Digital Communications

Types of Processes

Question 1
Marks : +2 | -2
Pass Ratio : 100%
The auto-correlation of white noise is
A delta function
A constant
Gaussian
None of the mentioned
Explanation:
The auto-correlation of white noise is a delta function.
Question 2
Marks : +2 | -2
Pass Ratio : 100%
The line code has a zero dc component for pulse transmission of random binary data is
NRZ
RZ
Alternate mark inversion
None of the mentioned
Explanation:
The line code has a zero dc component for pulse transmission of random binary data is alternate mark inversion.
Question 3
Marks : +2 | -2
Pass Ratio : 100%
Ionospheric communication can take place in
High frequency band
Very high frequency band
Ultra high frequency band
Super high frequency band
Explanation:
Ionospheric communication takes place in high frequency band.
Question 4
Marks : +2 | -2
Pass Ratio : 100%
The power spectral density function of the stochastic process is
Real
Odd
Real & odd
None of the mentioned
Explanation:
The power spectral density function of a stochastic function is real and even.
Question 5
Marks : +2 | -2
Pass Ratio : 100%
A stationary stochastic process has
Finite energy signal
Infinite zero signal
Zero energy signal
None of the mentioned
Explanation:
A stationary stochastic process is an infinite energy signal and hence its fourier transform does not exist.
Question 6
Marks : +2 | -2
Pass Ratio : 100%
The capacity of a channel is given by
Number of digits used in coding
Volume of information it can take
Maximum rate of information transmitted
Bandwidth requires information
Explanation:
The capacity of the channel is given by a maximum rate of information transmitted.
Question 7
Marks : +2 | -2
Pass Ratio : 100%
For a periodic function, the spectral density and auto correlation functions form
Fourier transform pair
Laplace transform pair
Hilbert transform pair
Z transform pair
Explanation:
For a periodic function, the spectral density and auto correlation function forms fourier transform pair.
Question 8
Marks : +2 | -2
Pass Ratio : 100%
A rectangular pulse of duration T is applied to a matched filter. The output of the filter is a
Rectangular pulse of duration T
Rectangular pulse of duration 2T
Triangular pulse
Sine function
Explanation:
The output of the matched filter when a rectangular pulse of duration T is applied is a triangular pulse.
Question 9
Marks : +2 | -2
Pass Ratio : 100%
In a communication system, a process in which statistical averages and time averages are equal is called as
Stationary
Ergodic
Gaussian
Poisson
Explanation:
In ergodic process statistical averages and time averages are equal.
Question 10
Marks : +2 | -2
Pass Ratio : 100%
Satellite communication takes place in
Ultra high frequency band
Super high frequency band
Ultra & Super high frequency band
None of the mentioned
Explanation:
Satellite communication takes place in ultra high and super high frequency bands.