Total No. of Questions: 05 Total No. of Printed Pages: 02

Time: 3 Hrs.

Roll No.: _

BTEC 105B.Tech. [CCE]

I Year Examination, December 2017

Analog and Digital CommunicationChoice Based Credit System (CBCS)

Maximum Marks : 60Minimum Pass Marks: 24

Note: (1) All questions carry equal marks, out of which part 'A' and '8' carry 3 marks and part 'C' carries 6 marks.~

(2) From each question, part 'A' and '8' are compulsory and part 'C' has internal choice.

(3) Draw the neat diagram, wherever necessary.

(4) Assume suitable data wherever necessary.

Q.1.(A)

(8)

(C)

..•.....•..

l.2.(A)

(8)

(C)

Define Signals. Briefly explain various types of signals.

Find the Fourier transform of everlasting sinusoid sinwot. Also draw its spectrum.

State and Prove the Parseval's theorem for power signal and also define power

spectral density.

OR

State and Prove the time shifting and frequency shifting properties of Fourier

transform .

Define modulation and demodulation. Why modulation is needed?

Briefly explain the block diagram of Communication System.

Explain the working of Envelope Detector.../

OR

A carrier Accoswct. is amplitude modulated by a single tone modulating signal

met) = Amcoswmt. derive the expression for Amplitude modulation. Also

compute its spectrum, bandwidth and total power transmitted.

Contd .

1

•

0303

06

030306

Q.3.(A) Define Angle modulation. Explain how Phase Modulation (PM) can be obtained

from Frequency Modulation (FM). 03

(8) Briefly explain Phase Locked Loop (PLL) detector with block diagram. 03(C) Explain the generation of FM using Direct method. 06

OR

Derive an expression for frequency modulated wave. Also define frequency

deviation and modulation index of FM.

Q.4.(A)

(8)

(C)

Q.S.(A)

."

Define: Bit rate, Baud rate and Nyquist rate.

What is aliasing and how it can be reduced?

Explain Pulse code modulation with its block diagram?

OR

Derive the expression for flat top sampled signal and also obtain its spectrum.

(8)

Write mathematical expression of Binary frequency shift keying (BFSK). What is

the bandwidth of BFSK and M-ary FSK?

Define Binary Phase Shift Keying. Sketch the BPSK waveform for the input binary

sequence 1 1 0 1 0 0 1 0 1 1

Explain the generation of QPSK. Also draw its spectrum and find the bandwidth.

OR

Explain Quadrature amplitude modulation in detail.

(C)

xxxxxxx

2

0303o , .

03

0306