SRM University 2007 B.Tech Information Technology BANK : Principles of Communication - Question Paper

6. What is the impulse response of matched filter
7. What is the value of maximum signal to noise ratio of the matched filter
8. In wahat factor,the fault probability of matched filter depends
9. What are synchronization errors
10. Give the advantages & disadvantages of DPSK
11. Define: BPSK,ASK,DPSK,FSK & PSK
12. Give any 2 properties of matched filters
13. Give the S/N for a base-band receiver
14. What is meant by inter-symbol interference.How to decrease it
15. What is diversity transmission
16. Give the probabilities of fault expressions for ASK,FSK & PSK
17. What is meant by equalization.what are its kinds
18. What is meant by MCM technique
19. What are the disadvantages of MCM technique
20. What is OFDM
21. What is multi-path interference
22. What is meant by fading
23. Give examples of signaling schemes not requiring coherent carrier references at the receiver.
24. Give examples of coherent signaling techniques
25. What happens when signals are transmitted through band limited channels
Part-B
1. Derive an expression for probability of fault in baseband data transmission in white Gaussian noise
2. Derive an expression for fault probability for the matched filter receiver
3. Derive an expression for fault probability for i)DPSK ii) Non-Coherent FSK
4. Discuss about ASK,FSK and PSK & provide the needed equations
5. Compare different digital modulation systems
6. Write short notes on a) multi-path interference b) Flat fading channels
7. What is equalization.Explain it in detail.
8. Write a short note on multi-carrier modulation and OFDM

Unit –IV - ADVANCED DATA COMMUNICATION
Part-A
1. Under what circumstances M-ary signaling schemes are preferred over binary schemes
2. Define pseudo noise sequence
3. Explain why FH spread spectrum is not affected by near far issue
4. Compare BW efficiency of M-ary PSK signals & M-ary FSK signals
5. What is meant by spread spectrum
6. What is meant by QPSK and OQPSK
7. Define MSK
8. What is QAM
9. Give the bandwidth efficiencies of different M-ary digital modulation schemes
10. What is NRZ and unipolar RZ
11. What is meant by carrier synchronous
12. What is bit synchorization & word synchronization
13. What are the reasons for employing spread spectrum modulation
14. What is DS-SS
15. What is FH-SS
16. Differentiate FDMA & TDMA
17. What is CDMA
18. What is code synchronization
19. What are the various kinds of synchronization
20. Explain briefly satellite communications
21. What is the basic principle of cellular radio communication
22. What are the characteristics of 2G cellular systems

Part – B
1. Explain in detail about the M-ary schemes based on Quadrature multiplexer.
2. Explain in detail about MSK systems.
3. Write short notes on bandwidth efficiencies of digital modulation formats.
4. Write short notes on pseudo- noise sequences.
5. What is synchronization? elaborate its types? discuss it in detail.
6. What is spread spectrum technique? discuss DS-SS in detail.
7. Write short notes on FH-SS
8. Explain in detail about satellite communication systems.
9. With a diagram discuss the acquisition circuit for FH signal.
10. discuss in detail about the cellular radio communication systems

UNIT – V - info THEORY AND CODING
Part- A
1. What is meant by info theory?
2. What is self – information?
3. State the cause , why base two logarithm is used to measure information?
4. Define entropy.
5. What is meant by joint and conditional entropy?
6. Give the properties of entropy.
7. Define encoding and decoding.
8. Define rate of info and provide the unit of info.
9. What is meant by coding efficiency?
10. What is mutual information?
11. Give the properties of mutual info.
12. What are the various kinds of channel?
13. What is meant by channel capacity?
14. What is meant by loss-less channel?
15. What is meant by deterministic channel?
16. What is noiseless and useless channel?
17. What is symmetric channel?
18. Give the channel capacity for BEC and BSC.
19. State Shannon’s theorem.
20. State Shannon Hartley Theorem.
21. What is meant by redundancy?
22. What is systematic code?
23. What is linear code?
24. State the conditions satisfied by hamming codes.
25. What are fault detection and correction capabilities of block codes?
26. Define cyclic codes.
27. What are convolution codes? How they are various from block codes?
28. Define coding gain and provide its significance.
29. What is weight of the code? compute the weight of x = 01110101
30. Check the bits of the code provided as C1 = m1 + m3 C2 = m2 + m3 C3 = m1+ m2
31. Give the advantages and disadvantages of convolution codes.

PART – B
1. Determine the coding efficiency redundancy of a source which is transmitting 6 of a messages with probabilities 0.30,0.25,0.15,0.12,0.10 and 0.08 by Huffman coding.
2. Derive Huffman’s code for the source having p(x) 0.07 0.08 0.04 0.26 0.14 0.09 0.07 and 0.025.
3. Construct Shannon- Fano code for 6 messages.
Messages X1 X2 X3 X4 X5 X6
Prob’s 0.333 0.25 0.125 0.125 0.083 0.083
4. Apply Shannon Fano coding for,
Messages m1 m2 m3 m4 m5 m6 m7 m8
Prob’s ¼ 1/8 1/16 1/16 1/16 ¼ ¼ 1/8
5. Explain in detail about the channel classification. provide the channel capacity of every channel.
6. Write short notes on (a) Mutual info (b) Joint and conditional entropy.
7. If p(x1) = 0.6 P(x2) = 0.3 p(x3) = 0.1 Determine the mutual info of trans info for the provided channel.








8. (a) Determine the avg. length and entropy for the messages
Messages X1 X2 X3 X4 X5 X6 X7 X8 X9 X10
Prob’s 0.18 0.17 0.16 0.15 0.10 0.08 0.05 0.05 0.04 0.02
(b) A communication system with avg. power limitation has a BW of 1MHz and SNR= 10 Determine the channel capacity.
9. Write short notes on (a) Linear block codes (b) Convolution Codes
10. Write short notes on (a) Cyclic codes (b) Hamming codes
11. discuss in detail about fault control coding.

Earning:   Approval pending.