Spread Spectrum Modulation Techniques

Wireless & Mobile Communications

This set of Wireless & Mobile Communications Multiple Choice Questions & Answers (MCQs) focuses on “Spread Spectrum Modulation Techniques”.

1. The transmission bandwidth of spread spectrum techniques is equal to the minimum required signal bandwidth.
a) True
b) False

2. Why spread spectrum technique is inefficient for a single user?
a) Large transmission bandwidth
b) Small transmission bandwidth
c) Fixed transmission bandwidth
d) Fixed null bandwidth

3. Which of the following is not a property of spread spectrum techniques?
a) Interference rejection capability
b) Multipath fading
c) Frequency planning elimination
d) Multiple user, multiple access interface

4. Which of the following is not a characteristic of PN sequence?
a) Nearly equal number of 0s and1s
b) Low correlation between shifted version of sequence
c) Non deterministic
d) Low cross-correlation between any two sequences

5. PN sequence can be generated using sequential logic circuits.
a) True
b) False

6. The period of a PN sequence produced by a linear m stage shift register cannot exceed _____ symbols.
a) 2m
b) m
c) 2m
d) 2m-1

7. DSSS system spreads the baseband signal by ________ the baseband pulses with a pseudo noise sequence.
a) Adding
b) Subtracting
c) Multiplying
d) Dividing

8. Frequency hopping involves a periodic change of transmission _______
a) Signal
b) Frequency
c) Phase
d) Amplitude

9. What is the set of possible carrier frequencies in FH-SS?
a) Hopset
b) Hop
c) Chips
d) Symbols

10. The bandwidth of the channel used in the hopset is called _________
a) Hopping bandwidth
b) Total hopping bandwidth
c) Instantaneous bandwidth
d) 3 dB bandwidth

11. The processing gain of FH systems is given by ratio of _______
a) Hopping bandwidth and hopping period
b) Instantaneous bandwidth and hopping duration
c) 3 dB bandwidth and bit rate
d) Total hopping bandwidth and instantaneous bandwidth

12. FH systems do not have collisions.
a) True
b) False

13. In fast frequency hopping, hopping rate is less than the information symbol rate.
a) True
b) False
View AnswerAnswer: b

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