Digital Communications

Digital Communication Signal Processing

Question 1
Marks : +2 | -2
Pass Ratio : 100%
Equalizer is used for?
Filtering
Diminish distortion
All of the mentioned
None of the mentioned
Explanation:
Equalizer is used as a filtering option and also diminishes or reduces the distortion.
Question 2
Marks : +2 | -2
Pass Ratio : 100%
What is the ASCII value of space?
32
48
96
65
Explanation:
The ASCII value of space is 32 and ASCII value of 0 is 48.
Question 3
Marks : +2 | -2
Pass Ratio : 100%
Pulse shaping is done by which block or system?
Encoder
Baseband modulator
Pulse code modulator
Demodulator
Explanation:
Pulse code modulator does filtering process to build pulses that occupy more than one bit time.
Question 4
Marks : +2 | -2
Pass Ratio : 100%
Which circuit is called as regenerative repeaters?
Analog circuits
Digital circuits
Amplifiers
A/D converters
Explanation:
The main advantage of digital communication is that the signals can be reproduced easily. Thus digital circuits are called as regenerative repeaters.
Question 5
Marks : +2 | -2
Pass Ratio : 100%
What is the code rate?
k/n
n/k
All of the mentioned
None of the mentioned
Explanation:
Here n is the total bits of sequence and k bits are mapped. Amount of redundancy introduced is given by n/k and its reciprocal is the code rate.
Question 6
Marks : +2 | -2
Pass Ratio : 100%
How many different combinations can be made from a n bit value?
2(n+1)
2(n)
2(n)+1
None of the mentioned
Explanation:
2(n) different combinations can be made from n bit value. For example, from 2 bit value 22 different combinations-00,01,10,11 can be made.
Question 7
Marks : +2 | -2
Pass Ratio : 100%
Source coding block is used for?
Compressing
Digitizing
A/D conversion
All of the mentioned
Explanation:
Source encoding does all these processes-compression, digitizing the signal and performs analog to digital conversion.
Question 8
Marks : +2 | -2
Pass Ratio : 100%
What are the advantages of digital circuits?
Less noise
Less interference
More flexible
All of the mentioned
Explanation:
Digital circuits are less subject to noise, distortion and interference as it works on digital pulses and also the pulses can be regenerated.
Question 9
Marks : +2 | -2
Pass Ratio : 100%
How many bytes does a gigabyte have?
1 million bytes
10 million bytes
1 billion bytes
10 billion bytes
Explanation:
One gigabyte has 1 billion bytes.
Question 10
Marks : +2 | -2
Pass Ratio : 100%
Which block or device does the data compression?
Channel encoder
Source encoder
Modulator
None of the mentioned
Explanation:
Source encoder converts the digital or analog signal to a sequence of binary digits. This process is called as source encoding or compression.