PRINCIPLES OF COMMUNICATION (POC) ANNA UNIVERSITY MODEL QUESTION PAPER NOVEMBER/DECEMBER 2011 ...

PRINCIPLES OF COMMUNICATION (POC) ANNA UNIVERSITY MODEL QUESTION PAPER NOVEMBER/DECEMBER 2011 ...

Posted by R.Anirudhan

B.E./B.Tech. DEGREE EXAMINATION, NOVEMBER/DECEMBER 2011.

B.Tech. – Information Technology

Third Semester

142302 — PRINCIPLES OF COMMUNICATION

(Regulation 2010)

Time : Three hours Maximum : 100 marks

Answer ALL questions.

PART A — (10 ´ 2 = 20 marks)

1. What is the necessity of Modulation.

2. Differentiate between AM and FM, What is your choice for radio broadcast?

Justify your answer.

3. Define Probability of Error.

4. Compare: coherent and non-coherent communications.

5. Define quantization noise.

6. State sampling theorem.

7. What is PN Sequence?

8. What do you mean by Source Coding?

9. List the advantage and limitations of fibre Optical Communication.

10. Give uplink and downlink frequencies in satellite communication.

PART B — (5 ´ 16 = 80 marks)

11. (a) (i) Derive AM Modulated signal with relevant waveforms and

notations and draw the frequency spectrum of AM and explain. (10)

(ii) Explain AM Voltage and Power Distributions. (6)

Or

(b) (i) Discuss on frequency analysis of angle modulated waves. (8)

(ii) Describe the bandwidth requirements for angle modulated wave. (8)



12. (a) (i) Define FSK and give the symbols of BFSK and explain the

modulation mechanism with relevant waveforms and expressions.

(8)

(ii) Draw FSK transmitter and receiver block diagrams and explain the

functions of each block. (8)

Or

(b) (i) Explain the QPSK system with appropriate expressions and

diagrams. (8)

(ii) Draw QPSK transmitter and receiver block diagrams and describe

the functions of each block. (8)

13. (a) Explain the modulation and demodulation process of PCM in detail.

Discuss on companding. (16)

Or

(b) (i) Compare PCM with DM (3)

(ii) Discuss on the Principle and Process of delta modulation with

necessary sketches and formulae. (8)

(iii) What are the limitations of delta modulation and how will you

overcome them in adaptive delta modulation? (5)

14. (a) Explain the principle and operation of direct sequence spread spectrum

system in detail with an appropriate example. (16)

Or

(b) (i) Explain and compare FDMA, TDMA and CDMA (8)

(ii) Explain the advantages and limitations of a CDMA based wireless

communication system. (8)




15. (a) Explain the principles and operation of LEO, MEO and GEO satellites.

(16)

Or

(b) Describe the following with reference to Fibre Optical communication

system.

(i) Sources. (4)

(ii) Detectors. (4)

(iii) Fibre types. (4)

(iv) Losses encountered in optical communication systems. (4)