Question 21 : The coherent modulation techniques are
1. PSK
2. FSK
3. ASK
4. All of the mentioned
View Answer   Discuss with Members

Question 22 : In orthogonal signalling with symbols containing more number of bits we need ____ power.
1. More
2. Less
3. Double
4. None of the mentioned
View Answer   Discuss with Members

Question 23 : The error probability of DPSK is ________ worse than PSK.
1. Twice
2. 3 db
3. Twice (3db)
4. None of the mentioned
View Answer   Discuss with Members

Question 24 : Which modulation scheme is also called as on-off keying method?
1. ASK
2. FSK
3. PSK
4. GMSK
View Answer   Discuss with Members

Question 25 : The FSK signal which has a gentle shift from one frequency level to another is called as
1. Differential PSK
2. Continuous PSK
3. Differential & Continuous PSK
4. None of the mentioned
View Answer   Discuss with Members

Question 26 : The minimum required spacing is the difference between the
1. Center of the spectral main lobe and first zero crossing
2. First and second zero crossing
3. First and last zero crossing
4. None of the mentioned
View Answer   Discuss with Members

Question 27 : M-ary signalling produces _______ error performance with orthogonal signalling and _______ error performance with multiple phase signalling.
1. Degraded, improved
2. Improved, degraded
3. Improved, improved
4. Degraded, degraded
View Answer   Discuss with Members

Question 28 : The term heterodyning refers to
1. Frequency conversion
2. Frequency mixing
3. Frequency conversion & mixing
4. None of the mentioned
View Answer   Discuss with Members

Question 29 : The limit which represents the threshold Eb/N0 value below which reliable communication cannot be maintained is called as
1. Probability limit
2. Error limit
3. Shannon limit
4. Communication limit
View Answer   Discuss with Members

Question 30 : The relation between the probability of bit error and probability of symbol error in M-ary orthogonal signalling is
1. M/M-1
2. 2M/M-1
3. (M/2)/M-1
4. M/M+1
View Answer   Discuss with Members