Modulation and Coding Trade-off MCQ [Free PDF] – Objective Question Answer for Modulation Coding Trade-off Quiz

1. QPSK is a composite of

A. Two BPSK
B. Three BPSK
C. Two FSK
D. Two M-ary PSK

Answer: A

QPSK is effectively a composite of two BPSK signals transmitted on orthogonal components of the carrier.

 

2. The IF transmission bandwidth of MFSK is

A. M/T
B. T/M
C. 2M/T
D. M/2

Answer: A

In non-coherent orthogonal MFSK modulation, the IF transmission bandwidth is WIF = M/T.

 

3. The bandwidth efficiency of MFSK is

A. M/log2M
B. log2M/M
C. M/log10M
D. log10M/M

Answer: B

For non-coherent orthogonal MFSK modulation, the bandwidth efficiency is R/W=log2M/M.

 

4. The bandwidth efficiency increases as M increases.

A. True
B. False

Answer: B

The bandwidth efficiency decreases as M increases.

 

5. The bandwidth efficiency of QFSK is _______ that of BFSK.

A. Greater than
B. Less than
C. Equal to
D. None of the mentioned

Answer: C

The bandwidth efficiency of QPSK is equal to that of the BFSK.

 

6. Which modulation is the most efficient one?

A. BPSK
B. BFSK
C. QPSK
D. QAM

Answer: D

Of all the modulation shown, QAM is the most bandwidth-efficient one.

 

7. The primary communication resource is

A. Transmitted power
B. Received power
C. Efficiency
D. None of the mentioned

Answer: A

The primary communication resources are transmitted power and channel bandwidth.

 

8. Greater the redundancy lesser is the bandwidth expansion.

A. True
B. False

Answer: B

Within the same block size, the code with greater redundancy requires more bandwidth expansion.

 

9. Which modulation scheme uses nonlinear transponders?

A. MSK
B. Offset QPSK
C. MSK & Offset QPSK
D. None of the mentioned

Answer: C

Offset QPSK and MSK are two examples of constant envelope modulation schemes that are attractive for systems using non-linear transponders.

 

10. Which modulation requires more bandwidth?

A. QPSK
B. OQPSK
C. BPSK
D. BFSK

Answer: C

BPSK requires more bandwidth than the other modulation techniques for the given level of spectral density.

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