15 Feb 2013





JSS Noida Electrical Engineering

 
Communications - Questions - 1 Unit by Mr Varun Saxena

1. Consider as FDM, a channel Bandwidth of 55 to 120 kHz. And the following 3 signals to be transmitted along it :

a) 10 MHz
b)  7 MHz
c)  8 MHz

Explain how they can be accomodated in the channel bandwidth with Suitable carrier frequenies.

2. Consider a triangle wave as a message signal, draw the spectrum of DSB-SC Wave.

3. Evaluate Fourier Transforms of the following functions :

a) (t)
b) ( t -t0 )
c) rect ( t2)
d) u (t)
e) ejt

4. Discuss the modulation & demodulation schemes for Amplitude Modulation.

5. Consider a message signal of Bandwidth ‘B’ Hertz and carrier frequency  fc Hz. Prove that signal can be demodulated if “fc > B”.
Also plot the Spectrum Plot and find Conclusions.



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