FAQ

DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING

YEAR/SEM

: III / VI

NAME OF THE SUBJECT

: COMMUNICATION ENGINEERING

NAME OF THE FACULTY

: R.HARIHARAN

UNIT I

ANALOG COMMUNICATION

SYLLABUS

( X )AM – Frequency spectrum – vector representation – power relations – generation of AM

– DSB,DSB/SC, SSB, VSB AM Transmitter & Receiver

(Y) FM and PM – frequency spectrum – power relations: NBFM & WBFM, Generation of FM and DM, Amstrong method & Reactance modulations: FM & PM frequency.

PART – A

I X 1. A transmitter radiates 9 KW with the carrier unmodulated and 10.125 KW

when a carrier is sinusoidally modulated. Calculate the modulation index. ( Nov /

Dec 2014)

I X 2. Why is VSB preferred for TV video transmission? (Nov / Dec 2014)

I X 3. State the significance of modulation index. (May / June 2014)

I X 4. Discuss the principle of AM based radio frequency receiver with block diagram. . (Nov / Dec 2013)

I X 5. Draw the frequency spectrum of AM wave. (Nov / Dec 2012)

I X 6. Write down the basic principle used in super heterodyne receivers? (Apr / May

2012)

I X 7. Draw the frequency spectrum of the amplitude modulated signal (Apr / May

2011)

S (t) = 5 cos 2π105 t + 3 cos 2π10 5 t 5cos 2π10 3 t

I X 8. Mention the disadvantages of single sideband transmission. (Nov / Dec 2010)

I X 9. A carrier signal with power of 40 Watts is amplitude modulated by a sinusoidal

signal. Find the power of the modulated signal if the modulation index

0.7. (Nov / Dec 2009)

I X 10. State Carson Rule. (May 2012)

I X 11. Define Modulation and Demodulation? What is the need for Modulation?

I X 12. Calculate the percentage modulation in AM if carrier amplitude is 20V and

modulating signal is 15 V?

I X 13. Mention the disadvantages of single sideband transmission. (Nov 2010)

I X 14. Diagrammatically differentiate Under modulation, Over modulation and Critical

Modulation?

I X 15. What is VSB? Draw its spectrum?

I X 16. Explain a method of generating a single sideband signal using balance

modulators. . (Nov / Dec 2013)

I Y 1. Obtain the relationship between phase and frequency modulation. (M / J 2014)

I Y 2. Find transmission power efficiency for a tone modulated signal when modulation index is 0.5. (Nov / Dec 2013)

I Y 3. Define the modulation index of FM. (Nov / Dec 2013)

I Y 4. Draw and explain the block diagram of Armstrong system of generating FM

signal. (Nov / Dec 2013)

I Y 5. Derive the equation for the spectrum of FM signal. (Nov / Dec 2013)

I Y 6. Mention the advantage and disadvantage of FM. (Nov / Dec 2012)

I Y 7. The carrier frequency of an FM broadcast transmission is 100 MHZ and

maximum frequency deviation is 75 KHZ. Find the Bandwidth of the signal

when the highest audio frequency modulating the carrier is 15 KHZ. (Nov /

Dec 2010)

I Y 8. State the advantages of FM over AM. (Nov / Dec 2009)

I Y 9. Compare NBFM and WBFM. (Nov 2011) (May 2013)

I Y 10. What is Deviation ratio?

I Y 11. Define percent modulation for angle modulation?

I Y 12. What is image frequency?

PART – B

I X 1. Name the methods used for the suppression of unwanted side band in AM

transmission? Discuss the working of any one of them. (Nov / Dec 2014) (10)

I X 2. Explain the working of a SSB transmitter and receiver. (May / June 2014)(16)

I X 3. Explain a method of generation of an amplitude modulated signal and sketch the

time domain waveform of message, carrier and modulated signals. (12) (Apr /

May 2011)

I X 4. Derive the power relationship of Amplitude modulated signal. (Apr / May 2011)(12)

I X 5. A carrier wave of 10 MHZ is amplitude modulated to 50% level with a tone of

5000 HZ. Sketch the waveform and amplitude distribution in time and frequency

domain. Assume carrier amplitude as 10 V. (8) (Nov / Dec 2010)

I X 6. Draw the block diagram for generation and demodulation of a VSB signal and explain the principle of operation. (16) (Nov / Dec 2010)

I X 7. With suitable sketch discuss about square law detector.(8)

I X 8. What is meant by image frequency rejection? Calculate the image frequency at

1000 KHz, for an AM receiver. (6) (Nov / Dec 2009)

I X 9. What are the advantages of SSB technique? Explain any one method of generation of SSB generation? (May 2012)(Nov 2013)(10)

I X 10. Explain the envelope detector circuit used for AM demodulation. (Nov / Dec

2009) (8)

I X 11. A sinusoidal modulating frequency is modulated with carrier frequency having a peak voltage of 8V. The output is connected to a 5K Ω load. Determine (16)

1. Power of the carrier

2. Power of each sideband

3. Power in both Sidebands

4. Total Power

5. Efficiency of the modulator

For each of the following modulation indices: m = 0.25, 0.5, 0.75, 1.

I X 12. For an AM – DSBFC modulator with a carrier frequency fc = 100 KHZ and a

maximum modulating signal frequency fm (max) = 10 KHZ, Determine,

(i) Frequency limits for upper and lower side bands. (16)

(ii) Bandwidth.

(iii) Upper and lower side frequencies produced when the modulating signal is a

single – frequency 3 KHZ tone.

(iv) Draw the output frequency spectrum. ( Apr / May 2015)

I Y 1. Compare the features of FM with AM. Also write the merits and demerits of FM. (Nov / Dec 2014) (6)

I Y 2. Discuss the Armstrong method of FM generation. (Nov / Dec 2014) (12)

I Y 3. Explain in detail Armstrong method of FM generation and compare NBFM and

WBFM. (Nov / Dec 2012) (16)

I Y 4. Explain the direct and indirect method generation of FM signal. (16)(May / June

2014)

I Y 5. Explain the generation of frequency modulated signal using reactance modulation scheme with neat diagram. (8) (Apr / May 2011)

I Y 6. Describe the relationship between FM and PM. (6)(Apr / May 2011)

I Y 7. Derive the mathematical expression for the FM and PM waves?(8)

I Y 8. Explain the generation of frequency modulated signal using reactance modulation

scheme with neat diagram. (8)(May 2011)

I Y 9. Explain the operation of Foster – Seeley discriminator with the following. (16) (Apr / May 2015)

(i) Schematic diagram

(ii) Vector diagrams for fin = fo, f in < fo, f in > fo,

QUESTION BANK

DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING

YEAR/SEM

: III / VI

NAME OF THE SUBJECT : COMMUNICATION ENGINEERING

NAME OF THE FACULTY

: R.HARIHARAN

UNIT II

DIGITAL COMMUNICATION

SYLLABUS

( X ) Pulse modulations – concepts of sampling and sampling theorems, PAM, PWM, PPM,

PTM, quantization and coding : DCM, DM, slope overload error. ADM, DPCM,

(Y) OOK systems – ASK, FSK, PSK, BSK, QPSK, QAM, MSK, GMSK, applications of Data communication.

PART A

II X 1. State sampling theorem (May/Jun 2014)(Nov/Dec 13)

II X 2. What is the principle of delta modulation (Nov/Dec 13)

II X 3. What is meant by slope overload distortion (May 2013) (May/Jun12)

II X 4. Define Quantization error. (May 2013)

II X 5. What is aliasing (May/Jun12) (May 2011) (Nov 2011)

II X 6. State Sampling Theorem and Nyquist rate? (Nov 2012)

II X 7. What is aliasing?

II X 8. What are the effects of under sampling and what are the ways to avoid Aliasing?

II X 9. Compare PCM, DM, ADM ,DPCM.

II X 10. Compare PAM, PPM, PDM

II X 11. Explain companding and its type?

II X 12. What is uniform Quantization and Non uniform quantization?

II X 13. For a PAM transmission of voice signal with W=3KHz.Calculate Bandwidth if

fs=8KHZ and τ=0.1Ts.

II X 14. List any two advantages and limitations of DPCM

II X 15. Define slope overload noise and granular noise in Delta modulation.

II X 16. What is the principle of ADM?

II X 17. Consider an audio signal em(t)=2cos(1000πt).Find the signal to noise ratio when

the signal is quantized to 8 bits.

II X 18. State Shannon’s capacity theorem.

II X 19. Two different message signals each of bandwidth 10 KHz are to be

multiplexed and transmitted. Determine the minimum bandwidth required for

PAM/TDM system.

II X 20. Give the difference between coherent and non coherent receiver.

II X 21. Explain slope overload error in delta modulation. (Nov 2011) (May 2013)

IY 1. Compare MPSK and MFSK modulation techniques with respect to their probability

of error and bandwidth. (May/Jun 2014)

I Y 2. Why FSK is preferred over ASK? Give reasons.(May 2013)

I Y 3. Define PSK. (Nov 2012)

I Y 4. How is PPM obtained from PWM? (May 2011)

I Y 5. What are the elements of digital communication system? (Nov 2010)

I Y 6. How does the phase of carrier vary for the message m (n) = {1,0,1,1,0,1,...}? (Nov 2010)

I Y 7. Why is binary ASK is called on-off keying?

I Y 8. What is Quadrature phase shift keying?

I Y 9. Give the difference between coherent and non-coherent receiver

I Y 10. Define Coding efficiency

IY11.Compare the performance of FSK and PSK based on power and bandwidth efficiency

IY12. What is MSK for a bit sequence of 1011010101? Show that MSK waveform has

phase continuity.

I Y 13. Compare MSK and QPSK

I Y 14. Compare different digital modulation techniques.

I Y 15. Explain bit rate, signalling rate, baud rate.

I Y 16. Compare QPSK and QASK.

PART B

II X 1. Explain the working of a delta modulation system (8) (May/Jun 2014)

IIX 2. Derive the expressions for quantisation noise in PCM and DM systems (8)

(May/Jun 2014)

II X 3. Discuss the generation method of PWM. Explain how you will convert PWM to

PPM with diagram (6) (Nov/Dec 13)

II X 4. Explain a pulse code modulation system with its block diagram (10) (Nov/Dec 13)

IIX 5. Explain the generation of and demodulation of PWM wave and explain the advantage

of PTM.(16) (Nov 2011) (May 2013)

IIX 6. Explain DPCM technique with neat block diagram. For minimum line speed with

an 8 bit PCM for speech signal ranging upto 1 volt. Calculate the resolution and

quantisation error. Calculate the coding efficiency for a resolution of 0.01volt with the

8 bit PCM(16)(May 2013)

II X 7. State and prove sampling theorem (8)(May/jun 2012) (Nov 2011)

II X 8. Explain the generation and PWM and PPM waves (8)(May/jun 2012)

II X 9. Compare PCM and DM (6) (May/june 2012)

II X 10. What is meant by quantization? Explain in detail DPCM communication system

(16) (Nov 2012)

II X 11. Compare PCM and DM.(6)

II X 12. How do you achieve PPM from PDM? (4)

II X 13. Describe pulse code modulation Scheme and draw the waveforms.(8)

II X 14. Explain Delta modulation with suitable waveforms.(8)

II X 15. Explain quantization noise in PCM system. How can it be reduced.(6)

II X 16. Explain the PCM transmission and reception with block diagrams. (10)

II X 17. Explain the generation and noise performance of delta modulation.(10)

II X 18. Explain the working of PWM constructed using monostable multivibrator. Give

circuit diagram.(8)

II X 19. With neat sketch Explain the generation of Delta Modulated signal and derive the expression for SNR. (10) (May 2011)

II X 20. State the drawbacks of DM and suggest a method to overcome it. (6)(May 2011)

II X 21. With a neat block diagram explain the PAM modulation and demodulation

process and derive an expression for PAM wave and depth of modulation. (12)(Nov

2010)

II Y 1. Explain the operation of a QPSK receiver and derive the expression for its bit error probability (10)(May/Jun 2014)

II Y 2. Explain Frequency shift Keying method with equations (8)(Nov/Dec 13)

II Y 3. Discuss the method of modulation and demodulation in MSK with equations and block diagram (8)(Nov/Dec 13)

II Y 4. .Explain the concept of BPSK and QPSK techniques in data communication

(10)(May/jun 2012)

II Y 5. Discuss the advantage of data Communications and explain QPSK and QAM techniques with neat diagram.(16) (Nov 2012)

II Y 6. Explain the concept of BPSK and QPSK technique in date communication.(8) (Nov

2011)

II Y 7. Bandwidth of the input pulse code modulator is restricted to 4KHZ.The signal varies from -3.8V to3.8 V and has the average power of 30mW.The requires SNR is

20 dB. The modulator produces binary output. Find (8)

i) Number of bits required per sample.

ii) Output of 30 such PCM codes are time multiplexed signal.

b. What is the minimum required transmission bandwidth for the multiplexed signal

II Y 8. Draw the block diagram of a BPSK /QPSK/ASK transmitter and receiver. Explain the same digital modulation scheme with constellation diagram (16)

II Y 9. Explain the working of FSK modulator and demodulator and with the signal

constellation diagram (16)

II Y 10. Explain Transmitter and receiver arrangement for MSK (12)

II Y 11. For the binary data transmission obtain the expressions and waveforms for ASK,

FSK ,PSK schemes.(16)

II Y 12. Explain the relationship between the minimum bandwidth required for FSK system and the bit rate, the mark and space frequencies.(6)

II Y 13. Explain the QPSK modulation schemes with its constellation diagram .(10) (May

2011)

II Y 14. Briefly describe the concept of QAM and draw the constellation diagram of 16 QAM. (12)(May 2011)

II Y 15. Explain working principle of ASK modulator and detector with neat diagram.

(12)(Nov 2010)

II Y 16. Draw ASK, FSK, PSK signal to transmit the data stream 1111000111.

(4)(Nov 2010)

QUESTION BANK

DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING

YEAR/SEM

: III / VI

NAME OF THE SUBJECT

: COMMUNICATION ENGINEERING

NAME OF THE FACULTY

: R.HARIHARAN

UNIT III

SOURCE CODES, LINE CODES & ERROR CONTROL (Qualitative only)

SYLLABUS

( X ) Primary communication – entropy, properties, BSC, BEC, source coding : Shaum, Fao, Huffman coding : noiseless coding theorem,

(Y) BW – SNR trade off codes: NRZ, RZ, AMI, HDBP, ABQ,

MBnBcodes : Efficiency of transmissions, error control codes and applications: convolutions & block codes.

PART A

III X 1. A source transmits messages Q1 to Q5 having probabilities ½, 1/4, 1/8, 1/16,

1/16 respectively. Calculate the average information of the source(May/Jun 2014)

III X 2. Why is Huffman code called as minimum redundancy coding? (May/Jun 2014)

III X 3. State the significance of source coding. (May 2013)

III X 4. Define entropy. (May 2011) (May 2012)

III X 5. What is information rate? (Nov 2011)

III X 6. An event has six possible outcomes with probabilities {1/2, 1/4, 1/8, 1/16, 1/32, 1/32}. Find the entropy of the system. (Nov 2010)

III X 7. What is average information or entropy

III X 8. Calculate the capacity of the BSC

III X 9. What is coding efficiency

III X 10. State Shannon’s theorem on channel capacity

III X 11. What is BSC and BEC?(Nov/Dec 2013)

IIIY 1. What is the rule for AMI code? (Nov/Dec 2013)

III Y 2. For a 12-bit data string of 1011 0001 0010, determine the number of hamming bits

required. (Nov 2012)

III Y 3. Compare block and convolution codes. (Nov 2012)

III Y 4. Draw the NRZ signaling format of given binary sequence 1101001. (May 2011)

III Y 5. Draw the NRZ and RZ waveforms for the pulse stream 10101011. (May 2012)

III Y 6. Mention the significance of AMI code. (Nov 2011)

III Y 7. For an AWGN channel with 4 KHZ bandwidth and noise power spectral density

N0/2=10-2W/Hz .the signal power required at the receiver is0.1mW.calculate capacity of this channel

III Y 8. For a given binary sequence 1100100111 ,draw the digital format waveforms

corresponding to i)Polar Manchester coding waveform ii)Bipolar NRZ waveform

iii)q-ary signalling waveform

III Y 9. What is the difference between systematic codes and non-systematic codes?

III Y 10. What ate the functions of the parity check matrix and generator matrix in linear

block codes?

III Y 11. What are hamming codes? What are their properties?

III Y 12. How error correction and detection capabilities are related to minimum distance d min

III Y 13. What are cyclic codes?

III Y 14. What are BCH codes?

III Y 15. What are convolutional codes?

III Y 16. What is the constraint length for convolutional encoders?

III Y 17. What are code tree, code trellis and state diagram for convolutional encoders?

III Y 18. What are the advantages and disadvantages of convolutional codes?

III Y 19. Give the decoding methods for convolutional codes.

III Y 20. Find the Hamming distance between the following code words C1= {1000111}

and C2 = {0001011}. (Nov 2010)

PART B

III X 1.State and Prove Shannon noiseless coding theorem. (8) (May/Jun 2014)

III X 2.Given states S = {S0,S1,S2,S3,S4} and their probabilities

P = {0.4,0.2,0.2,0.1,0.1}. Find coding efficiency and entropy for Huffman coding.(8) (Nov/Dec 2013)

III X 3.Given states S = {S0,S1,S2,S3,S4} and their probabilities

P = {0.4,0.2,0.2,0.1,0.1}. Find coding efficiency and entropy for Huffman

coding.(8) (Nov/Dec 2013)

III X 4. Give the procedure for Shannon Fano coding and use the procedure to obtain the

code for the source symbols

S0,S1,S2,S3,S4,S5 with their respective probabilities

½,1/3,1/12,1/15,1/120,1/120.(8) (Nov/Dec 2013)

III X 5. Explain the concept of noiseless coding theorem and state its significance.(8) (May 2013)

III X 6.Discuss in detail BSC and BEC. (6)(Nov 2012)

III X 7. Two BSC are connected in cascade .i) calculate the channel matrix of resultant channel .ii)find P(z1) and P(Z2) if P(x1)=0.6 and P(x2)=0.4.(8)

III X 8. With suitable examples, explain Shannon fano encoding scheme.(8)

III X 9. Explain Huffman coding with suitable example.(8) (May 2012)

III X 10. With suitable examples, explain the various line coding techniques.(16) (May

2012)

III X 11. A discrete memory less source has five source has five symbols x1,x2,x3,x4,x5

with the probabilities 0.4,0.19,0.16,0.15,0.15 respectively. Construct a Shannon fano

code for the source and calculate the coding efficiency. (16)(May 2011) (Nov 2013)

III X 12. Discuss in detail binary symmetric channel and binary erasure channel. Find the

Shannon-Fano code for the following seven messages with probabilities

indicated.[S1,S2,S3,S4,S5,S6,S7] = [0.05,0.15,0.2,0.05,0.15,0.3,0.1] (16) (Nov

2012)

III X 13. Explain the concept of block codes and coding efficiency. Find the Huffman code

for the following seven messages with probabilities as

indicated.[S1,S2,S3,S4,S5,S6,S7] = [0.05,0.15,0.2,0.05,0.15,0.3,0.1] (16) (Nov

2012)

III X 14. A discrete memory less source has five source has five symbols x1,x2,x3,x4,x5

with the probabilities 0.55,0.15,0.15,0.10,0.05. Respectively apply Huffman coding

algorithm and place the combined message as low as possible when its probability is

equal to that of another message.

a. i)Calculate the code word length for the messages

b. ii)calculate the average code word length(i.e.)average number of binary digits

per message.(16) (Nov 2010) (Nov 2013)

III X 15. Brief the properties of entropy (4) (Nov 2010)

III X 16. Five symbols of the alphabet of discrete memory less source and their

a. Probabilities are given below. S = { S0,S1,S2,S3,S4} P(S) =

b. {0.4,0.2,0.2,0.1,0.1} Code the symbols using Huffman coding(12) (Nov 2010)

III X 17. Draw the polar, unipolar, bipolar and Manchester NRZ line code format for an

information {1 0 11 0 0}.(6)(Nov 2010)

III Y 1. Discuss the Bandwidth – SNR trade off of a communication system.(6)

III Y 2. Apply the following coding technique and obtain the output wave form for

a. the bit stream 10011100 on NRZ, RZ, AMI, HDBP, ABQ and MBnB(12)

b. (May/Jun 2014)

III Y 3. Design a convolutional coder of constraint length 6 and rate efficiency ½ (6)

III Y 4. Discuss the concept of coding and decoding methods of block codes with its mathematical frame work and diagram(16) (Nov/Dec 2013)

III Y 5. Explain Bandwidth – SNR trade off in source coding. (6)(May 2011) (Nov 2011)

(May 2013)

III Y 6. Discuss about error control codes and their application.(8) (May 2013)

III Y 7. Explain the concept of block code. (8)(Nov 2012)

III Y 8. Discuss any one of the decoding methods of convolution coding precisely.

(8)(Nov 2011)

III Y 9. Explain the coding and decoding process of block code. (10)(Nov 2011)

III Y 10. Briefly discuss on various error control codes and explain in detail with one

example for convolution code(12) (Nov 2010)

III Y 11. Consider that a source is transmitting equi probable 1/0 at the rate if

a. 103 b/s and the probability of error is Pe = 1/16. Determine the rate of

transmission (12) (Nov 2010)

III Y 12. In a facsimile transmission of a picture, there are about 2.25x106 picture

elements per frame. For good reception,12 brightness levels are necessary. Assuming

all these levels to be equi probable, calculate bandwidth required to transmit one

picture in every 3 minutes for a SNR of 30 dB. If SNR requirement increases by 40

dB, Calculate the new bandwidth. Explain the trade-off between bandwidth and SNR

by comparing two results. (16)

III Y 13. A (15,5) linear cyclic codes has a generator polynomial

G(p)=p10+p8+p5+p4+p+1.

i)Draw the block diagrams of encoder and syndrome calculator circuit for this

code. ii)find the code polynomial for the message polynomial

M(p)=p4+p2+1(10)

III Y 14. Sketch the encoder and syndrome calculator for the generator polynomial

g(x)=1+x2+x3 and obtain the syndrome for the received codeword 1001011(8) A

rate ½, K=3 binary convolutional encoder. Draw the tree diagram, trellis diagram

and the state diagram for above encoder.(16)

III Y 15. if the received signal at the decoder for eight message bits is, Y=(00 01 10 00

00 00 10 01)Trace the trellis or code tree diagram and find out message bit sequence.(8)

III Y 16. Compare linear block codes and convolutional codes.(6)

III Y 17. For the convolutional encoder with rate 1/3 has the generating vectors as g1=(1

0 0 ) g2=(1 1 1) and g3=(1 0 1) draw the state diagram and trellis diagram and the code

tree, is the code generated systematic? By using Viterbi algorithm, decode sequence

0100010000 (12)

III Y 18. Compare the coding schemes HDBP and MBnB codes in terms of bandwidth, SNR and transmission efficiency. (10)(May 2011 )

III Y 19. What are the various error control codes and explain in detail with one example

for convolution code. (16)(Nov 2010)

Consider a (6,3) linear code whose generator matrix is G = 1 0 0 1 0 1

0 1 0 1 1 0 1 1 0 1 1 1 i)find all code vectors

ii)find all hamming weights and distances

iii)find minimum weight parity check matrix iv)Draw

the encoder circuit

QUESTION BANK

DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING

YEAR/SEM

: III / VI

NAME OF THE SUBJECT

IV Y 1.

: COMMUNICATION ENGINEERING

NAME OF THE FACULTY

: R.HARIHARAN

UNIT IV

MULTIPLE ACCESS TECHNIQUES

SYLLABUS

( X ) SS&MA techniques : FDMA, TDMA, CDMA, SDMA

(Y) application in wire and wireless communication: Advantages (merits) :

PART A

IV X 1. Define multiple access. (N/D 2013)

IV X 2. What is the principle of SDMA? (N/D 2013)

IV X 3. What is SDMA? (M/J 2014)

IV X 4. What is near far problem? (M/J 2014, N/D 2011)

IV X 5. What is FDMA? (N/D 2012)

IV X 6. Mention the significance of CDMA techniques. (N/D 2012)

IV X 7. Draw the block diagram of a typical FDMA system. (N/D 2011)

IV X 8. What are the popular coding sequences of CDMA system? (N/D 2014)

IV X 9. Give out the merits of TDMA system. (N/D 2014)

IV Y 1. Mention the applications of multiple access technique in wired communication. (A/M 2011)

IV Y 2. Briefly explain the multiple access technique used in satellite link. (A/M 2011)

PART B

IV X 1. Explain the principle of FDMA with diagram. (8)(N/D 2013, A/M 2011)

IV X 2. Discuss TDMA technique in detail and compare it with FDMA. (12)(N/D 2013)

IV X 3. Describe CDMA technique in detail.(8) (N/D 2013)

IV X 4. Explain about TDMA and FDMA systems. (16)(M/J 2014)

IV X 5. Explain a CDMA system. (8)(M/J 2014,, A/M 2011)

IV X 6. How is interference avoided by using code division multiplexing? Explain.

(8)(N/D 2012)

IV X 7. With a neat block diagram explain the operation of typical TDMA system and

compare it with FDMA.(12) N/D 2011)

IV X 8. Discuss the concepts of CDMA techniques and mention its merits and demerits.(10) N/D 2011)

IV X 9. Draw the typical TDMA system. Explain the operation with the time pattern.

(8).(N/D 2014)

IV X 10. 500 users employ FDMA to transmit 1000 packets of data. The channel

bandwidth is 100MHz and QPSK is used at each of the 500 carrier frequencies

employed.

(i) What is the maximum bandwidth allocated to each user?

(ii) What is the bit rate employed by each user?

(iii) How long does it take to transmit packet? (16)(M/J 2014)

IV Y 1. Explain the role of SDMA in wire and wireless communication.(10) (N/D 2013)

IV Y 2. Compare wired and wireless communication systems.(8) (M/J 2014)

IV Y 3. Discuss in detail the concept of TDMA and SDMA and their applications in wire and wireless communication.(16) (N/D 2012) IV Y 4.

QUESTION BANK

DEPARTMENT OF ELECTRICAL AND ELECTRONICS ENGINEERING

YEAR/SEM : III / VI

NAME OF THE SUBJECT : COMMUNICATION ENGINEERING

NAME OF THE FACULTY

: R.HARIHARAN

UNIT V

SATELLITE, OPTICAL FIBER – POWERLINE, SCADA

SYLLABUS

( X )AM – Orbits : types of satellites : frequency used link establishment, MA techniques used in satellite communication, earth station; aperture actuators used in satellite – Intelsat and Insat

(Y) fibers – types: sources, detectors used, digital filters, optical link: power line carrier communications: SCADA

PART A

V X 1. Classify the communication satellites along with their band of frequency allocation(May 2014)

V X 2. What is satellite’s footprint (Nov 2013)

V X 3. Define apogee, perigee and geo center. (May 2013)

V X 4. List the merits and demerits of the geostationary satellite. (Nov 2012)

V X 5. What is geo stationary orbit? (May 2012)

V X 6. State Snell’s law (May 2012)

V X 7. What are the essential components of a satellite system? (Nov 2011)

V X 8. Write down the uplink and downlink frequencies used in satellite communication

systems. (May 2011, Nov 2010)

V X 9. Specify uplink and downlink frequency ranges for satellite communication.

V X 10. What is geosynchronous satellite? (Nov 2010)

V X 11. Define satellite

V X 12. State Kepler’s first law.

V X 13. State Kepler’s second law.

V X 14. State Kepler’s third law

V X 15. Define orbital satellite

V X 16. Define Protrude orbit

V X 17. Define Retrograde orbit

V X 18. Define Geo synchronous satellite

V X 19. Define angle of inclination

V X 20. Define Descending node

V X 21. Define ascending node

V X 22. Define line of nodes

V X 23. Define angle of elevation.

V X 24. Define Azimuth angle.

V X 25. Expand and define EIRP

V X 26. Name some domestic Satellite.

V X 27. Give two advantages of Satellite communication.

V X 28. What are the basic components of Satellite subsystem and earth station

subsystem?

V X 29. Distinguish active and passive Satellite.

V X 30. What is the function of transponder in a Satellite system?

V X 31. What is meant by frequency translation?

V X 32. Define angle of elevation. (M/J 2015)

V Y 1.State the advantages of optical communication(May 2014)

V Y 2.What is SCADA? (Nov 2013)

V Y 3.Why is single mode propagation impossible in graded index fibres? (May 2013)

V Y 4.What are the types of optical mode structure? (Nov 2012)

V Y 5.What are the types of optical fibre available? (Nov 2011)

V Y 6.Mention the types of sources and detectors used in optical fibre communication

systems. (May 2011)

V Y 7.State the advantages of fibre optic system. (Nov 2010) V

Y 8.What are the advantages of optical fibre communication? V

Y 9.Define a fibre optic system V Y 10. Define critical angle.

V Y 11. Define single mode and multimode propagation.

V Y 12. Define refractive index.

V Y 13. Define acceptance angle.

V Y 14. Define numerical aperture.

V Y 15. Define modal dispersion.

V Y 16. What are the advantages of heterojunction LEDs?

V Y 17. What are the disadvantages of injection laser diode?

V Y 18. What is the need for optical fibre communication?

V Y 19. What is meant by Dispersion and what is its unit of measurement?

V Y 20. Distinguish between step index and graded index fibre?

V Y 21. Define single mode fibre.

V Y 22. Distinguish LASER and LED sources?

V Y 23. What are the characteristics of LASER diode?

V Y 24. What are the primary advantages of optical fibre systems? (M/J 2015)

PART B

V X 1. What is geosynchronous satellite? Explain the advantages and limitations of

geosynchronous satellite.(8)(May 2008)

V X 2. Explain the characteristics of an uplink, a transponder and a downlink model for a satellite system.(12) (Nov 2008) (May 2012)

V X 3. What are the benefits of satellite communication systems? How the position /

Location of satellite tracked from the earth station? Derive the satellite link equations

and component on it.(16) (May 2010)

V X 4. Describe the fundamental characteristics of uplink, transponder and downlink model of satellite system. (8)(May 2011)

V X 5. List the advantages and disadvantages of geosynchronous orbits.(6) (May 2008)

V X 6. Explain satellite system link models.(8) (Nov 2008)

V X 7. Derive the satellite system link equation.(8) (Nov 2009)

V X 8. Give short notes on (i) satellite subsystems

(ii) Power line carrier system. (16)(Nov 2011)

V X 9. Explain Kepler’s Law and explain how they link with the satellite. (10)(May 2013)

V X 10. Describe the significance of satellite link budgets and how they are calculated.

(8) (May 2012) (May 2013)

V X 11. Explain the concept of satellite communication system and its application.

(8)(8)(8)(Nov 2012)

V X 12. Explain types and multiple access technique used in satellite communication.(12)

(Nov 2011)

V X 13. An X band transponder of a geo synchronous satellite at a height of 35,760 KM

from the surface of the earth and operating at 7.6GHz has its antenna oriented toward

earth station antenna. The input power and directive gain of the transponder antennas

are 18 watts and 36 dB respectively. Assuming no losse occurring in the down link

determine.(16)

(1) Power received by earth station antenna of aperture diameter and efficiency given as 3 meters and 62% respectively.

(2) EIRP of the transponder antenna

V X 14. Draw and explain the block diagram of an earth station (10)

V X 15. Describe the aperture actuators used in satellites (8)(Nov 2013)

V Y 1. Explain the characteristics of different types of optical fibre.(8) (May 2008)

V Y 2. Explain the construction of an optical fibre link (8)(Nov 2007)

V Y 3. Give the significance of numerical aperture of optical fibre.(8) (Nov 2007)(Nov 2013)

V Y 4. With the block diagram explain the operation of fibre optic communication.

V Y 5. Compare single and multimode fibres. (May 2009)

V Y 6. Explain how light beam propagates through fibre. What are the different types of

losses and its effects (Nov 2008)

V Y 7. With neat sketch for the ray propagation into and down an optical fibre cable, derive an expression for acceptance angle. (Nov 2009)

V Y 8. List the merits and demerits of optical communication systems. What are the

components and losses? (May 2010)

V Y 9. Derive the expression for numerical aperture. (May 2011)

V Y 10. Explain the principle operation of Avalanche photo diode. (May 2009)

V Y 11. Describe the losses with fibre cables. (Nov 2008)

V Y 12. Explain the losses associated with fibre cables. (May 2011)

V Y 13. Describe the primary characteristics of light detectors. (May 2011)

V Y 14. Briefly describe the losses associated with fibre optical communication systems.

V Y 15. List the advantages of using optical fibre as a medium of communication in telephone network. (Nov 2009)

V Y 16. Draw the block diagram of fibre optical communication link. Explain the principle

of operation of light sources detectors. (Nov 2009)(May 2012)

V Y 17. Write a note on power line carrier communications (May 2012)

V Y 18. Explain the operation of PIN diode and APD. (May 2010)

V Y 19. Compare optical fibre cable with RF cable. (Nov 2010)

V Y 20. Distinguish among single-mode step index, multimode step index and

Multi mode graded index optical fibres. (Nov 2010)

VY21.Explain the operation of injection LASER diode. (May 2013) Avalanche photodiode (Nov 2013)

V Y 22. Discuss various types of fibres (Nov 2013)

V Y 23. Discuss power line carrier communication with suitable example. (May 2012)

(May 2013)

VY 24. Write short note on:

1. Optical sources and detector (Nov 2011)

2. SCADA (Nov 2012)

V Y 25. Write notes on SCADA and Intelsat (May 2014)

VY26. Describe briefly and compare the three types of optical fibre

configurations?(May/June 2015)