Download PTU. I.K. Gujral Punjab Technical University (IKGPTU) M.Tech. ECE 1st Semester 74148 ADVANCED COMMUNICATION SYSTEM Question Paper.

1 | M-74148 (S9)-1895
Roll No. Total No. of Pages : 02
Total No. of Questions : 08
M.Tech. (ECE) (2016 Batch) (Sem.?1)
Subject Code : MTEC-103
M.Code : 74148
Time : 3 Hrs. Max. Marks : 100

INSTRUCTIONS TO CANDIDATES :
1. Attempt any FIVE questions out of EIGHT questions.
2. Each question carries TWENTY marks.

1. a) Assume that the input to a DM is 0.lt
8
? 5t+ 2 .The step size of the DM is 1V. The
sampler operates at 10 samples/s. Sketch the input waveform, the delta modulator
output and the integrator output over a time interval of 0 to 2 s. Denote the Granular
noise and slope over load regions. 15
b) Draw and explain Block diagram of Digital Communication System. 5
2. a) For
4
?
QPSK signaling, Calculate the carrier phase shifts when the input data stream
is 10110100101010, where the left most bits are first applied to the transmitter. Find
the absolute band width of the signal if r = 0.5 raised cosine -roll off filtering is use
and the data rate is 1.5 Mbits/s. 10
b) A CDMA mobile measures the signal strength from the base as ?100 dBm. What
should the mobile transmitter power be set to as a first approximation 5
c) How does GSM handle handoff requests from base to mobile? 5
3. a) Explain the Architecture of optical transport network. 10
b) Describe what a Satellite link budget is and how it is used? 10
4. a) An earth station receiving system consist of a 20dB gain antenna with T
AR
= 80K , an
RF amplifier G
a
= 40dB and T
e
= 30K and a down converter with T
e
= 15,000K. What
is the over all Effective input noise temperature of the receiving system? 10
b) Write a note on Link management protocols. 10
5. a) Draw the signal space representation of QPSK and BPSK signals. 10
b) Draw QPSK wave forms for the Binary sequence 00110100. 10
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1 | M-74148 (S9)-1895
Roll No. Total No. of Pages : 02
Total No. of Questions : 08
M.Tech. (ECE) (2016 Batch) (Sem.?1)
Subject Code : MTEC-103
M.Code : 74148
Time : 3 Hrs. Max. Marks : 100

INSTRUCTIONS TO CANDIDATES :
1. Attempt any FIVE questions out of EIGHT questions.
2. Each question carries TWENTY marks.

1. a) Assume that the input to a DM is 0.lt
8
? 5t+ 2 .The step size of the DM is 1V. The
sampler operates at 10 samples/s. Sketch the input waveform, the delta modulator
output and the integrator output over a time interval of 0 to 2 s. Denote the Granular
noise and slope over load regions. 15
b) Draw and explain Block diagram of Digital Communication System. 5
2. a) For
4
?
QPSK signaling, Calculate the carrier phase shifts when the input data stream
is 10110100101010, where the left most bits are first applied to the transmitter. Find
the absolute band width of the signal if r = 0.5 raised cosine -roll off filtering is use
and the data rate is 1.5 Mbits/s. 10
b) A CDMA mobile measures the signal strength from the base as ?100 dBm. What
should the mobile transmitter power be set to as a first approximation 5
c) How does GSM handle handoff requests from base to mobile? 5
3. a) Explain the Architecture of optical transport network. 10
b) Describe what a Satellite link budget is and how it is used? 10
4. a) An earth station receiving system consist of a 20dB gain antenna with T
AR
= 80K , an
RF amplifier G
a
= 40dB and T
e
= 30K and a down converter with T
e
= 15,000K. What
is the over all Effective input noise temperature of the receiving system? 10
b) Write a note on Link management protocols. 10
5. a) Draw the signal space representation of QPSK and BPSK signals. 10
b) Draw QPSK wave forms for the Binary sequence 00110100. 10
2 | M-74148 (S9)-1895
6. a) Explain frequency reuse and cell splitting in mobile radio. Why they are required?
10
b) Write a note on Digital transmission and transmission impairments. 10
7. a) A PCS cellular site base station operates with 10W into an antenna with 18 Db gain at
1800 MHz the path loss reference distance is d
0
= 0.25 miles, X
dB
= 0 and PCS
antenna has 0 dB gain. Find the received power in dBm at the output of the base
station antenna where PCS phone when the PCS phone is located at distance of
1 mile, 2 miles, 5 miles and 10 miles from BS if the path loss exponent is n = 2,
n = 3,n = 4. 10
b) What is meant by a logical channel and how is the control channel divided into
logical channels in TDMA system? 10
8. Write a note on following :
a) SONET 10
b) VSAT 10

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