Digital Communications

Cellular Systems

Question 1
Marks : +2 | -2
Pass Ratio : 13%
If the active users using a cell doubles, the required Eb/I0
Doubles
Halves
Remains the same
None of the mentioned
Explanation:
If the active users were to double, then the received Eb/I0 would essentially be halved.
Question 2
Marks : +2 | -2
Pass Ratio : 7%
Which has more user capacity?
CDMA
AMPS
TDMA
None of the mentioned
Explanation:
CDMA has more user capacity compared to AMPS and TDMA.
Question 3
Marks : +2 | -2
Pass Ratio : 20%
Which technique is dimension limited?
TDMA
FDMA
TDMA & FDMA
None of the mentioned
Explanation:
TDMA and FDMA capacity is dimension limited.
Question 4
Marks : +2 | -2
Pass Ratio : 7%
Which type of channel does the forward link contain?
Paging
Pilot
Traffic
All of the mentioned
Explanation:
The forward link contains different types of channels such as paging, pilot, synchronization and traffic.
Question 5
Marks : +2 | -2
Pass Ratio : 7%
The types of channels that reverse channel contains are
Traffic
Access
Traffic & Access
None of the mentioned
Explanation:
The reverse channel contains two types of channels – traffic and access.
Question 6
Marks : +2 | -2
Pass Ratio : 27%
Bandwidth efficiency improvement involves
Dividing the geographical region into cells
Allowing frequency allocation
Dividing the geographical region into cells & Allowing frequency allocation
None of the mentioned
Explanation:
The idea of dividing the geographical region into cells and allowing frequency allocation of one cell can be reused represents bandwidth efficiency improvement methods.
Question 7
Marks : +2 | -2
Pass Ratio : 20%
In CDMA ______ frequency reuse is possible.
No
50%
90%
100%
Explanation:
In CDMA, 100% frequency reuse can be employed.
Question 8
Marks : +2 | -2
Pass Ratio : 13%
Which technique is interference limited?
TDMA
CDMA
AMPS
None of the mentioned
Explanation:
CDMA technique capacity is interference limited.
Question 9
Marks : +2 | -2
Pass Ratio : 53%
In the case of direct CDMA, interference will occur if the PN codes are
Orthogonal to each other
Non orthogonal to each other
Orthogonal & Non orthogonal to each other
None of the mentioned
Explanation:
If the PN codes are not purely orthogonal in direct CDMA interference will occur.
Question 10
Marks : +2 | -2
Pass Ratio : 20%
The steps followed in forward channel CDMA includes
Modulo 2 addition
Channelization
Modulo 2 addition & Channelization
None of the mentioned
Explanation:
Forward channel CDMA includes steps like modulo 2 addition, channelization, and base station identification.