B.Tech VI (Sixth) Semester Examination 2011-12
Course Code: EEC606 Paper ID: 0966127
Analog & Digital Communication Engineering
Time: 3 Hours Max. Marks: 70 Max Marks: 75
Note: Attempt six questions in all. Q. No. 1 is compulsory.
1. Answer any five of the following (limit your answer to 50 words). (4x5=20)
a) What is vestigial side band modulation?
b) Explain the quantization process in brief.
c) What is the role of Intermediate Frequency (IF) Amplifier?
d) What is Frequency Division Multiplexing?
e) What is aliasing? What is the effect of aliasing?
f) What is bit rate and baud rate?
g) What do you mean by FSK?
h) What are the advantages of a spread spectrum technique?
2. Draw the block diagram of a superheterodyne receiver and explain the functions of each block. Enlist the advantages of a superheterodyne receiver. (10)
3. What is demodulation? Enlist various types AM detector. What are the requirements of envelope detector? Explain the envelope detector with diagram. (10)
4. a) A 500-Hz modulating voltage fed into a PM generator produces a frequency deviation of 2.25 KHz. What is the modulation index? If the amplitude of the modulating voltage is kept constant, but its frequency is raised to 6 KHz, what is the new deviation? (05)
b) Explain the effect of multiple frequency modulations in FM Systems with an example. (05)
5. For the given samples apply the Shannon Fano coding for binary codes: (10)
S = s1 s2 s3 s4 s5 s6
P = 0.2 0.2 0.1 0.10 0.1 0.3
6. What is binary PSK? Explain the Binary PSK transmitter and receiver with block diagram (10)
7. What is sampling? Draw the circuit diagram of the Pulse Amplitude Modulation (PAM) Modulator and Demodulator circuit and explain. (10)
8. What is TDM and FDM? Explain the synchronous and Asynchronous Time division multiplexing of PCM signals. (10)