EE 230B Final Examination, Spring 2008 UCLA Electrical Engineering Department Prof. G. Pottie
NAME:_
Instructions: Attempt all five questions; they are of equal weight but not necessarily of equal difficulty. A sheet of useful formulae and other facts is
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hapler Two: Probability and Stochastic Processes 77
C
no The random variable 1’ is deﬁned as
I l H
l = — X,
1'1 .
t=l
where XI, 1' : 1.1.n. are statisticallyr independent and identically distributed
random variable: each of which has the Cauchy PDF given
EE 231E Channel Coding Instructor: Rick Wesel 116 pts, 180 minutes
Spring 2008 Final Thursday, June 12, 2008 11:30 a.m. - 2:30 p.m.
Your Name: Your ID Number:
Problem 1 2 3 4 5 6 7 Total
Score
Possible 24 20 16 21 5 18 12 116
1
1. (24 pts) T (W, I ). Anal
Discussion 1 - YSR
1. A/D and D/A conversion
Any band-limited random process can be completely represented by its samples (A/D) and the original process can be completely reconstructed (D/A) with the samples. (See lecture note 2-18) So, in digital communi
EE 230B Final Examination, Winter 2008 UCLA Electrical Engineering Department Prof. G. Pottie
NAME:_
Instructions: Attempt all five questions; they are of equal weight but not necessarily of equal difficulty. A sheet of useful formulae and other facts is
CS 118 Computer Network Fundamentals Purpose and content of the course: In this course we study the way a Computer Communications Network such as the Internet works. Namely, we investigate the building blocks required to make the Network work correctly an
EE 230B Digital Communications
Instructor
Gregory Pottie E-mail: pottie@ee.ucla.edu Office: 56-147G Engr. IV Office hours: Mon./Thur. 5-6 PM (Tentative)
TA
Seung Yang E-mail: ryanyang@ucla.edu Office: 3551G Boelter Hall Office hours: Thur. 8PM, Sat 11AM o
EE 231E Channel Coding Instructor: Rick Wesel 82+10 pts, 110 minutes
Spring 08 Midterm Tuesday, May 6, 2008
SOLUTIONS:
1. (10 pts) Proof of Singleton. State and prove the Singleton Bound: Solution: The Singleton bound states that dmin n k + 1. The proof i
(e) (4 pts) Compute an upper bound on the probability of error Pe for this code on the binary symmetric channel with probability of error p = 104 . You may assume that 1 104 1 dT (W, I ) dI
Pe =
I =1,W =
(8)
4p(1p)
W 3 (1 IW ) + IW 4 (1 IW )2 W 3 IW 4 + I
Simulating Digital Communication Systems
Digital communication systems are always simulated via a discrete, baseband equivalent model of the passband continuous time system. That is, we consider a system where the carrier is removed by means of a complex
CS 118 Winter 05 Midterm Prepared by: M Gerla and Johnny Tsao Revised by: M Gerla and Daeki Cho
1. TCP properties 15 pts Which properties does TCP share with Go-Back-N, and which does it share with Selective Repeat? Give at least one property in each cate
EE 230B Quiz 3 Solution Spring 2009 UCLA Electrical Engineering Department Prof. G. Pottie Consider the following channel: z-1 2-1/2 X 2-1/2 X To this is added AWGN with variance N0= 0.01. a) Determine and sketch the folded spectrum. Why would linear equa
EE 230B Quiz 3, Spring 2008 Solutions Prof. G. Pottie 1 1 1 + z: For the channel f ( z) = 2 2 z-1 1/ 2 X 1/ 2 1/ 2
X
a) Show X (e jT ) = 1 + cos T . Why is this channel problematic? Solution: Since this is a minimum phase channel (no precursors), we can
Quiz 2 Solution Spring 09
EE230B Prof. Greg Pottie
1
a) Error Probability for BPSK
For binary PSK, s (t ) = E1 (t ), s2 (t ) = E1 (t ), 1 where 1 (t ) = 2 /T cos(2 f t ), 0 t T c Signal space: E E
Error probability:
+1 -1
2E P (e) = Q N0
X X
dt
T
+1 -1
Quiz 1 Solutions
EE230B Prof. Greg Pottie
1
2
s2 s1
(a) 4-QAM
1
s3
s4
May alternatively replace correlators with matched filters.
X
In phase bits X
dt
T
1(t)
X Quadrature bits
1(t)
X
dt
T
2(t)
Modulator
2(t)
Demodulator
EE230B Prof. Greg Pottie 2
(b) 4