(Define a DT LTI System)
(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).
  
* <math> \,\ x(t) = 5cos(2t) - 4sin(5t) </math><br><br>
+
According to his work:
* <math> \,\ T = 2\pi </math><br><br>
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* <math> \,\ X[n] = 3cos(3\pi n + \pi) </math>
* <math> \,\ x(t) = \frac{5}{2} * e</math><sup>(j2t)</sup> <math> \,\ + \frac{5}{2} * e</math><sup>(-j2t)</sup><math> - \frac{4}{2j} * e</math><sup>(j5t)</sup> <math>+ \frac{4}{2j} * e</math><sup>(-j5t)</sup><br>
+
* <math> \,\ a_0 = 0 </math>
* <math> \,\ w_0 = 1 </math><br><br>
+
* <math> \,\ a_1 = -3 </math>
* <math>\mathbf{a_2} = \mathbf{\frac{5}{2}}</math><br><br>
+
* <math> \,\ a_k = 0 </math> elsewhere
* <math>\mathbf{a}</math><sub>-2</sub><math> = \mathbf{\frac{5}{2j}}</math><br><Br>
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* <math> \,\ N = 2 </math>
* <math>\mathbf{a_5} = \mathbf{-2}</math><br><br>
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* <math>\mathbf{a}</math><sub>-5</sub><math> = \mathbf{\frac{2}{j}}</math><br><br>
+
* <math> \,\ a_x = 0 </math> elsewhere
+

Revision as of 17:33, 25 September 2008

Define a DT LTI System

$ \,\ x[n] = 5*u[n-5] + 6*u[n+6] $

a) h[n] and H(z)



We obtain $ h[n] $ by finding the response of $ x[n] $ to the unit impulse response ($ \delta[n] $).

$ \,\ h[n] = 5*\delta[n-5] + 6*\delta[n+6] $

$ \,\ H[z] = \sum_{m=-\infty}^\infty h[m] * Z $($ -m $)

$ \,\ H[z] = \sum_{m=-\infty}^{\infty} (5*\delta[n-5] + 6*\delta[n+6]) * Z $($ -m $)

By the sifting property, this sum equals:
$ \,\ H[z] = 5*Z $-5$ \,\ + 6*Z $6


b) Response of Signal in 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).

According to his work:

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

Alumni Liaison

Questions/answers with a recent ECE grad

Ryne Rayburn