Exam 17: Wireless Transmission Techniques

The first type of spread spectrum developed is known as _________ .

The ________ reverses the FFT operation.

OFDMA subcarriers are divided into groups and each group is named a ______ .

FFT is a family of algorithms that form a special case of the __________ ,which refers to any algorithm that generates a quantized Fourier transform of a time-domain function.

MIMO exploits the space dimension to improve wireless systems in terms of _________.

__________ extends the basic MIMO concept to multiple endpoints,each with multiple antennas.

Together,MIMO and OFDM technologies are the cornerstone of emerging broadband wireless networks.

The signal processing for OFDM involves two functions known as fast Fourier transform and ______________ .

SC-FDMA performs a _______ prior to the IFFT operation,which spreads the data symbols over all the subcarriers carrying information and produces a virtual single-carrier structure.

MIMO systems are characterized by the number of antennas at each end of the wireless channel.

Diverse multipath fading offers multiple views of the transmitted data at the receiver,thus increasing robustness.

_________ is a common modulation scheme used with OFDM.

________ is used on the downlink channel to enable the base station to transmit different data streams to multiple users over the same frequency band.

With __________ the same data is coded and transmitted through multiple antennas.

Subchannelization is not useful for battery-powered devices.

Orthogonal Frequency-Division Multiple Access employs multiple closely spaced subcarriers.

MU-MIMO techniques are used in both Wi-Fi and 4G cellular networks.

_________,also called multicarrier modulation,uses multiple carrier signals at different frequencies,sending some of the bits on each channel.

OFDM cannot overcome intersymbol interference in a multipath environment.

In OFDM all of the subcarriers are dedicated to a single data source.