(2 intermediate revisions by the same user not shown)
Line 4: Line 4:
 
[[Category:problem solving]]
 
[[Category:problem solving]]
 
[[Category:random variables]]
 
[[Category:random variables]]
 +
[[Category:probability]]
 +
 +
<center>
 +
<font size= 4>
 +
[[ECE_PhD_Qualifying_Exams|ECE Ph.D. Qualifying Exam]]
 +
</font size>
 +
 +
<font size= 4>
 +
Communication, Networking, Signal and Image Processing (CS)
 +
 +
Question 1: Probability and Random Processes
 +
</font size>
 +
 +
January 2001
 +
</center>
 +
----
 +
----
 +
=Part 4=
 +
Let <math class="inline">\mathbf{X}_{t}</math>  be a band-limited white noise strictly stationary random process with bandwidth 10 KHz. It is also known that <math class="inline">\mathbf{X}_{t}</math>  is uniformly distributed between <math class="inline">\pm5</math>  volts. Find:
 +
 +
'''(a) (10 pts)'''
 +
 +
Let <math class="inline">\mathbf{Y}_{t}=\left(\mathbf{X}_{t}\right)^{2}</math> . Find the mean square value of <math class="inline">\mathbf{Y}_{t}</math> .
 +
 +
'''(b) (10 pts)'''
 +
 +
Let <math class="inline">\mathbf{X}_{t}</math>  be the input to a linear shift-invariant system with transfer function:
 +
<br>
 +
<math class="inline">H\left(f\right)=\begin{cases}
 +
\begin{array}{lll}
 +
1    \text{      for }\left|f\right|\leq5\text{ KHz}\\
 +
0.5    \text{  for }5\text{ KHz}\leq\left|f\right|\leq50\text{ KHz}\\
 +
0    \text{      elsewhere. }
 +
\end{array}\end{cases}</math>
 +
<br>
 +
 +
Find the mean and variance of the output.
  
==Question from [[ECE_PhD_QE_CNSIP_Jan_2001_Problem1|ECE QE January 2001]]==
 
Question here
 
 
----
 
----
 
==Share and discuss your solutions below.==
 
==Share and discuss your solutions below.==
 
----
 
----
=Solution 1 (retrived from [[ECE600_QE_2000_August|here]])=
+
=Solution 1 =
 
Write it here
 
Write it here
 
----
 
----

Latest revision as of 10:37, 13 September 2013


ECE Ph.D. Qualifying Exam

Communication, Networking, Signal and Image Processing (CS)

Question 1: Probability and Random Processes

January 2001



Part 4

Let $ \mathbf{X}_{t} $ be a band-limited white noise strictly stationary random process with bandwidth 10 KHz. It is also known that $ \mathbf{X}_{t} $ is uniformly distributed between $ \pm5 $ volts. Find:

(a) (10 pts)

Let $ \mathbf{Y}_{t}=\left(\mathbf{X}_{t}\right)^{2} $ . Find the mean square value of $ \mathbf{Y}_{t} $ .

(b) (10 pts)

Let $ \mathbf{X}_{t} $ be the input to a linear shift-invariant system with transfer function:
$ H\left(f\right)=\begin{cases} \begin{array}{lll} 1 \text{ for }\left|f\right|\leq5\text{ KHz}\\ 0.5 \text{ for }5\text{ KHz}\leq\left|f\right|\leq50\text{ KHz}\\ 0 \text{ elsewhere. } \end{array}\end{cases} $

Find the mean and variance of the output.


Share and discuss your solutions below.


Solution 1

Write it here


Solution 2

Write it here.


Back to QE CS question 1, January 2001

Back to ECE Qualifying Exams (QE) page

Alumni Liaison

Correspondence Chess Grandmaster and Purdue Alumni

Prof. Dan Fleetwood