LTE 4G 1

OFDMA stands for ________

• omnidirectional frequency division multiple access

• orthogonal frequency duplex multiple access

• orthogonal frequency divider multiple access

• orthogonal frequency division multiple access

Why is a cyclic prefix required in an OFDMA?

• To ensure symbol time is an integer number

• To help overcome multipath and ISI

• To maintain orthogonality

• To make OFDMA scalable

What does the DC sub-carrier indicate?

• Identity of the cell

• Antenna configuration

• Center of OFDM channel

• Format of data channel

What processing step combines multiple OFDM subcarriers into a single signal for transmission?

• FFT

• IFFT

• RF combining

• Channel mapping

Which property of OFDMA system allows adjacent subcarriers to be used without interference?

• Orthogonality

• Orthodoxy

• Octagonality

• Originality

In OFDMA, what is the relationship between the subcarrier spacing f and symbol time t?

• f=t

• f=1/2t

• f=1/t

• no relation

OFDM is a technique for 3G mobile communication.State whether True or False.

• True

• False

OFDM uses complex equalizers. State whether True or False.

• True

• False

When we divide band of Orthogonal Frequency Division Multiplexing (OFDM) into sub bands, it diminishes effects of ____

• noise

• collision

• interference

• signals absence

Common data rates of IEEE 802.11 OFDM are ______

• 18 Mbps

• 200 Mbps

• 50 Mbps

• 54 Mbps