EE 121: Introduction to Digital Communication Systems
Midterm Solutions
1. Consider the following discrete-time communication system. There are two equallly likely
messages to be transmitted, and they are encoded into an input process fXn g such that if
m
EE 121, Midterm #1, Spring 2001
EE 121, Spring 2001
Midterm 1
Professor V. Anantharam
Problem #1
Problem #2
EE 121, Spring 2001 Midterm 1 Professor V. Anantharam
1
EE 121, Midterm #1, Spring 2001
Problem #3
Problem #4
Problem #2
2
EE 121, Midterm #1, Spri
Tuan Le
EE 121 - Midterm Solutions
Spring 1997
Problem 1
a) False. If X and Y are continuous-valued random variables, then
=
Z
1
Z
1
1
Z
E (X + Y ) =
1
1
Z
x
1
(x + y)fX;Y (x; y)dxdy
1
Z1
1
fX;Y (x; y)dydx +
Z
1
Z
1
1
y
Z
1
1
fX;Y (x; y)dxdy
=
xfX (x)dx +
EE 121 Digital Communication Systems
Gastpar
University of California, Berkeley: Spring 2005
March 3, 2005
First Midterm Exam
Last name
First name
SID
You have two hours to complete this exam.
There are 100 points for this exam. Points for the individua
Spring 1994, EECS 121 - Midterm 1
University of California
College of Engineering
Department of Electrical Engineering
and Computer Science
Professor Wong
Spring 1994
EECS 121 - MIDTERM 1
(Closed book and notes)
1. Consider a linear and time-invariant sys
Chapter 8
Detection, co ding, and deco ding
8.1
Intro duction
The previous chapter showed how to characterize noise as a random process and this chapter
uses that characterization to retrieve the signal from the noise corrupted received waveform.
As one m
EECS 121 * Final Exam
Spring 2004 *
The examination is for 180 minutes. The maximum score is 90 points. Your answers should be unambiguous. 1. (4 + 4 + 6 points) State whether the following statements are true or false, and give a reason for your answer.
EECS 121, Midterm #1, Spring 1996
EECS 121, Spring 1996
Midterm #2
Note : Please answer all questions. Please answer with sufficient detail and clarity that there is no ambiguity
about your answer.
Problem #1
The diagram show is that of a balanced modulat
Name: _
UNIVERSITY OF CALIFORNIA
College of Engineering
Department of Electrical Engineering
and Computer Sciences
Professor David Tse
EECS 121 FINAL EXAM
21 May 1997, 5:00-8:00 p.m.
Please write answers on blank pages only. Answer all 5 questions. Clear
EE121 Midterm Solution
by Lizhong Zheng
Problem 1 (a) We can use the binary tree to construce a mapping from code words to
subintervals of 0; 1) as following: for a code word b b : : : bl, let s = (0:b b : : :bl)b be the
number in 0; 1) whose binary expan
EE 121 Midterm 1 Solutions
Mar, 19, 2003 Kiran
2 1. (a) Cov(X, Y ) = E[XY ] EXEY = E[X(X + Z)] 0 = EX 2 + E[XZ] = X as X and Z are uncorrelated, E[XZ] = 0.
(b)Yes. The covariance has the unit of power and hence depends on the unit of measure. X The correl
Electrical Engineering 121
Introduction to Digital Communication Systems
Logistics
Time and Location: TuTh 9:30-11am, 241 Cory
Instructor: Professor Kannan Ramchandran
Email: [email protected]
Oce hours: Tu 11am-12pm, 258 Cory. Or by appointment.
GSI: Hao Z
ECE 461: Digital Communications
Lecture 1: Discrete Nature of information
Introduction
The currency of todays information age is digital: bits. Digital communication is reliable
transmission of this currency over an unreliable physical medium. It is an in