COMMUNICATION ENGINEERING

COMMUNICATION ENGINEERING
SEM-IV, 2013
B.TECH EXAMINATION
UTTARAKHAND TECHNICAL UNIVERSITY
(UTU)

Marks: 50

Time: 2 hrs

Q1: Attempt any four

1. Why do we require modulation?
2. Derive the equation that represents amplitude modulation?
3. Draw the block diagram of superheterodyne receiver.
4. Explain a method to demodulate single sideband signal.
5. Explain the square law diode modulator for AM generation.
6. Derive the power relation for amplitude modulated wave.

Q2: Attempt any four.

1. Explain the balanced slope detector for the FM demodulation.
2. What is angle modulation?
3. Give a method to generate frequency modulated signal.
4. What are the sources of noise and different types of noise encountered in communication system?
5. Derive the expression for the frequency modulation.
6. What is noise figure?

Q3: Attempt any two.

1. Draw the block diagram of pulse code modulation system and explain each block.
2. What are Delta modulation and Adaptive delta modulation? Discuss the errors that are encountered in Delta Modulation.
3. What is QPSK? How is it transmitted and received? Explain with circuit diagram. Give its signal space representation.

Q4: Attempt any two.

1. What are the elements of a satellite communication? Explain each of them with a suitable block diagram.
2. Explain ground wave propagation.
3. The total power content of an AM signal is 1000W. Determine the power being transmitted at the carrier frequency and at each of the sidebands frequencies when the percentage of modulations is 100%.

----------------------------