RGPV Exam Previous Question Papers CSE 4th Semester
Analog and Digital Communication june 2002
Note: Attempt any five question.
All question carry equal marks.
(a) Find the Fourier transforms of following function and sketch them:
(i) sgn (ii) rect (tT) (iii) cos Ω0 t u(t)
(b) Define PSD of a signal and list the properties of it.
(a) Describe the operation of a switching modulator , for generating DSB-SC waves with the help of
diagram and wavefourms .
(b) Distuingsh between AM signal and PM signal .
(a) Prove the sampling theorem for a signal band limited to BHz. How the sampled signal is recovered
Using LPF ?
(b) Draw the black diagram of a PCM system
(a) Briefly explain BFSK technique . specify the bandwidth requirement and probability of error.
(b) What are the problems associated with deta modulator? How they overcome ?
(a) Define CDF,PDF, average value , variance concerned with a random variable.
(b) Prove that ESD is the Fourier transform of autocorrelation function ( of energy signal) .
Define following terms-
(i) Unit of information and information
(iii) Channel capacity
(iv) Rate of information
(a) Encode (1011) using (7,4) cyclic code.
(b) A television transmission requires 30 frames of 3,00,000 picture element each to be transmitted
Per second. Estimate theoretical BW if SNR required is 50 dB . assume missing data .
8. Write short on any two of the following :
(i) Superheaterodyne Radio Receiver
(ii) Companding Technique
(iii) VSB Modulation and demodulation
(iv) Time division and frequency division multiplexing