Digital Communications

Noise

Question 1
Marks : +2 | -2
Pass Ratio : 100%
Which offers better SQNR?
Delta modulation
PCM
Delta modulation & PCM
None of the mentioned
Explanation:
PCM offers better SQNR than delta modulation.
Question 2
Marks : +2 | -2
Pass Ratio : 100%
The maximum likelihood function is
Positive
Negative
Any of the mentioned
None of the mentioned
Explanation:
The maximum likelihood function is always positive.
Question 3
Marks : +2 | -2
Pass Ratio : 100%
Eigen functions are not orthogonal.
True
False
Explanation:
An important property of eigen function is that they are orthogonal.
Question 4
Marks : +2 | -2
Pass Ratio : 100%
Which consists of less ISI?
Nyquist filter
Raised cosine filter
Nyquist & Raised cosine filter
None of the mentioned
Explanation:
Raised cosine filter results in less ISI than Nyquist filter.
Question 5
Marks : +2 | -2
Pass Ratio : 100%
Shot noise is produced by
Electrons
Photons
Electrons & Photons
None of the mentioned
Explanation:
Shot noise occurs due to particle like the behaviour of electron and photon.
Question 6
Marks : +2 | -2
Pass Ratio : 100%
Which occurs due to equilibrium fluctuations?
Thermal noise
Johnson noise
Thermal & Johnson noise
None of the mentioned
Explanation:
Thermal noise occurs due to equilibrium fluctuations. This noise is also called as Johnson noise.
Question 7
Marks : +2 | -2
Pass Ratio : 100%
Thermal noise is
Energy signal
Power signal
Energy & Power signal
None of the mentioned
Explanation:
Thermal noise is considered as power signal as it has infinite energy.
Question 8
Marks : +2 | -2
Pass Ratio : 100%
Which has the same power spectral density?
White noise
Brown noise
White & Brown noise
None of the mentioned
Explanation:
White noise has same power spectral density where as it decreases in case of brown noise.
Question 9
Marks : +2 | -2
Pass Ratio : 100%
Matched filtering operation includes
Spectral phase matching
Spectral amplitude matching
Spectral phase & amplitude matching
None of the mentioned
Explanation:
Matched filtering includes two operations – spectral amplitude matching and spectral phase matching.
Question 10
Marks : +2 | -2
Pass Ratio : 100%
Which noise is useful for dithering?
White noise
Pink noise
Brown noise
None of the mentioned
Explanation:
Brown noise is sometimes useful for dithering.