valliammai engineering college semester/ec6651...4. i) draw the block diagram for generation and...
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EC6651 CE_Qbank_2017-18(Even) VI Sem_EEE G.Saravanan_M.A.Seenivasan
VALLIAMMAI ENGINEERING COLLEGE
SRM Nagar, Kattankulathur – 603 203
DEPARTMENT OF
ELECTRONICS AND COMMUNICATION ENGINEERING
QUESTION BANK
VI SEMESTER
EC6651 Communication Engineering
Regulation – 2013
Academic Year 2017 – 18
Prepared by
Mr. G.Saravanan, Assistant Professor/ECE
Mr. M.A.Seenivasan, Assistant Professor/ECE
EC6651 CE_Qbank_2017-18(Even) VI Sem_EEE G.Saravanan_M.A.Seenivasan
VALLIAMMAI ENGINEERING COLLEGE
SRM Nagar, Kattankulathur – 603 203.
DEPARTMENT OF ELECTRONICS & COMMUNICATION ENGINEERING
QUESTION BANK SUBJECT : EC6651 Communication Engineering
SEM / YEAR : VI/ III Year B.E EEE.
UNIT I - ANALOG COMMUNICATION
AM – Frequency spectrum – vector representation – power relations – generation of AM –
DSB, DSB/SC, SSB, VSB AM Transmitter & Receiver; FM and PM – frequency spectrum –
power relations: NBFM & WBFM, Generation of FM and DM, Armstrong method &
Reactance modulations : FM & PM frequency.
PART - A
Q.No Questions BT
Level
Competence
1. State the need for modulation. BTL 1 Remembering
2. Define the modulation index of FM. BTL 1 Remembering
3. Draw the frequency spectrum of AM. BTL 1 Remembering
4. Tell about amplitude modulation? BTL 1 Remembering
5. Recall sensitivity of radio receiver? BTL 1 Remembering
6. What is super heterodyne receiver? BTL 1 Remembering
7. Obtain the relationship between phase and frequency
modulation. BTL 2 Understanding
8. Mention the advantages and disadvantages of SSB
transmission.
BTL 2 Understanding
9. Summarize modulation coefficient and percent modulation. BTL 2 Understanding
10. Describe the envelope of AM waveform and its significance? BTL 2 Understanding
11. A carrier signal with power of 40 watts is amplitude
modulated by a sinusoidal signal. Calculate the power of the
modulated signal if the modulation index is 0.7.
BTL 3 Applying
12. Interpret pre-emphasis? How is it used to improve the signal
to noise ratio of the FM transmission? BTL 3 Applying
13. When a super heterodyne receiver is tuned 555 kHz, its local
oscillator provides the mixer with an input at 1010 kHz.
Calculate the image frequency.
BTL 3 Applying
14. Compare AM and FM. BTL 4 Analysing
15. Explain Carson’s rule of FM bandwidth. BTL 4 Analysing
EC6651 CE_Qbank_2017-18(Even) VI Sem_EEE G.Saravanan_M.A.Seenivasan
16. A 107.6 MHz carrier is frequency modulated by a 7 kHz sine
wave. The resultant FM signal has a frequency derivation of
50 kHz. Analyse the modulation index of the FM wave.
BTL 4 Analysing
17. AM Transmitter radiates 9 kW with the unmodulated carrier
and 10.125 kW when the carrier is modulated. Estimate the
modulation index.
BTL 5 Evaluating
18. An AM transmitter is modulated by three sources of audio
with m1=0.5, m2=0.7, m3=0.4. The unmodulated carrier
power is 50 kW. Predict the modulated power output.
BTL 5 Evaluating
19. The carrier frequency of a broadcast signal is 100 MHz. The
maximum frequency deviation is 75 kHz. If the highest audio
frequency modulating the carrier is limited to 15 kHz,
formulate the approximate bandwidth of the modulating
signal?
BTL 6 Creating
20. One input to a conventional AM modulator is a 500kHz
carrier with an amplitude of 20 Vp. The second input is a
10kHz modulating signal that is of sufficient amplitude to
cause a change in the output wave of 7.5−+ Vp. Determine
Upper, lower sideband frequency and Modulation efficiency.
BTL 6 Creating
PART – B (13 Marks)
1. i) Identify an Expression for the amplitude modulated wave,
its current and power relations. (9)
ii) How would you explain double conversion AM receiver?
(4)
BTL 1 Remembering
2. With the neat circuit diagram explain the operation of round
travis detector and ratio detector. (13) BTL 1 Remembering
3. i) Describe a method of generating of an amplitude modulated
signal and sketch the time domain waveform of message,
carrier and modulated signals. (8)
ii) Name the methods used for suppression of unwanted
sideband in AM transmission? Discuss the working of any
one of them. (5)
BTL 1 Remembering
4. i) Draw the block diagram for generation and demodulation
of a VSB signal and explain the principle of operation.
(8)
ii) How FM is generated with the help of varactor diode?
Explain with the help of neat diagram. (5)
BTL 1 Remembering
5. i) Explain a method of generating a DSBSC using balanced
modulators. (7)
ii) Discuss the principle of AM super heterodyne receiver
with block diagram. (6)
BTL 2 Understanding
6. i) With suitable sketch discuss about Envelope and square law
detector. (7)
ii) Demonstrate high level and low level transmitters. (6)
BTL 2 Understanding
EC6651 CE_Qbank_2017-18(Even) VI Sem_EEE G.Saravanan_M.A.Seenivasan
7. i) Interpret the expressions for narrowband and Wideband FM
wave. (8)
ii) Relate the circuit diagram of FET reactance modulator with
its operation. (5)
BTL 2 Understanding
8. In a FM system the frequency deviation is 1 kHz/V. A
sinusoidal modulating voltage of amplitude 15 V and
frequency 3 KHz is applied. Calculate the maximum
frequency deviation and Modulation index. (13)
BTL 3 Applying
9. Illustrate the Armstrong method of FM generation and
compare NBFM and WBFM. (13)
BTL 3 Applying
10. Analyse the operation of Foster-seeley discriminator with the
Schematic diagram, Vector diagrams for 𝑓𝑖𝑛 = 𝑓𝑜 , 𝑓𝑖𝑛 < 𝑓𝑜
and 𝑓𝑖𝑛 > 𝑓𝑜. (13)
BTL 4 Analysing
11. Discuss two transmitters that generate FM by modulating the
carrier frequency directly. (13) BTL 4 Analysing
12. i) What is Pre-emphasis and De-emphasis? Why it is
required? (5)
ii) Compare the features of FM with AM. Also write the
merits and demerits of FM. (5)
iii) Write notes on PLL FM demodulator. (3)
BTL 4 Analysing
13. A telephone transmitter using AM has unmodulated carrier
output power of 20 kW and can be modulated to a maximum
depth of 80% by a sinusoidal modulating voltage without
causing overloading. Evaluate the value to which
unmodulated carrier power may be increased without
resulting in overloading if the maximum permitted
modulation index is restricted to 60%. (13)
BTL 5 Evaluating
14. Describe the relationship between FM and PM along with
modulation index, Bandwidth requirement and Average
power. (13)
BTL 6 Creating
PART – C (15 Marks)
1. i) Summarize the operation of diode detector in the process of
demodulating of AM Signal. (8)
ii) Discuss the Armstrong method for the generation of FM
Signal. (7)
BTL 5 Evaluating
2. i) Derive the expression for the power calculation in DSB-SC
–AM wave. (8)
ii) A broadcast transmitter radiates 20KW when the
modulation percentage is 75%. Calculate carrier power
and power of each sidebands. (7)
BTL 6 Creating
EC6651 CE_Qbank_2017-18(Even) VI Sem_EEE G.Saravanan_M.A.Seenivasan
3. Construct frequency discrimination method of generating
SSB modulated wave and a method to demodulate it. Discuss
the design issues involved in this method of generation. What
is the cause and effect of phase error in demodulated signal?
(15)
BTL 6 Creating
4. Compare the various analog communication systems with
appropriate waveforms and expressions.
(15)
BTL 5 Evaluating
UNIT II - DIGITAL COMMUNICATION
Pulse modulations – concepts of sampling and sampling theorem, PAM, PWM, PPM, PTM,
quantization and coding: DCM, DM, slope overload error. ADM, DPCM, OOK systems –
ASK, FSK, PSK, BSK, QPSK, QAM, MSK, GMSK, applications of Data communication.
PART - A
Q.No Questions BT
Level
Competence
1. List out the few demerits of DPCM. BTL 1 Remembering
2. Define sampling theorem. BTL 1 Remembering
3. What is the principle of delta modulation? BTL 1 Remembering
4. State Shannon capacity limit BTL 1 Remembering
5. List the primary differences between QPSK and MSK
systems. BTL 1 Remembering
6. What are the elements of digital communication systems? BTL 1 Remembering
7. Outline on quantization error? BTL 2 Understanding
8. Show the difference between coherent and non-coherent
receiver. BTL 2 Understanding
9. Write the advantages of GMSK. BTL 2 Understanding
10. Describe the methods of pulse modulation? BTL 2 Understanding
11. Illustrate the term slope overload noise. BTL 3 Applying
12. Sketch ASK, FSK, PSK signal for the data stream 1101001. BTL 3 Applying
13. How would you explain aliasing? BTL 3 Applying
14. State Nyquist rate and Nyquist interval. BTL 4 Analysing
15. Analyze the advantages of QPSK. BTL 4 Analysing
16. Explain why binary ASK is called on-off keying? BTL 4 Analysing
17. Compare between PAM and PWM. BTL 5 Evaluating
18. Formulate the performance of FSK and PSK based on power
and BW efficiency. BTL 5 Evaluating
EC6651 CE_Qbank_2017-18(Even) VI Sem_EEE G.Saravanan_M.A.Seenivasan
19. Determine the minimum bandwidth for a BPSK modulator
with a carrier frequency of 40 MHz and an input bit rate of
500 kbps.
BTL 6 Creating
20. Can you elaborate on Companding? BTL 6 Creating
PART – B (13 Marks)
1. i) Explain PCM systems with neat diagram. (8)
ii) Evaluate the process of “Companding” and its
Characteristics. (5)
BTL 1 Remembering
2. i) With a neat block diagram, describe the PAM modulation
and demodulation process and develop an expression for
PAM wave. (8)
ii) Compare PAM, PWM and PPM. (5)
BTL 1 Remembering
3. List the advantages of digital carrier system and describe
MSK techniques with neat diagram. (13) BTL 1
Remembering
4. i) Explain in detail the applications of digital modulation
techniques. (7)
ii) Briefly describe the concept of QAM and draw the
constellation diagram of 16 QAM. (6)
BTL 1
Remembering
5. With neat sketch explain the generation of DM signals. State
the drawbacks of DM and suggest a method to correct it. (13)
BTL 2 Understanding
6. i) How does ADM differ from DM, Support your answer
with block diagram and waveform. (6)
ii) Enumerate the generation of PWM wave with neat sketch.
(7)
BTL 2 Understanding
7. Explain with the block diagram QPSK Transmitter and
Receiver. Also analyse about the bandwidth considerations
for QPSK. (13)
BTL 2 Understanding
8. With a neat block diagram, explain BPSK transmitter and
receiver. Also analyse the spectrum and bandwidth
considerations of BPSK. (13)
BTL 3 Applying
9. Explain DPCM with required diagram. How does it differ
from PCM? (13) BTL 3 Applying
10. (i) Describe in detail Frequency shift keying method with
necessary diagrams. (7)
(ii) Discuss GMSK with advantages and disadvantages. (6)
BTL 3 Applying
11. (i) Discuss about the working principle of ASK modulator and
detector with neat diagram. (6)
(ii) What is DPSK? Discuss its operation with the required
diagrams. (7)
BTL 4 Analyzing
EC6651 CE_Qbank_2017-18(Even) VI Sem_EEE G.Saravanan_M.A.Seenivasan
12. i) Analyse modulation and demodulation of PPM? (6)
ii) Tell about uniform quantization, noise and SNR in PCM.
(7)
BTL 4 Analyzing
13. State and prove sampling theorem. Obtain the reconstructed
signal and explain about aliasing? (13) BTL 5 Evaluating
14. (i) Compare between ASK, BPSK, QPSK and FSK digital
modulation techniques. (7)
(ii) Represent QPSK signals in the signal space to find the
distance between the signal points. Give the spectrum of
QPSK signal. (6)
BTL 6 Creating
PART – C (15 Marks)
1. Draw the transmitter and receiver block diagram of Binary
Phase shift keying scheme and compare its error performance
with Binary Frequency Shift keying scheme. (15)
BTL 5 Evaluating
2. i) Explain the QPSK modulation schemes with its
constellation diagram. (10)
ii) Briefly describe the concept of QAM and draw the
constellation diagram of QAM. (5)
BTL 6 Creating
3. i) A data bit sequence consists of the following string of bits
10 11 10 10. Evaluate and draw the nature of waveform
transmitted by BPSK transmitter. (8)
(ii) For an 8 PSK modulator with an input data rate equal to
10 Mbps & a carrier frequency of 70 MHz, measure minimum
double sided Nyquist bw, Baud rate, Sketch the output
spectrum. Judge the results with BPSK & QPSK modulators.
(7)
BTL 5 Evaluating
4. How would you compare the various digital communication
systems? (15) BTL 6 Creating
UNIT III - SOURCE CODES, LINE CODES & ERROR CONTROL
Primary communication – entropy, properties, BSC, BEC, source coding: Shannon Fano,
Huffman coding: noiseless coding theorem, BW – SNR trade off codes: NRZ, RZ, AMI, HDBP,
ABQ, MBnB codes : Efficiency of transmissions, error control codes and applications:
convolutions & block codes.
PART - A
Q.No Questions BT
Level
Competence
1. What is entropy and give its mathematical equation. BTL 1 Remembering
2. Define source coding. State the significance of source coding. BTL 1 Remembering
3. Draw the NRZ and RZ waveform for the pulse stream
10101011. BTL 1 Remembering
EC6651 CE_Qbank_2017-18(Even) VI Sem_EEE G.Saravanan_M.A.Seenivasan
4. What is BSC? BTL 1 Remembering
5. What is the rule for AMI code? BTL 1 Remembering
6. Name few error control codes. BTL 1 Remembering
7. Why is Huffman code called as minimum redundancy code? BTL 2 Understanding
8. Describe information rate? BTL 2 Understanding
9. Outline the features of convolutional code? BTL 2 Understanding
10. Mention the significance of AMI code BTL 2 Understanding
11. An event has six possible outcomes with probabilities {1/2,
1/4, 1/8, 1/16, 1/32, 1/32}. Solve for the entropy of the system. BTL 3 Applying
12. Interpret how many errors can be detected and corrected by a
(7, 4) Hamming code? BTL 3 Applying
13. Calculate the amount of information if 𝑝𝑘 =1/4. BTL 3 Applying
14. List out the properties of Hamming distance. BTL 4 Analysing
15. Compare block and convolution codes. BTL 4 Analysing
16. Differentiate error detection from error correction. BTL 4 Analysing
17. Evaluate the Hamming distance between the following code
words C1={1,0,0,0,1,1,1} and C2={0,0,0,1,0,1,1}. BTL 5 Evaluating
18. Explain the disadvantages of convolutional codes BTL 5 Evaluating
19. How would you list the main methods used for error control
coding BTL 6 Creating
20. Can you elaborate on syndrome? BTL 6 Creating
PART – B (13 Marks)
1. Enumerate Shannon’s Fano algorithm and Huffman coding
with a suitable example. (13) BTL 1 Remembering
2. Explain convolutional coding with time domain and
transform domain approach. (13)
BTL 1 Remembering
3. i) Brief the properties of entropy. (8)
ii) Describe the BSC and BEC with their channel diagram
and transition matrix. (5)
BTL 1 Remembering
4. Describe about the Viterbi algorithm by showing the possible
path through the trellis of a coder. Assume the state diagram
of any coder. (13)
BTL 1 Remembering
5. Six symbols of the alphabet of discrete memory less source
and their probabilities are given below, S={S0, S1,S2,S3,S4)
P(S)={0.4,0.19,0.16,0.15,0.15}. Code the symbols using
Huffman coding and Shannon Fano coding and compare the
efficiency. (13)
BTL 2 Understanding
EC6651 CE_Qbank_2017-18(Even) VI Sem_EEE G.Saravanan_M.A.Seenivasan
6. Discuss the concept of coding and decoding methods of block
codes with its mathematical frame work and diagram. (13)
BTL 2 Understanding
7. The parity check matrix of a particular (7,4) linear block code
is given by,
[𝐻] = [1 1 11 1 0 1 0 1
0 1 01 0 11 0 0
0 0 1
]
i) Find the generator matrix (G).
ii) List all the code vectors.
iii) What is the minimum distance between code vectors?
iv) How many errors can be detected? How many errors can
be corrected? (13)
BTL 2 Understanding
8. Write short notes on :
i) Code tree, trellis and state diagram for
convolutional encoder. (7)
ii) Sequential decoding for convolutional codes. (6)
BTL 3 Applying
9. The generator matrix for a (6, 3) block codes given below.
Inspect all code vectors of this code.
𝐺 = [1 0 00 1 00 0 1
: 0 1 1: 1 0 1: 1 1 0
] (13)
BTL 3 Applying
10. i) Explain the Bandwidth-SNR trade off of a communication
system. (3)
ii) Plot the output wave form for the bit stream 10011100 on
NRZ, RZ, AMI and split phase. (10)
BTL 4 Analysing
11. i) Compare Linear and Convolution codes. (4)
ii) Analyse the conditions which hamming codes has to
satisfy. (4)
iii) Explain the following terms Code efficiency, Channel
data rate and code rate. (5)
BTL 4 Analysing
12. Explain various digital data formats (line coding techniques)
and compare them. (13)
BTL 4 Analysing
13. 9 i) Write notes on HDBP, ABQ and mBnB. (7)
ii) What is the use syndromes? Explain syndrome decoding?
(6)
BTL 5 Evaluating
14. A rate 1/3 convolution encoder has generating vectors as
g1=(1 0 0) , g2=(1 1 1) and g3 = (1 0 1)
i) Sketch the encoder configuration. (7)
ii) Draw the code tree, state diagram and trellis
diagram. (6)
BTL 6 Creating
PART – C (15 Marks)
1. The source of information A generates the symbols {A0, A1,
A2, A3 & A4} with the corresponding probabilities {0.4, 0.3,
0.15, 0.1 and 0.05}. Encoding the source symbols using
binary encoder and Shannon-Fano encoder and compare its
efficiency. (15)
BTL 5 Evaluating
EC6651 CE_Qbank_2017-18(Even) VI Sem_EEE G.Saravanan_M.A.Seenivasan
2. i) Predict the main idea of Source Coding Theorem with
suitable examples. (8)
ii) The binary erasure channel has two inputs and three
outputs. The inputs are labeled 0 and 1, and the outputs are
labeled 0, 1 and e. A fraction α of the incoming bits are erased
by the channel. Measure the capacity of the channel. (7)
BTL 6 Creating
3. Consider a systematic block code whose parity check
equation are P1=m1+m2+m4, P2=m1+m3+m4,
P3=m1+m2+m3, P4=m2+m3+m4 Where mi is the message
digits and Pi are the parity digits.
(i) Evaluate the generator matrix and parity check matrix for
this code. (8)
(ii) Show how many errors can be detected and corrected? If
the received code word is 10101010, find the syndrome.
(7)
BTL 5 Evaluating
4. The generator polynomial of a (15, 11) Hamming code is
given by 𝑔(𝑋) = 1 + 𝑋 + 𝑋2. Design encoder and
syndrome calculator for this code using systematic form.
(15)
BTL 6 Creating
UNIT IV MULTIPLE ACCESS TECHNIQUES
SS&MA techniques : FDMA, TDMA, CDMA, SDMA application in wire and wireless
communication: Advantages (merits)
PART A
Q.No Questions BT
Level Competence
1. List the primary applications of FDMA. BTL 1 Remembering
2. Explain about DSSS technique. BTL 1 Remembering
3. Define Pseudo noise sequence. BTL 1 Remembering
4. List out the merits of TDMA system. BTL 1 Remembering
EC6651 CE_Qbank_2017-18(Even) VI Sem_EEE G.Saravanan_M.A.Seenivasan
5. Explain CDMA technique. BTL 1 Remembering
6. Give out the merits of FDMA system. BTL 1 Remembering
7. Describe near –far problem. BTL 2 Understanding
8. What are the different multiple access techniques BTL 2 Understanding
9. Define multiple access. BTL 2 Understanding
10. Demonstrate about FHSS technique. BTL 2 Understanding
11. Mention the applications of multiple access
techniques in wired communication. BTL 3 Applying
12. Classify SS techniques based on modulation
employed. BTL 3 Applying
13. Brief about SDMA technique. BTL 3 Applying
14. Explain about the working principle of TDMA. BTL 4 Analyzing
15. Describe briefly about FDMA. BTL 4 Analyzing
16. Summarize the application of spread spectrum
modulation. BTL 4 Analyzing
17. Compare TDMA and FDMA. BTL 5 Evaluating
18. Generalize the advantages of SDMA technique. BTL 5 Evaluating
19. Difference between multiple access and
multiplexing. BTL 6 Creating
20. Give the advantage of CDMA system. BTL 6 Creating
PART –B (13 Marks)
1. (i) Distinguish between FDMA and TDMA
technique. (8)
(ii) Explain the application of CDMA in wireless
communication. (5)
BTL 1 Remembering
2. State the need for spread spectrum modulation and
explain its operation with neat block diagram. (13) BTL 1 Remembering
3. List out various multiple access techniques and
explain any two in detail. (13) BTL 1 Remembering
4. Explain the principle of operation of direct
sequence spread spectrum with its noise
performance parameters. How pseudo noise is
generated? (13)
BTL 1 Remembering
5. With neat block diagram explain the frequency
division multiple access technique. Discuss its
application in communication. (13)
BTL 2 Understanding
EC6651 CE_Qbank_2017-18(Even) VI Sem_EEE G.Saravanan_M.A.Seenivasan
6. What is Code Division Multiple Access technique
in detail and mention its merits and demerits. (13) BTL 2 Understanding
7. Explain the principle of operation of FHSS with
necessary diagrams. (13) BTL 2 Understanding
8. (i) How is interference avoided by using code
division multiplexing? Explain. (7)
(ii) What is the role of SDMA in wireless
communication? (6)
BTL 3 Applying
9. (i) Compare the performance of TDMA, FDMA
and CDMA. (8)
(ii)Describe briefly about the applications of SS
modulation. (5)
BTL 3 Applying
10. Describe in detail SDMA and explain how it works
in wireless communication systems. (13) BTL 4 Analyzing
11. Illustrate the operation of a typical TDMA system
with neat block diagram. And compare it with
FDMA. (13)
BTL 4 Analyzing
12. Demonstrate how TDMA is used in mobile
communication. (13) BTL 4 Analyzing
13. Draw the block diagram and explain in detail the
model of spread spectrum digital communication
system. (13)
BTL 5 Evaluating
14. Classify SS modulation technique based upon the
operating concept and explain in detail DSSS and
FHSS. (13)
BTL 6 Creating
PART – C (15 Marks)
1. i) Validate the properties of Pseudo noise
sequences. (5)
ii) Summarize the direct sequence spread spectrum
techniques with neat block diagram. (10)
BTL 5 Evaluating
2. i) A spread spectrum communication system is
characterised by the following parameters
Tb=4.09ms, Tc=1µs. Propose the processing gain
and jamming margin if Eb/N0=20 and the average
probability of error Pe=0.5×10-5. (5)
ii) A PN sequence generator using a feedback shift
register of length 4. If the chip rate is 108 chips/sec.
Calculate the chip and PN sequence duration. (5)
iii) A slow FH/MFSK system has the following
paramters: The number of bits/MFSK symbol=4,
The number of MFSK symbol per hop =10.
Estimate the processing gain in dB. (5)
BTL 6 Creating
3. i) In the AMPS system, the system bandwidth is
12.5mHz, the channel spacing is 30KHz, and the
edge guard spacing is 10KHz. The number of
BTL 5 Evaluating
EC6651 CE_Qbank_2017-18(Even) VI Sem_EEE G.Saravanan_M.A.Seenivasan
channel allocated for control signalling is 21.
Evaluate
a) The number of channels available for message
transmission.
b) Spectral efficiency of FDMA. (8)
ii) If a normal GSM time slot consists of six trailing bits,
8.25 guard bits 26 training bits, and two traffic bursts of
58 bits of data, find the frame efficiency? (7)
4. Discuss in detail the multiple access techniques that
are used in wireless communications. What
difference is taken into account here as the channel
is now wireless? (15)
BTL 6 Creating
UNIT V SATELLITE, OPTICAL FIBER – POWERLINE, SCADA
Orbits : types of satellites : frequency used link establishment, MA techniques used
in satellite communication, earth station; aperture actuators used in satellite –
Intelsat and Insat: fibers – types: sources, detectors used, digital filters, optical link:
power line carrier communications: SCADA
PART A
Q.No Questions BT
Level
Competence
1. What are the essential components of a satellite
system? BTL 1 Remembering
2. State snells law. Give the significance in optics. BTL 1 Remembering
3. Explain about SCADA. BTL 1 Remembering
4. What are the types of optical fiber available? BTL 1 Remembering
5. Expand and define EIRP. BTL 1 Remembering
6. Define geosynchronous satellite. BTL 1 Remembering
7. Write the difference between optical fiber cable and
RF cable BTL 2 Understanding
8. Compare the advantages and disadvantages of
geosynchronous satellite BTL 2 Understanding
9. Distinguish between single mode and multimode
fibers BTL 2 Understanding
10. Give the primary advantages of optical fiber systems BTL 2 Understanding
11. Calculate the critical angle of a fiber with n1=
1.4917and n2 =1.4894. BTL 3 Applying
12. Illustrate the applications of geostationary satellite BTL 3 Applying
13. Specify uplink and downlink frequency for satellite
communication BTL 3 Applying
14. Analyze the differences between LASER and LED BTL 4 Analyzing
EC6651 CE_Qbank_2017-18(Even) VI Sem_EEE G.Saravanan_M.A.Seenivasan
15. Point out the types of sources and detectors in optical
communication systems. BTL 4 Analyzing
16. Explain the multiple access technique in satellite BTL 4 Analyzing
17. Explain apogee and perigee BTL 5 Evaluating
18. Estimate the acceptance cone angle for an optical fibre
with core and cladding refractive index of n1=1.48 and
n2=1.46 respectively.
BTL 5 Evaluating
19. Formulate the expression for the term numerical
aperture BTL 6 Creating
20. Write the expression of path loss L of satellite
communication system in dB. BTL 6 Creating
PART –B (13 Marks)
1. (i) Describe the principle of operation of power line carrier communication-SCADA. (7)
(ii) Explain various types of losses in optical fibre. (6)
BTL 1 Remembering
2. Explain various light generating and detecting systems
in a fibre optic communication. (13) BTL 1 Remembering
3. (i) Illustrate Kepler’s law and how they relate to
satellite communication. (7)
(ii) Illustrate the significance of satellite link budgets
and how they are calculated. (6)
BTL 1 Remembering
4. (i)Identify the various blocks and its functionalities of a fibre optic communication system. (8)
(ii)State advantages of Fiber optic communication. (5)
BTL 1 Remembering
5. Classify the multiple access techniques in satellite
Communication. (13) BTL 2 Understanding
6. (i) Explain with the block diagram of a satellite earth
station. (7)
(ii) Explain in detail about the aperture actuators used
in satellites. (6)
BTL 2 Understanding
7. Write short notes on
(i) Satellite Sub system. (5) (ii) Satellite frequency allocation and reuse
concept. (5) (iii) Digital filters. (3)
BTL 2 Understanding
8. Estimate the uplink and downlink model of satellite
communication system. (13) BTL 3 Applying
9. (i) Explain the principle of light propagation in fibre
along with NA. (8)
(ii)What is dispersion? Explain various types of
dispersion in fibres. (5)
BTL 3 Applying
10. Explain the concept of geostationary earth orbit, its
advantages, limitations and applications. (13) BTL 4 Analysing
EC6651 CE_Qbank_2017-18(Even) VI Sem_EEE G.Saravanan_M.A.Seenivasan
11. (i) Define index profile for the optical fibre and explain
various types of fibre (8)
(ii) Draw the block diagram and explain optical fibre link budget. (5)
BTL 4 Analysing
12. (i) Elaborate the concept of geostationary satellite and
brief about INTELSAT and INSAT. (7)
(ii) Explain briefly the modulation techniques for
satellite links. (6)
BTL 4 Analysing
13. A multimode step index fibre with a core refractive
index of 1.4917, core diameter of 60 um and
normalized frequency =12 at wavelength of 1.3um.
Calculate NA, relative index difference, critical angle
and total number of guided modes. (13)
BTL 5 Evaluating
14. (i) What are the modes of operation suggested in
optical fibres? How are optical fibres classified
according to this? Discuss elaborately. (9)
(ii) The numerical aperture NA for a fibre is 0.352 and
it has a core diameter of 50um and used at light of
wavelength of 0.8um. Determine the V-number,
number of modes in step index and graded index fibre
(where alpha is 2). (4)
BTL 6 Creating
PART – C (15 Marks)
1. i) Summarize in detail, a satellite communication
system. Also list out typical frequency spectrum used
in this communication. What is the relation between
the uplink frequency and the downlink frequency in a
satellite link? Which one is higher? Why? (10)
ii) Describe the technique of SCADA. (5)
BTL 5 Evaluating
2. Draw the block diagram of satellite communication
system and derive the link equations. (15) BTL 6 Creating
3. Briefly elaborate about optical sources such as LED
and Laser Diode. (15) BTL 5 Evaluating
4. I
)
i) Discuss about a fiber optic communication system.
State the major merits of an optical fiber systems. If
there are so many compelling reasons for opting this
type of communication, why is it not used
everywhere? (10)
ii) Formulate the optical fibers based on the material
used and profile structure. (5)
BTL 6 Creating