Download AKTU B-Tech 6th Sem 2016-2017 NEC609 Communication Engineering Question Paper

Download AKTU (Dr. A.P.J. Abdul Kalam Technical University (AKTU), formerly Uttar Pradesh Technical University (UPTU) B-Tech 6th Semester (Sixth Semester) 2016-2017 NEC609 Communication Engineering Question Paper

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B. TECH.
THEORY EXAMINATION (SEM?VI) 2016-17
COMMUNICATION ENGINEERING
T ime : 3 Hours Max. Marks : 100
Note .' Be precise in your answer. In case ofnumericalproblem assume data wherever not provided.
SECTION-A
1 Explain the following: (10X2=20)
a) Communication Process f) Probability Of Error Dueto Noise
b) Modulation Process g) Band-Pass Transmission Model
0) Nonlinear Effects in PM Systems h) Uncertainty
(1) White Noise i) Channel Capacity
e) The Sampling Process j) Lossless Data Compression
SECTION-B
2 Attempt any ?ve of the following: (10X5=50)
3. Describe an expression for the effective modulation index of a multi-tone modulated AM
signal.
b. What is quantization? How can you minimize the quantization error? How quantizing and
coding is done? Explain with suitable waveform.
c. Analyze noises present in amplitude modulation system and derive its signal to noise ratio.
Find out the figure of merit in DSB-SC system.
(1. What is pre?emphasis and de?emphasis and how SNR improves by using pre?emphasis and de?
emphasis? Find out the figure of merit in SSB?SC system.
e. What is digital phase locked loop? Explain the working of an EX?OR gate based digital phase
comparator. Define Frequency Division Multiplexing and Time Division Multiplexing. Define
concept of bandwidth and frequency spectrum?
f. Explain the functioning of a FSK digital transmitter cum receiver operation in detail with the
relevant diagrams.
g. Explain with suitable diagram the operation of Super heterodyne receiver and compare its
performance with Tunal Radio frequency receiver.
h. What do you mean by power spectral densities? Explain Noise in AM receivers and FM
Receivers with suitable diagram.
SECTION-C
Attempt any two of the following: (15X2=30)
3. What do you understand by instantaneous frequency, frequency deviation and bandwidth of
FM wave? A carrier wave of frequency 100 MHz is frequency modulated by a sinusoidal wave
of amplitude 20V and frequency 100 kHz. The frequency sensitivity of the modulator is 25
kHz per volt. Determine approximate bandwidth of FM signal.
4. a. Explain the functioning of a ASK and PSK digital transmitter cum receiver operation.
b. Why QPSK is better than PSK? Explain with suitable examples.
5. Write short note with suitable diagram and example:
a. OFDM& Source Coding Theorem
b. PPM & TDM
c. 181 & Eye Pattern