Explore topic-wise MCQs in Digital Communications.

This section includes 21 Mcqs, each offering curated multiple-choice questions to sharpen your Digital Communications knowledge and support exam preparation. Choose a topic below to get started.

1.

If the quantization level of a demodulator output is ________ then it is called as soft decision decoding.

A. Equal to 2
B. More than 2
C. Less than 2
D. None of the mentioned
Answer» C. Less than 2
2.

For a binary code, the maximum number of possible sequence made up of L branch words is

A. L2
B. 2L
C. 2L
D. L/2
Answer» C. 2L
3.

In maximum likelihood detector the error probability is

A. Maximum
B. Minimum
C. Zero
D. None of the mentioned
Answer» C. Zero
4.

In maximum likelihood decoding technique, the likelihood function compares the

A. Joint probabilities
B. Individual probabilities
C. Conditional probabilities
D. None of the mentioned
Answer» D. None of the mentioned
5.

Example for convolution encoder state diagram is

A. Tree diagram
B. Trellis diagram
C. Tree & Trellis diagram
D. None of the mentioned
Answer» D. None of the mentioned
6.

In trellis diagram, the number of nodes ______ at successive branching.

A. Increases by 1
B. Doubles
C. Triples
D. None of the mentioned
Answer» C. Triples
7.

The method used for representing convolution encoder are

A. Connection pictorial
B. State diagram
C. Tree diagram
D. All of the mentioned
Answer» E.
8.

IN_MAXIMUM_LIKELIHOOD_DECODING_TECHNIQUE,_THE_LIKELIHOOD_FUNCTION_COMPARES_THE?$

A. Joint probabilities
B. Individual probabilities
C. Conditional probabilities
D. None of the mentioned
Answer» D. None of the mentioned
9.

For a binary code, the maximum number of possible sequence made up of L branch words is$

A. L2
B. 2L
C. 2L
D. L/2
Answer» C. 2L
10.

In_maximum_likelihood_detector_the_error_probability_is$

A. Maximum
B. Minimum
C. Zero
D. None of the mentioned
Answer» C. Zero
11.

Branch word synchronization is the process of determining the

A. Beginning of received sequence
B. Beginning of transmitted sequence
C. End of received sequence
D. End of transmitted sequence
Answer» B. Beginning of transmitted sequence
12.

Gaussian channel is a hard decision channel.

A. True
B. False
Answer» C.
13.

Binary symmetric channel is hard decision channel.

A. True
B. False
Answer» B. False
14.

A binary symmetric channel is a

A. Discrete memoryless channel
B. Continuous memoryless channel
C. Discrete memory channel
D. Continuous memory channel
Answer» B. Continuous memoryless channel
15.

Soft decision decoding requires

A. Less memory
B. More memory
C. More speed
D. None of the mentioned
Answer» C. More speed
16.

If_the_quantization_level_of_a_demodulator_output_is__________then_it_is_called_as_soft_decision_decoding.

A. Equal to 2
B. More than 2
C. Less than 2
D. None of the mentioned
Answer» C. Less than 2
17.

How many number of transitions can be made at each bit time?

A. One
B. Two
C. Three
D. Half
Answer» C. Three
18.

Finite state machines have

A. Past memories also
B. Only present and future memories
C. Only future memories
D. Only present memories
Answer» B. Only present and future memories
19.

Periodic truncation is done by

A. Appending zero to end of the input data sequence
B. Appending zero to the beginning of the input data sequence
C. Appending one’s to end of the data sequence
D. Appending one’s to beginning of the data sequence
Answer» B. Appending zero to the beginning of the input data sequence
20.

The number of k bit shift over which a single information bit influences the encoder output is given by

A. Code rate
B. Constraint length
C. Code length
D. Code weight
Answer» C. Code length
21.

The measure of the amount of redundancy is given by

A. Code size
B. Code weight
C. Code rate
D. Minimum distance
Answer» D. Minimum distance