Rajasthan Technical University 2009-4th Sem B.E Electrical Engineering : (- ) Principal of communication system - Question Paper
Rajasthan tech. University(RTU)
B.Tech IV sem. back exam
2009
Principal of communication system
The candidate should ensure that this question
paper contains 3 printed pages.
4182
PCS
II B.E. (IV SEMESTER) (BACK) EXAMINATION, 2009
(New Four Year Semester Scheme)
[Branch : Electrical Engineering]
PRINCIPLES OF COMMUNICATION SYSTEM
Time Allowed : Three Hours Maximum Marks 80
(1) No supplementary answer-book will be given to any candidate. Hence' the candidates should write the answer precisely in the Main answer-book only.
(2) All the parts of one question should be answered at one place in the answer-book One complete question should not be answered at different places in the answer-book,
iurn over
A ttempt any five questions.
All questions carry equal marks.
1. (a) Compute the convolution of the given signal
(b) Determine the fourier transform of the signal x(n)=u(n)-u(n-S). 8
2. (a) With the help of a circuit diagram explain the
working of ring modulator for generating a DSB-SC signal. 8
(b) With the help of a suitable sketch, explain the phase shift method for the generation of SSB signals. 8
3. For a modulation coefficient of M= 0-2 and an unmodulated carrier power Pc=1000 W, determine:
(z) Total sideband power
(ii) Upper sideband power
(iii) Modulated carrier power
(iv) Total transmitted power. 4x4=16
4. (a) Explain pre-emphasis and de-emphasis in FM
broadcasting. 8
(b) Explain the working of phase locked loop in carrier acquisition giving its block diagram. 8
5. (a) What are the NBFM and WBFM bandwidth?
How are they generated? 8
(b) Compare the noise performance in phase modulation and frequency modulation. 8
4182 2
6. (a) Explain the Armstrong system for generation of a
FM signal. 8
(b) Compare AM and FM systems. 8
7. Write short notes on any two of the following:
(a) Vestigial sideband modulation
(b) Threshold in FM
(c) Superheterodyne receiver
(d) PCM. 8+8=16
3
4182
|
Attachment: |
| Earning: Approval pending. |
