Download AKTU (Dr. A.P.J. Abdul Kalam Technical University (AKTU), formerly Uttar Pradesh Technical University (UPTU) B-Tech 8th Semester (Eight Semester) 2015-16 EEC 801 Wireless Mobile Communication Question Paper
(Following Paper ID and Roll No. to be ?lled in your
Answer Books)
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B.TECH.
Theory Examination (Semester-VIII) 2015-16
WIRELESS & MOBILE COMMUNICATION
Time : 3 Hours Max. Marks : 100
Section-A
Q1. Attempt all parts. All parts carry equal marks. Write
answer of each part in short. (ZXI0=20)
(a) Find the number of duplex channels, if ZOMHz of total
spectrum is allocated for a duplex Wireless cellular
system and each simplex channel has 25 KHz RF
bandwidth.
(b) What is fading?
(0) Compare the different second generation mobile
communication systems, particularly in terms of multiple
access technology, modulation technique and channel
. Bandwidth.
(1-) P.T.O.
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(d)
(e)
(f)
(g)
(h)
G)
How equalization, channel coding and diversity are
different in link performance improvement?
How call termination can be avoided during handoff?
How scattering is different ?om re?ection with re-
spect to surface?
What is slow fading channel, fast fading channel and
frequency selective channel?
How IMT-2000 is use?il for node to node communica-
don?
Consider a GSM system, which is a TDMA/FDD sys?
tem that uses 20 MHz for forward link which is broken
into radio channels of ZOOkHz and if no guard band is
assumed, ?nd the number of simultanems users that can
be accommodated in GSM.
Write range of frequency for forward and reverse link
operation for 18-95.
(2)
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Section-B
Q2. Attempt any FIVE questions from this section.
(a)
(b)
(C)
(10x5=50)
(1) Name the techniques used to increase the capacity
of a cellular system and compare them.
(i1) Calculate the total available channels for a cellular
system having a total bandwidth 'of 6OMI-Iz which
uses two 50 KHz simplex channel to provide full
duplex voice and control channels. Assume that the
system uses nine cell reuse pattern and lMHz 0f
the total bandwidth is allocated for control chan-
nels. Also calculate the number of control channels
and voice channels per cell.
(i) Show that an equalizer is an inverse ?lter of the
channel.
(ii) Draw the Block diagram of LPG system and
explainit.
Den've an expression for selection diversity improve-
ment in terms of probability of receiving signal using
single branch or using M branches.
(3) BIG.
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(d)
(e)
(f)
(:9
Acellt?arsewicepmviderdecides touseadigitalTDMA
scheme which can tolerate a signal to interference ratio
of 1 MB in the worst case. Find the optimal value of N
for 1) omnidirectional antennas, 2) 120? Secton'ng, and
3) 60? Sectoring. Should sectoring be used? Ifso, which
case should be used? Assume a path loss exponent of
n=4 and consider tmnking e?iciency.
(1) What is small scale mul?path propagation? Discuss
the factors in?uencing small scale fading.
(i1) Prove that in the two ray ground re?ection model,
A = d?1 ? d1 = 2 ht?hr/?d. Show When this hoids
as a good approximation.
(i) What is basic concept of Add-hoc network? Why
and how proper route is required to discuss in
addhoc network?
(i1) Explain in brief 4G technologies and also compare
with 1G, 2G and 3G technology.
(1) Explain various important parametets of power de-
lay pro?le of multipath channel.
(i1) Assume a receiver is located 10 Ian from a 50 W
transmitter. The carrier frequency is 900 MHz, free
(4)
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00
space propagation is assumed, Gt= 1, and GI =
2, ?nd (a) the power at the receiver, (b) the
magnitude of the E-?eld at the receiver antenna.
A cellular architectme is con?gured with regular hexago-
nal cell geometry. The total service area is divided into
cell clusters with frequency reuse. Prove that the dis-
tance (D) between the centers of two closest channel
cells is given by D = R ?1 {3 (i2 +j2 + i x j)}; where
R is the eeil radius, having'same units as D; and i,j are
non-negative integers which describe the geomehy rela-
tion between adjacent cells.
Section-C
Attempt any two questions from this section.
(15X 2=30)
Q3 . (a) How priortizing Handoffs technique is used to decrease
the probability of forced termination of a call due to lack
of available channels?
(b) Discuss Umbrella cell approach with diagram to en-
hance the connectivity in mobile communication.
Q4. (3) Explain signal processing and GSM operations from
speech input to speech output with diagram.
(5) R110.
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(b) Consider a GSM system, which is a TDMA/FDD
systemthatusesZOlV?izforforwaxdlinkwhichisbmken
into radio channels and if no guard band is assumed,
?nd the number of simultaneous users that can be ac-
commodated in GSM.
Q5. (3) Explain various applications and service of Next Gen-
eration Network (NGN).
(13) Draw and explain the component of mobile network
structure of IMT-ZOOO.
(6)
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This post was last modified on 29 January 2020