# Coding Modulation - Electronic Engineering (MCQ) questions & answers

1)   For fixed symbol rate, increase in bits/symbol ultimately improves rb/B bits/s/Hz & hence, regarded as _____.

a. Power efficiency
b. Spectral efficiency
c. Transmission efficiency
d. Modulation eficiency
 Answer  Explanation ANSWER: Spectral efficiency Explanation: No explanation is available for this question!

2)   For designing a communication system, which among the following parameters should be maximum?

A. Transmission rate
C. Error probability
D. Bandwidth requirement

a. A & B
b. C & D
c. A & C
d. B & D
 Answer  Explanation ANSWER: A & B Explanation: No explanation is available for this question!

3)   For designing trellis code, the emphasis must be on maximizing __________

a. Euclidean distance between code vectors
b. Hamming distance of error correcting codes
c. Both a and b
d. None of the above
 Answer  Explanation ANSWER: Euclidean distance between code vectors Explanation: No explanation is available for this question!

4)   dfree is defined as the Euclidean distance of coded signal in terms of _________ possible distance between all allowed sequences.

a. smallest
b. largest
c. average
d. constant
 Answer  Explanation ANSWER: smallest Explanation: No explanation is available for this question!

5)   The distance between each symbol in given sequence and reference sequence is known as _______.

a. Euclidean Distance
b. Distance between sequences
c. Manmattan Distance
d. Hamming Distance
 Answer  Explanation ANSWER: Distance between sequences Explanation: No explanation is available for this question!

6)   In coding gain & bandwidth of TCM, if the signal energy is kept constant, the ________of constellation reduces the noise margin and results into the degradation of performance.

a. Expansion
b. Compression
c. Both a and b
d. None of the above
 Answer  Explanation ANSWER: Expansion Explanation: No explanation is available for this question!

7)   In digital communication system, if both power and bandwidth are limited, then which mechanism/choice is preferred?

a. Power efficient modulation
b. Bandwidth efficient modulation
c. Error control coding
d. Trellis coded modulation
 Answer  Explanation ANSWER: Error control coding Explanation: No explanation is available for this question!

8)   With respect to power-bandwidth trade-off, for reducing the transmit power requirement, the bandwidth needs to be ________.

a. Increased
b. Constant
c. Decreased
d. None of the above
 Answer  Explanation ANSWER: Increased Explanation: No explanation is available for this question!

9)   For a Gaussian channel of 1 MHz bandwidth with the signal power to noise spectral density ratio of about 104 Hz, what would be the maximum information rate?

a. 12000 bits/sec
b. 14400 bits/sec
c. 28000 bits/sec
d. 32500 bits/sec
 Answer  Explanation ANSWER: 14400 bits/sec Explanation: No explanation is available for this question!

10)   For a baseband system with transmission rate 'rs' symbols/sec, what would be the required bandwidth?

a. rs / 2 Hz
b. rs / 4 Hz
c. rs / 8 Hz
d. rs / 16 Hz
 Answer  Explanation ANSWER: rs / 4 Hz Explanation: No explanation is available for this question!