Fall10_Final

Fall10_Final - The Hong Kong University of Science and...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
The Hong Kong University of Science and Technology Department of Electronic and Computer Engineering ELEC 210: Probability and Random Processes in Electrical Engineering 2010 Fall Semester Final Examination December 14, 2010 Name: Student ID: Instructions: 1. This is a 3-hour test. 2. You may use a non-programmable calculator. 3. There are 2 sections : a. Section 1: 10 Multiple Choice Questions b. Section II: 6 Problems 4. Try to attempt all questions. 5. Answer each question in your answer booklet . 6. The distribution of marks is shown in the table below: Question Mark Multi. Choice 10 1 6 2 7 3 6 4 7 5 7 6 7 Total 50
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
SECTION I: Multiple Choice [10 Marks] Notes: For each multiple-choice question below, select only ONE answer. Write your answer in your ANSWER BOOKLET (not this question sheet) [1 Mark Per Question] 1. Which of the following statements about two random variables, X and Y , is not true: a) The correlation of X and Y is symmetrical b) The covariance of X and Y is symmetrical c) The correlation coefficient of X and Y is symmetrical d) The covariance and correlation have the same units e) The covariance and correlation coefficient have the same units 2. Which of the following statements is true: a) Correlation of X and Y gives a meaningful measure of how much X and Y vary together b) Scaling X or Y by a constant does not change their covariance c) Scaling X or Y by a constant does not change their correlation d) Scaling X or Y by a constant does not change their correlation coefficient e) None of the above 3. Consider the following communication system: A transmitter sends a binary value B to a receiver. The received signal is R = B + N , where N denotes independent random noise obeying a Gaussian distribution. Based on R , the receiver successfully decodes B with probability p ; otherwise it makes a mistake and the transmitter tries again. Let n be the number of times that B must be transmitted before it is received successfully. Which of the following is not true: a) Conditioned on B , the received signal R is a Gaussian random variable b) Conditioned on B , the received signal R has zero-mean c) Conditioned on N , the received signal R is a Bernoulli random variable d) The received signal R is a continuous random variable e) n is a geometric random variable 4. Assume that Y 1 , Y 2 , Y 3 are IID jointly Gaussian random variables. Identify which of the following is not true: a) Y 1 and Y
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

Page1 / 6

Fall10_Final - The Hong Kong University of Science and...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online