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

Unit II - MODULATION SYSTEMS
Part A

1. Define: Amplitude modulation, Frequency modulation and Phase modulation
2. Differentiate Narrow band FM and wideband FM
3. What are the advantages & disadvantages of FM over AM
4. State Carson’s rule of FM bandwidth
5. What is figure of merit. What is its significance
6. Give a comparison of FM and PM
7. Define AM and draw its spectrum
8. What is meant by companding
9. What is meant by hunting in delta modulation
10. Differentiate coherent and non-coherent detection methods
11. Define modulation index
12. What is quantization noise
13. Distinguish linear and angular modulation
14. What is meant by threshold effect
15. What is pre-emphasis and de-emphasis
16. Give the expressions for S/N for AM, DSB-SC,SSB and PCM
17. How threshold extensions can be made in FM
18. Define: Signal to noise (S/N)0 x (S/N)c
19. What is meant by interference
20. Give the applications of AM,DSB-SC,SSB & VSB modulation techniques
21. What is meant by NB noise
22. What is meant by slope-overload fault
23. What are the advantages of digital communication
24. A 400w carrier is modulated to a depth of 80%.Calculate the total power in the modulated wave.

Part-B
1. Explain the working principles of square legal regulations modulator. Mention its merits and demerits
2. Describe with neat diagrams, the method of generation of direct FM signal
3. Explain the operation of indirect FM with a neat block diagram
4. Explain delta modulation in detail with suitable diagram & also explain quantization noise in delta modulation
5. Derive an expression for S/N ratio of DSB-SC signal
6. With a block diagram discuss the princile of pulse code modulation.Compare the performance of PCM with delta modulation for voice signals
7. With neat block diagram discuss DPCM
8. What is adaptive delta modulation. discuss it in detail
9. Write short notes on: a) PAM b) PPM c) PWM
10. Explain in detail about frequency division multiplexing
11. Explain time division multiplexing
12. Give an expression for S/N for SSB signal
13. Give an expression for S/N for PCM
14. Explain in detail “how demodulation of AM waves can be done using envelope detector”
Unit-III - BINARY DATA TRANSMISSION
Part-A
1. What are antipodal signals
2. Which digital modulation technique provide better fault probability
3. What is correlation
4. What is base-band signal receiver
5. What is matched filter

Earning:   Approval pending.