Anna University Coimbatore 2008 B.Tech Information Technology Principles of communication - Question Paper

Anna University 2009
B.Tech info Technology
IT 2202-Principles Of Communication
ques. Paper Regulation 2008

PART-A

1. describe amplitude modulation.
2. What is modulation index?
3. Why is ASK called as ON-OFF keying ?
4. What is the difference ranging from QASK and QPSK ?
5. describe sampling rate.
6. What is ISI ?
7. describe Pseudo noise sequence.
8. elaborate the various kinds of multiple access techniques ?
9. describe Kepler's 3 laws of planetary motion.
10. elaborate the losses encountered by optical fiber ?

PART-B

11. (a) (i)Write short notes on
(1) AM voltage distribution. (4)
(2) AM power distribution. (4)
(ii) An audio frequency signal 10sin2p*500t is used to amplitude modulate a carrier of 50 sin2p*10^5t.Calculate.
(1) Modulation index. (2)
(2)Side band frequencies. (2)
(3)BW needed. (2)
(4)Total power delivered to the load of 600O. (2)
(OR)
(b) (i)Compare FM and AM.(12)
(ii) The phase deviation constant in a phase modulation system is K=0.01rad/v.Calculate the maximum phase deviation when the modulating signal of 10V is applied. (4)

12. (a) (i)Explain the principle of FSK transmitter and receiver (10)
(ii)Write short note on spectrum and bandwidth of FSK. (6)
(OR)
(b) (i)Compare the different kinds of digital modulation techniques. (8)
(ii)Explain the eye trend in base band digital transmission with neat diagram. (8)

13. (a) (i)Explain the elements of PCM system with a neat block diagram. (12)
(ii)What is companding ? (4)
(OR)
(b) (i)Find the signal amplitude for minimum quantization fault in a delta modulation system if step size is one volt having repetition period one ms.The info signal operates at 100Hz. (4)
(ii) define the operations of DPCM system with relevant diagram. (12)

14. (a) (i)Write short notes on Frequency hop spread spectrum. (10)
(ii)Explain the applications of spread spectrum techniques. (6)
(OR)
(b) (i)Give a detailed account of multiple access techniques. (10)
(ii)Compare TDMA and CDMA. (6)

15. (a) (i)Discuss briefly the basic satellite communication system . (8)
(ii)Write short notes on LEO and GEO orbits. (8)
(OR)
(b) Enumerate the elements of an optical fiber transmission link. (16)

Earning:   Approval pending.