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a)
 
a)
  
<math>y[n]= \frac{x[n]+x[n-1]}{2} </math><br>  
+
<math>y[n]= \frac{x[n]+x[n-1]}{2} </math>
  
Applying Z-transform on both sides and grouping terms, we can obtain the transfer function<br/>
+
Applying Z-transform on both sides and grouping terms, we can obtain the transfer function
  
 
<math>\begin{align}
 
<math>\begin{align}
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Frequency Response <math>H(\omega)</math>  
 
Frequency Response <math>H(\omega)</math>  
 +
 
<math>\begin{align}
 
<math>\begin{align}
 
H[e^{j\omega }] &= \frac{1+e^{-j\omega }}{2} \\
 
H[e^{j\omega }] &= \frac{1+e^{-j\omega }}{2} \\
Line 29: Line 30:
 
<math>y[n]= \frac{x[n]-x[n-1]}{2}</math>  
 
<math>y[n]= \frac{x[n]-x[n-1]}{2}</math>  
  
Applying Z-transform on both sides and grouping terms, we can obtain the transfer function<br>
+
Applying Z-transform on both sides and grouping terms, we can obtain the transfer function
  
 
<math>\begin{align}
 
<math>\begin{align}
Line 38: Line 39:
  
 
Frequency Response <math>H(\omega)</math>
 
Frequency Response <math>H(\omega)</math>
 +
 
<math>\begin{align}
 
<math>\begin{align}
 
H[e^{j\omega }] &= \frac{1-e^{-j\omega }}{2} \\
 
H[e^{j\omega }] &= \frac{1-e^{-j\omega }}{2} \\

Revision as of 10:15, 29 October 2011

Homework 6, ECE438, Fall 2011, Prof. Boutin


Question 1

a)

$ y[n]= \frac{x[n]+x[n-1]}{2} $

Applying Z-transform on both sides and grouping terms, we can obtain the transfer function

$ \begin{align} Y[z]&= \frac{X[z]+X[z].z^{-1}}{2} \\ \frac{Y[z]}{X[z]}&= \frac{1+z^{-1}}{2} \\ H[z] &= \frac{1+z^{-1}}{2} \\ \end{align} $

Frequency Response $ H(\omega) $

$ \begin{align} H[e^{j\omega }] &= \frac{1+e^{-j\omega }}{2} \\ &= e^{-j\frac{\omega }{2}} \left( \frac{e^{j\frac{\omega }{2}}+e^{-j\frac{\omega }{2}}}{2} \right) \\ &= e^{-j\frac{\omega }{2}} cos \left( \frac{\omega }{2} \right) \\ \end{align} $

HW6Q1fig1.jpg

b)

$ y[n]= \frac{x[n]-x[n-1]}{2} $

Applying Z-transform on both sides and grouping terms, we can obtain the transfer function

$ \begin{align} Y[z]&= \frac{X[z]-X[z].z^{-1}}{2} \\ \frac{Y_2[z]}{X[z]}&= \frac{1-z^{-1}}{2} \\ H[z] &= \frac{1-z^{-1}}{2} \\ \end{align} $

Frequency Response $ H(\omega) $

$ \begin{align} H[e^{j\omega }] &= \frac{1-e^{-j\omega }}{2} \\ &= e^{-j\frac{\omega }{2}} \left( \frac{e^{j\frac{\omega }{2}}-e^{-j\frac{\omega }{2}}}{2} \right) \\ &= je^{-j\frac{\omega }{2}} \left( \frac{e^{j\frac{\omega }{2}}-e^{-j\frac{\omega }{2}}}{2j} \right) \\ &= je^{-j\frac{\omega }{2}} sin \left( \frac{\omega }{2} \right) \\ \end{align} $

HW6Q1fig2.jpg


Question 2

File:HW6Q2fig1.jpg



Question 3


Question 4

File:HW6Q4fig2.jpg



Question 5


Back to Homework 6

Back to ECE 438 Fall 2011

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