Digital Communications

Modulation and Entropy

Question 1
Marks : +2 | -2
Pass Ratio : 100%
Which has higher error probability performance?
Uni-polar base-band signalling
Bipolar base-band signalling
ASK
FSK
Explanation:
Bipolar base-band signalling has high error probability performance than the others. The probability of error value is A2T.
Question 2
Marks : +2 | -2
Pass Ratio : 100%
Modulation process corresponds to ______ the amplitude, frequency or phase.
Switching
Keying
Switching or keying
None of the mentioned
Explanation:
Modulation process corresponds to switching or keying the amplitude, frequency or phase of CW carrier.
Question 3
Marks : +2 | -2
Pass Ratio : 100%
Matched filter
Is a non linear filter
Produces maximum output SNR
All of the mentioned
None of the mentioned
Explanation:
Matched filter is a linear filter which produces maximum output SNR for a given transmitted signal.
Question 4
Marks : +2 | -2
Pass Ratio : 100%
For which quantization process is used?
Amplitude discretization
Time discretization
Amplitude & Time discretization
None of the mentioned
Explanation:
Sampling process is used for time discretization and quantization process is used for amplitude discretization.
Question 5
Marks : +2 | -2
Pass Ratio : 100%
Which has same probability of error?
ASK and FSK
ASK and PSK
PSK and FSK
None of the mentioned
Explanation:
Uni-polar base-band signalling, PSK and FSK has same probability of error.
Question 6
Marks : +2 | -2
Pass Ratio : 100%
In TDM, at the receiver end, ____ filter is used.
Low pass
High pass
Band pass
Band stop
Explanation:
In TDM, at the receiver end low pass filtering is done to obtain individual signals.
Question 7
Marks : +2 | -2
Pass Ratio : 100%
PCM includes the process of
Amplitude discretization
Time discretization
Amplitude & Time discretization
None of the mentioned
Explanation:
Time discretization and amplitude discretization are the two processes done in PCM system.
Question 8
Marks : +2 | -2
Pass Ratio : 100%
Which provides more secure communication?
CDMA
FDMA
TDMA
None of the mentioned
Explanation:
CDMA provides more secure communication than TDMA and FDMA.
Question 9
Marks : +2 | -2
Pass Ratio : 100%
Entropy is the measure of
Randomness
Information
Randomness & Information
None of the mentioned
Explanation:
Entropy can be defined as the measure of randomness or information.
Question 10
Marks : +2 | -2
Pass Ratio : 100%
Time division multiplexing uses
High pass filter
Commutator
High pass filter & Commutator
None of the mentioned
Explanation:
Time division multiplexing uses low pass filter and commutator.