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Energy or Power Signal

  1. May 20, 2017 #1
    1. The problem statement, all variables and given/known data
    Determine whether u[n] - u[n-4] is a power or energy signal.

    2. Relevant equations
    form.PNG

    3. The attempt at a solution
    img.jpg
    I am stuck here. I don't know how to simply further. Please help.
     
  2. jcsd
  3. May 20, 2017 #2

    lewando

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    Gold Member

    You could tell by inspection based on the definitions of "energy signal" and "power signal". If you want to use that formula, what can you say about the equivalence of u[n] - u[n-4] and |u[n] - u[n-4]|2 ?
     
  4. May 20, 2017 #3
    I think u[n] - u[n-4] = 1 for n=0,1,2,3 and 0 elsewhere.
    So, Ex becomes 4. So, it's an Energy Signal. Am I right?
     
  5. May 20, 2017 #4

    lewando

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    Gold Member

    That is exactly right.
    You might want to indicate (for others who might want to follow your logic) what is so special about "4" that leads you to classify the signal as you have. What if the result was "5"?
     
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