Jaypee Institute of Information Technology (JIIT) 2008 B.E Electronics & Tele-Communication Engineering Test 1 : Analogue Communication - Question Paper
Jaypee University of Information Technology Waknaghal Test -1 IV Semester 2008
Department of Electronics and Communication Engineering
Paper name: Analogue Communication . , Max Time: 1 hr.
Paper Code 07B41 EC 108 UlHirf axars:
Attempt all four questions. Answers should be brief and to the point.
The marks allotted to each question are given at the end of the question.
1. State and prove Rayleigh's Theorem. Use this theorem to find the energy of the signal: x(f) = 3Smc2 x 10*/. (4)
2. Define convolution. State the properties of convolution.
Find x(t)*y(l), where x(t) 3n< and y(t) =6n|jrj (1)
3. A signal having a bandwidth of 100 kHz is transmitted through a 100 km cable which has a loss of ldB/km. You have a receiver whose input noise is specified by a temperature of 1000 K. Design a system such that the S/N|[jis not less than 40 dB. (6)
A signal x(() is used to modulate a carrier Ac Cos 2nfct with (t) AM having
modulation index, m=l and (ii) DSB-SC. For each case, give
(i) the expression for the waveform of the modulated signal
(ii) the Spectrum of the modulated signal
(iii) the power in the carrier and in each sideband, if < x2(t) > = 0.8 and St W. Sketch the modulated signals when x(t) is a sincwave. (6)
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| Earning: Approval pending. |
