Wireless & Mobile Communications Questions & Answers

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Your preferred telecommunications specialists
Taiz Telecom for Telecom & IT Services
Wireless & Mobile Communications – (1000)
Questions & Answers
For Yemen Mobile Exam2018
Prepared by
Eng: AbdulEllah Qasim

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1. Which of the following is not a standard used for paging system?
a) POCSAG
b) ERMES
c) IS-95
d) FLEX
View Answer
Answer: c
2. Paging system uses which mode of transmission?
a) Full duplex
b) Simplex
c) Half Duplex
d) Duplex
View Answer
Answer: b
3. The information sent by paging system is known as a:
a) Note
b) Line
c) Message
d) Page
View Answer
Answer: d
4. Which type of message cannot be sent with the help of paging system?
a) Alphanumeric message
b) Video message
c) Voice message
d) Numeric message
View Answer
Answer: b
5. What is a paging access number?
a) An e mail id
b) A username
c) A toll free telephone number
d) A registration number
View Answer
Answer: c

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6. Which type of transmission technique is employed by paging system?
a) Simulcasting
b) Multicasting
c) Unicasting
d) Hybrid
View Answer
Answer: a
7. Which of the following is not the property of paging system?
a) Asymmetric communication
b) Light weight
c) High cost
d) Wide area coverage
View Answer
Answer: c
8. Which of the following properties describes the transmitters and receivers in paging system?
a) High complexity and high power transmitter, high complexity and high power receivers
b) Low complexity and low power transmitter, low complexity and low power receivers
c) Low complexity and low power transmitter, high complexity and high power receivers
d) High complexity and high power transmitter, low complexity and low power receivers
View Answer
Answer: d
9. What is a pager in the paging system?
a) A transmitter
b) A receiver
c) A transceiver
d) An equalizer
View Answer
Answer: b
10. Who introduced the paging system for the first time?
a) Al Gross
b) Teri Pall
c) Alexander Graham Bell
d) Martin Cooper
View Answer
Answer: a
11. Which of the following is a protocol used for cordless telephone system?
a) PACS
b) ERMES
c) IS-95
d) FLEX
View Answer
Answer: a

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12. In which frequency range do the cordless phones mostly work?
a) 43-50 MHz
b) 88-108 MHz
c) 540-1600 KHz
d) 200-540 KHz
View Answer
Answer: a
13. Which of the following is the drawback for cordless telephones?
a) Wireless technology
b) Limited coverage area
c) Mobile
d) Security
View Answer
Answer: b
14. Which of the following is a fully digital cordless system?
a) CT0
b) CT1
c) CT1+
d) DECT
View Answer
Answer: d
15. Which of the following is an example of local wireless system?
a) GSM
b) Cordless telephone system
c) UMTS
d) EDGE
View Answer
Answer: b
16. Which of the following is not a standard for cordless telephony?
a) CT-2
b) DECT
c) UMTS
d) PHS
View Answer
Answer: c
17. What is the range of cell diameter of DECT?
a) 300 m
b) 2 km
c) 10 km
d) 70 km
View Answer
Answer: a

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18. Which of the following standard of cordless telephone system is also approved as a 3G standard?
a) PHS
b) PACS
c) DECT
d) CT2
View Answer
Answer: c
19. Cordless telephone system will not work under which of the following criteria?
a) Within a home
b) Within a building
c) Within campus
d) Within a city
View Answer
Answer: d
20. Which of the following is not an application of DECT?
a) Multimedia processing
b) Cordless private branch exchange
c) Wireless local loop
d) Home cordless phones
View Answer
Answer: a
21. Which of the following is not a characteristic of cellular telephone system?
a) Accommodate large number of users
b) Large geographic area
c) Limited frequency spectrum
d) Large frequency spectrum
View Answer
Answer: d
22. What is the responsibility of MSC in cellular telephone system?
a) Connection of mobile to base stations
b) Connection of mobile to PSTN
c) Connection of base station to PSTN
d) Connection of base station to MSC
View Answer
Answer: b
23. Who has the responsibility of billing and system maintenance function in cellular system?
a) Base Station
b) PSTN
c) MSC
d) Mobile system
View Answer
Answer: c

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24. What is the function of FVC (Forward Voice Channel)?
a) Voice transmission from base station to mobiles
b) Voice transmission from mobile to base station
c) Initiating mobile calls
d) Broadcast all traffic request for all mobile
View Answer
Answer: a
25. Which two channels are responsible for initiating mobile calls?
a) FVC and FCC
b) FVC and RVC
c) FCC and RCC
d) FCC and RVC
View Answer
Answer: c
26. Of the total channels present in the cellular system, what is the percentage of voice and control channels?
a) 95% voice channels, 5% control channels
b) 5% voice channels, 95% control channels
c) 50% voice channels, 50% control channels
d) 25% voice channels, 75% control channels
View Answer
Answer: a
27. What is MIN?
a) Subscriber’s telephone number
b) Paging message
c) Traffic request number
d) Mobile Internet
View Answer
Answer: a
28. What is transmitted along with the call initiation request during the origin of call by a mobile?
a) MIN
b) ESN
c) ESN and SCM
d) MIN, ESN and SCM
View Answer
Answer: d
29. What does SCM indicates?
a) Maximum receiver power level for a particular user
b) Maximum transmitter power level for a particular user
c) Minimum receiver power level for a particular user
d) Minimum transmitter power level for a particular user
View Answer
Answer: b

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30. What is the shape of the cell present in the cellular system?
a) Circular
b) Square
c) Hexagonal
d) Triangular
View Answer
Answer: c
31. Why the size of the cell is kept small in cellular network?
a) Increase capacity
b) Decrease capacity
c) Increased size of base station electronics
d) Slow process of handoffs
View Answer
Answer: a
32. What is handoff?
a) Forward channel
b) Switching technique
c) Roamer
d) Guard channel
View Answer
Answer: b
33. Which of the following multiple access techniques are used by second generation cellular systems?
a) FDMA/FDD and TDMA/FDD
b) TDMA/FDD and CDMA/FDD
c) FDMA/FDD and CDMA/FDD
d) FDMA/FDD only
View Answer
Answer: b
34. Which one is not a TDMA standard of second generation networks?
a) GSM
b) IS-136
c) AMPS
d) PDC
View Answer
Answer: c
35. Which of the following is a CDMA standard of second generation network?
a) IS-95
b) IS-136
c) ETACS
d) EDGE
View Answer

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Answer: a
36. Popular 2G CDMA standard IS-95 is also known as ______
a) CdmaOne
b) CdmaTwo
c) IS-136
d) IS-95B
View Answer
Answer: a
37. How many users or voice channels are supported for each 200 KHz channel in GSM?
a) Eight
b) Three
c) Sixty four
d) Twelve
View Answer
Answer: a
38. How many voice channels are supported for each 30 KHz radio channel in IS-136?
a) Eight
b) Thirty
c) Three
d) Sixteen
View Answer
Answer: c
39. How many users are supported in IS-95 for each 1.25 MHz?
a) Eight
b) Sixty four
c) Sixteen
d) Twenty five
View Answer
Answer: b
40. Which modulation technique is used by GSM?
a) GMSK
b) BPSK
c) QPSK
d) GFSK
View Answer
Answer: a
41.IS-95 uses which modulation technique?
a) GMSK
b) BPSK
c) QAM
d) AFSK
View Answer

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Answer: b
42. IS-136 uses which modulation technique?
a) π/4 DQPSK
b) BPSK
c) GMSK
d) AFSK
View Answer
Answer: a
43. Which is one of the disadvantages of 2G standards?
a) Short Messaging Service (SMS)
b) Digital modulation
c) Limited capacity
d) Limited Internet Browsing
View Answer
Answer: d
44. GSM (Global System for Mobile) was earlier also known as _______
a) Group System Mobile
b) Global Special Meaning
c) Group Special Mobile
d) Global Special Mobile
View Answer
Answer: c
45. What is the name of the web browsing format language supported by 2.5G technology?
a) Wireless Application Protocol
b) Hypertext Markup Language
c) Extensible Markup Language
d) Hypertext Transfer Protocol
View Answer
Answer: a
46. What is the name of the internet micro browser technology used by NTT DoCoMo in Japan?
a) Wireless Application Protocol
b) I-mode
c).W-mode
d) Hypertext Markup Language
View Answer
Answer: b
47. 2.5G upgrade path for a particular wireless carrier does not match the original 2G technology choice made
earlier by the same carrier. (True or False).
a) True
b) False
View Answer
Answer: b

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48. Which of the following is not a TDMA standard of 2.5G network?
a) HSCSD
b) GPRS
c) EDGE
d) GSM
View Answer
Answer: d
49. Which of the following is a 2.5G CDMA standard?
a) IS-95
b) Cdma2000
c) IS-95B
d) CdmaOne
View Answer
Answer: c
50. HSCSD supports which 2G standard?
a) GSM
b) IS-136
c) GSM and IS-136
d) PDC
View Answer
Answer: a
51. How does HSCSD differs from the GSM to obtain higher speed data rate?
a) By allowing single user to use one specific time slot
b) By allowing single user to use consecutive user time slots
c) By using 8-PSK modulation technique
d) By allowing multiple users to use individual time slot
View Answer
Answer: b
52. GPRS and EDGE supports which 2G standard?
a) GSM only
b) IS-136 only
c) GSM and IS-136 both
d) PDC
View Answer
Answer: c
53. How is HSCSD different from GPRS?
a) Infrastructure
b) Multiple Access Scheme
c) Modulation technique
d) Switching Technique
View Answer
Answer: d

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54. What changes GPRS need to acquire while upgrading itself from GSM?
a) A whole new base station
b) New transceiver at base station
c) New channel cards
d) New packet overlay including routers and gateways
View Answer
Answer: d
55. Which new modulation technique is used by EDGE?
a) BPSK
b) 8- PSK
c) DQPSK
d) AFSK
View Answer
Answer: b
56. Various air interface formats used by EDGE are also known as ______
a) Modulation and coding schemes
b) Coding schemes
c) Modulating air interface
d) Air interface coding schemes
View Answer
Answer: a
60. Which of the following is not a characteristic of 3G network?
a) Communication over VoIP
b) Unparalleled network capacity
c) Multi-megabit Internet access
d) LTE based network
View Answer
Answer: d
61. What is the term used by ITU for a set of global standards of 3G systems?
a) IMT 2000
b) GSM
c) CDMA
d) EDGE
View Answer
Answer: a
62. Which of the following leads to evolution of 3G networks in CDMA systems?
a) IS-95
b) IS-95B
c) CdmaOne
d) Cdma2000
View Answer

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Answer: d
63. Which of the following leads to the 3G evolution of GSM, IS-136 and PDC systems?
a) W-CDMA
b) GPRS
c) EDGE
d) HSCSD
View Answer
Answer: a
64. What is 3GPP?
a) Project based on W-CDMA
b) Project based on cdma2000
c) Project based on 2G standards
d) Project based on 2.5G standards
View Answer
Answer: a
65. What is 3GPP2?
a) Project based on W-CDMA
b) Project based on cdma2000
c) Project based on 2G standards
d) Project based on 2.5G standards
View Answer
Answer: b
66. Which of the following is not a standard of 3G?
a) UMTS
b) Cdma2000
c) TD-SCDMA
d) LTE
View Answer
Answer: d
67. Which of the following 3G standard is used in Japan?
a) Cdma2000
b) TD-SCDMA
c) UMTS
d) UTRA
View Answer
Answer: c
68. What does the number 2000 in IMT-2000 signifies?
a) Year
b) Number of subscribers per cell
c) Number of cells
d) Area (Km)
View Answer

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Answer: a
69. Which of the following is not an application of third generation network?
a) Global Positioning System (GPS)
b) Video conferencing
c) Mobile TV
d) Downloading rate upto 1 Gbps
View Answer
Answer: d
70. What is the full form of UMTS?
a) Universal Mobile Telephone System
b) Ubiquitous Mobile Telephone System
c) Ubiquitous Mobile Telemetry System
d) Universal Machine Telemedicine System
View Answer
Answer: a
71. UMTS uses which multiple access technique?
a) CDMA
b) TDMA
c) FDMA
d) SDMA
View Answer
Answer: a
72. UMTS does not has backward compatibility with ____
a) GSM
b) IS-136
c) IS-95
d) GPRS
View Answer
Answer: c
73. UMTS is also known as _____
a) IS-95
b) GPRS
c) CdmaOne
d) W-CDMA
View Answer
Answer: d
74. What is the chip rate of W-CDMA?
a) 1.2288 Mcps
b) 3.84 Mcps
c) 270.833 Ksps
d) 100 Mcps
View Answer

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Answer: b
75. W-CDMA works in FDD mode only. (True/ False)
a) True
b) False
View Answer
Answer: b
76. How much packet data rate per user is supported by W-CDMA if the user is stationary?
a) 2.048 Kbps
b) 100 Mbps
c) 2.048 Mbps
d) 1 Gbps
View Answer
Answer: c
77. What is the minimum spectrum allocation required by W-CDMA?
a) 5 MHz
b) 20MHz
c) 1.25 MHz
d) 200 KHz
View Answer
Answer: a
78. W-CDMA requires a complete change of RF equipment at each base station. (True/False)
a) True
b) False
View Answer
Answer: a
79. How much increase in spectral efficiency is provided by W-CDMA in comparison to GSM?
a) Two times
b) Three times
c) No increase
d) Six times
View Answer
Answer: d
80. Which of the following has no backward compatibility with 3G Cdma2000?
a) IS-95
b) GPRS
c) IS-95A
d) IS-95B
View Answer
Answer: b
81.2G and 2.5G CDMA operators may selectively introduce 3G capabilities at each cell without changing entire
base stations and reallocate spectrums. (True or False)
a) True

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b) False
View Answer
Answer: a
82. Which of the following the first 3G CDMA air interface?
a) IS-95
b) IS-95B
c) Cdma2000 1xRTT
d) CdmaOne
View Answer
Answer: c
83. Within ITU IMT-2000 body, Cdma2000 1xRTT is also known as ____
a) Cdma2000 1xEV-DO
b) Cdma2000 1xEV-DV
c) IS-95B
d) G3G-MC-CDMA-1X
View Answer
Answer: d
84. How many users are supported by Cdma2000 1X in comparison to 2G CDMA standard?
a) Half
b) Twice
c) Six times
d) Ten times
View Answer
Answer: b
85. Cdma2000 works in TDD mode only. State whether True or False.
a) True
b) False
View Answer
Answer: b
86. Which of the following is not a characteristic of Cdma2000?
a) Adaptable baseband signalling rates
b) Adaptable baseband chipping rates
c) Multicarrier technologies
d) OFDMA
View Answer
Answer: d
87. Cdma2000 1xEV was developed by ____
a) Motorola
b) AT&T Laboratories
c) Qualcomm
d) NTT
View Answer

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Answer: c
88. How is bandwidth increased in Cdma2000?
a) Clubbing adjacent radio channels
b) Changing the hardware of base stations
c) Change of spectrum
d) Change of RF equipment
View Answer
Answer: a
89. What are the two options provided by Cdma2000 1xEV?
a) Cdma2000 1xRTT. Cdma2000 3xRTT
b) Cdma2000 1xEV-DO, Cdma2000 1xEV-DV
c) Cdma2000 1xEV-DT, Cdma2000 1xEV-DO
d) Cdma2000 1xRTT, Cdma2000 1xEV-DV
View Answer
Answer: b
90. What is the full form of WLAN?
a) Wide Local Area Network
b) Wireless Local Area Network
c) Wireless Land Access Network
d) Wireless Local Area Node
View Answer
Answer: b
91. WLANs use high power levels and generally require a license for spectrum use. (True or False)
a) True
b) False
View Answer
Answer: b
92. What is the name of 300 MHz of unlicensed spectrum allocated by FCC in ISM band?
a) UNII
b) Unlicensed PCS
c) Millimetre wave
d) Bluetooth
View Answer
Answer: a
93. Which of the following specifies a set of media access control (MAC) and physical layer specifications for
implementing WLANs?
a) IEEE 802.16
b) IEEE 802.3
c) IEEE 802.11
d) IEEE 802.15
View Answer
Answer: c

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94. Which of the following is not a standard of WLAN?
a) HIPER-LAN
b) HIPERLAN/2
c) IEEE 802.11b
d) AMPS
View Answer
Answer: d
95. Which of the following is the 802.11 High Rate Standard?
a) IEEE 802.15
b) IEEE 802.15.4
c) IEEE 802.11g
d) IEEE 802.11b
View Answer
Answer: d
96. Which of the following spread spectrum techniques were used in the original IEEE 802.11 standard?
a) FHSS and DSSS
b) THSS and FHSS
c) THSS and DSSS
d) Hybrid technique
View Answer
Answer: a
97. Which of the following WLAN standard has been named Wi-Fi?
a) IEEE 802.6
b) IEEE 802.15.4
c) DSSS IEEE 802.11b
d) IEEE 802.11g
View Answer
Answer: c
98. Which of the following is developing CCK-OFDM?
a) IEEE 802.11a
b) IEEE 802.11b
c) IEEE 802.15.4
d) IEEE 802.11g
View Answer
Answer: d
99. What is the data rate of HomeRF 2.0?
a) 10 Mbps
b) 54 Mbps
c) 200 Mbps
d) 1 Mbps
View Answer
Answer: a

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100. HIPER-LAN stands for ______
a) High Precision Radio Local Area Network
b) High Performance Radio Local Area Network
c) High Precision Radio Land Area Network
d) Huge Performance Radio Link Access Node
View Answer
Answer: b
101. What is the range of asynchronous user data rates provided by HIPER-LAN?
a) 1-100 Mbps
b) 50-100 Mbps
c) 1-20 Mbps
d) 500 Mbps to 1 Gbps
View Answer
Answer: c
102. What is the name of the European WLAN standard that provides user data rate up to 54 Mbps?’
a) UNII
b) WISP
c) MMAC
d) HIPERLAN/2
View Answer
Answer: d
103. What is WISP?
a) Wideband Internet Service Protocol
b) Wireless Internet Service Provider
c) Wireless Instantaneous Source Provider
d) Wideband Internet Source Protocol
View Answer
Answer: b
104. The price of WLAN hardware is more than 3G telephones and fixed wireless equipment.(True or False)
a) True
b) False
View Answer
Answer: b
105. Which of the following is not an open standard?
a) Bluetooth
b) WWW
c) HTML
d) VPN
View Answer
Answer: d
106. What is the nominal range of Bluetooth?
a) 1 Km

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b) 10 m
c) 1 m
d) 10 Km
View Answer
Answer: b
107. Bluetooth standard is named after ______
a) King Ronaldo Bluetooth
b) Pope Vincent Bluetooth
c) King Herald Bluetooth
d) Pope Francis Bluetooth
View Answer
Answer: c
108. Bluetooth operates in which band?
a) Ka Band
b) L Band
c) Ku Band
d) 2.4 GHz ISM Band
View Answer
Answer: d
109. Which of the following scheme is used by Bluetooth?
a) Frequency hopping TDD scheme
b) Frequency hopping FDD scheme
c) DSSS TDD scheme
d) DSSS FDD scheme
View Answer
Answer: a
110. What is the range of time slot in Bluetooth?
a) 120 milliseconds
b) 625 microseconds
c) 577 microseconds
d) 5.7 seconds
View Answer
Answer: b
111. Which modulation scheme is used by Bluetooth?
a) DQPSK
b) MSK
c) GFSK
d) BPSK
View Answer
Answer: c
112. What is the channel symbol rate in Bluetooth for each user?
a) 270.833 Kbps

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b) 1 Gbps
c) 100 Mbps
d) 1 Mbps
View Answer
Answer: d
113. What is the raw channel bit error rate of Bluetooth?
a) 10-3
b) 10-10
c) 103
d) 10-1
View Answer
Answer: a
114. Which of the following standard committee specifies Bluetooth and other Personal Area Networks (PAN)?
a) IEEE 802.11b
b) IEEE 802.15
c) IEEE 802.11g
d) IEEE 802.16
View Answer
Answer: b
115. Cellular concept replaces many low power transmitters to a single high power transmitter. (True or False)
a) True
b) False
View Answer
Answer: b
116. Why neighboring stations are assigned different group of channels in cellular system?
a) To minimize interference
b) To minimize area
c) To maximize throughput
d) To maximize capacity of each cell
View Answer
Answer: a
117. What is a cell in cellular system?
a) A group of cells
b) A group of subscribers
c) A small geographical area
d) A large group of mobile systems
View Answer
Answer: a
118. What is frequency reuse?
a) Process of selecting and allocating channels
b) Process of selection of mobile users
c) Process of selecting frequency of mobile equipment

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d) Process of selection of number of cells
View Answer
Answer: a
119. Which of the following is a universally adopted shape of cell?
a) Square
b) Circle
c) Triangle
d) Hexagon
View Answer
Answer: d
120. Actual radio coverage of a cell is called _____
a) Fingerprint
b) Footprint
c) Imprint
d) Matrix
View Answer
Answer: b
121. Why the shape of cell is not circle?
a) Omni directionality
b) Small area
c) Overlapping regions or gaps are left
d) Complex design
View Answer
Answer: c
122. What is the main reason to adopt hexagon shape in comparison to square and triangle?
a) Largest area
b) Simple design
c) Small area
d) Single directional
View Answer
Answer: a
123. Which type of antenna is used for center excited cells?
a) Dipole antenna
b) Grid antenna
c) Sectored antenna
d) Omnidirectional antenna
View Answer
Answer: d
124. Which type of antenna is used for edge excited cells?
a) Omnidirectional antenna
b) Grid antenna
c) Sectored directional antenna

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d) Dipole antenna
View Answer
Answer: c
125. For a cellular system, if there are N cells and each cell is allocated k channel. What is the total number of
available radio channels, S?
a) S=k*N
b) S=k/N
c) S=N/k
d) S=kN
View Answer
Answer: a
126. What is a cluster in a cellular system?
a) Group of frequencies
b) Group of cells
c) Group of subscribers
d) Group of mobile systems
View Answer
Answer: b
127. What is a frequency reuse factor for N number of cells in a system?
a) N
b) N2
c) 2*N
d) 1/N
View Answer
Answer: d
128. Capacity of a cellular system is directly proportional to _____
a) Number of cells
b) Number of times a cluster is replicated
c) Number of Base stations
d) Number of users
View Answer
Answer: b
129. A spectrum of 30 MHz is allocated to a cellular system which uses two 25 KHz simplex channels to provide full
duplex voice channels. What is the number of channels available per cell for 4 cell reuse factor?
a) 150 channels
b) 600 channels
c) 50 channels
d) 85 channels
View Answer
Answer: a
130. Which of the following is not an objective for channel assignment strategies?
a) Efficient utilization of spectrum

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b) Increase of capacity
c) Minimize the interference
d) Maximize the interference
View Answer
Answer: d
131. The choice of channel assignment strategy does not impact the performance of the system. State whether
True or False.
a) True
b) False
View Answer
Answer: b
132. In fixed channel assignment strategy, each cell is allocated a predetermined set of _______
a) Voice channels
b) Control channels
c) Frequency
d) base stations
View Answer
Answer: a
133. What happen to a call in fixed channel strategy, if all the channels in a cell are occupied?
a) Queued
b) Cross talk
c) Blocked
d) Delayed
View Answer
Answer: c
134. What is a borrowing strategy in fixed channel assignments?
a) Borrowing channels from neighbouring cell
b) Borrowing channels from neighbouring cluster
c) Borrowing channels from same cell
d) Borrowing channels from other base station in same cell
View Answer
Answer: a
135. In dynamic channel assignment strategy, voice channels are allocated to different cells permanently. State
whether True or False.
a) True
b) False
View Answer
Answer: b
136. In dynamic channel assignment strategy, base station requests channel from ______
a) MSC
b) Neighbouring cell
c) Neighbouring cluster

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d) Neighbouring base station
View Answer
Answer: a
137. Dynamic channel assignment reduces the likelihood of blocking in comparison to fixed channel assignment.
State whether True or False.
a) True
b) False
View Answer
Answer: a
138. RSSI stands for ________
a) Radio System Signal Indicator
b) Restricted Signal Strength Indicator
c) Radio Signal Strength Indication
d) Restricted System Software Indicator
View Answer
Answer: a
139. What is the drawback of dynamic channel assignment?
a) Decrease channel utilization
b) Increase probability of blocked call
c) Cross talk
d) Increase storage and computational load on system
View Answer
Answer: d
140. What is the condition for handoff?
a) A mobile moves into a different cell while in conversation
b) A mobile remains in the same cell while in conversation
c) A mobile moves to different cell when idle
d) A mobile remains in the same cell and is idle
View Answer
Answer: a
141. Handoff does not require voice and control channel to be allocated to channels associated with the new base
station. State whether True or False.
a) True
b) False
View Answer
Answer: b
142. The time over which a call can be maintained within a cell without handoff is called ______
a) Run time
b) Peak time
c) Dwell time
d) Cell time
View Answer

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Answer: c
143. Dwell time does not depend on which of the following factor?
a) Propagation
b) Interference
c) Distance between subscriber and base station
d) Mobile station
View Answer
Answer: d
144. Which of the following is associated with the handoff in first generation analog cellular systems?
a) Locator receiver
b) MAHO
c) Cell dragging
d) Breathing cell
View Answer
Answer: a
145. MAHO stands for ______
a) MSC assisted handoff
b) Mobile assisted handoff
c) Machine assisted handoff
d) Man assisted handoff
View Answer
Answer: b
146. A handoff is initiated when the power received from the base station of a neighbouring cell falls behind the
power received from the current base station by certain level. State whether True or False.
a) True
b) False
View Answer
Answer: b
147. What is the condition for intersystem interference?
a) Mobile moves from one cell to another cell
b) Mobile remains in the same cell
c) Mobile moves from one cellular system to another cellular system
d) Mobile remains in the same cluster
View Answer
Answer: c
148. What is the disadvantage of guard channel?
a) Efficient utilization of spectrum
b) Cross talk
c) Near far effect
d) Reduce total carried traffic
View Answer
Answer: d

26
149. Which of the following priority handoff method decrease the probability of forced termination of a call due
to lack of available channels?
a) Queuing
b) Guard channel
c) Cell dragging
d) Near far effect
View Answer
Answer: a
150. Umbrella cell approach is possible by using ______
a) Antenna of same heights
b) Antenna of different heights
c) Different voice channels
d) Different control channels
View Answer
Answer: b
151. Cell dragging is a problem occur due to ______
a) Pedestrian users
b) Stationary users
c) High speed mobile systems
d) Base stations having same frequency
View Answer
Answer: a
152. Which of the following is not a source of interference?
a) Base station in different cluster
b) Another mobile in same cell
c) A call in progress in neighbouring cell
d) Any BS operating on same frequency
View Answer
Answer: a
153. Interference on voice channels causes _______
a) Blocked calls
b) Cross talk
c) Queuing
d) Missed calls
View Answer
Answer: b
154. Interference in control channel leads to ________
a) Cross talk
b) Queuing
c) Blocked calls
d) Voice traffic
View Answer

27
Answer: c
155. Interference is more severe in rural areas. State whether True or False.
a) True
b) False
View Answer
Answer: b
156. What are co-channel cells?
a) Cells having different base stations
b) Cells using different frequency
c) Cells using adjacent frequency
d) Cells using same frequency
View Answer
Answer: d
157. Co-channel interference is a function of ______
a) Radius of cell
b) Transmitted power
c) Received power
d) Frequency of mobile user
View Answer
Answer: a
158. Co-channel reuse ratio is define by ______
a) Q=D*R
b) Q=D/R
c) Q=D^R
d) Q=1/R
View Answer
Answer: b
159. Co-channel ratio in terms of cluster size is defined as ______
a) √(3N)
b) N
c) 3N
d) √N
View Answer
Answer: a
160. What is the cluster size for CDMA?
a) N=10
b) N=100
c) N=1
d) N=50
View Answer
Answer: c
161. What is breathing cell effect?

28
a) Fixed coverage region
b) Dynamic and time varying coverage region
c) Large coverage region
d) Very small coverage region
View Answer
Answer: b
162. Adjacent channel interference occurs due to _______
a) Power transmitted by Base station
b) MSCs
c) Same frequency of mobile users
d) Imperfect receiver filters
View Answer
Answer: d
163. Which of the following problem occur due to adjacent channel interference?
a) Blocked calls
b) Cross talk
c) Near-far effect
d) Missed calls
View Answer
Answer: c
164. In near-far effect, a nearby transmitter captures the __________
a) Receiver of the subscriber
b) Transmitter of the subscriber
c) Nearby MSC
d) Neighbouring base station
View Answer
Answer: a
165. Adjacent channel interference can be minimized through _______
a) Changing frequency of base stations
b) Careful filtering and channel assignments
c) Increasing number of base stations
d) Increasing number of control channels
View Answer
Answer: b
166. In dynamic channel assignment, any channel which is being used in one cell can be reassigned simultaneously
to another cell in the system at a reasonable distance. State whether True or False.
a) True
b). False
View Answer
Answer: a
167. What is the concept for accommodating a large number of users in a limited radio spectrum?
a) Grade of service

29
b) Trunking
c) Multiplexing
d) Multitasking
View Answer
Answer: b
168. On termination of call, the occupied channel is not returned to the pool of available channels in trunking.
a) True
b) False
View Answer
Answer: b
169. In trunking system, when the channel is already in use, the call is blocked or queued. State whether True or
False.
a) True
b) False
View Answer
Answer: a
170. Who developed the fundamental of trunking theory?
a) Newton
b) Ohm
c) Erlang
d) Einstein
View Answer
Answer: c
171. What is the unit for the measure of traffic intensity?
a) Meters
b) Henry
c) Ohm
d) Erlang
View Answer
Answer: d
172. One Erlang represents _________
a) One call- hour per hour
b) One call-minute per hour
c) One call- hour per minute
d) Many calls- hour per hour
View Answer
Answer: a
173. What is the measure of the ability of user to access a trunked system during the busiest hour?
a) Trunking
b) Grade of Service (GOS)
c) Multiplexing

30
d) Sectoring
View Answer
Answer: a
174. GOS is typically given as a likelihood that a ________
a) Call is in progress
b) Channels are busy
c) Call is blocked
d) Channel are free
View Answer
Answer: c
175. The time requires to allocate a trunked radio channel to a requesting user is called _______
a) Dwell time
b) Holding time
c) Run time
d) Set up Time
View Answer
Answer: d
176. Average duration of a typical call is called ________
a) Holding time
b) Dwell time
c) Set up time
d) Run time
View Answer
Answer: a
177. The average number of call requests per unit time is also known as ________
a) Request rate
b) Load
c) Grade o Service
d) Traffic intensity
View Answer
Answer: a
178. Traffic intensity offered by each user is the product of __________
a) Set up time and holding time
b) Call request rate and holding time
c) Load and holding time
d) Call request rate and set up time
View Answer
Answer: b
179. AMPS cellular system is designed for a GOS of _____ blocking.
a) 10%
b) 50 %

31
c) 2%
d) 1%
View Answer
Answer: c
180. Blocked calls cleared formula is also known as _______ formula.
a) Erlang C
b) Erlang A
c) Erlang D
d) Erlang B
View Answer
Answer: d
181. Blocked calls delayed formula is also known as _______
a) Erlang A
b) Erlang B
c) Erlang C
d) Erlang D
View Answer
Answer: c
182. Which of the following techniques do not help in expanding the capacity of cellular system?
a) Sectoring
b) Scattering
c) Splitting
d) Microcell zone concept
View Answer
Answer: b
183. ________ uses directional antennas to control interference.
a) Sectoring
b) Cell splitting
c) Repeaters
d) Micro cell zone concept
View Answer
Answer: a
184. _______ allows an orderly growth of cellular system.
a) Sectoring
b) Scattering
c) Cell splitting
d) Micro cell zone technique
View Answer
Answer: c
185. Which of the following technology distributes the coverage of the cell and extends the cell boundary to hard-
to-reach places?
a) Cell splitting

32
b) Scattering
c) Sectoring
View Answer
Answer: d
186. Which of the following increases the number of base stations in order to increase capacity?
a) Cell splitting
b) Sectoring
c) Repeaters
View Answer
Answer: a
187. Which of the following trunking inefficiencies?
a) Cell splitting
b) Micro cell zone technique
c) Sectoring
d) Repeaters
View Answer
Answer: c
188. The process of subdividing a congested cell into smaller cells is called _______
a) Cell splitting
b) Sectoring
c) Micro cell technique
d) Repeaters
View Answer
Answer: a
189. Cell splitting increases the capacity of a cellular system since it increases the number of times ________ are
reused.
a) Cells
b) Channels
c) Transmitters
d) Mobile stations
View Answer
Answer: b
190. Cell splitting do not maintain the minimum c-channel reuse ratio. State whether True or False.
a) True
b) False
View Answer
Answer: b
191. Which of the following technique is used to limit radio coverage of newly formed microcells?
a) Sectoring
b) Splitting

33
c) Antenna downtilting
d) Scattering
View Answer
Answer: c
192. Sectoring increases SIR (Signal to Interference Ratio). State True or False.
a) True
b) False
View Answer
Answer: a
193. Which of the following has range extension capability?
a) Sectoring
b) Repeaters
c) Scattering
View Answer
Answer: b
194. Repeaters has one drawback of reradiating ____________
a) Frequency
b) Channels
c) Power
d) Repeater noise and interference
View Answer
Answer: d
195. Which of the following is not an advantage of micro cell zone technique?
a) Reduced co channel interference
b) Improved signal quality
c) Increase in capacity
d) Increasing number of base stations
View Answer
Answer: d
196. In a micro cell zone concept, when a mobile travels from one zone to another within the cell, it retains the
same _________
a) Power level
b) Base station
c) Channel
d) Receiver
View Answer
Answer: c
197. The mechanism behind electromagnetic wave propagation cannot be attributed to _____
a) Reflection
b) Diffraction
c) Scattering

34
d) Sectoring
View Answer
Answer: d
198. The propagation model that estimates radio coverage of a transmitter is called ___________
a) Large scale propagation model
b) Small scale propagation model
c) Fading model
d) Okumura model
View Answer
Answer: a
199. Propagation model that characterize rapid fluctuation is called _________
a) Hata model
b) Fading model
c) Large scale propagation model
d) Okumura model
View Answer
Answer: b
200. Small scale propagation model is also known as _______
a) Fading model
b) Micro scale propagation model
c) Okumura model
d) Hata model
View Answer
Answer: a
201. Free space propagation model is to predict ______
a) Received signal strength
c) Gain of transmitter
d) Gain of receiver
View Answer
Answer: a
202. Which of the following do not undergo free space propagation?
a) Satellite communication system
b) Microwave line of sight radio links
c) Wireless line of sight radio links
d) Wired telephone systems
View Answer
Answer: d
203. The free space model predicts that received signal decays as a function of _____
a) Gain of transmitter antenna
b) T-R separation

35
c) Power of transmitter antenna
d) Effective aperture of the antenna
View Answer
Answer: b
204. Relation between gain and effective aperture is given by ______
a) G=(4πAe)/λ2
b) G=(4π λ2)/ Ae
c) G=4πAe
d) G=Ae/λ2
View Answer
Answer: a
209. Relation between wavelength and carrier frequency is _____
a) λ=c/f
b) λ=c*f
c) λ=f/c
d) λ=1/f
View Answer
Answer: a
210. Which of the following antenna radiates power with unit gain uniformly in all directions?
a) Directional antenna
b) Dipole antenna
c) Isotropic antenna
d) Loop antenna
View Answer
Answer: c
211. EIRP is abbreviated as __________
a) Effective isotropic radiated power
b) Effective isotropic radio power
c) Effective and immediate radiated power
d) Effective and immediate ratio of power
View Answer
Answer: a
212. Path loss in free space model is defined as difference of ________
a) Effective transmitted power and gain
b) Effective received power and distance between T-R
c) Gain and received power
d) Effective transmitter power and receiver power
View Answer
Answer: d
213. Far field region is also known as _________
a) Near field region
b) Fraunhofer region

36
c) Erlang region
d) Fresnel region
View Answer
Answer: b
214. Fraunhofer distance is given by _____
a) 2D2/λ
b) 2D/λ
c) D/λ
d) 2D/λ2
View Answer
Answer: a
215. Which of the following is called an ideal antenna?
a) Dipole antenna
b) Directional antenna
c) Isotropic antenna
d) Loop antenna
View Answer
Answer: c
216. Which of the following mechanism do not impact propagation in mobile communication system?
a) Reflection
b) Diffraction
c) Scattering
d) Refraction
View Answer
Answer: d
217. What is the dimension of object as compared to wavelength of propagating wave when reflection occurs?
a) Large
b) Small
c) Same
d) Very small
View Answer
Answer: a
218. When does the wave propagating from one medium to another gets partially reflection and partially
transmitted?
a) Both mediums have same electrical properties
b) Both mediums have different electrical properties
c) Both mediums have same magnetic properties
d) Both mediums have different magnetic properties
View Answer
Answer: b
219. What is the case of reflection, in course of second medium being a perfect dielectric?
a) Loss of energy during absorption

37
b) Total energy reflected back to first medium
c) No loss of energy in absorption
d) Total energy transmitted into second medium
View Answer
Answer: c
220. What is the case of reflection, in course of second medium being a perfect conductor?
a) Loss of energy during absorption
b) Total energy reflected back to first medium
c) Partly transmission and reflection
d) Total energy transmitted into second medium
View Answer
Answer: b
221. Which of the following relates the incident and reflected & transmitted wave?
a) Fresnel transmission coefficient
b) Scattering coefficient
c) Diffraction coefficients
d) Fresnel reflection coefficient
View Answer
Answer: d
223. Reflection coefficient is not a function of __________
a) Material property
b) Diffraction loss
c) Wave polarization
d) Angle of incidence
View Answer
Answer: b
224. Polarized wave can be mathematically represented as sum of ________
a) Four orthogonal components
b) Two spatially adjacent components
c) Two spatially orthogonal components
d) Six orthogonal components
View Answer
Answer: c
225. The plane of incidence contains only incident rays. State True or False.
a) True
b) False
View Answer
Answer: b
226. Permittivity and conductivity are insensitive to ______ for a good conductor.
a) Operating frequency
b) Polarization density
c) Electric field

38
d) Property of material
View Answer
Answer: a
227. Velocity of electromagnetic wave can be given by _______
a) 1/√(μ∈)
b) μ/∈
c) 1/(μ∈)
d) μ∈
View Answer
Answer: a
228. The boundary condition at the surface of incidence obeys ________
a) Kepler’s law
b) Gauss law
c) Faraday law
d) Snell’s law
View Answer
Answer: d
229. The angle at which no reflection occurs in the medium of origin is called _________
a) Azimuth angle
b) Elevation angle
c) Brewster angle
d) Inclination angle
View Answer
Answer: c
230. Diffraction occurs when radio path between Tx. And Rx. Is obstructed by ________
a) Surface having sharp irregularities.
b) Smooth irregularities
c) Rough surface
d) All types of surfaces
View Answer
Answer: a
231. At high frequencies, diffraction does not depends on ______
a) Geometry of the object
b) Distance between Tx and Rx
c) Amplitude of incident wave
d) Polarization of incident wave
View Answer
Answer: b
232. Diffraction allows radio signals to propagate around ________
a) Continuous surface
b) Smooth surface
c) Curved surface of Earth

39
d) Does not allow propagation
View Answer
Answer: c
233. Which principle explains the phenomenon of diffraction?
a) Principle of Simultaneity
b) Pascal’s Principle
c) Archimedes’ Principle
d) Huygen’s principle
View Answer
Answer: d
234. Diffraction is caused by propagation of secondary wavelets into _______
a) Bright region
b) Shadowed region
c) Smooth region
d) Large region
View Answer
Answer: b
235. Difference between the direct path and the diffracted path is called _______
a) Average length
b) Radio path length
c) Excess path length
d) Wavelength
View Answer
Answer: c
236. The phase difference between a direct line of sight path and diffracted path is function of _______
a) Height and position of obstruction
b) Only height
c) Operating frequency
d) Polarization
View Answer
Answer: a
237. Which of the following explains the concept of diffraction loss?
a) Principle of Simultaneity
b) Pascal’s Principle
c) Fresnel zone
d) Archimedes’ Principle
View Answer
Answer: c
238. In mobile communication system, diffraction loss occurs due to ______
a) Dielectric medium
b) Obstruction
c) Electric field

40
d) Operating frequency
View Answer
Answer: b
239. For predicting the field strength in a given service area, it is essential to estimate ______
a) Polarization
b) Magnetic field
c) Height of transmitter
d) Signal attenuation
View Answer
Answer: d
240. Scattering occurs when medium consists of objects with dimensions _______ compared to wavelength.
a) Same
b) Small
c) Large
d) Very large
View Answer
Answer: b
241. Scattered waves are produced at ________
a) Rough surface
b) Shadowed region
c) Smooth surface
d) Horizon
View Answer
Answer: a
242. The actual received signal is ______ than what is predicted by reflection and diffraction model.
a) Weaker
b) Equal
c) Stronger
d) Very weak
View Answer
Answer: c
243. Scattered energy in all directions provides _________ at a receiver.
a) Channels
b) Loss of signal
c) No energy
d) Additional radio energy
View Answer
Answer: d
244. Surface roughness are often tested using ______
a) Rayleigh criterion
b) Lawson criterion
c) Barkhausen stability criterion

41
d) Nyquist criterion
View Answer
Answer: a
245. A surface is considered rough if protuberance is ______ than critical height.
a) Equal
b) Less
c) Greater
d) No relation
View Answer
Answer: c
246. RCS of scattering object is defined as the ratio of ______
a) Power density of signal scattered to power density of radio wave incident
b) Power density of radio wave incident to power density of signal scattered
c) Power density of incident waves to power density of reflected wave
d) Power density of reflected wave to power density of incident waves
View Answer
Answer: a
247. Which equation is used to calculate the received power due to scattering for urban mobile radio system?
a) Laplace equation
b) Bistatic radar equation
c) Poisson’s equation
d) Maxwell equation
View Answer
Answer: b
248. In ionosphere propagation, waves arriving at the receiving antenna using the phenomenon of _______
a) Scattering
b) Refraction
c) Diffraction
d) Radiation
View Answer
Answer: a
249. Power density is basically termed as ________ power per unit area.
a) Reflected
b) Refracted
c) Radiated
d) Diffracted
View Answer
Answer: c
250. Empirical approach is based on fitting curve or analytical expressions. State whether True or False.
a) True
b) False
View Answer

42
Answer: a
251. Which of the following is not a practical path loss estimation technique?
a) Log distance path loss model
b) Log normal shadowing
c) Determination of percentage of coverage area
d) Hata model
View Answer
Answer: a
252. Average received signal power decreases __________ with distance.
a) Exponentially
b) Logarithmically
c) Two times
d) Four times
View Answer
Answer: b
253. What does path loss exponent indicates?
a) Rate at which path loss decreases with distance
b) Rate at which path loss increases with distance
c) Rate at which path loss decreases with power density
d) Rate at which path loss increases with power density
View Answer
Answer: b
254. The reference distance should not be in the far field of the antenna. State whether True or False.
a) True
b) False
View Answer
Answer: b
255. Which distribution describes the shadowing effect?
a) Log normal distribution
b) Nakagami distribution
c) Cauchy distribution
d) Rayleigh distribution
View Answer
Answer: a
256. Log normal shadowing is a phenomenon that occurs with same T-R separation having same level clutter on
the propagation path. State True or False.
a) True
b) False
View Answer
Answer: b
257. Log normal shadowing implies that measured signal levels at specific T-R separation have ______ distribution
when signal levels have values in dB units.

43
a) Rayleigh
b) Gamma
c) Gaussian
d) Nakagami
View Answer
Answer: c
258. A link budget is accounting of all __________
a) Gain and losses from the transmitter
b) Power transmitted by transmitter
c) Power received by receiver
d) Power transmitted and received
View Answer
Answer: a
259. Antenna’s efficiency is given by the ratio of __________
a) Losses
b) Physical aperture to effective aperture
c) Signal power to noise power
d) Effective aperture to physical aperture
View Answer
Answer: a
260. Which of the following is not an outdoor propagation model?
a) Longley-Rice model
b) Ericson Multiple Breakpoint Model
c) Hata model
d) Okumura model
View Answer
Answer: b
261. Longley –Rice model is applicable to _________
a) Point to point communication
b) All to all communication
c) Point to multipoint communication
d) Multipoint microwave distribution sstem
View Answer
Answer: a
262. Longley-Rice prediction model is also referred as _________
a) Okumura model
b) Hata model
c) ITS irregular terrain model
d) Bertoni model
View Answer
Answer: c
263. The extra term for additional attenuation due to urban clutter near the receiving antenna is called _____

44
a) Power factor
b) Urban gain
c) Clutter factor
d) Urban factor
View Answer
Answer: d
264. Longley Rice model’s merit is to provide corrections due to environmental factors. State whether True or
False.
a) True
b) False
View Answer
Answer: b
265. Which method is used by Edwards and Durkin algorithm to calculate the loss associated with diffraction
edges?
a) Epstein and Peterson method
b) Interpolation method
c) Knife edge diffraction method
d) Fresnel- Kirchoff method
View Answer
Answer: a
266. Durkin’s model can read digital elevation map. State whether True or False.
a) True
b) False
View Answer
Answer: a
267. Which of the most widely used model for signal prediction in urban areas?
a) Ericsson Multiple Breakpoint Model
b) Log distance path loss model
c) Okumura model
d) Attenuation factor model
View Answer
Answer: c
268. Okumura model is applicable for distances of _________
a) 1 m to 10 m
b) 1 km to 100 km
c) 100 km to 1000 km
d) 10 km to 10000 km
View Answer
Answer: b
267. Okumura model is considered to be complex in predicting path loss. State whether True or False.
a) True
b) False

45
View Answer
Answer: b
268. Which of the following is the major disadvantage of Okumura model?
a) Complex
b) Inaccurate
c) Not practical
d) Slow response to rapid change in terrain
View Answer
Answer: d
269. The Hata model is empirical formulation of which model?
a) Okumura model
b) Longley- Rice model
c) Durkin’s model
d) Walfisch and Bertoni model
View Answer
Answer: a
270. The variability of the environment is slower for a smaller range of T-R separation distances in indoor models.
a) True
b) False
View Answer
Answer: b
271. Propagation within building is not influenced by ______
a) Layout of the building
b) Construction materials
c) Building type
d) Trees outside the building
View Answer
Answer: d
272. Smaller propagation distances make it more difficult to insure far-field radiation for all receiver location and
types of antenna. State whether True or False.
a) True
b) False
View Answer
Answer: a
273. What is hard partition?
a) Partition as part of the building
b) Partition that can be moved
c) Partition not touching ceiling
d) Partition between different floors
View Answer
Answer: a

46
274. Partitions that can be moved are called _______
a) Soft partitions
b) Hard partitions
c) Disk partition
d) Dynamic partition
View Answer
Answer: a
275. Losses between the floors of the building can be determined using ________
a) Internal dimensions
b) Material used to create antenna
c) External dimension
d) Line of sight path
View Answer
Answer: c
276. Technique of drawing a single ray between the transmitter and receiver is called ______
a) Secondary ray tracing
b) Primary ray tracing
c) Line of sight
d) Straight line tracing
View Answer
Answer :b
277. ________ is a process of converting plain text into cipher text.
a) Authentication
b) Decryption
c) Encryption
d) Compression
View Answer
Answer: c
278. _______reduces the cell size to increase capacity.
a) Intelligent cell approach
b) Microcell approach
c) Top down approach
d) Bottom up approach
View Answer
Answer: b
279. _________ configuration describes a desktop in an office.
a) Mobile and wired
b) Fixed and wired
c) Fixed and wireless
d) Mobile and wireless
View Answer
Answer: b

47
280. Small scale fading describes the _____ fluctuations of the amplitude, phases of signal.
a) Rapid
b) Slow
c) Instantaneous
d) Different
View Answer
Answer: a
281. Fading is caused by interference.(True/False)
a) True
b) False
View Answer
Answer: a
282. Which of the following is not an effect caused by multipath in radio channel?
a) Rapid changes in signal strength
b) Random frequency modulation
c) Power of base station
d) Time dispersion
View Answer
Answer: c
283. In urban areas, fading occurs due to height of mobile antenna ________ than height of surrounding
structure.
a) Same
b) Smaller
c) Greater
d) Very larger
View Answer
Answer: b
284. Fading does not occur when mobile receiver is stationary. State whether True or False.
a) True
b) False
View Answer
Answer: b
285. Apparent shift in frequency in multipath wave is caused due to relative motion between________
a) Base station and MSC
b) Mobile and surrounding objects
c) Mobile and MSC
d) Mobile and base station
View Answer
Answer: d
286. Doppler shift is directly proportional to __________
a) Velocity
b) Height of antenna

48
c) Power of receiving antenna
d) Power of transmitter
View Answer
Answer: a
287. Which of the following factor does not influence small scale fading?
a) Multipath propagation
b) Power density of base station
c) Speed of mobile
d) Speed of surrounding objects
View Answer
Answer: b
288. Signal will distort if transmitted signal bandwidth is greater than bandwidth of __________
a) Receiver
b) Radio channel
c) Multipath channel
d) Transceiver
View Answer
Answer: c
289. What is a measure of the maximum frequency difference for which signals are strongly correlated in
amplitude?
a) Coherence bandwidth
b) Narrow bandwidth
c) Incoherent bandwidth
d) Wide bandwidth
View Answer
Answer: a
290. The Doppler shift for mobile moving with constant velocity, v is given by _______
a) (v*cos θ)/λ
b) v/λ
c) v*cos θ
d) v*λ
View Answer
Answer: a
291. Doppler shift is positive if mobile is moving away from direction of arrival of the wave. State whether True or
False.
a) True
b) False
View Answer
Answer: b
292. Small scale variations of a mobile radio signal are directly related to _______
a) Impulse response of mobile radio channel
b) Impulse response of base station

49
c) Frequency response of antenna
d) Frequency response of base station
View Answer
Answer: a
293. Impulse response is a narrowband characterization. State whether True or False.
a) True
b) False
View Answer
Answer: b
294. Mobile radio channel can be modelled as a ______ filter.
a) Non-linear
b) Low-pass
c) Linear
d) Bandpass
View Answer
Answer: c
295. Impulse response does not play any role in characterization of the channel. State whether True or False.
a) True
b) False
View Answer
Answer: b
296. Received signal can be expressed as ______ of transmitted signal with channel impulse response.
a) Addition
b) Subtraction
c) Division
d) Convolution
View Answer
Answer: d
297. Discretization of multipath delay axis of impulse response into equal time delay segments is called
__________
a) Excess delay bins
b) Delay bins
c) Discrete bins
d) Digital bins
View Answer
Answer: a
298. Small scale received power is ____ of average powers received in each multipath component.
a) Log
b) Exponential
c) Multiplication
d) Sum
View Answer

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Answer: d
300. The received power of a wideband signal fluctuates significantly when a receiver is moved about a local area.
a) True
b) False
View Answer
Answer: b
301. Average power for a CW signal is _______ to average received power for a wideband signal in small scale
region.
a) Equivalent
b) Two times
c) Four times
d) Ten times
View Answer
Answer: a
302. The received local ensemble average power of wideband and narrowband signals are ________
a) Different
b) Equivalent
c) Not dependent
d) Double
View Answer
Answer: b
302. Which of the following is not a small scale multipath measurement technique?
a) Indirect pulse measurement
b) Direct pulse measurement
c) Spread spectrum sliding correlator measurement
d) Swept frequency measurement
View Answer
Answer: a
303. Direct RF pulse systems are complex. (True/False)
a) True
b) False
View Answer
Answer: b
304. What is the main disadvantage of RF pulse system?
a) Complexity
b) Not real time
c) Interference and noise
d) Simplicity
View Answer
Answer: c
305. Why is the phase of individual multipath components are not received in RF Pulse system?

51
a) Due to use of duplexer
b) Due to use of ADC
c) Due to use of flip flops
d) Due to use of envelope detector
View Answer
Answer: d
306. Spread spectrum sliding correlator has better ________ in comparison to RF pulse system.
a) Dynamic range
b) Frequency
c) Power density
d) Structure
View Answer
Answer: a
307. If a PN sequence has chip duration of Tc, then chip rate is given by ____-
a) Tc
b) 1/ Tc
c) 2 Tc
d) Tc2
View Answer
Answer: b
308. The maximal length of PN sequence, the sequence length for n number of shift register is ______
a) 2n
b) 1/2n
c) 2n -1
d) 2n +1
View Answer
Answer: c
309. The ratio between transmitter chip clock rate and the difference between the transmitter chip clock and
difference between transmitter and receiver chip clock rates is called ___________
a) Slide factor
b) Chip factor
c) Reuse factor
d) Shape factor
View Answer
Answer: a
310. Which of the following is not an advantage of spread spectrum channel sounding system?
a) Rejection of passband noise
b) Real time
c) Coverage range improvement
d) Less transmitter power required
View Answer
Answer: b

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311. Which of the following is a disadvantage of spread spectrum channel sounding system?
a) Passband noise
b) Less coverage area
c) Large transmitter power required
d) Not in real time
View Answer
Answer: d
312. There is no relationship between time domain and frequency domain techniques. State whether True or
False.
a) True
b) False
View Answer
Answer: a
313. Transmissivity is a _________ domain response.
a) Time
b) Frequency
c) Time-frequency
d) Spatial
View Answer
Answer: b
314. Power delay profile is represented as plots of __________ with respect to fixed time delay reference.
a) Relative received power
b) Frequency
c) Transmitted power
d) Relative power
View Answer
Answer: a
315. Which of the following is not a multipath channel parameter that can be determined from power delay
profile?
a) Mean excess delay
b) RMS delay spread
c) Excess delay spread
d) Doppler spread
View Answer
Answer: d
316. The time dispersive properties of wideband multipath channel are quantified by ______ and _______
a) Mean excess delay, rms delay spread
b) Doppler spread, rms delay spread
c) Doppler spread, coherence time
d) Mean excess delay, Doppler spread
View Answer
Answer: a

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317. _______ is the square root of the second central moment of the power delay profile.
a) Mean excess delay
b) Rms delay spread
d) Coherence time
View Answer
Answer: b
318. Which of the following is the first moment of the power delay profile?
a) Rms delay spread
b) Excess delay spread
c) Mean excess delay
d) Doppler spread
View Answer
Answer: c
319. What is the order of typical values of rms delay spread in outdoor mobile radio channels?
a) Microseconds
b) Nanoseconds
c) Seconds
d) Minutes
View Answer
Answer: a
320. Power delay profile and magnitude frequency response of a mobile radio channel are related through
_______
a) Laplace Transform
b) Fourier Transform
c) S Transform
d) Wavelet Transform
View Answer
Answer: b
321. ______ and coherence bandwidth are inversely proportional to one another.
a) Rms delay spread
b) Mean excess delay
d) Doppler spread
View Answer
Answer: a
322. Coherence bandwidth is a statistical measure of range of frequencies over which channel is considered
_______
a) Time dispersive
b) Frequency selective
c) Time variant
d) Flat

54
View Answer
Answer: d
323. Which of the following describes time varying nature of the channel in a small scale region?
a) Delay spread and coherence time
b) Coherence bandwidth and delay spread
c) Doppler spread and coherence time
d) Delay spread and doppler spread
View Answer
Answer: c
324. Doppler spread is a range of frequencies over which received Doppler spread is _______
a) Zero
b) Non zero
c) Infinite
d) One
View Answer
Answer: b
325. _______ is a statistical measure of time duration over which channel impulse response is invariant.
a) Coherence time
b) Doppler spread
c) Mean excess delay
d) Rms delay spread
View Answer
Answer: a
326. Which of the following is not a channel parameter?
a) Bandwidth
b) Coherence time
c) Rms delay spread
d) Doppler spread
View Answer
Answer: a
327. ______ leads to time dispersion and frequency selective fading.
a) Doppler spread
b) Multipath delay spread
c) Time dispersive parameters
d) Frequency delay spread
View Answer
Answer: b
328. Which of the following s not a characteristic of flat fading?
a) Mobile radio channel has constant gain
b) Linear phase response
c) Non linear phase response
d) Bandwidth is greater than the bandwidth of transmitted signal

55
View Answer
Answer: c
329. Spectral characteristics of the channel changes with time in flat fading. State whether True or False.
a) True
b) False
View Answer
Answer: b
330. Flat fading channel is also known as _____
a) Amplitude varying channel
b) Wideband channel
c) Phase varying channel
d) Frequency varying channel
View Answer
Answer: a
331. In a frequency selective fading, mobile radio channel possess a constant gain and a linear phase over
bandwidth smaller than bandwidth of transmitted signal. State whether True or False.
a) True
b) False
View Answer
Answer: a
332. Frequency selective fading channels are also known as ________
a) Narrowband channel
b) Wideband channel
c) Amplitude varying channel
d) Phase varying channel
View Answer
Answer: b
333. Frequency selective fading does not induce intersymbol interference. State whether True or False.
a) True
b) False
View Answer
Answer: b
334. For fast fading channel, the coherence time of the channel is smaller than _______ of transmitted signal.
a) Doppler spread
b) Bandwidth
c) Symbol period
d) Coherence bandwidth
View Answer
Answer: c
335. In slow fading channel, Doppler spread of the channel is much less than the ________ of baseband signal.
a) Symbol period
b) Phase

56
c) Coherence time
d) Bandwidth
View Answer
Answer: d
336. Which of the following distribution is used for describing statistical time varying nature of received envelope
of multipath component?
a) Log normal distribution
b) Levy distribution
c) Rayleigh distribution
d) Gaussian distribution
View Answer
Answer: c
337. Envelope of the sum of two quadrature Gaussian noise signal obeys _________ distribution.
a) Rayleigh
b) Inverse Gaussian
c) Nakagami
d) Gamma
View Answer
Answer: a
338. For a Rayleigh fading signal, mean and median differ by _______
a) 2 dB
b) 10 dB
c) 0.55 dB
d) 100 dB
View Answer
Answer: c
339. It is easy to compare different fading distributions using mean values instead of median values. State
a) True
b) False
View Answer
Answer: b
340. For a nonfading signal component present, the small scale fading envelope distribution is ______
a) Rayleigh
b) Gaussian
c) Log normal
d) Ricean
View Answer
Answer: d
341. Ricean distribution degenerates to ________ distribution when the dominant component fades away.
a) Log normal
b) Gamma

57
c) Rayleigh
d) Gaussian
View Answer
Answer: c
342. The envelope of a bandpass noise is ______
a) Uniformly distributed
b) Rayleigh
c) Ricean
d) Gaussian
View Answer
Answer: b
343. The envelope of a sinusoid plus bandpass noise has ____
a) Uniformly distributed
b) Rayleigh
c) Ricean
d) Gaussian
View Answer
Answer: c
344. What do you call an attenuation that occurs over many different wavelengths of the carrier?
a) Rayleigh fading
b) Ricean fading
c) Wavelength fading
d) Slow fading
View Answer
Answer: d
345. Which of the reception problems below that is not due to multipath?
a) Delayed spreading
b) Rayleigh fading
c) Random Doppler shift
d) Slow fading
View Answer
Answer: d
346. Which of the following is not a statistical models for multipath fading channels?
a) Clarke’s model for flat fading
b) Saleh and Valenzuela indoor statistical model
c) Two ray Rayleigh fading model
d) Faraday model
View Answer
Answer: d
347. Who presented the first statistical model for multipath fading channel?
a) Ossana
b) Rayleigh

58
c) Newton
d) Faraday
View Answer
Answer: a
348. Clarke’s model assumes a horizontal polarized antenna. State whether True or False.
a) True
b) False
View Answer
Answer: b
349. A wave that is incident on mobile does not undergo Doppler shift. State whether True or False.
a) True
b) False
View Answer
Answer: b
350. Which of the following is an important statistics of a Rayleigh fading useful for designing error control codes
and diversity schemes?
a) Mobile speed
b) Doppler frequency
c) Level crossing rate (LCR)
d) Power density
View Answer
Answer: c
351. The level crossing rate (LCR) is defined as expected rate at which _______ fading envelope crosses a specified
level.
a) Rayleigh
b) Saleh
c) Vanezuela
d) Faraday
View Answer
Answer: a
352. Level crossing rate is a function of _______
a) Power transmitted by base station
b) Power density of receiver
c) Mobile speed
d) Bit error rate
View Answer
Answer: c
353. Clarke’s model considers the multipath time delay. State whether True or False.
a) True
b) False
View Answer
Answer: b

59
354. Saleh and Venezuela reported the results of ______ propagation measurements.
a) Indoor
b) Outdoor
c) Air
d) High frequency
View Answer
Answer: a
355. Saleh and Venezuela show that indoor channel is _______ time varying.
a) Not
b) Very slow
c) Fast
d) Very fast
View Answer
Answer: b
356. What is the full form of SIRCIM?
a) Simulation of Indoor Radio Channel Impulse response Model
b) Statistical Indoor Radio Channel for Impulse Model
c) Statistical Impulse Radio Channel for Indoor Model
d) Simulation of Impulse Radio Channel for Indoor Model
View Answer
Answer: a
357. The term small scale fading describes the slow fluctuations of received power level due to changes in receiver
position. State whether True or False.
a) True
b) False
View Answer
Answer: b
358. The rapid fluctuations due to small scale fading affect the _________ design.
a) Receiver
b) Transmitter
c) MSC
d) Base station
View Answer
Answer: a
359. An approximately omnidirectional channel model accurately describes fading statistics if directional antennas
are employed at the receiver. State whether True or False.
a) True
b) False
View Answer
Answer: b
360. Which of the following is not a principle shape factor?
a) Angular spread

60
b) Angular constriction
c) Azimuthal direction of maximum fading
d) Angle of arrival
View Answer
Answer: d
361. Angular spread is a measure of how multipath concentrates about ___________.
a) Angle of arrival
c) Single azimuthal direction of arrival
d) Received power
View Answer
Answer: c
362. Angular constriction is a measure of how multipath concentrates about ______ azimuthal direction.
a) Single
b) Two
c) Three
d) Four
View Answer
Answer: b
363. Shape factor, azimuthal direction of maximum fading is a directional parameter. State whether True or False.
a) True
b) False
View Answer
Answer: a
364. _______of a stationary process is actually the variance of the rate of change.
a) Mean
b) Mean square
c) Mean squared derivative
d) Mean squared integral
View Answer
Answer: c
365. Complex received voltage is a summation of __________ that have impinged upon receiver antenna.
a) Multipath waves
b) Waves
c) Power density
d) Single path waves
View Answer
Answer: a
366. Which of the following is equal to received power?
a) Square of complex voltage
b) Complex voltage
c) Magnitude of complex voltage

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d) Magnitude squared of complex voltage
View Answer
Answer: d
367. Which of the following is equal to received envelope?
a) Square of complex voltage
b) Complex voltage
c) Magnitude of complex voltage
d) Magnitude squared of complex voltage
View Answer
Answer: c
368. Which of the following describes the average fading rate within a local area?
a) Angular spread
b) Angular constriction
c) Azimuthal direction of maximum fading
d) Angle of arrival
View Answer
Answer: a
369. Angular constriction affects the average fading rate within local area. State whether True or False.
a) True
b) False
View Answer
Answer: b
370. Which is the process of encoding information from a message source in suitable manner for transmission?
a) Modulation
b) Demodulation
c) Encryption
d) Decryption
View Answer
Answer: a
371. The bandpass signal is called the modulating signal.
a) True
b) False
View Answer
Answer: b
372. AM signal have all information in ______ of the carrier.
a) Amplitude
b) Magnitude
c) Frequency
d) Power
View Answer
Answer: a
373. In frequency modulation, the amplitude of modulated carrier signal is ______and its frequency is ______ by

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the modulating message signal.
a) Constant, constant
b) Varied, constant
c) Constant, varied
d) Varied, varied
View Answer
Answer: c
374. FM signals have all their information in ______ of the carrier.
a) Amplitude
b) Magnitude
c) Frequency
d) Power
View Answer
Answer: c
375. Amplitude modulation has ______ relationship between the quality of the received signal and the power of
the received signal.
a) No
b) Non linear
c) Constant
d) Linear
View Answer
Answer: d
376. FM has _______ noise immunity when compared to amplitude modulation.
a) Same
b) Less
c) No
d) Better
View Answer
Answer: d
377. FM signals are _____ susceptible to atmospheric and impulse noise as compared to AM.
a) Largely
b) Less
c) Not
d) Better
View Answer
Answer: b
378. Burst noise affects FM systems. State whether True or False.
a) True
b) False
View Answer
Answer: b
379. AM has a modulation index. State whether True or False.

63
a) True
b) False
View Answer
Answer: b
380. Which of the following is an advantage of AM systems in comparison to FM sysytems?
a) Occupy less bandwidth
b) Superior performance in fading
c) Better noise immunity
d) Not susceptible to impulse noise
View Answer
Answer: a
381. An FM signal is a ______ envelope signal.
a) Varied
b) Small
c) Large
d) Constant
View Answer
Answer: d
382. FM uses class______ amplifiers and AM uses class ______ amplifiers.
a) C, C
b) A, C
c) C, A
d) AB, C
View Answer
Answer: c
383. AM exhibits capture effect characteristics. State whether True or False.
a) True
b) False
View Answer
Answer: b
384. Which of the following is a drawback of FM systems?
a) Burst noise
b) Susceptible to atmospheric noise
c) Wider frequency band
d) Poor performance in fading
View Answer
Answer: c
385. Carrier signal in modulation technique is _______ signal.
a) High frequency
b) Low frequency
c) High amplitude
d) Low amplitude

64
View Answer
Answer: a
386. Modulation index of an AM signal is ratio of _____ to the _______
a) Peak carrier amplitude, Peak message signal amplitude
b) Peak message signal amplitude, Peak carrier amplitude
c) Carrier signal frequency, Message signal frequency
d) Message signal frequency, Carrier signal frequency
View Answer
Answer: b
387. If the peak message signal amplitude is half the peak amplitude of the carrier signal, the signal is _____
modulated.
a) 100%
b) 2%
c) 50%
d) 70%
View Answer
Answer: c
388. A percentage of modulation greater than ____ will distort the message signal.
a) 10%
b) 25%
c) 50%
d) 100%
View Answer
Answer: d
389. The RF bandwidth of AM is _____ the maximum frequency contained in the modulating message signal.
a) Equal
b) Two times
c) Four times
d) Ten times
View Answer
Answer: b
390. Single sideband AM systems occupy same bandwidth as of conventional AM systems. State whether True or
False.
a) True
b) False
View Answer
Answer: b
391. How is the performance of SSB AM systems in fading channels?
a) Poor
b) Best
c) Good
d) Average

65
View Answer
Answer: a
392. Which of the following is a disadvantage of tone-in-band SSB system?
a) High bandwidth
b) Bad adjacent channel protection
c) Effects of multipath
d) Generation and reception of signal is complicated
View Answer
Answer: d
393. FFSR in AM systems stands for ________
a) Feedforward signal regeneration
b) Feedbackward signal regeneration
c) Feedbackward system restoration
d) Feedforward system restoration
View Answer
Answer: a
394. AM demodulation technique can be divided into _____ and _____ demodulation.
a) Direct, indirect
b) Slope detector, zero crossing
c) Coherent, noncoherent
d) Quadrature detection, coherent detection
View Answer
Answer: c
395. Non coherent detection requires the knowledge of transmitted carrier frequency and phase at the receiver.
a) True
b) False
View Answer
Answer: b
396. A product detector in AM systems is also called ______
a) Envelope detector
b) Differentiator
c) Integrator
d) Phase detector
View Answer
Answer: d
397. AM system use only product detector for demodulation. They never use envelope detectors. State whether
True or False.
a) True
b) False
View Answer
Answer: b

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398. FM is a part of general class of modulation known as ______
a) Angle modulation
b) Phase modulation
c) Amplitude modulation
d) Frequency modulation
View Answer
Answer: a
399. FM is called constant envelope because ______ of carrier wave is kept constant.
a) Frequency
b) Amplitude
c) Phase
d) Angle
View Answer
Answer: b
400. Which of the following are two most important classes of angle modulation?
a) Amplitude modulation, frequency modulation
b) Amplitude modulation, phase modulation
c) Frequency modulation, phase modulation
d) Single sideband amplitude modulation, phase modulation
View Answer
Answer: c
401. Frequency modulated signal is regarded as the phase modulated signal in which the modulating wave is
differentiated before modulation. State whether True or False.
a) True
b) False
View Answer
Answer: b
402. Frequency modulation index defines the relationship between the ______ and bandwidth of transmitted
signal.
a) Frequency of message signal
b) Amplitude of message signal
c) Amplitude of carrier signal
d) Frequency of carrier signal
View Answer
Answer: b
403. FM bandwidth is approximated using _______ rule
a) Carson’s
b) Faraday’s
c) Maxwell’s
d) Armstrong’s
View Answer
Answer: a

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404. Which of the following are two methods for generating FM signal?
a) Coherent method, noncoherent method
b) Product detector, envelope detector
c) Direct method, indirect method
d) Slope detector, Zero crossing detector
View Answer
Answer: c
405. In indirect method, the carrier frequency is directly varied in accordance with the input modulating signal.
a) True
b) False
View Answer
Answer: b
406. Which of the following is used to vary the frequency of the carrier frequency in accordance with the
baseband signal amplitude variations in direct method of FM generation.
a) Integrator
b) Envelope detector
c) Multivibrator
d) Voltage controlled oscillators
View Answer
Answer: d
407. Frequency demodulator is a frequency to amplitude converter circuit. State whether True or False.
a) True
b) False
View Answer
Answer: a
408. Which of the following is not a technique for FM demodulation?
a) Slope detection
b) Zero crossing detection
c) Product detector
d) Phase locked discriminator
View Answer
Answer: c
409. Which of the following FM demodulator is sometimes known as pulse averaging discriminator?
a) Slope detection
b) Zero crossing detection
c) Quadrature detection
d) Phase locked discriminator
View Answer
Answer: b
410. PLL in FM detection stands for ______
a) Phase locked loop

68
b) Programmable logic loop
c) Phase locked logic
d) Programmable locked loop
View Answer
Answer: a
411. In angle modulation, signal to noise ratio before detection is a function of ______
a) Modulation index
b) Input signal to noise ratio
c) Maximum frequency of the message
d) IF filter bandwidth
View Answer
Answer: d
412. FM can improve the receiver performance through adjustment of transmitted power. State whether True or
False.
a) True
b) False
View Answer
Answer: b
413. Modern mobile communication systems use analog modulation techniques. State whether True or False.
a) True
b) False
View Answer
Answer: b
414. Which of the following is not an advantage of digital modulation?
a) Greater noise immunity
b) Greater security
c) Easier multiplexing
d) Less bandwidth requirement
View Answer
Answer: d
415. A desirable modulation scheme provides ____ bit error rates at _____ received signal to noise ratios.
a) Low, low
b) Low, high
c) High, high
d) High, low
View Answer
Answer: a
416. The performance of modulation scheme is not measured in terms of _____
a) Power efficiency
b) Bandwidth efficiency
c) Cost and complexity
d) Transmitted power

69
View Answer
Answer: d
417. In digital communication system, in order to increase noise immunity, it is necessary to increase _____.
a) Signal power
b) Signal amplitude
c) Signal frequency
d) Signal magnitude
View Answer
Answer: a
418. Which of the following is the ratio of signal energy per bit to noise power spectral density?
a) Bandwidth efficiency
b) Spectral density
c) Power efficiency
d) Power density
View Answer
Answer: c
419. Increasing the data rate implies the increase in pulse width of digital symbol. State whether True or False.
a) True
b) False
View Answer
Answer: b
420. Which of the following is the ratio of the throughput data rate per Hertz?
a) Bandwidth efficiency
b) Spectral density
c) Power efficiency
d) Power density
View Answer
Answer: a
421. Which of the following is defined as the range of frequencies over which the signal has a non zero power
spectral density?
a) Null to null bandwidth
b) Half power bandwidth
c) 3 dB bandwidth
d) Absolute bandwidth
View Answer
Answer: d
422. _______ is equal to width of main spectral lobe.
a) Null to null bandwidth
b) Half power bandwidth
c) 3 dB bandwidth
d) Absolute bandwidth
View Answer

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Answer: a
423. Half power bandwidth is also called ______
a) Absolute bandwidth
b) Null to null bandwidth
c) 3 dB bandwidth
d) Zero dB bandwidth
View Answer
Answer: c
424. Intersymbol interference (ISI) leads to ________ probability of the receiver for making an error in detecting
the symbols.
a) Increased
b) Decreased
c) Zero
d) One
View Answer
Answer: a
425. ISI is ________ by increasing channel bandwidth.
a) Maximized
b) Minimized
c) Zero
d) Infinite
View Answer
Answer: b
426. Why is pulse shaping technique used?
a) To increase ISI
b) To increase spectral width of modulated signal
c) To reduce ISI
d) To reduce power spectral density
View Answer
Answer: c
427. Who was the first to solve the problem of ISI?
a) Manchester
b) Faraday
c) Graham Bell
d) Nyquist
View Answer
Answer: d
428. According to Nyquist, the impulse response of the overall communication system should have ______ decay
with _______ magnitude for sample values not equal to zero.
a) Fast, small
b) Slow, small
c) Slow, large

71
d) Fast. Large
View Answer
Answer: a
429. Raised cosine filter does not satisfy Nyquist criteria. State whether True or False.
a) True
b) False
View Answer
Answer: b
430. As the roll off factor in raised cosine rolloff filter ________, the occupied bandwidth ______.
a) Increases, decreases
b) Decreases, constant
c) Increases, increases
d) Decreases, increases
View Answer
Answer: c
431. Gaussian pulse shaping filter follows Nyquist criterion. State whether True or False.
a) True
b) False
View Answer
Answer: b
432. Gaussian filter has zero crossings at adjacent symbol peaks. State whether True or False.
a) True
b) False
View Answer
Answer: b
433. Which of the following is true for a Gaussian filter?
a) Large bandwidth
b) Minimum ISI
c) High overshoot
d) Sharp cut off
View Answer
Answer: d
434. Gaussian pulse shaping filter reduces the spectral occupancy and ISI. State whether True or False.
a) True
b) False
View Answer
Answer: b
435. Gaussian pulses are used when cost and power efficiency are major factors. State whether True or False.
a) True
b) False
View Answer
Answer: a

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436. Linear modulation techniques are not bandwidth efficient. State whether True or False.
a) True
b) False
View Answer
Answer: b
437. Which of the following is not a linear modulation technique?
a) OQPSK
b) π/4 QPSK
c) FSK
d) BPSK
View Answer
Answer: c
438. In BPSK, the _____ of constant amplitude carrier signal is switched between two values according to the two
possible values.
a) Amplitude
b) Phase
c) Frequency
d) Angle
View Answer
Answer: b
439. By applying cos(2πft), BPSK signal is equivalent to ________
a) Double sideband suppressed carrier amplitude modulated waveform
b) Single sideband suppressed carrier amplitude modulated waveform
c) Frequency modulated waveform
d) SSB amplitude waveform
View Answer
Answer: a
440. BPSK uses non-coherent demodulator. State whether True or False.
a) True
b) False
View Answer
Answer: b
441. DPSK uses coherent form of PSK. State whether True or False.
a) True
b) False
View Answer
Answer: b
442. In DPSK system, input signal is differentially encoded and then modulated using a _____ modulator
a) Amplitude
b) Frequency
c) BPSK
d) QPSK

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View Answer
Answer: c
443. The energy efficiency of DPSK is ______ to coherent PSK.
a) Superior
b) Same
c) Zero
d) Inferior
View Answer
Answer: d
444. QPSK has _____ the bandwidth efficiency of BPSK.
a) Twice
b) Same
c) Half
d) Four times
View Answer
Answer: a
445. QPSK provides twice the bandwidth efficiency and ____ energy efficiency as compared to BPSK.
a) Twice
b) Half
c) Same
d) Four times
View Answer
Answer: c
446. What is the full form of OQPSK?
a) Optical Quadrature Phase Shift Keying
b) Orthogonal Quadrature Pulse Shift Keying
c) Orthogonal Quadrature Phase Shift Keying
d) Offset Quadrature Phase Shift Keying
View Answer
Answer: d
447. The bandwidth of OQPSK is _______ to QPSK.
a) Identical
b) Twice
c) Half
d) Four times
View Answer
Answer: a
448. QPSK signals perform better than OQPSK in the presence of phase jitter. State whether True or False.
a) True
b) False
View Answer
Answer: b

74
449. Which of the following is not a detection technique used for detection of π/4 QPSK signals?
a) Baseband differential detection
b) IF differential detection
c) FM discriminator detection
d) Envelope detection
View Answer
Answer: d
500. In non-linear modulation, the amplitude of the carrier varies with the variation of modulating signal. State
a) True
b) False
View Answer
Answer: b
501. In constant envelope family of modulation, class C amplifiers introduces degradation in spectrum occupancy.
a) True
b) False
View Answer
Answer: b
502. Constant envelope modulation techniques occupy ______ bandwidth than linear modulation schemes.
a) Larger
b) Smaller
c) Same
d) Twice
View Answer
Answer: a
503. In BFSK, _____of constant amplitude carrier signal is switched between two values.
a) Phase
b) Angle
c) Frequency
d) Amplitude
View Answer
Answer: c
504. MSK stands for ________
a) Maximum shift keying
b) Minimum shift keying
c) Minimum space keying
d) Maximum space keying
View Answer
Answer: b
505. What is the modulation index of MSK?
a) 0.1

75
b) 1
c) 0.5
d) 0
View Answer
Answer: c
506. The modulation index of an FSK signal is similar to modulation index of _____
a) Amplitude modulation
b) Phase modulation
c) QPSK
d) Frequency modulation
View Answer
Answer: d
507. The name minimum phase shift keying implies minimum ______
a) Frequency separation
b) Amplitude separation
c) Phase change
d) Amplitude deviation
View Answer
Answer: a
508. MSK is sometimes also referred as ______
a) Slow FSK
b) Fast FSK
c) Slow PSK
d) Fast PSK
View Answer
Answer: b
509. Which of the following is not a property of MSK?
a) Variable envelope
b) Spectral efficiency
c) Good BER performance
d) Self synchronizing capability
View Answer
Answer: a
510. MSK is a special form of OQPSK. State whether True or False.
a) True
b) False
View Answer
Answer: a
511. GMSK is a ________ of MSK.
a) Integral
b) Opposite
c) Derivative

76
d) Similar
View Answer
Answer: c
512. Which of the following is a combined linear and constant envelope technique?
a) MPSK
b) PSK
c) BPSK
d) QPSK
View Answer
Answer: a
513. In an M-ary signalling scheme two or more bits are grouped together to form a _______
a) Chip
b) Symbol
c) Byte
d) Pattern
View Answer
Answer: b
514. The number of possible signal in M-ary signalling is given by M and M=_____, where n is an integer.
a) n
b) 2n
c) 2n
d) n2
View Answer
Answer: c
515. M-ary signalling techniques are not sensitive to timing jitters. State whether True or False.
a) True
b) False
View Answer
Answer: b
516. M-ary modulation schemes have very good power efficiency. State whether True or False.
a) True
b) False
View Answer
Answer: b
517. The constellation of M-ary PSK is _______ dimensional.
a) One
b) Does not exist
c) Two
d) Three
View Answer
Answer: c
518. What is the radius of the circle in M-ary PSK on which message points are equaly spaced?

77
a) √Es
b) √Eb
c) Eb
d) Es
View Answer
Answer: a
519. As the value of M _________ the bandwidth efficiency ________
a) Increases, same.
b) Increases, decreases
c) Increases, increases
d) Decreases, same
View Answer
Answer: c
520. The power efficiency of the M ary PSK decreases because of the _____
a) Freely packed constellation
b) Increment of bandwidth efficiency
c) Fixed null bandwidth
d) Densely packed constellation
View Answer
Answer: d
521. In QAM, the amplitude is _______ and phase is _______
a) Varied, constant
b) Varied, varied
c) Constant, varied
d) Constant, constant
View Answer
Answer: b
522. M-ary QAM signal have constant energy per symbol. State whether True or False.
a) True
b) False
View Answer
Answer: b
523. In comparison to M-ary PSK, M-ary QAM bandwidth efficiency is _____ and power efficiency is ________
a) Identical, superior
b) Less, superior
c) Identical, identical
d) Superior, superior
View Answer
Answer: a
524. The bandwidth efficiency of an M-ary FSK signal ________ with ________ in M.
a) Constant, increase
b) Increases, increase

78
c) Decreases, increase
d) Decreases, decrease
View Answer
Answer: c
525. Power efficiency of M-ary FSK increases, since _________
a) Constellation is densely packed
b) M signals are non-orthogonal
c) Fixed null bandwidth
d) M-signals are orthogonal
View Answer
Answer: d
526. The transmission bandwidth of spread spectrum techniques is equal to the minimum required signal
bandwidth.
a) True
b) False
View Answer
Answer: b
527. 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
View Answer
Answer: a
528. 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
View Answer
Answer: b
529. 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
View Answer
Answer: c
530. PN sequence can be generated using sequential logic circuits.
a) True
b) False
View Answer

79
Answer: True
531. 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
View Answer
Answer: d
532. DSSS system spreads the baseband signal by ________ the baseband pulses with a pseudo noise sequence.
a) Adding
b) Subtracting
c) Multiplying
d) Dividing
View Answer
Answer: c
533. Frequency hopping involves a periodic change of transmission _______
a) Signal
b) Frequency
c) Phase
d) Amplitude
View Answer
Answer: b
534. What is the set of possible carrier frequencies in FH-SS?
a) Hopset
b) Hop
c) Chips
d) Symbols
View Answer
Answer: a
535. 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
View Answer
Answer: c
536. 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
View Answer

80
Answer: d
537. FH systems do not have collisions. State whether True or False.
a) True
b) False
View Answer
Answer: b
538. In fast frequency hopping, hopping rate is less than the information symbol rate. State whether True or False.
a) True
b) False
View Answer
Answer: b
539. Bit error rate provides the information about the type of error.
a) True
b) False
View Answer
Answer: b
540. Which of the following is specified by a specific number of bit errors occurring in a given transmission?
a) Bit error rate
b) Equally likely event
c) Outage event
d) Exhaustive events
View Answer
Answer: c
541. Irreducible BER floor is created in frequency selective channels due to ____________
a) Intersymbol interference
b) Random spectral spreading
c) Time varying Doppler spread
d) Blind speed
View Answer
Answer: a
542. Irreducible BER floor is created in non frequency selective channels due to ____________
a) Intersymbol interference
b) Multipath time delay
c) Time varying Doppler spread
d) Blind speed
View Answer
Answer: c
543. The performance of BPSK is best is term of BER because _______
a) Symbol offset interference does not exist
b) Existence of cross rail interference
c) No multipath delay
d) Doppler spread

81
View Answer
Answer: a
544. High capacity mobile systems are interference limited. State whether True or False.
a) True
b) False
View Answer
Answer: a
545. Which of the following do not impact bit error rate in mobile communication systems?
a) Mobile velocity
b) Channel delay spread
c) Modulation format
d) Base station
View Answer
Answer: d
546. Coherence time refers to ___
a) Time required attaining a call with the busy base station
b) Time required for synchronization between the transmitter and the receiver
c) Minimum time for change in magnitude and phase of the channel
d) None of the above
View Answer
Answer: c
547. Doppler spread refers to _________
a) Signal fading due to Doppler shift in the channel
b) Temporary failure of message transfer
c) Large coherence time of the channel as compared to the delay constraints
d) All of the above
View Answer
Answer: a
548. A rake receiver uses multiple ______
a) Delay circuits
b) Correlators
c) Detectors
d) Flip flops
View Answer
Answer: b
549. Equalization is used to compensate __________
a) Peak signal to noise ratio
b) Intersymbol interference
c) Channel fading
d) Noises present in the signal
View Answer
Answer: b

82
550. Training and tracking are the operating modes of _________
a) Diversity techniques
b) Channel coding techniques
c) Equalization techniques
d) Demodulation techniques
View Answer
Answer: c
551. An equalizer is said to be converged when it is properly _______
a) Trained
b) Tracked
c) Installed
d) Used
View Answer
Answer: a
552. Time for convergence of an equalizer is not a function of _______
a) Equalizer algorithm
b) Equalizer structure
c) Time rate of change of multipath radio channel
d) Transmitter characteristics
View Answer
Answer: d
553. Equalizer is usually implemented in __________
a) Transmitter
b) Baseband or at IF in a receiver
c) Radio channel
d) Modulator stage
View Answer
Answer: b
554. Equalizer is ________ of the channel.
a) Opposite
b) Same characteristics
c) Inverse filter
d) Add on
View Answer
Answer: c
555. ______ controls the adaptive algorithm in an equalizer.
a) Error signal
b) Transmitted signal
c) Received signal
d) Channel impulse response
View Answer
Answer: a

83
556. The adaptive algorithms in equalizer that do not require training sequence are called ________
a) Linear adaptive algorithms
b) Blind algorithms
c) Non-linear adaptive algorithms
d) Spatially adaptive algorithms
View Answer
Answer: b
557. Which of the following is a blind algorithm?
a) Linear adaptive algorithms
b) Constant modulus algorithm
c) Non-linear adaptive algorithms
d) Spatially adaptive algorithms
View Answer
Answer: b
558. Equalization techniques can be categorised into _______ and ______ techniques.
a) Linear, non linear
b) Active, passive
c) Direct, indirect
d) Slow, fast
View Answer
Answer: a
559. Equalization is linear, if an analog signal is fed back to change the subsequent outputs of the equalizer. Sate
a) True
b) False
View Answer
Answer: b
560. In the context of equalizers, LTE stands for ________
a) Long transversal equalizer
b) Least time-varying equalizer
c) Linear transversal equalizer
d) Linear time-varying equalizer
View Answer
Answer: c
561. Which of the following is not a characteristic of FIR filter?
a) Many zeroes
b) Poles only at z=0
c) Transfer function is a polynomial of z-1
d) Many poles
View Answer
Answer: d
562. Which of the following is not an advantage of lattice equalizer?

84
a) Simple structure
b) Numerical stability
c) Faster convergence
d) Dynamic assignment
View Answer
Answer: a
563. Non-linear equalizers are used in applications where channel distortion is not severe.
a) True
b) False
View Answer
Answer: b
564. Which of the following is not a non-linear equalization technique?
a) Decision feedback equalization
b) Maximum likelihood symbol detection
c) Minimum square error detection
d) Maximum likelihood sequence detection
View Answer
Answer: c
565. For a distorted channel, LTE performance is superior to DFE. State whether True or False.
a) True
b) False
View Answer
Answer: b
566. Which of the following does not hold true for MLSE?
a) Minimizes probability of sequence error
b) Require knowledge of channel characteristics
c) Requires the statistical distribution of noise
d) Operates on continuous time signal
View Answer
Answer: d
567. MLSE decodes each received signal by itself.
a) True
b) False
View Answer
Answer: b
568. Which of the following factor could not determine the performance of algorithm?
a) Structural properties
b) Rate of convergence
c) Computational complexity
d) Numerical properties
View Answer
Answer: a

85
569. Rate of convergence is defined by _____ of algorithm.
a) Time span
b) Number of iterations
c) Accuracy
d) Complexity
View Answer
Answer: b
570. Computational complexity is a measure of ________
a) Time
b) Number of iterations
c) Number of operations
d) Accuracy
View Answer
Answer: c
571. Choice of equalizer structure and its algorithm is not dependent on ________
a) Cost of computing platform
b) Power budget
c) Radio propagation characteristics
d) Statistical distribution of transmitted power
View Answer
Answer: d
572. Coherence time is dependent on the choice of the algorithm and corresponding rate of convergence.
a) True
b) False
View Answer
Answer: a
573. Which of the following is an algorithm for equalizer?
a) Zero forcing algorithm
b) Least mean square algorithm
c) Recursive least square algorithm
d) Mean square error algorithm
View Answer
Answer: d
574. Which of the following is a drawback of zero forcing algorithm?
a) Long training sequence
b) Amplification of noise
c) Not suitable for static channels
d) Non zero ISI
View Answer
Answer: b
575. Zero forcing algorithm performs well for wireless links. State whether True or False.
a) True

86
b) False
View Answer
Answer: b
576. LMS equalizer minimizes __________
a) Computational complexity
b) Cost
c) Mean square error
d) Power density of output signal
View Answer
Answer: c
577. For N symbol inputs, LMS algorithm requires ______ operations per iterations.
a) 2N
b) N+1
c) 2N+1
d) N2
View Answer
Answer: c
578. Stochastic gradient algorithm is also called ________-
a) Zero forcing algorithm
b) Least mean square algorithm
c) Recursive least square algorithm
d) Mean square error algorithm
View Answer
Answer: b
579. Convergence rate of LMS is fast. State whether True or False.
a) True
b) False
View Answer
Answer: b
580. Which of the following does not hold true for RLS algorithms?
a) Complex
b) Adaptive signal processing
c) Slow convergence rate
d) Powerful
View Answer
Answer: c
581. Which of the following algorithm uses simple programming?
a) LMS Gradient DFE
b) FTF algorithm
c) Fast Kalman DFE
d) Gradient Lattice DFE
View Answer

87
Answer: a
582. Diversity requires training sequence. State whether True or False.
a) True
b) False
View Answer
Answer: b
583. Diversity decisions are made by ______
a) Receiver
b) Transmitter
c) Channel
d) Adaptive algorithms
View Answer
Answer: a
584. Small scale fades are characterized by _____ amplitude fluctuations.
a) Large
b) Small
c) Rapid
d) Slow
View Answer
Answer: b
585. ______ is used to prevent deep fade for rapidly varying channel.
a) Modulation
b) Demodulation
c) Macroscopic diversity technique
d) Microscopic diversity technique
View Answer
Answer: d
586. Space diversity s also known as ________
a) Antenna diversity
b) Time diversity
c) Frequency diversity
d) Polarization diversity
View Answer
Answer: a
587. Which of the following is not a category of space diversity technique?
a) Selection diversity
b) Time diversity
c) Feedback diversity
d) Equal gain diversity
View Answer
Answer: b
588. In selection diversity, the gain of each diversity branch provides different SNR. State whether True or False.

88
a) True
b) False
View Answer
Answer: b
589. Polarization diversity uses the ________ as the diversity element.
a) Modulation index
b) Carrier frequency
c) Reflection coefficient
d) Coherence time
View Answer
Answer: c
590. Which of the factor does not determine the correlation coefficient?
a) Polarization angle
b) Cross polarization discrimination
c) Offset angle from the main beam direction
d) Coherence time
View Answer
Answer: d
591. Frequency diversity is implemented by transmitting information on more than one _____
a) Carrier frequency
b) Amplitude
c) Phase
d) Modulation scheme
View Answer
Answer: a
592. Frequency diversity uses ________ as a diversity element.
a) Correlation coefficient
b) Coherence time
c) Coherence bandwidth
d) SNR
View Answer
Answer: c
593. Frequency diversity is good for low traffic condition. State whether True or False.
a) True
b) False
View Answer
Answer: b
594. Time diversity repeatedly transmits information at time spacings that exceed _____
a) Coherence bandwidth
b) Dwell time
c) Run time
d) Coherence time

89
View Answer
Answer: d
595. In maximal ratio combining, the output SNR is equal to _______
a) Mean of all individual SNRs
b) Maximum of all SNRs
c) Sum of individual SNR
d) Minimum of all SNRs
View Answer
Answer: c
596. In CDMA spread spectrum systems, chip rate is less than the bandwidth of the channel. State whether True
or False.
a) True
b) False
View Answer
Answer: b
597. A RAKE receiver collects the __________-versions of the original signal.
a) Time shifted
b) Amplitude shifted
c) Frequency shifted
d) Phase shifted
View Answer
Answer: a
598. RAKE receiver uses separate _________ to provide the time shifted version of the signal.
a) IF receiver
b) Equalizer
c) Correlation receiver
d) Channel
View Answer
Answer: c
599. Each correlation receiver in RAKE receiver is adjusted in______
a) Frequency shift
b) Amplitude change
c) Phase shift
d) Time delay
View Answer
Answer: d
600. The range of time delays that a particular correlator can search is called ________
a) Search window
b) Sliding window
c) Time span
d) Dwell time
View Answer

90
Answer: a
601. RAKE receiver is used for _______ technique.
a) CDMA
b) TDMA
c) FDMA
d) OFDM
View Answer
Answer: a
602. A RAKE receiver uses ____ to separately detect the M strongest signals.
a) Single correlator
b) Multiple correlator
c) Single IF receiver
d) Multiple IF receivers
View Answer
Answer: b
603. In a RAKE receiver, if the output from one correlator is corrupted by fading, all the other correlator’s output
are also corrupted. State whether True or False
a) True
b) False
View Answer
Answer: b
604. A RAKE receiver uses ____
a) Equalization
b) Channel coding
c) Diversity
d) Encryption
View Answer
Answer: c
605. Interleaving is used to obtain _____ diversity.
a) Time
b) Frequency
c) Polarization
d) Antenna
View Answer
Answer: a
606. In block codes, parity bits are _____ to block of messages.
a) Added
b) Subtracted
c) Multiplied
d) Divided
View Answer
Answer: a

91
607. How many redundant bits are added in block codes for k information bits and n code bits?
a) n+k
b) n-k
c) k2
d) n2
View Answer
Answer: b
608. For (n,k) block codes, rate of the code is defined as _______
a) n2/k
b) k2/n
c) n/k
d) k/n
View Answer
Answer: c
609. The ability of the block code to correct errors is a function of ______
a) Number of parity bits
b) Number of information bits
c) Number of code bits
d) Code distance
View Answer
Answer: d
610. The weight of a code is given by number of _______
a) Non-zero elements in the codeword
b) Zero elements in the codeword
c) Total elements in the codeword
d) Elements in parity bits
View Answer
Answer: a
611. Which of the following is not a property of block code?
a) Linearity
b) Systematic
c) Cyclic
d) Non linearity
View Answer
Answer: d
612. In systematic codes, parity bits are appended at the ____
a) Beginning
b) End
c) End
d) Odd places
View Answer
Answer: b

92
613.. Which of the following is not an example of block code?
a) Hamming code
b) Cyclic code
c) Convolution code
d) BCH codes
View Answer
Answer: c
614. Which of the following code is a class of non-binary BCH?
a) Hamming code
b) Hadamard code
c) Golay code
d) Reed Solomon codes
View Answer
Answer: d
615. Which of the following linear codes achieve largest possible minimum distance?
a) Hamming code
b) Hadamard code
c) Golay code
d) Reed Solomon codes
View Answer
Answer: d
616. CDPD stands for _____
a) Cellular Digital Packet Data
b) Cellular Decoded Packet Data
c) Cellular Demodulated Packet Data
d) Cellular Decoded Plane Data
View Answer
Answer: a
617. Block codes can achieve a larger coding gain than convolution coding.
a) True
b) False
View Answer
Answer: b
618. Which of the following indicates the number of input bits that the current output is dependent upon?
a) Constraint length
b) Code length
c) Search window
d) Information rate
View Answer
Answer: a
619. Which of the following is not a way to represent convolution code?
a) State diagram

93
b) Trellis diagram
c) Tree diagram
d) Linear matrix
View Answer
Answer: d
620. Which of the following is not an algorithm for decoding convolution codes?
a) Viterbi algorithm
b) Stack algorithm
c) Fano’s sequential coding
d) Ant colony optimization
View Answer
Answer: d
621. Viterbi algorithm performs ______ decoding of convolutional codes.
a) Maximum likelihood
b) Maximum a posteriori
c) Minimum square
d) Minimum mean square
View Answer
Answer: a
622. Fano’s algorithm searches all the paths of trellis diagram at same time to find the most probable path. State
a) True
b) False
View Answer
Answer: b
623. Which of the following is not an advantage of Fano’s algorithm in comparison to Viterbi’s algorithm?
a) Less storage
b) Large constraint length
c) Error rate
d) Small delays
View Answer
Answer: d
624. In comparison to stack algorithm, Fano’s algorithm is simpler.
a) True
b) False
View Answer
Answer: b
625. Which of the following is not an error correction and detection code?
a) Block code
b) Convolutional codes
c) Passive codes
d) Turbo codes

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