RGPV Exam Previous Question Papers CSE 4th Semester Analog and Digital Communication june 2002

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

(ii)  Entropy

(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

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