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Convolution and Impulse Signals

  1. Sep 21, 2010 #1
    I am a little confused about convolutions.

    I know that convolution is the multiplication and then integral of the two signals. The confusion starts at the commutative property. If i try to change the time-shift from signal to another for any 2 general functions or equations the commutative property doesn't work out.

    for example:
    let x(t) = sin(t)
    and h(t) = t^2

    If you try to convolve the signals above with the commutative property you get 2 different results.

    However, the convolution's commutative property does work out if h(t) were to be a impulse function. So, does it mean that convolution is only an integral between an impulse signal and a generic signal and not two generic signals? (which is the part i am confused because i have seen examples of convolving 2 different signals)
  2. jcsd
  3. Sep 22, 2010 #2


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    Science Advisor
    Gold Member

    I'm not sure what you are referring to. This article shows how convolutions are symmetric
    http://en.wikipedia.org/wiki/Convolution" [Broken]
    Scroll down to "Definitions" for the commutative property.
    Last edited by a moderator: May 4, 2017
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