### EC2311 Communication Engineering Question bank Fifth semester

UNIT I : ANALOG COMMUNICATION
TWO MARKS:
1. Define Amplitude Modulation.
2. What is AM wave envelope?
3. Define modulation index for an AM wave.
4. List out the advantages of AM.
5. Mention the advantages of FM.
6. What is the modulation index of FM?
7. DefineDSB-SC .
8. Define SSB.
9. Mention the applications of SSB.
10. Mention the advantages of VSB.

PART - B
1Draw the block diagram for the generation and demodulation of a VSB signal
and explain the principle of operation.                                                    (16)
2. Discuss the coherent detection of DSB-SC modulated wave with a block diagram of detector and Explain.                                                                     (16)

3. Explain the generation of AM signals using square law modulator                      (8)
4. Explain the superhetrodyne receiver (16)

UNIT-II: DIGITAL COMMUNICATION
TWO MARKS:
1. What are the different pulse modulation techniques? Discuss their advantages
2. Define Frequency deviation
3. State the applications of FSK
4. Define modulation index of FM and PM..
5. Differentiate between phase and frequency modulation
6. State the errors in DM.
7. Draw the GMSK demodulator block
8. Draw the constellation diagram for 16-QAM
10. What are the applications of data communication?

PART-B
1 . Illustrate QPSK                                                                                       (16)
2. Write a note on Delta modulation                                                           (8)
3.Explain DPCM                                                                                          (16)
4. Write a detail note on PWM,PAM,PPM                                                (16)

UNIT-III: SOURCE CODES, LINE CODES & ERROR CONTROL
TWO MARKS:
What is entropy?
2. What is prefix code?
3. Define information rate.
4. What is channel capacity of binary synchronous channel with error probability of 0.2?
5. State channel coding theorem.
6. Define entropy for a discrete memory less source.
7. What is channel redundancy
8. Write down the formula for the mutual information.
9. When is the average information delivered by a source of alphabet size 2, maximum?
10. Name the source coding techniques.

PART - B
Discuss Source coding theorem, give the advantage and disadvantage of channel coding in detail, and discuss the data compaction. (16)
2. Explain in detail Huffman coding algorithm and compare this with the other types of coding. (8)
3. Explain the properties of entropy and with suitable example, explain the entropy of binary memory less source. (8)
4. What is entropy? Explain the important properties of entropy.   (8)
5. What do you mean by binary symmetric channel? Derive channel capacity formula for symmetric channel.

UNIT-IV: MULTIPLE ACCESS TECHNIQUES
TWO MARKS
1. What do you mean by multiple access and mention a few MA techniques?
2. Advantages of FDMA over TDMA?
3. Distinguish CDMA and SDMA?
5. Applications of CDMA?
6. List the applications of SDMA in wire and wirelessvcommunication
7. Drawbacks of TDMA
PART - B
1. Explain TDMA in detail                                                                           .           (10)
2. Write a note on cellular CDMA             (16)
3. Compare TDMA, CDMA, SDMA :advantages and drawbacks                    (16)

UNIT-V: SATELLITE, OPTICAL FIBER – POWERLINE, SCADA
TWO MARKS:
1. What are the major regions are classified the world for frequency planning?
2. How many broadcasting services provided in satellite?
3. What is meant by distance insensitive?
4. List out the coverage area for INTELSAT?
5. What are the classify the Domsats in terms of power?
6. State Kepler’s first law.
7. State Kepler’s second law.
8. State Kepler’s third law.
.9. Name some optical sources and detectors