SRM University 2007 B.Tech Information Technology BANK : Principles of Communication - Question Paper

S.R.M. Institute of Science & Technology
School of Electronics & Communication Engineering
ques. BANK
Subject Code : EC215
Subject Name : Principles of Communication
Year & Semester : II Year III Sem ( for IT)

Unit-I - INTRODUCTION
Part-A
1. What is the need for modulation?
2. describe a) Energy signal b) Power signal
3. describe a) Odd & Even signal b) Deterministic and Random Signal
4. describe a) Periodic b) Aperiodic signal
5. Determine the power of the signal x(t)=C cos (?0t +0)
6. Determine the energy of x(t)=e-5tu(t)
7. What is meant by internal noise and external noise
8. Check for the Causality a) y(t)=x(t2) b) y(t)=x(t)+5 x(t)
9. Check for time invariant and variant a) y(t)=t x(t) b) y(t)=x(t)-x(t-1)
10. describe Energy spectral density and Power spectral density
11. describe Auto-correlation and Cross-correlation.
12. provide 2 properties of Power Spectral density
13. provide 2 properties of auto-correlation function of energy signals
14. What is sampling theorem
15. What is aliasing
16. What is Hilbert Transform
17. write the properties of Hilbert transform
18. State Parseval’s theorem
19. What is Fourier series.Give the trigonometric form of Fourier series an also provide the Dirichlets Conditions
20. obtain the frequency spectrum of a rectangular pulse shown in fig and provided by the
formula. F(t) = V , -t /2 < t < t /2
0 , otherwise
f(t)
V


-? /2 0 ? / two
21. What is an Impulse signal.Give its function.
22. describe System and provide their classification.
23. describe causal and time invariant system

Part-B
1. With the help of a neat sketch, discuss the block diagram of a communication system.
2. Explain in detail about the signal classifications
3. Give short notes on channel characteristics
4. Explain in detail about Hilbert transform
5. Explain in detail, about the system classifications
6. Check for LTI system a) y(t)=10 x(t) +5 b) y(t)=x(t2)
7. Calculate the FT of a) Decaying exponential pulse x(t)=exp(-t)u(t) b)rectangular pulse x(t) is provided by

X(t)




t
8. Explain in detail about the energy spectral density and Power spectral density
9. Obtain the FT of the impulse function




10. Obtain the FT of a triangular pulse

Earning:   Approval pending.