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

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

COMMUNICATION SYSTEMS

(Electronics & Communication Engineering)

SET-I

1. (a) Write short notes on the following :-

i. Harmonic generators

ii. transmitter power supplies

(b) Explain with suitable block diagram the various stages of a frequency modulated broadcast transmitter. Draw the block schematic of a crystal controlled frequency modulation broadcast station operating on 96.5MHZ.The modulating frequency employed cover the range 60 to 12000 HZ .& a maximum deviation of 75 KHZ is desired.

 

2. (a) Write short notes on:

i. Frequency synthesizers

ii. Spurious responses in radio receivers

(b) Bring out the factors influencing the choice of IF and indicate the values of

IF employed in each of the following cases

i. AM Broadcast receivers

ii. FM Broadcast receiver

iii. TV receivers in the VHF and UHF bands.

 

3. (a) Differentiate between simple, delayed and amplified AGC and explain their action with the help of simple circuits blocks.

(b) Discuss briefly similarities and differences between FM and AM receivers.

(c) Write in detail about the limiter used in FM receiver.

 

4. (a) What are the advantages of two processor configurations?

(b) Explain about the concept of stored program control?

 

5. (a) Explain about a two stage time space switch?

(b) Write about space time space switch?

 

6. Explain about the architecture of the SS7?

 

7. (a) Write about numbering plan for ISDN?

(b) Explain about the functioning of transponder in satellite communications?

 

8. (a) Write about the modeling of propagation channel in mobile radio environment?

(b) Discuss about multiple accessing techniques?

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