JNTU III B.Tech Supplimentary Examinations, Aug/Sep 2008

JNTU III B.Tech Supplimentary Examinations, Aug/Sep 2008

COMMUNICATION SYSTEMS

(Electronics & Communication Engineering)

SET-II

 

1. (a) An AM transmitter of 1KW power is fully modulated. Calculate the power transmitted if it is transmitted as SSB.

(b) Calculate the filter requirement to convert DSB signal to SSB Signal, given that the two side bands are separated by 200HZ. The suppressed carrier is 29MHZ.

(c) Give and explain 3 areas of applications where standard FM transmission is needed?

 

2. (a) Discuss the factors influencing the choice of Intermediate frequency for a radio receiver.

(b) Explain the operation of a self-excited transistor mixer by 3-frequency approach, with a neat diagram.

(c) Write about double spotting.

 

3. Write short notes on: –

(a) Fading and Diversity reception

(b) Squelch circuit

(c) Double conversion and variable selectivity.

 

4. Derive the expressions for availability figures for single and dual processor?

 

5. (a) Obtain blocking probability for a time space time switch?

(b) Draw the block diagram for memory controlled time division space Switch?

 

6. (a) What are the major systems in any telecommunication network?

(b) Describe about subscriber loop systems?

 

7. (a) What are the bearer service functions in ISDN?

(b) Write the differences between the code – division multiple access and frequency division multiple access?

 

8. (a) Discuss about interactive services in B-ISDN?

(b) Explain about SONET system?

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