
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1answer
18 views

What is the difference between positive matrix coefficients and negative matrix coefficients of an audio?

I have turned an audio file into an one dimensional array by using audioread function in matlab and found several positive and negative fractional coefficient values.What is the basic difference of ...
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22 views

Channel information from power spectra

Linked below is a previous post regarding a multipath channel. Equalisation of FFT spectra I am reusing the images here: The first image is that of the power spectra when there is no multipath and ...
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25 views

Low pass representation of Bandpass Random process

Can A WSS random process with non-zero mean be also represented in such form.
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67 views

How to find Coefficients of Autoregressive (AR) model using least means square (LMS) Algorithm without having future signal?

I want to do two things. Estimating Coefficients of AR model using LMS Using Coefficients found in step 1 and predict future samples of a signal using AR equation. I don't have a desired signal so I ...
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40 views

How to Derive Rayleigh distribution using transformation formula

Consider a complex random variable $Z=X+\jmath Y$, where the probability density function of $X$ and $Y$ are given by $$p(x) = \frac{1}{\sqrt{2\pi\sigma^2}} {\rm e}^{-\frac{x^2}{2\sigma^2}}\quad\mbox{...
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1answer
35 views

How to apply baseline methods to MNE preprocessed raw EEG signals?

I am new at EEG preprocessing and classification. I have followed Clemens Brunner's blog https://cbrnr.github.io/2018/01/29/removing-eog-ica/ as a tutorial for MNE. This is how I have preprocessed ...
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2answers
44 views

Augmentation for EEG signal classification using Deep Learning

Augmentation is a technique that we use in deep learning for expanding the training dataset. It includes different ways of modifying an image and adding it to the training dataset. My question is if ...
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1answer
41 views

Algorithm for detecting whether a signal stored in rolling buffer is Increasing, Decreasing or staying Constant

I have a data signal which is generated at constant time interval. It is a real world measurement and thus exhibits some noise in its value (it fluctuates approx + or - 20 units). The noise is fairly ...
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0answers
31 views

Envelope detector for AM signals

How or what are the constraints for deciding factors of envelope detector for AM As far as I know that charging time of capacitor should be below 20T where T is periodic time of carrier and ...
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35 views

Dual FFT - difficulties extracting phase

I am performing dual FFT analysis on a system. 1) I generate a Log Sine Sweep signal and save it as my reference array 2) I then produce an inverse filter to correct for amplitude and save this as ...
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0answers
48 views

How to find fundamental frequency of two signals?

I am facing difficulty with finding fundamental frequency of signals I mean by fundamental frequency=(1/Time period) Correct me if I am wrong consider two continuous time signals with Time period ...
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0answers
20 views

How can I find inverse Z transform using synthetic division method when Region of convergence is bounded rather than right sided or left sided?

Explanation of synthetic division method Above example has region of convergence of type mod(z)>mod(a) I want to solve problems when region of convergence of type mod(e)>mod(z)>mod(d)
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0answers
6 views

How would one reduce dimensionality/covariance in a dataset with nonlinearly covariant variables? Is M-SSA a no-go?

I am familiar with the Principal Component Analysis method of covariance and dimensionality reduction. I am considering using its multivariate time series brother, Multivariate Singular Spectrum ...
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0answers
20 views

Detecting changes in signal due to server delay

I'm currently working on an application that can be used to determine when a signal changes due to a server delay. Essentially, I have an API that is used to output data to a UI. However, for reasons ...
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1answer
21 views

Similarity or Relation between Walsh Hadamard Transform and Slant Transform

Is there any relation between Walsh Hadamard Transform and Slant Transform? Or is there any common property or similarity?
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117 views

How to measure SINAD of an audio signal?

I tried to measure the SINAD and SNR of a recorded audio signal using MATLAB. The following is the process I did to measure the 2 parameters: Firstly, I generated an FM modulated signal(1 kHz audio ...
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0answers
16 views

the model need backgound

Suppose the multivariate one-way anova model for the raw data , i.e. $$ \label{Example_model_1} \mathbf{y}_{ij}=\mathbf{\mu}+\mathbf{z}_i+\mathbf{e}_{ij}, ~~ i=1,\ldots,m,~~j=1,\ldots,n_i,~~~~~~~~~~...
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0answers
12 views

What frequency energy estimation technique for 60 bands spectrum analyzer

I'm making a 60 bands spectrum analyzer for audio and I have tried 2 different algorithms one with a bank of band-pass filters and second the Goertzel filter. With the bank of bandpass filters I don't ...
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0answers
27 views

Spectrum Analyzer - Acquisition time computation

Using a spectrum analyzer, is there a theorical equation that links acquisition duration and acquisition parameters ( Span, RBW, VBW, sweep time and averages number ) Does this equation depends on the ...
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1answer
42 views

Continuous wavelet transform

Continuous wavelet transformation has been quite widely used for various applications. Most of the papers that I found were using CWT for non-stationary signals. Can we use CWT for stationary signal ...
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1answer
54 views

Recommendations for SINAD equipment

I am interested in buying a device that measures the SINAD of the audio signal(FM signal) that I receive from PC. Here is the setup: Signal generator (generating 1kHz FM signal ) $\rightarrow$ ...
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17 views

Derivation of the reassigned STFT magnitude of a complex exponential

I have a complex exponential defined as $x(t)=Ae^{i2\pi f_{0}t}$ and its short time Fourier transform with respect to the analysis window, $g(t)$ is defined as, $$X_{g}(b,f) = \int_\mathbb{R} x(t+b)g(...
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0answers
33 views

How to generate wireless O-QPSK modulated signal in Matlab?

I am trying to create a small simulation where I would need to transmit a wireless signal from one wireless node to another and then transmit one more message back to node 1. Considering this is LR-...
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0answers
57 views

High quality removing gravity from accelerometer data without Sensor Fusion

My smartphone have only accelerometer sensor. I need to get data close to (0,0,0) in hold in my own application. I did use some app from Google Play and data was very close to it (some like 0.1 and ...
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1answer
57 views

What are some of the disadvantages of parametric PSD estimation methods?

Roughly speaking, the methods of power-spectra estimation can be divided in two categories : parametric and non-parametric. From what I understood, parametric methods assumes that the signal can be ...
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0answers
24 views

How to compare two 802.15.4 O-QPSK modulated digitals signals?

I am working on wireless sensors project and I am trying to simulate a transmission between two nodes. So let's say I have two nodes which transmit the message to each other, i.e. node 1 transmits ...
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0answers
78 views

Which equipment to use for testing performance of AM, FM, and DAB

I want to test the performance of AM, FM and DAB radio in RTL-SDR. I want to measure sensitivity, adjacent channel selectivity, cross-modulation/blocking, and third-order intermodulation to be some of ...
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0answers
28 views

barker sequence in signal processing

In our class test we were given a signal with barker sequence and a 10101010... sequence ahead of that and were asked it's importance. So what is the significance of that 10101... sequence?
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30 views

Binary vs 4-PAM PSD

I'm struggling to understand how you would form an expression for the PSD of a 4-PAM signal which is using rectangular pulse shaping. I understand for binary the likelihood of +/1 is equal so the ...
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0answers
24 views

What is k and n in this Discrete Hilbert Transform formula and how to use it with a time series?

I have a time series and I need to find the Discrete Hilbert Transform of that. This paper says that about the Hilbert Transform. Suppose I have a time series f(t)...
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1answer
44 views

SNR of a pulsed signal in noise

I have a digitized acoustic data of length L in which a pulsed signal (chirp) of finite duration and bandwidth is merged starting at some time instant t1 and ending at time instant t2. I wan to ...
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1answer
88 views

Down sampling an EEG signal

I have a set of 10 minute EEG signals that were sampled at 400 Hz and have 16 channels which corresponds to a 16x240000 matrix. These EEG signals belong to two different classes. I am trying to ...
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0answers
16 views

Partitioning data for minima detection

I am working with signals that consist of consecutive equidistant dips. I am trying to write an algorithm that finds the absolute lowest (minimum) point in each of the dips. We don't know the ...
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0answers
32 views

Finding threshold for noisy pulse train

I have a noisy signal that roughly switches between two distinct amplitude levels, i.e. looks like a pule train with irregular pulse with and small variations in the "on" and "off" amplitude over time,...
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0answers
26 views

Log Sine Sweep Acoustic Measurements

I am currently trying to understand the Sine Sweep Method for taking acoustic measurements. I am following this paper: https://www.thinksrs.com/downloads/pdfs/applicationnotes/SR1_SweptSine.pdf I ...
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0answers
27 views

How to find the filter coefficient of matched filter to detect the pulse of a signal?

I would to understand how to find the coefficient of a matched filter. Let's consider we have a signal and the signal is buried in the following noise. we want to find the coefficient of a matched ...
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0answers
10 views

Looking to simulate sound level meter (read microphone audio signal into 1/3 octave)

I am looking to pull audio from a microphone and analyse the 1/3 octave data. Can anyone suggest a software library to do this that I could then build a software interface on top of? Initially looking ...
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0answers
17 views

Analysis of linear acceleration and angular velocity, how to?

Excuse me If you don't feel that this question is good enough, but at the moment this is my level of entry knowledge. Imagine that you have 200 recordings from the sensors, and information that you ...
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0answers
85 views

I want to plot a gaussian pulse in MATLAB in the frequency domain, with its centre at the highest value

I have tried one way but i am getting 2 peaks at the edges as shown in the picture. I have used 1 part of my code for the signal generation where i used the gauspuls command (reference: www.simsonic....
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0answers
19 views

Signal ECG , collecte & visualize data

I am currently working on a sensor that visualizes an ECG signal and visualizes its data. Its principle is that it has 3 electrodes that must be placed in specific parts of the body .... I would like ...
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1answer
30 views

Higher side lobe levels in linear array beam pattern

I am working on beam forming of high frequency (>400 KHz) linear array for imaging sonar. I have gathered sensor data of 80 channel linear array sub merged halfway in 8 m deep water tank with a ...
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0answers
135 views

Why does power spectral density of OFDM signal changes with number of zero subcarriers

I am trying to plot the power spectral density (PSD) of an OFDM signal with $N_{dsc}$ subcarriers and $N_{zeros} = N_{fft}-N_{dsc}$ zero subcarriers. I am using the matlab function pwelch() to plot ...
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1answer
94 views

Please help me understand this paper about Discrete Wavelet Transform!

I am trying to understand this paper says. I have found this paragraph to be vague: (a) Preprocessing Stage. The first step in this stage was to apply the Discrete Wavelet Transform (DWT). This ...
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0answers
48 views

processing a very noisy signal

I work on an ECG signal that I collect from a sensor, and it is very noisy. Having researched it above I read that FFT or so Nyquist-Shawon's casting theories were advised, being novice in the field ...
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0answers
46 views

Drawbacks of kalman filter

What are the drawbacks of kalman for attitude angels estimation...or what are advantages of mahony filter over kalman filter for attitude angels estimation?
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0answers
67 views

How enhance amplitude of audio signal without distortion?

After FFT I've set to zero some frequencies and I'd like to enhance the amplitude in order to recover the leak. I'd like to do a normalization in order to avoid distortion. I've done in this way but ...
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0answers
26 views

Impulse response of discrete time system

I am learning about discrete systems and in this derivation something struck me as quite odd. Solving for $A_0$ in this equation seems dubious as it ignored all other values of $n$. For example, at $n=...