Questions tagged [cross-correlation]
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346
questions
2
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1answer
42 views
Why is peak of the signal taken as the Time Delay
I was reading this research paper titled 'The generalized Correlation Method for Estimation of Time Delay' by C. Knapp and G.C. Carter. They develop an ML estimator and in the introduction mention ...
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1answer
23 views
Relation between bandwidth and amplitude of auto correlation of chirp signal
I am trying to understand the properties of chirp signals and their characteristics.
I plotted the autocorrelation of a chirp signal in MATLAB.
How can I compute the relation between the amplitude of ...
0
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1answer
82 views
Estimate the time delay of two signals
I am having 2 sets of data data1 and data2 .I wanted to find the delay between the two datasets.
Assume data1=[1 2 3 4 5 6 7 8 9 10] and data2=[0 0 0 0 1 2 3 4 5 6].From the data I know that, data2 is ...
2
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1answer
48 views
Method to generate binary sequences with desired cross-correlation and autocorrelation properties
I am looking for a method to generate two binary sequences of length $N$ with the following properties:
Very good cross-correlation for all shifts.
Good enough autocorrelation for all shifts except ...
1
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1answer
54 views
RF-Chain Signal Delay for Sensor Switching
Lets have a RF-chain as above with system bandwith from HP corner to the green line say 1 MHz.
The signal accumulates delay as it passes through this analog chain, and due to it being non-liner filter ...
0
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1answer
38 views
Extraction of the phase lag form cross-correlation function
I would like to find out the phase offset that my signal contains at the receiver side. For this, I use the cross-correlation function, where I cross-correlate signal before and after matched filter. ...
1
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1answer
26 views
How does a correlation receiver ensure which transmitted data does a user see?
Hello! I understand that using correlation, one can set up a system wherein multiple users can transmit at the same time using the same channel. And theoretically, I understand that if the correlation ...
1
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1answer
83 views
Real Data Complex Transfer Function using H0, H1, H2 Estimators
BACKGROUND:
This question is attempting to consolidate material discussed in two previous topics. These are:
Understanding the H1 and H2 estimators @Pontus S
Frequency-domain deconvolution: "...
1
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1answer
60 views
Comparing spectrogram similarity over time
I have a data set of spectrograms from moving audio recorders. As the recorders get closer, I expect the spectrograms to become more "similar". I expect this "similarity" to be a ...
0
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1answer
28 views
Difference between cross correlation definitions (signal processing / random processes)
I'm trying to understand the similarities/differences between the following definitions for cross correlation)
Signal Processing: (or it's discrete equivalent)
$$R_{XY}(\tau) = \int_{-\infty}^{+\infty}...
0
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2answers
104 views
Which algorithm could be used to compare two waveforms from an oscilloscope in XY mode?
I would like to receive some hint as to which algorithm could be used to compare two waveforms from an oscilloscope in XY mode, as shown in the image:
Note that the image shows a percentage ...
2
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0answers
33 views
Blind TDOA Estimation
I am not EE or DSP engineer, however I am working on a project that uses TDOA estimation for location finding. I am able to get the localization algorithm working using cross correlation to estimate ...
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0answers
35 views
Cross-correlation estimation in MATLAB using a method similar to pwelch for the PSD
Is there a function in MATLAB to estimate the cross correlation function of two wide-sense stationary signals (or the autocorrelation of the signal with itself) in a way similar to the estimation of ...
0
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1answer
45 views
What is the difference between Goertzel algorithm and cross correlation in time
Im reading https://en.wikipedia.org/wiki/Goertzel_algorithm,
when we want to discover the amplitude of a some frequency in a given signal what is the difference between applying Goertzel algorithm and ...
0
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0answers
28 views
Generating data with given Auto and Cross Correlations
I have two discrete vectors $\mathbf{x}_1$ and $\mathbf{x}_2$, and I'm trying to generate more data $\mathbf{f}_1$ and $\mathbf{f}_2$ that has some basics properties of $\mathbf{x}_1$ and $\mathbf{x}...
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29 views
Can cross correlation be used to see if filtering of a signal has changed it too much?
I am filtering a signal, and want to check if I am not over filtering it. I am doing a low pass filter, for a signal of input frequency of 512Hz, first with 250Hz pass band, then )I was intending to ...
0
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1answer
93 views
Impulse response $h[n]$ from input and output signal using cross correlation on Matlab
I have two signals on Matlab, one being input and the other output. I want to know if taking the cross correlation of these signals would give me the impulse response?And if so, will taking the ...
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0answers
35 views
How to prevent (or remove) aliasing when a cross-correlation between spectra is performed
This is my problem: I'm implementing a tool which cross-correlates a spectrum (fluxes as function of wavelength, obtained directly from an instrument) with a template (fluxes as function of wavelength,...
0
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2answers
61 views
$f \star (g \,* \,h) = (f \star g) * h$?
In this paper that I'm reading, I see this equation:
$$S_0 \star (S_0 * N) = N,$$
where $\star$ denotes cross-correlation, $*$ denotes convolution and $S_0 \star S_0 = \delta$. Is it true in general ...
1
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1answer
50 views
Is there any way to align temporally two signals in spectrogram?
I am keen to know that If I have two signals say :
Farend_signal (y[n]) and Nearend_signal (x[n])
and x[n] also contains an echo of y[n] with some delay.
Is there any technique to align these two ...
0
votes
1answer
76 views
How to run Welch’s method on cross-spectral density
I have a multivariate time series and I’m trying to figure out the cross spectral density of all pairs of variables efficiently. I’m unsure of how to implement Welch’s method in this context. Do I ...
2
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1answer
138 views
Is `xcov()`More Accurate Than `xcorr()` to Compute the Cross Correlation of Signals with Non Zero Mean Values?
I have to compute the cross-correlation between two transient signals, which could be decomposed into a trend (with non-zero mean value) + noise.
In particular I am interested in the max of the cross-...
0
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1answer
93 views
Cross-correlation of two signals
I want to find the direction of a sound source in 2D space. I use two microphones and one sound source for that. I have recorded audio data into two arrays. When a sound is detected, it starts to ...
1
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1answer
40 views
Map time/scene differences between two similar videos
Goal:
Given two videos that are episodes from series but in different format (one Bluray/one TV for example), map the time differences between the two (which scenes are not in one of the two) and be ...
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0answers
39 views
Is it possible to normalize an un-normalized cross-correlation vector after computation
I have a C++ code that computes cross-correlation for a given 2 vectors as input. It doesn't have an implicit normalization or normalized implementation of cross-correlation. But I would prefer a ...
1
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1answer
248 views
CWT at low scales: PyWavelets vs Scipy
Low scales are arguably the most challenging to implement due to limitations in discretized representations. Detailed comparison here; the principal difference is in how the two handle wavelets at ...
1
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1answer
32 views
Finding delay where squared error between signal and data is minimal
I have a set of points which correspond to part of a known signal. What I want to do is estimate the delay between the set of points and the known signal.
In this case, I don't think cross ...
1
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1answer
79 views
Produce musical signal from instantaneous frequency
I'm implementing the Yin Algorithm in Python so as to extract the pitch of my voice when whistling or humming. My goal is to produce the Gate (Envelop Control) and CV (Pitch Control) signals which can ...
0
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0answers
69 views
How to use cross-correlation to verify speech data and determine delay
I have been experimenting with cross-correlation function to verify the presence of speech in a recorded file wrt a source file. I tried the following in Matlab:
<...
1
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1answer
169 views
Fourier Transforms, Convolution, Cross-correlation: what is their physical unit exactly?
Let us assume we are talking about real, deterministic, electrical signals $x(t)$ and $y(t)$ (magnitude in Volts).
There are different kind of Fourier Transforms. I made a table to summarize:
NB: By ...
1
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1answer
208 views
Proving the upper bound of cross correlation
I am reading about cross-correlation from this document and equation (5) states that
The maximum value of the crosscorrelation is not always when the shift
equals zero; however, we can prove the ...
1
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1answer
64 views
Convolution and Cross Correlation Blackbox
Suppose I was handed a blackbox that I know is either a Convolution filter or Cross-Correlation filter, and my job is to find out which it is.
My idea is to pretend that it's Cross-Correlation and ...
1
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1answer
189 views
GCC-PHAT always peaks at zero when estimating delay offset
My question is that when I used gcc-phat to estimate delay between two audio signals, it always returns zero offset. However normal cross correlation Xcorr gives a good result. I don't know the reason....
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0answers
28 views
The normalized cross-correlation of two signals
I wanted to calculate the normalized cross-correlation function of two signals.
I use the command ...
2
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0answers
66 views
Strange behavior in fixed-point FFT
This is a problem I encountered some time ago while doing my thesis, which still now, I am not sure to understand.
By then, I was implementing the circular correlation in an FPGA using this Xilinx FFT ...
1
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1answer
113 views
SVD vs matched filter
Reading about singular value decomposition (SVD) in the context of signal processing applications, one can separate the signal from the noise into orthogonal subspaces. On the surface this sounds like ...
2
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0answers
229 views
Fast calculation of normalization factor for normalized cross correlation
There has been a number of posts here I've browsed through that explain implementations of normalized cross-correlation in Python. One such implementation that is frequently cited is found below.
<...
2
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1answer
48 views
Interpreting the cross correlation results
I am new to this forum. I am just trying to understand how to calculate delay (in terms of samples) between two signals using cross-correlation function. I wrote a small Matlab code in order to ...
1
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2answers
61 views
Comparing similarity of two simultaneously recorded EEGs in freq domain
I have two EEG signals that are simultaneously recorded during the night (sleep). Imagine one device recorded from channel F4 and the other from Fp2. Now I would like to check the similarity of these ...
0
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1answer
74 views
Matlab: xcorr: Having trouble when I try to calculate delay between two sinusoids
I have a problem when I try to use Matlab built-in function for cross-correlation 'xcorr'.
Background: I created two sinusoids, one of them delayed in time. I choose center frequencies of these ...
0
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0answers
31 views
aperiodic auto correlation properties
I'm reading about PSC (primary synchronization code) in UMTS. It is a so-called Golay sequence.
It is said it has a good aperiodic auto correlation properties.
What does it mean (in terms of aperiodic)...
0
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1answer
55 views
Having Problem about DownConversion
I hope, you are doing well. I want to ask question about baseband conversion.
Background:
I generated two AM signals in MATLAB, which one of them is shifted in time.
I multiply the signals with $\cos(...
0
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1answer
579 views
Calculating the bit period
I want to calculate the bit period in my RF packets that I transmit them with 50Kbaud (Symbol rate=bit rate in my case) , how can I calculate the bit period?
0
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1answer
25 views
Spectral analysis of a cross correlation function [duplicate]
So it's widely known that the Cross Correlation of 2 signals helps us in figuring out the time delay in those signals by analyzing the peak of the correlation coefficient in the time domain.
For ...
0
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1answer
48 views
Cross-correlation with SDPSK modulation
I'm trying to detect a sync word in a signal using Symmetrical Differential PSK (bit 0 = +90° phase, bit 1 = -90° phase).
Given the signal is encoded in the phase difference between two symbols, the ...
0
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0answers
63 views
Probability of similarity for two random white noises
I'm looking for the method to calculate theoretical similarity of two random noises $x$ and $y$ with mean $0$ and standard deviation $1$, I've got also $12500$ samples of signal, sampled $2.5$ Ga/s.
...
0
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1answer
245 views
Get the lag of a signal with respect to the other with cross correlation
I have 2 vector of length 20 each. The first 15 entries of $a$ are exactly the same as the last 15 entries of $b$. There is random noise in the 5 last entries of $a$ as well as the 5 first entries of $...
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0answers
42 views
Instantaneous frequency, PLLs, frequency mixing, cross-correlation and the cross-correlation matrix
This is as much a request for comment and critique as anything else. I am looking at tracking how a system perturbs an input that is a (real) sinoid of varying frequency.
...
0
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2answers
117 views
Cross Correlation of output with input is equivalent to impulse response of a large bandwidth input (LTI System)?
What is the practical way to found the impulse response of a system ? As impulse function has a very large amplitude at zero time (analog signal).
So the cross corelation of output of a large ...
1
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1answer
47 views
Correlation of discrete time periodic sequences
So I was reading this textbook - Digital Signal Processing by Proakis and Manolakis. The authors define the cross-correlation operation for 2 energy signals $x(n)$ and $y(n)$ in section 2.6.1 as:
$$ ...
