Wireless & Mobile Communications Multiple Choice Questions & Answers (MCQs) on “Multiple Input Multiple Output (MIMO)”.
1. MIMO stands for _______
a) Many input many output
b) Multiple input multiple output
c) Major input minor output
d) Minor input minor output
Answer: b
Clarification: MIMO stands for Multiple Input and Multiple Output. It refers to the technology where there are multiple antennas at the base station and multiple antennas at the mobile device.
2. In MIMO, which factor has the greatest influence on data rates?
a) The size of antenna
b) The height of the antenna
c) The number of transmit antennas
d) The area of receive antennas
Answer: c
Clarification: By increasing the number of receiving and transmitting antennas, it is possible to linearly increase the throughput of the channel with every pair of antennas added to the system.
3. MIMO was initially developed in the year __________
a) 1980
b) 1990
c) 1980
d) 1975
Answer: b
Clarification: Since the initial development in the year 1990, MIMO Wireless Communications have become integral part of the most forthcoming commercial and next generation wireless data communication systems.
4. MIMO is a smart antenna technology.
a) True
b) False
Answer: a
Clarification: MIMO is one of several forms of smart antenna technology, the others being MISO (multiple input, single output) and SIMO (single input, multiple output). It is an antenna technology for wireless communications in which multiple antennas are used at both the source and the destination.
5. MIMO technology makes advantage of a natural radio wave phenomenon called _________
a) Reflection
b) Multipath
c) Refraction
d) Diffraction
Answer: b
Clarification: MIMO technology makes use of multipath phenomenon to maximize transmission by receiving bounced signals from obstructions. Multipath is a phenomenon in wave propagation.
6. Which of the following technology does not use MIMO?
a) 4G
b) Wifi
c) WiMax
d) AMPS
Answer: d
Clarification: MIMO is used in mobile radio telephone standards such as recent 3GPP and 3GPP2. In 3GPP, High-Speed Packet Access plus (HSPA+) and Long Term Evolution (LTE) standards take MIMO into account. Moreover, MIMO is also used in Wifi and WiMax.
7. MIMO means both transmitter and receiver have multiple antennas.
a) True
b) False
Answer: a
Clarification: MIMO provides a way of utilising the multiple signal paths that exist between a transmitter and receiver to significantly improve the data throughput available on a given channel with its defined bandwidth. It uses multiple antennas at the transmitter and receiver along with some complex digital signal processing.
8. _______ is a technique of transmit diversity used in UMTSS third-generation cellular systems.
a) STTD
b) SM
c) Collaborative Uplink MIMO
d) MU-MIMO
Answer: a
Clarification: Space Time Transmit Diversity (STTD) is a technique of transmit diversity used in UMTSS third-generation cellular systems. Space Time Transmit Diversity is optional in the UTRANN air interface, but compulsory for user equipment.
9. _______ is a transmission method used in MIMO wireless communications to transmit encoded data signals independently.
a) STTD
b) SM
c) Collaborative Uplink MIMO
d) MU-MIMO
Answer: b
Clarification: Spatial multiplexing is a transmission method used in MIMO wireless communications to transmit encoded data signals independently and separately (so-called streams) from each of the multiple transmit antennas.
10. _______ is an additional open-loop MIMO technique considered by the WiMAX vendors.
a) STTD
b) SM
c) Collaborative Uplink MIMO
d) MU-MIMO
Answer: c
Clarification: Collaborative MIMO is an open-loop MIMO technique considered by the WiMAX vendors to surge the spectral efficiency and capacity of the uplink communications path. It is compared with the regular spatial multiplexing, wherein data streams are transmitted multiplying from multiple antennas on the same device.
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