Signal Processing Stack Exchange
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Questions tagged [coherence]

Coherence is a stastic to examine the relation between two signals.

It is commonly used to estimate the power transfer between input and output of a linear system. If the signals are ergodic, and the system function linear, it can be used to estimate the causality between the input and output.

Source: Wikipedia.

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Intuitive explanation of coherence

I am a biologist so apologies for the basic question. I am trying to get an intuitive understanding of what the coherence between 2 signals actually means. I have read a couple of introductory texts and an idea that keeps coming up is that…
Apollo23
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Statistical significance of coherence values

I have two signals sampled at $100\textrm{ Hz}$ during $3\textrm{ seconds}$. So I have $300$ sample points at each signal series. I want to calculate coherence values between these two time series and would like to know whether this coherence value…
Sean
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Coherence of a single function given a single frequency

I have a signal sampled from a hardware, s. I would like to compute the coherence of the sampled signal given a single frequency, f. Below are the approaches I can think of. Base on f generate a synthetic signal and compute the coherence of s and…
NcJie
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Mscohere in Matlab-why would the coherence tends to 1 as nfft increases?

Does anyone have a clue as to why -using mscohere- the coherence becomes exactly one for all frequencies if nfft is set to about 190-200. I know it's standard practice to set it to a number that is a power of 2. I tried with 1024, and all I got was…
Fede C
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Simulating two signals with a desired coherence

I'm trying to simulate two frequency-domain signals with a desired coherence, and I'd like to check if my idea is right. To simulate two time-domain signals with a desired correlation, we can use the following method: Suppose $\Sigma$ is the desired…
Anon
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High temporal precision in coherence?

I am new to signal processing, and I am a bit confused by the use of coherence in academic literature. In several articles in neuroscience, coherence between signals (eg. EEG signals) is determined at a very high temporal resolution. See for an…
Scipio
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Using spectral coherence for computing similarity between time series data

I don't really know anything about signal processing. I need to find similairty between two 1-dimensional time series. I read somewhere that spectral coherence could be used to find similarity between two time series. But i am not able to get around…
vigenere
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Difference between Coherent and Non-Coherent in Fibre Optics?

I have been given the following equation to show the difference between coherence and non-coherence in optics and how the third term represents the interference between two optical pulses. Can someone explain what the terms represents and how this…
prof123
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Synchronicity of two signals

I am trying to determine the synchronicity between two oscillating signals. I was attempting to do this by making use of the cross correlation between the two signals and looking at the maximum value. Is this a correct approach? If so, which would…
branny12000
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