6.2
Z
3
2
1
+0. 8
7.15
N = 21, C = 0.5
h ' ( n) =
sin(n 10)C
(n 10)
1 0 n 20
w(n) =
otherwise
0
h(n) = h ' (n) w( n)
sin(n 10)C
(n 10)
0
0 n 20
otherwise
8.9
N 2
(c ) 2
H a (S ) =
( S c e
=
3
j
4
)( S c e
0.4225
S2 +
5
j
4
1
T2
0.919
1
S + 0.4225 2
T
T
Week 5&6, DCN section
Data communications
1. Given a channel which information rate is 3 times of signalling rate, how many
different levels (symbols) were used to encode binary data?
C = 3Rx log 2 M log 2 M = 3 M = 8
2. Give a channel of bandwidth of 4 k
Tutorials
Numerical solutions for Week 3&4 tutorial questions
Sinusoids - Time Domain
1. If the period of a sinusoid is (a) 2.5 ms, (b) 800 m s, (c) 30 ns, and (d) 0.125 s,
calculate the frequency in each case.
1
T
f=
(a) T1 = 2.5 ms
(b) T2 = 800 ms f 2 =
Tutorials
Week 8&9, MM section
1.
2.
3.
4.
What is modulation?
Why modulate?
Consider a message signal with a bandwidth of 20 kHz,
1) What is the bandwidth of the DSB-SC modulated signal?
40 kHz
2) What is the bandwidth of the SSB-SC modulated signal?
20
Review for engineering mathematics
Part I. Complex functions
1.Complex numbers
Three types of expressions ,
z = x + iy ,
z = r (cos + i sin ),
z = re
i
Modulus , argument and Argument
Roots of complex numbers (Principal value)
+ 2 k
z = | z | exp
n
1
n
Review outline
Part I. Complex functions
1. Complex numbers
Three types of expressions z = x + iy , z = r (cos + i sin ) , z = re i .
Modulus and argument
Roots of complex numbers
2. Analytic functions
Derivatives (definition, computation)
Sufficient cond
CDMA2000 - one of the important satands
of 3G mobile communication
Mobile
communication
radiocommunication
is
is
actually
born
when
the
invented, but the Mobile communication
industry developed rapidly during the past twenty years. You can see
people usin
As we all know, all the technological development can not be
achieved
overnight.
We
take
the
mobile
communication
development for example,from GSM, GPRS to the fourthgeneration, all of these technologies need to constantly evolve, and
these technologies c
Question 1
Complete the blanks in the following subquestions.
a) The convergence interval of the power series
n
n+1 x
n
is
(-1, 1) .
n= 0
[4 marks]
x , x 0
b) Suppose that f is a periodic function with period 2 and defined by f ( x ) =
,
1, 0 < x <
1
Time allowed:
2 hours
No of qu to be answered
4
Rest of rubric
This paper contains FOUR Questions. ALL Questions must be answered
correctly to achieve full marks.
Question 1 comprises 40 single-choice parts, worth a total of 80 marks and
each 2 marks.
THE
Question 1
1).
A
11).
A
21).
C
31)
C
2).
D
12).
B
22).
B
32)
B
3).
D
13).
D
23).
A
33)
D
4).
B
14).
D
24).
D
34)
B
5).
A
15).
C
25).
C
35)
C
6).
C
16).
C
26).
A
36)
B
7).
A
17).
D
27).
B
37)
C
8).
B
18).
C
28).
D
38)
D
9).
C
19).
D
29).
A
39)
C
10).
B
20)
12/19/2009
Marks shown as
k
r23 3
Surface area of hexagon is S =
2
1
2
7 cell cluster has area 7r7 3 3 but same area as 3cell so:
2
1
2
2
r32
7r7 3 3 3r3 3 3
2
2
or 7r7 3r3 or 2 7 / 3
r
2
2
7
2
Alternative
Cluster radius us given by
(in the notes)
So h
In a simple free-space radio propagation model,
the received signal power is proportional to
1/d4, where d is distance.
Assume that the same area is covered by a 3-cell
cluster or a 7-cell cluster.
Calculate the interfering power from the cochannel cells
Marks shown in notes
If use systematic form by multiplying message by P(x) and get the answer right - accept it but deduct 1 mark
If count third bit from right in error and get it right give full marks
If a message word of 10 bits is to be protected again
Cyclic coding is to be used to encode a message
1011 using a generator polynomial x3+x+1
i) Determine the codeword to be transmitted in a
systematic form.
ii) If the 3rd bit is in error when the codeword is
transmitted calculate the Syndrome that the
deco
Enter the information in the table below, which will be entered into a database to produce the
front page automatically.
Time allowed:
2 hours 30 minutes
No of qu to be answered
Answer any four (4) out five (5) questions
Rest of rubric
Any special require
Joint Programme Degrees
ELB3374 Signals and Systems Theory
Paper A
January 2009 Examinations
02/11/2008 15:02
Time allowed 2hours 30 minutes
Answer FOUR questions only
Examiners
Dr Yue (Frank) Gao
Mr Andy Watson
Copyright Beijing University of Posts and
Page 1
ELE404 (2004)
Enter the information in the table below, which will be entered into a
database to produce the front page automatically.
Time allowed: 2 hours 30 minutes
No of questions to be answered: ALL Questions
Any special requirements for resit
Tutorials
Week 8&9, MM section
Note: Please work out all the problems marked in red.
1. What is modulation?
2. Why modulate?
3. Consider a message signal with a bandwidth of 20 kHz,
1) What is the bandwidth of the DSB-SC modulated signal?
2) What is the b
Tutorials
Week 5&6, DCN section
Work out all the problems marked in red color.
Due: Dec. 30.
Data communications
1. Given a channel which information rate is 3 times of signalling rate, how many
different levels (symbols) were used to encode binary data?
Sample exam questions
in multiple choice format
In the examination, you will have 2.5 hours to attempt 50 questions in a multiple choice format,
and ALL questions must be answered correctly to achieve full marks.
Each question is provided with 4 answers,
BUPT1921 Advanced Mathematics
Time allowed:
No of qu to be answered
Rest of rubric
Is calculator allowed?
Is translation device allowed?
Is an appendix included?
Examiners
2 hours
5
Answer all FIVE questions
No
No
No
Prof. Wenbao AI, Doctor Wenbo Zhang
Pa
Unit 6
Women, Half the Sky
Feminism
In the 1960s feminism, the belief that women and men are equal in
abilities and should enjoy rights and opportunities, became the
subject of intense debate when the womens liberation movement
encourage women to reject t
Unit 2
Values
Values
What Are Values?
The guidelines and beliefs a person uses when confronted with a situation
in which a choice is made.
moral or professional standards of behavior; principles
What Do You Value?
Your personal values are the center of yo
Unit 6
Unit
Animal Intelligence
Animal
What Animals Re ally Think
Eugene Linden
Eugene Linden is an American author of several non-fiction books, he writes about
science, technology, the environment and humanity's relationship with nature in
books, articl
UnitFive
Romance
Marriage vows
*Marriage vows are promises a couple makes to each other during a wedding ceremony.
*Traditional vows (Book of Common Prayer)
*"To have and to hold, from this day forward, for better for worse, for richer for poorer, in
sick