Download GTU (Gujarat Technological University) BE/BTech (Bachelor of Engineering / Bachelor of Technology) 2019 Summer 6th Sem New 2163206 Analog And Digital Communication Ict Previous Question Paper
Seat No.: ________ Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE - SEMESTER ?VI(NEW) ? EXAMINATION ? SUMMER 2019
Subject Code:2163206 Date:16/05/2019
Subject Name:Analog and Digital Communication (ICT)
Time:10:30 AM TO 01:00 PM Total Marks: 70
Instructions:
1. Attempt all questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
MARKS
Q.1 (a) Explain General Communication System with Block Diagram. 03
(b) Derive Mathematical Representation of Amplitude Modulation and
Explain Signification of Modulation Index with necessary
Waveforms.
04
(c) Write a Short note on Super Heterodyne Receiver. 07
Q.2 (a) Explain CDMA in brief. 03
(b) An Amplifier operating over the Frequency Range from 19 MHz to
22 MHz has a 5 K? input resistor. Using thermal agitation noise
formula, find RMS Noise Voltage and Noise Power at the input to
this amplifier if the ambient temperature is 29?C. Boltzmann?s
Constant k=1.38 x 10
-23
J/K.
04
(c) What are the different methods for Generation of FM Signals?
Explain any one method in detail.
07
OR
(c) Explain the importance of Pre-emphasis and De-emphasis circuits in
FM. Sketch a typical Pre-emphasis and De-emphasis circuit.
07
Q.3 (a) Write a short note on Radio Communication with neat Sketch. 03
(b) State Friss Formula for overall Noise Factor of amplifiers in cascade
and Using Friss Formula, Find Overall Noise Figure of three stage
cascaded amplifier, each stage having a power gain of 10 dB and
noise figure of 5 dB
04
(c) Draw Block diagram of frequency hopping spread spectrum (FHSS)
system and Explain Frequency Hopping with necessary waveforms.
07
OR
Q.3 (a) Give comparison of Wideband and Narrowband FM. 03
(b) Write a short note on Full carriers AM transmitters 04
(c) An AM modulating signal 5*Sin (2? x 200t) is used to modulate a
carrier signal 25*Sin (2? x 25000t). Find modulation index,
percentage modulation, frequencies of sideband components and
their amplitude. Draw the spectrum of AM wave.
07
Q.4 (a) Introduce pulse width modulation. With neat sketch explain
generation of PWM.
03
(b) Derive the formula for the instantaneous value of an FM voltage and
define the modulation index. And draw the waveforms of information
signal and its FM modulated signal.
04
(c) Enlist and compare different digital modulation techniques. 07
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Seat No.: ________ Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE - SEMESTER ?VI(NEW) ? EXAMINATION ? SUMMER 2019
Subject Code:2163206 Date:16/05/2019
Subject Name:Analog and Digital Communication (ICT)
Time:10:30 AM TO 01:00 PM Total Marks: 70
Instructions:
1. Attempt all questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
MARKS
Q.1 (a) Explain General Communication System with Block Diagram. 03
(b) Derive Mathematical Representation of Amplitude Modulation and
Explain Signification of Modulation Index with necessary
Waveforms.
04
(c) Write a Short note on Super Heterodyne Receiver. 07
Q.2 (a) Explain CDMA in brief. 03
(b) An Amplifier operating over the Frequency Range from 19 MHz to
22 MHz has a 5 K? input resistor. Using thermal agitation noise
formula, find RMS Noise Voltage and Noise Power at the input to
this amplifier if the ambient temperature is 29?C. Boltzmann?s
Constant k=1.38 x 10
-23
J/K.
04
(c) What are the different methods for Generation of FM Signals?
Explain any one method in detail.
07
OR
(c) Explain the importance of Pre-emphasis and De-emphasis circuits in
FM. Sketch a typical Pre-emphasis and De-emphasis circuit.
07
Q.3 (a) Write a short note on Radio Communication with neat Sketch. 03
(b) State Friss Formula for overall Noise Factor of amplifiers in cascade
and Using Friss Formula, Find Overall Noise Figure of three stage
cascaded amplifier, each stage having a power gain of 10 dB and
noise figure of 5 dB
04
(c) Draw Block diagram of frequency hopping spread spectrum (FHSS)
system and Explain Frequency Hopping with necessary waveforms.
07
OR
Q.3 (a) Give comparison of Wideband and Narrowband FM. 03
(b) Write a short note on Full carriers AM transmitters 04
(c) An AM modulating signal 5*Sin (2? x 200t) is used to modulate a
carrier signal 25*Sin (2? x 25000t). Find modulation index,
percentage modulation, frequencies of sideband components and
their amplitude. Draw the spectrum of AM wave.
07
Q.4 (a) Introduce pulse width modulation. With neat sketch explain
generation of PWM.
03
(b) Derive the formula for the instantaneous value of an FM voltage and
define the modulation index. And draw the waveforms of information
signal and its FM modulated signal.
04
(c) Enlist and compare different digital modulation techniques. 07
2
OR
Q.4 (a) For FM System, the modulating frequency is 10 KHz and maximum
deviation is 75 KHz Calculate bandwidth of system using Carson?s
Rule.
03
(b) Write short note on latest trends in Digital Communication. 04
(c) Explain working principle of Delta modulation with help of block
diagram. What are the problems associated with Delta Modulation?
07
Q.5 (a) What do you mean by VSB Modulation and Why it is used? 03
(b) For Binary data: 1101001100111001 Draw ASK, FSK and PSK
waveform.
04
(c) Compare Amplitude Modulation, Frequency Modulation and Phase
Modulation.
07
OR
Q.5 (a) State the Advantages and Application of Spread Spectrum
Communication.
03
(b) Explain Pulse Code Modulation with necessary waveforms. 04
(c) What is the difference between Coherent and Non-Coherent
Detection techniques? Discuss Coherent Detection of FSK signal.
07
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This post was last modified on 20 February 2020