(b) Response of Signal in Question 1)
(b) Response of Signal in Question 1)
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== Define a DT LTI System ==
 
 
<math> \,\ x[n] = 5*u[n-5] + 6*u[n+6] </math>
 
 
=== a)  h[n] and H(z) ===
 
----
 
<br>
 
 
We obtain <math> h[n] </math> by finding the response of <math> x[n] </math> to the unit impulse response (<math> \delta[n] </math>).
 
 
<math> \,\ h[n] = 5*\delta[n-5] + 6*\delta[n+6] </math>
 
<br><br>
 
 
<math> \,\ H[z] = \sum_{m=-\infty}^\infty h[m] * Z</math><sup>(<math>-m</math>)</sup><br><br>
 
<math> \,\ H[z] = \sum_{m=-\infty}^{\infty} (5*\delta[n-5] + 6*\delta[n+6]) * Z</math><sup>(<math>-m</math>)</sup>
 
 
By the sifting property, this sum equals:<br>
 
<math> \,\ H[z] = 5*Z</math><sup>-5</sup><math> \,\ + 6*Z</math><sup>6</sup>
 
 
 
 
=== b)  Response of Signal in Question 1 ===
 
=== b)  Response of Signal in Question 1 ===
 
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From Question 1:
 
From Question 1:
Unfortunately, I did not not read ahead and make a DT signal for Parts 1/2.  Instead of going back and redoing my work, I am going to "steal" the work of a Mr. Collin Phillips (my apologies and gratitude to Mr. Collin Phillips).
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Unfortunately, I did not make a DT signal for Parts 1/2.  Instead of going back and redoing my work, I am going to "steal" the work of a Mr. Collin Phillips (my apologies and gratitude to Mr. Collin Phillips).
  
 
According to his work:
 
According to his work:
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* <math> \,\ a_k = 0 </math> elsewhere
 
* <math> \,\ a_k = 0 </math> elsewhere
 
* <math> \,\ N = 2 </math>
 
* <math> \,\ N = 2 </math>
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Response of the System <math> \,\ y[n] = \sum_{k = <N>}^{\infty} a_k H[e</math><sup><math> j2\pi k/N</math></sup><math> \,\ ]e</math><sup><math> jk(2\pi /N) n</math></sup>
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Because <math> a_k </math> only has one value, this shouldn't be that hard to calculate.
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<math> \,\ a_k </math> is only valid at <math> a_1 = -3 </math>.  Therefore...
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<math> \,\ y[n] = -3 *

Revision as of 17:57, 25 September 2008

b) Response of Signal in Question 1


From Question 1: Unfortunately, I did not make a DT signal for Parts 1/2. Instead of going back and redoing my work, I am going to "steal" the work of a Mr. Collin Phillips (my apologies and gratitude to Mr. Collin Phillips).

According to his work:

  • $ \,\ X[n] = 3cos(3\pi n + \pi) $
  • $ \,\ a_0 = 0 $
  • $ \,\ a_1 = -3 $
  • $ \,\ a_k = 0 $ elsewhere
  • $ \,\ N = 2 $


Response of the System $ \,\ y[n] = \sum_{k = <N>}^{\infty} a_k H[e $$ j2\pi k/N $$ \,\ ]e $$ jk(2\pi /N) n $

Because $ a_k $ only has one value, this shouldn't be that hard to calculate.

$ \,\ a_k $ is only valid at $ a_1 = -3 $. Therefore...

$ \,\ y[n] = -3 * $

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