Signals and Systems: Determine the convolution of x(t) and h(t)

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Discussion Overview

The discussion centers around the convolution of two signals, specifically the mathematical formulation and evaluation of the convolution integral. Participants explore the implications of the convolution operation in the context of given signals, addressing limits of integration and the behavior of the output signal.

Discussion Character

  • Technical explanation
  • Mathematical reasoning
  • Homework-related

Main Points Raised

  • One participant describes the convolution integral and the transformation of the signal ##h(t)## to ##h(-\tau)##, noting the presence of an impulse signal at ##\tau = -2##.
  • The same participant expresses uncertainty about determining the limits of integration when there is overlap between the two signals, particularly when ##t<1## and ##t>5##.
  • Another participant asserts that the limits of integration for convolution are always from ##-\infty## to ##\infty##, emphasizing that this is not critical in this case due to ##h(t)## being nonzero at only one point.
  • Several participants acknowledge the clarification regarding the limits and the nature of the convolution as a function of ##t##.

Areas of Agreement / Disagreement

There is a general agreement that the limits of integration for convolution can be considered from ##-\infty## to ##\infty##, particularly in this case where ##h(t)## is nonzero at a single point. However, the initial participant's uncertainty about the limits and overlap indicates that some aspects of the discussion remain unresolved.

Contextual Notes

The discussion reflects limitations in understanding how to apply the convolution integral when dealing with impulse signals and the implications of signal overlap. The specific behavior of the output signal ##y(t)## is also mentioned but not fully explored.

SumDood_
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Homework Statement
Determine the convolution of x(t) and h(t)
Relevant Equations
Specified in the solution attempt
So, the convolution of two signals is described as follows:
$$ \int_{-\infty}^{\infty} x(\tau)h(t-\tau) \, d\tau $$
The figure shows the given signals. Now, as described in the convolution integral, I transformed ##h(t)## to ##h(-\tau)## by flipping the signal horizontally. So, now I have an impulse signal when ##\tau = -2##.

Now, the ##t## represents a horizontal shift in signal ##h(t-\tau)##. After which both signals are multiplied and then integrated. When, ##t<1##, then there is no overlap between ##h(\tau)## and ##x(\tau)##. The same is true when ##t>5##.
Now, I need to determine what the limits of the integration would be when there is an overlap between the two signals. If ##h(\tau)## were a rectangular signal, then it would be straightforward.
1691869231971.png


The impulse signal means the only overlap between the two signals exist at the exact point to where the impulse is shifted. Because of this, I don't know how to find the limits to evaluate the convolution integration. From what I have read online, I see that the output signal ##y(t)## is probably a horizontal shifted signal of ##x(t)## by 2 units to the right.

I can't seem to get the answer because I don't know what the limits of the integration are supposed to be. I thought the upper limit and the lower limit would be equal, but then the integration would evaluate to 0.
 
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The limits are always from ##-\infty## to ##\infty##. It is not not very important for this example because ##h(t)## is only nonzero at one point. You do not need to consider the limits to evaluate the integral. You should look at where that point is involved in the convolution integral. That convolution is a function of ##t##.
 
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FactChecker said:
The limits are always from ##-\infty## to ##\infty##. It is not not very important for this example because ##h(t)## is only nonzero at one point. You do not need to consider the limits to evaluate the integral. You should look at where that point is involved in the convolution integral. That convolution is a function of ##t##.
Makes sense now.
Thanks!
 
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