Explore topic-wise MCQs in Digital Communications.

This section includes 15 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.

WHICH_SYSTEM_ALLOWS_LARGER_PROCESSING_GAIN??$

A. Direct sequence
B. Frequency hopping
C. Direct sequence & Frequency hopping
D. None of the mentioned
Answer» C. Direct sequence & Frequency hopping
2.

Which type of demodulator is used in the frequency hopping technique?$

A. Coherent
B. Non coherent
C. Coherent & Non coherent
D. None of the mentioned
Answer» C. Coherent & Non coherent
3.

In which technique is phase coherence hard to maintain?$

A. Direct sequence
B. Frequency hopping
C. Direct sequence & Frequency hopping
D. None of the mentioned
Answer» C. Direct sequence & Frequency hopping
4.

Which duration is shorter?

A. Hop duration
B. Symbol duration
C. Chip duration
D. None of the mentioned
Answer» B. Symbol duration
5.

Fast frequency hopping is

A. Several modulations per hop
B. Several modulations per symbol
C. Several symbols per modulation
D. None of the mentioned
Answer» E.
6.

Slow frequency hopping is

A. Several hops per modulation
B. Several modulations per hop
C. Several symbols per modulation
D. None of the mentioned
Answer» C. Several symbols per modulation
7.

Chips are the

A. Repeated symbols
B. Non repeated symbols
C. Smallest length symbols
D. None of the mentioned
Answer» B. Non repeated symbols
8.

Robustness gives the inability of a signal to withstand the impairments.

A. True
B. False
Answer» C.
9.

The minimum spacing between consecutive hop positions gives th?

A. Minimum number of chips necessary
B. Maximum number of chips necessary
C. Chip rate
D. None of the mentioned
Answer» B. Maximum number of chips necessary
10.

The frequency hopping system uses ______ modulation scheme.

A. FSK
B. BPSK
C. MFSK
D. MPSK
Answer» D. MPSK
11.

Which modulation scheme is preferred for direct sequence spread spectrum process?

A. BPSK
B. QPSK
C. BPSK & QPSK
D. None of the mentioned
Answer» D. None of the mentioned
12.

Chip is defined as

A. Shortest uninterrupted waveform
B. Largest uninterrupted waveform
C. Shortest diversion
D. None of the mentioned
Answer» B. Largest uninterrupted waveform
13.

The processing gain is given as

A. Wss/R
B. R/Wss
C. Wss/2R
D. R/2Wss
Answer» B. R/Wss
14.

In direct sequence process which step is performed first?

A. De-spreading
B. Demodulation
C. Despreading & Demodulation
D. None of the mentioned
Answer» B. Demodulation
15.

DS/BPSK includes

A. Despreading
B. Demodulation
C. Despreading & Demodulation
D. None of the mentioned
Answer» D. None of the mentioned