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The CORRECT option is (c) COLLABORATIVE Uplink MIMO

To EXPLAIN: 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.

The correct ANSWER is (a) STTD

To explain: 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.

The CORRECT choice is (C) f=1/t

Explanation: In OFDMA, the relationship between the subcarrier SPACING f and symbol time t is f=1/t. They are INVERSELY proportional.

Right answer is (a) Multirate management

The EXPLANATION is: 4G is the fourth generation of broadband cellular NETWORK technology, succeeding 3G. Its characteristics INCLUDE FULLY converged services, software dependency and diverse user DEVICES.

Right OPTION is (d) PCFICH

Easy explanation: PCFIH channel indicates the NUMBER of symbols USED by the PDCCH. The actual number of OFDM symbols occupied in any given subframe is indicated in the PCFICH (Physical Control Format Indicator Channel), which is located in the FIRST OFDM SYMBOL of each subframe.

Correct option is (a) Only CATEGORY 5

To explain: Category information is USED to allow the eNB to communicate effectively with all the UEs CONNECTED to it. The UE-category defines a COMBINED uplink and downlink capability. Only UE category 5 supports 64 QAM on the uplink.

The correct OPTION is (a) 18 Mbps

Easiest EXPLANATION: The IEEE 802.11a standard specifies a modulation that divides a high-speed serial information signal into multiple lower-speed sub SIGNALS. Common data RATES of IEEE 802.11 OFDM is 18 Mbps.

Right option is (a) SERVING GPRS Support Node

To explain: The Serving GPRS Support Node (SGSN) is a main component of the GPRS network, which handles all packet switched data WITHIN the network, e.g. the mobility management and authentication of the users. The SGSN performs the same functions as the MSC for VOICE traffic.

The correct CHOICE is (d) Improved UPLINK coverage, lower UE power consumption and reduced EQUALIZER

Explanation: PAPR is the relation between the maximum power of a sample in a given OFDM transmit symbol divided by the average power of that OFDM symbol. PAPR reduction in the uplink leads to improved uplink coverage, lower UE power consumption and reduced equalizer COMPLEXITY.

Correct ANSWER is (b) 3GPP

The explanation: The 3rd Generation Partnership Project (3GPP) is a COLLABORATION between groups of telecommunications standards associations, known as the Organizational Partners. LTE (LONG Term Evolution) INTRODUCED in 3GPP R8, is the access part of the Evolved Packet SYSTEM (EPS).

Correct OPTION is (b) SM

Explanation: 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.

The correct choice is (d) 2-5 Mbps

Explanation: Verizon 4G LTE wireless BROADBAND is 10 times FASTER than 3G able to HANDLE download speeds between 5 and 12 Mbps (Megabits per second) and UPLOAD speeds between 2 and 5 Mbps.

Correct answer is (a) HARD handover only

Best explanation: LTE SUPPORTS only hard handover. It does not receive data from two FREQUENCIES at the same time because switching between different carrier frequencies is very FAST so soft handover is not required.

The correct answer is (b) Multiple input multiple OUTPUT

To elaborate: 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.

Correct answer is (b) False

The explanation: OFDM has developed into a popular scheme for WIDEBAND digital communication, USED in applications such as digital TELEVISION and audio broadcasting, DSL internet access, wireless networks, power line networks, and 4G mobile communications.

Correct option is (b) Physical cell ID

To elaborate: The PBCH is scrambled prior to modulation with a cell-specific SEQUENCE that DEPENDS on the CELLS’ identity. In CONTRAST to the SYNCHRONIZATION signals, the PBCH is transmitted on the 72 reserved subcarriers, which are QPSK-modulated.

The correct choice is (d) TRANSPARENT mode (TM)

To EXPLAIN: The transparent mode ENTITY in RLC does not add any overhead to the upper LAYER SDUs. The entity just TRANSMITS the SDUs coming from upper layer to MAC.

Right option is (b) 1990

Explanation: 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.

Right choice is (C) interference

Explanation: OFDM uses the same BANDWIDTH to DELIVER roughly the same data rate as a single carrier modulation by introducing multiple lower-bandwidth channels. Each of the lower-bandwidth channels has a lower rate, and by combining them together, the original rate is achieved.

Right choice is (a) Verizon Wireless

Explanation: In 2007, Verizon announced plans to DEVELOP and DEPLOY its FOURTH generation mobile broadband network using LTE, the technology developed within the THIRD Generation Partnership PROJECT (3GPP) standards organization.

Right answer is (b) Multipath

The explanation is: MIMO technology makes use of multipath PHENOMENON to MAXIMIZE transmission by receiving BOUNCED signals from obstructions. Multipath is a phenomenon in WAVE propagation.

Correct option is (c) The number of transmit antennas

To EXPLAIN: 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.

The correct choice is (a) True

Easy explanation: 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.

The correct option is (b) IFFT

Explanation: IFFT combines multiple OFDM subcarriers into a single signal for transmission. These transforms are IMPORTANT from the OFDM perspective because they can be viewed as mapping digitally modulated input DATA (data symbols) ONTO ORTHOGONAL subcarriers.

The correct choice is (a) Concatenated LOCATION Registration

To explain I WOULD SAY: 4G supports concatenated location registration. Concatenated location registration REPORTS to the network that they are concatenated to a common object.

The correct answer is (c) EVERY SUBFRAME

The explanation is: Resources can be located to the UE every subframe. CCE Index is the CCE number at which the control CHANNEL data (PDCCH) is allocated. Normally this index CHANGES for each subframe, i.e. even the same PDCCH data (e.g, a PDCCH for the same UE) allocated in each subframe changes subframe by subframe.

The correct answer is (a) True

To explain: 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.

The correct answer is (a) Orthogonality

Explanation: Orthogonality of sub-carriers simply MEANS their CORRELATION is zero. Orthogonality in OFDMA system allows adjacent SUBCARRIERS to be used without INTERFERENCE.

The CORRECT answer is (B) False

The best EXPLANATION: ODMA does not use complex EQUALIZERS. In OFDM, the equalizer only has to multiply each detected sub-carrier (each Fourier coefficient) in each OFDM symbol by a constant complex number, or a rarely changed value.

The correct choice is (C) CENTER of OFDM channel

Explanation: All the subcarriers of an OFDM symbol do not CARRY useful data. In OFDM and OFDMA PHY layers, the DC subcarrier is the subcarrier WHOSE frequency is EQUAL to the RF centre frequency of the transmitting station.

Correct CHOICE is (b) To help overcome multipath and ISI

Best explanation: Use of cyclic PREFIX is a KEY element of enabling the OFDM signal to operate reliably. The cyclic prefix acts as a buffer REGION or guard INTERVAL to protect the OFDM signals from intersymbol interference.

Correct option is (a) 1.08 MHz

Best explanation: Cell synchronization is the very FIRST STEP when UE wants to camp on any cell. 1.08 MHZ is required to TRANSMIT the primary and secondary synchronization signals.

Correct option is (d) AMPS

Easy explanation: 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.

Right ANSWER is (d) orthogonal frequency division multiple ACCESS

Best explanation: Orthogonal frequency-division multiple access (OFDMA) is a multi-user version of the popular orthogonal frequency-division multiplexing (OFDM) digital modulation scheme. Multiple access is achieved in OFDMA by assigning subsets of subcarriers to INDIVIDUAL users.

The correct option is (b) 20 MHz

The explanation is: The LTE format was first proposed by NTT DoCoMo of Japan and has been ADOPTED as the international STANDARD. LTE-Advanced accommodates the geographically AVAILABLE spectrum for channels above 20 MHz.

Correct option is (B) 2.8 MHz

Explanation: In telecommunication, Long-Term Evolution (LTE) is a standard for high-speed WIRELESS communication for mobile DEVICES and data terminals, BASED on the GSM/EDGE and UMTS/HSPA technologies. The minimum amount of RF spectrum needed for an FDD LTE RADIO channel is 2.8 MHz.