# RGPV Previous Exam Papers BE 4th Semester

# Analog and Digital Communication June 2006

**(Common for CS, EC, EE &EI, IT & BM Engg. )**

**Note: Attempt any five questions.**

**All question carry equal marks. **

**Assume any missing data.**

1. (a) Define the paresvel’s theorem and power spectral density. Give comparison of energy spectral

density function and power spectral density function.

(b) Explain Detection of AM with square –law detector and define pulse modulation.

2. (a) What is the sampling theorem? Prove the sampling theorem, consider a signal g(t) , whose

Spectrum is band limited to BHz .

(b) Explain Hilbert transform will properties and application.

3. (a) With the help of ahead fig., derive the expression for noise figure calculation.

(b) Define the noise and classify the noise brand groups.

4. (a) Explain the power spectral density and bandwidth of MSK.

(b) Describe the Gaussian distribution with distribution function.

5. (a) Explain the convolution cod with code tree and trellis diagram.

(b) Explain the Shannon’s theorem and shannnon-fano code.

6. Write about the following terms

(a) FDM

(b) Side bands with waveforms

© Comparison of AM and FM system

7. (a) Draw the block diagram of FM transmitter and explain each section in short.

(b) Explain in detail the following:

(i) Cyclic code (ii) Error correction code

8. Write short notes on any two the following:

(a) Probability density function (b) FEC and ARQ

© TDM and DPCM (d) Shannon-Hartley theorem