Questions tagged [cross-correlation]

The tag has no usage guidance.

Filter by
Sorted by
Tagged with
0 votes
1 answer
50 views

Cross-correlation of two processes generated from the same signal through different LTI systems

A problem in Statistical and Adaptive Signal Processing (problem 10.15) presents two WSS signals both generated from zero-mean white Gaussian noise with $\sigma_w = 1$. They are described by $v_1(n) = ...
Matthew Faigan's user avatar
2 votes
1 answer
80 views

Cross-correlation between brain signals: how to handle autocorrelation?

I've been asked to calculate the cross correlation in the 3-12 Hz band between two simultaneously recorded brain signals in two distinct brain areas. Data were acquired at 32 kHz then preprocessed by ...
NeuroDSP's user avatar
0 votes
1 answer
57 views

Correlation between two signals

I am having an input signal x[n]=[1 2 3 4 5 6] and another signal y[n]=[2 3 4]. In order to check whether y[n] is present in the signal x[n],I did cross correlation and the result obtained was [ 0 0 0 ...
Deepa's user avatar
  • 315
0 votes
0 answers
17 views

Cross correlation R^2 value improvement

I require some advice on achieving a better R^2 value using the cross correlation method. Is there any sort of way to improve an R^2 value to obtain better results? I have been looking at applying ...
Pacman's user avatar
  • 1
0 votes
1 answer
44 views

Is the noise at different sampling points related? [closed]

Given the power spectral density of noise, if the values at different sampling points of the same noise are added, what is the power spectral density at this time? Is there any correlation between the ...
fs s's user avatar
  • 1
1 vote
0 answers
86 views

second order cross correlation

I have two signal sequences $u$ and $y$, where the former is the input to a system and the latter is the output of the same system. I would like to find second-order correlation between the two ...
Neuling's user avatar
  • 103
1 vote
0 answers
56 views

Normalized audio cross corelation

I'm trying to cross corelate two audio files to see where they line up. In scipy im doing: correlation = correlate(audio1, audio2, mode='full') Given the graph ...
Ethan Itovitch's user avatar
0 votes
0 answers
24 views

Sliding Window correlation vs cosine of relative phase

I create two band limited signals having a specific time-varying covariance at each time point using cholesky decomposition. My aim for this experiment was to show a scenario where sliding window ...
Sir-Lord's user avatar
0 votes
1 answer
90 views

Calculation of frequency correlation function based on power delay profile

We know that the frequency-domain correlation function and the power delay profile appears as a Fourier transform pair, i.e., $$A_{c}(\Delta f) = \int_{-\infty}^{\infty}PDP(\tau) \cdot e^{-j2\pi \...
Vic's user avatar
  • 113
0 votes
1 answer
148 views

CFO limit for correct LTE Zadoff-Chu Synchronization

I am working with Zadoff-Chu sequences in a Python simulation of an LTE-like communication system and need to understand the effects of carrier frequency offset (CFO) on these sequences. Specifically, ...
Sonny Wandel's user avatar
0 votes
0 answers
37 views

Cross-quantilogram method

What is this method in general? What is the main difference between the quantile cross-spectrum (QS) approach developed by Baruník and Kley (2019) and the cross-correlation function (QS) developed by ...
gurbuz's user avatar
  • 1
1 vote
1 answer
231 views

Proving that the autocorrelation of a signal is the convolution with its time-reversed complex conjugate

I need to prove the property $$f(x)⊕f(x)=f(x)⊗f^*(-x)$$ That is the autocorrelation of a function is the convolution with its time-reversed complex conjugate. I have constructed most of the proof but ...
requiemman's user avatar
3 votes
1 answer
130 views

what degree of accuracy does quadratic interpolation add to fft cross-correlation?

I am not a dsp engineer, so I might be missing some obvious background, but I've been doing my best to educate myself. Let me know if there's more info needed. I am using an fft cross-correlation ...
Michael's user avatar
  • 31
2 votes
1 answer
60 views

Reference signal minimizes the MSE across similar signals with delays

I am dealing with the following problem: I have $M$ signals ($x_1, x_2, \cdots, x_M$), each of length $N$, which are supposed to be similar, up to a certain delay between them and noise. I am ...
Omri's user avatar
  • 21
1 vote
1 answer
63 views

Separate two images using a statistical approach

So I have a fundamental question (for which I can't find a good answer anywhere). Say we have two images (A and B) and their mixed image (C) as follows: Now say that I've been given Image (A) and ...
SpaceCadet2810's user avatar
2 votes
1 answer
94 views

How to simplify several cross correlations used for feature extraction

I have a system where I cross correlate recorded audio signals with several smaller generated signals to extract feature vectors that later I use in a kNN matching. The system works the way I want it ...
besabestin's user avatar
0 votes
0 answers
38 views

Confusion about convolution [duplicate]

I'm facing confusion about the definition of the convolution between two discrete periodic signals. Basically, the definition of convolution between s and ...
Franck Might's user avatar
1 vote
1 answer
50 views

Detect same point spread functions between two microscopy images

So say I'm given two image datasets (Image 1 and 2 - attached). I want to be able to find the point spread functions that are the same between the two images (so parameterize the PSFs based on some ...
SpaceCadet2810's user avatar
1 vote
0 answers
82 views

Finding delay between signals

This should be a simple problem, yet I can seem to figure out what am I doing wrong. I have a bunch of 1-D signals which I expect to look the same up to: shifting, maybe some scaling, and noise. I ...
Yair M's user avatar
  • 305
0 votes
1 answer
802 views

2D FFT Cross-Correlation in Python

How to replicate scipy.signal.correlate2d(x, h) with arbitrarily sized x and h? ...
OverLordGoldDragon's user avatar
1 vote
2 answers
462 views

Is 2D circular cross-correlation with FFT done as described in this source?

Given input images x and h of same size, greyscale 2D and potentially complex, we seek circular ...
OverLordGoldDragon's user avatar
2 votes
2 answers
144 views

Discrepancies in 2D cross correlation results using FFT

I'm trying to implement 2D cross-correlation to acquire the displacement of these two small images (interrogation windows). The issue is that the result from Cross-Correlation (CC) is different ...
ahmathelte's user avatar
3 votes
2 answers
759 views

Efficient 2D convolution/cross-correlation along only one axis (1D output)

I wish to convolve/cross-correlate two images and but, only horizontally, yielding 1D output. So, first output point would be sum(x * h), second ...
OverLordGoldDragon's user avatar
3 votes
0 answers
132 views

Emergence - what constitutes a minimally coherent source that "just begins" to produce stationary interference patterns?

A superposition of two signals with different frequencies will never produce visible (i.e. stationary) interference patterns. Such waveforms will produce spatiotemporal beat patterns, but they rapidly ...
srhslvmn's user avatar
  • 131
1 vote
2 answers
166 views

Examples of audio files that are challenging to cross-fade

What can be recommended as challenging tests for cross-fading/mixing of music? I am looking for examples of music-titles that exhibit severe volume dips when cross-faded or mixed. Ideally answers ...
Manfred Weis's user avatar
0 votes
0 answers
63 views

Similarity between signals

Let's say we have two signals with fast ascending in the beginning, then one slowly decays while another remains at a constant level. An illustration plot is attached. How to compare the similarity ...
colddie's user avatar
  • 101
1 vote
1 answer
137 views

Feasibility of TDOA localization with a single moving receiver and stationary source

Every paper/article I've read on the subject of TDOA localization is concerned with some combination of 2+ stationary receivers (or, sometimes, 1 stationary + 1 moving). There are also some papers ...
tkroman's user avatar
  • 163
1 vote
1 answer
94 views

Finding the variance of the normalized correlation coefficient

I saw in Correlation: A Magnitude or Power quantity? post the derivation for $\rho$ (the mean of the normalized correlation coefficient) and its relation to the SNR of the signal. I'm looking to see ...
Idan Uri's user avatar
0 votes
1 answer
734 views

Find out time offset between two substantially same audio tracks

Say we have two audio tracks of the same movie but from different sources. The length of the animated logos at the beginning is different, so the actual movie audio starts slightly earlier on one ...
Greendrake's user avatar
0 votes
0 answers
76 views

FFT2D on a vector 1D

My question is related to this post I have a 1D vector, the target vector, represented as 2D (knowing the nr of cols and rows) to which i need to apply an FFT2D. Having only the FFT1D, in order to ...
user3253067's user avatar
0 votes
1 answer
376 views

2D Cross-Correlation on different sized images

As per this post the cross-correlation between 2 images is obtained as it follows: ...
user3253067's user avatar
0 votes
0 answers
16 views

How to implement cross-correlation for 2 Images in c++ [duplicate]

I need to implement cross-correlation of 2 images in C++. The process is unclear to me since i do not seem to find a definite formula for it. What i thought this means: FFT2 on both images multiply ...
user3253067's user avatar
0 votes
1 answer
114 views

Cross corelation between two complex-valued Time Series Objects

I am exploring the cross correlation function in Julia between two complex-valued Time Series Objects Z1 and Z2 with this simple code: using DSP Compute the cross-...
Bouarfa Mahi's user avatar
4 votes
3 answers
2k views

2D Cross-Correlation using 1D FFT

I need to calculate cross correlation between 2 images which I read in 2 vectors, both of them uni-dimensional. As per my understanding I need to do the following operations: FFT(1D) on vector 1 and ...
user3253067's user avatar
2 votes
0 answers
65 views

Estimation of time-varying velocity

Objective: Estimate the mechanical tension of a cable using the velocity of the waves travelling along it. Experimental setup: I have a cable in tension equipped with accelerometers. I measure a ...
User327201's user avatar
1 vote
1 answer
146 views

Find $E[Z^2(t)]$ when $Z(t) = X(t) - Y(t)$ where $Y$ is the output of a LTI system with WSS process $X$ as its input

I received this as a practice problem (part b only). I was able to figure out that $E[Z^2(t)]$ = $R_X(0)+R_Y(0)-2R_\text{XY}(0)$ but did not see how to continue. Checking the answers, I saw this line ...
Robert Moore's user avatar
0 votes
0 answers
89 views

Cross correlation of OFDM short preamble produces two peaks

I am trying to cross correlate the short preamble of an OFDM transmission. This is the preamble I am using: ...
Aaron3219's user avatar
  • 101
2 votes
2 answers
488 views

Efficient way to calculate $n$ first elements of cross-correlation using FFT

The cross-correlation between two signals can be calculated using $\texttt{IFFT}\left(\texttt{FFT}(a) \cdot \overline{\texttt{FFT}(b)}\right)$ for two binary signals $a$ and $b$. How could one speed ...
fevar's user avatar
  • 21
1 vote
1 answer
170 views

Limited cross-correlation for multiple signals

I have $N$ signals, each of length $\tau$, with $N\ll \tau$, eg. $\tau=10^8$ samples and $N=100$. I want the $r=10$ first components of all pairwise cross-correlation for the $N$ signals. The naive ...
wavelet_surfer's user avatar
0 votes
2 answers
762 views

How to convert between 2d convolution and 2d cross-correlation?

I am using cross-correlation for the purposes of image stabilisation. The images which I'm processing can sometimes be rather large. The contents of the image are often repeating patterns. For these ...
I hate coding's user avatar
0 votes
1 answer
127 views

Link between maximum delay of cross-correlation and phase velocity

I try to express the relation between: the delay obtained by maximizing the cross-correlation between two signals $x$ and $y$ noted $\tau_{x,y}$ and the phase velocity noted $v_p(\omega)$ In the ...
User327201's user avatar
2 votes
1 answer
2k views

How to interpret cross correlation output?

The output of cross corelation shows the similarity between the two signals. But in what respect is there a similarity? I didn't quite understand how I should interpret the output. How should I ...
bb0667's user avatar
  • 103
1 vote
0 answers
64 views

CIR calculation from SDR data: RTL-SDR, bladeRF

We’re developing a prototype using bladeRF and various Python scripts for processing IQ samples. The system works mainly around 2.4 GHz frequencies: Wi-Fi and Bluetooth. One of the needed functions is ...
Oleg's user avatar
  • 11
4 votes
3 answers
842 views

How to decide whether a recording contains a signal of interest?

I am currently implementing an acoustic communication system in Matlab. For synchronization purposes, every transmission contains an upchirp preamble. The receiver uses cross-correlation to find the ...
F105's user avatar
  • 61
2 votes
1 answer
196 views

Using cross-correlation of spatially shifted data to gain geometric information

Cross-correlation is usually used to estimate e.g. lags between signals that are detected by different sensors at different times. In my case, the situation is slightly different in that I measure ...
DominikR's user avatar
4 votes
1 answer
174 views

Estimation of the attenuation of two waves on a linear sensor array

Context and objective I am trying to estimate the attenuation coefficients ($\alpha_u$ and $\alpha_v$) of two waves ($\overrightarrow{u}$ and $\overrightarrow{v}$). These waves propagate on a linear ...
User327201's user avatar
1 vote
2 answers
298 views

Detecting a known alarm signal in an audio stream

I am going to detect alarm sounds (like from a fire detector) in a live stream. (I have asked similar questions here before, I'm now at the stage of actually doing it). I will not really want to ...
Øyvind Teig's user avatar
0 votes
2 answers
347 views

Extract a signal from noise, so I can view noise spectrum only?

I have a perfect modulated signal. I have the same signal but with noise, this noise is from non linear amplification. Is it possible, to extract the clean signal so it's just leaving the noise? The ...
njk7's user avatar
  • 43
3 votes
2 answers
322 views

Autocorrelation & Cross-Correlation -> Main uses in DSP??

Please help understanding the DSP usage of Autocorrelation & Cross-correlation It seems this is strongly linked to calculating phase offsets, frequency offset for carrier recovery, symbol timing ...
Villere_DSP's user avatar
3 votes
1 answer
205 views

Cross Ambiguity Function Peak Width

I am trying to plot the Cross Ambiguity Function of two OFDM signal (1024 subcarriers) reflected from two targets, which are separated by 30m. The problem I am facing that the CAF peak width at the ...
wesam amiri's user avatar

1
2 3 4 5
9