1) The advantages of FDMA over TDMA includes
1. Division is simpler
2. Propagation delays are eliminated
3. Cheaper filters with less complicated logic functions
4. Linearity
a. 1, 2 and 3 are correct
b. 1 and 2 are correct
c. 1 and 4 are correct
d. All four are correct
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2) TDMA is a multiple access technique that has
a. Different users in different time slots
b. Each user is assigned unique frequency slots
c. Each user is assigned a unique code sequence
d. Each signal is modulated with frequency modulation technique
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3) In TDMA, the user occupies the whole bandwidth during transmission
a. True
b. False
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4) TDMA allows the user to have
a. Use of same frequency channel for same time slot
b. Use of same frequency channel for different time slot
c. Use of same time slot for different frequency channel
d. Use of different time slot for different frequency channels
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Answer
Explanation
Related Ques
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ANSWER: Use of same frequency channel for different time slot
Explanation:
No explanation is available for this question!
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5) GSM is an example of
a. TDMA cellular systems
b. FDMA cellular systems
c. CDMA cellular systems
d. SDMA cellular systems
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6) TDMA is employed with a TDMA frame that has preamble. The preamble contains Address of base station and subscribers
1. Synchronization information
2. Frequency allotted
3. Coded sequence
a. 1 and 2 are correct
b. 1, 2 and 3 are correct
c. 2 and 4 are correct
d. All four are correct
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7) CDMA is
1. Spread spectrum technology
2. Using same communication medium
3. Every user stays at a certain narrowband channel at a specific time period
4. Each user has unique PN code
a. 1, 2 and 3 are correct
b. 2 and 3 are correct
c. 1, 2 and 4 are correct
d. All four are correct
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8) Global Positioning System uses
a. CDMA
b. TDMA
c. SDMA
d. FDMA
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9) CDMA is advantageous over other Spread Spectrum techniques for
1. The privacy due to unique codes
2. It rejects narrow band interference
3. Resistance to multi path fading
4. Its ability to frequency reuse
a. 1, 2 and 3 are correct
b. 2 and 3 are correct
c. 1, 2 and 4 are correct
d. All the four are correct
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10) The wide band usage in CDMA helps in
1. Increased immunity to interference
2. Increased immunity to jamming
3. Multiple user access
4. Different spectrum allocation in different time slots
a. 1, 2 and 3 are correct
b. 2, 3 and 4 are correct
c. 1, 2 and 4 are correct
d. All the four are correct
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11) The advantages of using a CDMA technique over other spread spectrum techniques are
1. Increased capacity
2. Easier handoff
3. Better measure of security
4. Multiple users occupy different spectrum at a time
a. 1, 2 and 3 are correct
b. 2, 3 and 4 are correct
c. 1, 2 and 4 are correct
d. All the four are correct
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12) FHMA is
1. Spread spectrum technology
2. Using same communication medium
3. Every user has assigned unique frequency slot
4. Each user has unique PN code
a. 1 and 2 are correct
b. 1, 2 and 4 are correct
c. 2 and 4 are correct
d. All the four are correct
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13) OFDM is a technique of
1. Encoding digital data
2. Multiple carrier frequencies
3. Wide band digital communication
4. 4G mobile communication
a. 1, 2 and 3 are correct
b. 2 and 3 are correct
c. 1, 2 and 4 are correct
d. All the four are correct
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14) Advantages of using OFDM include
1. Avoids complex equalizers
2. Low symbol rate and guard interval
3. Avoids ISI
4. Multiple users at same frequency
a. 1, 2 and 3 are correct
b. 2 and 3 are correct
c. 1, 2 and 4 are correct
d. All the four are correct
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15) The troubles that OFDM faces over other spread spectrum techniques are
1. Sensitivity to Doppler shift
2. Frequency synchronization problems
3. Time synchronization problems
4. Low efficiency due to guard intervals
a. 1, 2 and 3 are correct
b. 2 and 3 are correct
c. 1, 2 and 4 are correct
d. All the four are correct
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16) The guard interval is provided in OFDM
a. To eliminate the need of pulse shaping filter
b. To eliminate ISI
c. High symbol rate
d. Both a and b
e. Both b and c
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17) Packet radio refers to
a. Multiple users on single channel
b. Single user on multiple channels as per demand
c. Multiple users on multiple channels at different time slots
d. Multiple users with coding techniques
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18) Disadvantages of packet radio are
a. Induced delays
b. Low spectral efficiency
c. Large spectrum required
d. Both a and b
e. Both b and c
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19) Pure ALOHA is a
a. Random access protocol
b. Scheduled access protocol
c. Hybrid access protocol
d. Demand access protocol
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20) The increase in number of users in PURE ALOHA causes
a. Increase in delay
b. Increase in probability of collision
c. Increase in spectrum
d. Both a and b
e. Both a and c
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21) SDMA technique employs
a. Smart antenna technology
b. Use of spatial locations of mobile units within the cell
c. More battery consumption
d. Both a and b are correct
e. Both b and c are correct
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22) The advantage of using SDMA over other spread spectrum technique is
a. Mobile station battery consumption is low
b. Reduced spectral efficiency
c. Increased spectral efficiency
d. Both a and b are correct
e. Both a and c are correct
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23) The increased capacity of SDMA is due to
a. Focused signal transmitted into narrow transmission beams
b. Smart antennas pointing towards mobile stations
c. Use of different frequencies at same time slot
d. Both a and b are correct
e. Both a and c are correct
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24) Coherence time is
a. Directly proportional to Doppler spread
b. Indirectly proportional to Doppler spread
c. Directly proportional to square of Doppler spread
d. Directly proportional to twice of Doppler spread
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25) Types of small scale fading, based on Doppler spread are
a. Fast fading
b. Frequency non selective fading
c. Flat fading
d. Frequency selective fading
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26) Flat fading or frequency nonselective fading is a type of
a. Multipath delay spread small scale fading
b. Doppler spread small scale fading
c. Both a & b
d. None of the above
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27) In Frequency Selective Fading, the
a. Coherence Bandwidth of the channel is less than bandwidth of transmitted channel
b. Coherence Bandwidth of the channel is more than bandwidth of transmitted channel
c. Coherence Bandwidth of the channel is equal to bandwidth of transmitted channel
d. None of the above
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Answer
Explanation
Related Ques
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ANSWER: Coherence Bandwidth of the channel is less than bandwidth of transmitted channel
Explanation:
No explanation is available for this question!
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28) If coherence time of the channel is smaller than the symbol period of the transmitted signal, it is
a. Fast fading
b. Slow fading
c. Frequency selective fading
d. Frequency non selective fading
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29) The power delay profile helps in determining
a. Excess delay
b. rms delay spread
c. Excess delay spread
d. All of the above
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30) Coherence bandwidth is
a. Channel that passes all spectral components with equal gain
b. The bandwidth of modulated signal
c. Channel that passes all spectral components with linear phase
d. Both a and c
e. Both a and b
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31) Small scale multipath propagation is caused due to waves with
1. Different propagation delays
2. Different amplitudes
3. Different phase
a. 1 and 2 are correct
b. 1 and 3 are correct
c. 2 and 3 are correct
d. All the three are correct
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32) The effects of small scale multipath propagation are
1. Changes in signal strength
2. Random frequency modulation
3. Time dispersion
a. 1 and 2 are correct
b. 1 and 3 are correct
c. 2 and 3 are correct
d. All the three are correct
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33) Impulse response of a multipath channel is determined by the fact that
a. Mobile radio channel may be modeled as linear filter
b. Impulse response is time varying
c. Both a & b
d. None of the above
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34) The received signal from a multipath channel is expressed as
a. Convolution of transmitted signal and impulse response
b. Addition of transmitted signal and impulse response
c. Subtraction of transmitted signal and impulse response
d. All of the above
e. None of the above
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Answer
Explanation
Related Ques
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ANSWER: Convolution of transmitted signal and impulse response
Explanation:
No explanation is available for this question!
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35) Direct RF pulse system helps in calculating
a. Impulse response in frequency domain
b. Impulse response in phase domain
c. Power delay of the channel
d. All of the above
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36) The techniques used for small scale multipath measurements are
1. Direct RF pulse system
2. Spread spectrum sliding correlator channel sounding
3. Frequency domain channel sounding
a. 1 and 2 are correct
b. 1 and 3 are correct
c. 2 and 3 are correct
d. All the three are correct
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