This preview shows pages 1–2. Sign up to view the full content.
EE 448 Midterm Exam
March 6, 2007
Name:
ID (last 4 digits):
Score:
Instructions:
This exam is closedbook and closednotes with the exception of an
8
.
5
±±
×
11
±±
crib sheet. You have 2 hours
to complete the exam. Write your name and ID number on all pages of your answers.
Show all work for full credit. Mark
your
ﬁ
nal answers.
Good luck!
1. (40 points) Mixed Problems:
(a) (5 points) Write down the expression of the convolution sum of two sequences
x
[
n
]
and
h
[
n
]
.
(b) (5 points) Write down the de
ﬁ
nition of the DTFT
X
(
e
jω
)
of a sequence
x
[
n
]
,andthede
ﬁ
nition of the inverse
DTFT.
(c) (5 points) What is the energy and average power of
μ
[
n
]
?
(d) (5 points) Is
˜
x
[
n
] = 2 cos(1
.
3
πn
−
0
.
5
π
) + 2 sin(0
.
25
)
a periodic sequence? If yes, what is the fundamental
period?
(e) (15 points) Determine whether the following statements are true or false. Brie
ﬂ
y justify your answer.
i. An absolutely summable sequence has a
ﬁ
nite energy.
ii. System
y
[
n
]=
x
[2
n
]
is timeinvariant.
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
This is the end of the preview. Sign up
to
access the rest of the document.
 Spring '08
 

Click to edit the document details