Exam 17: Wireless Transmission Techniques

The earliest applications of ________ were military,where it was used for its immunity to jamming.

In a multipath scenario where each receiving antenna would experience a different interference environment,there is a high probability that if one antenna is suffering a high level of fading, another antenna has sufficient signal level.

Like OFDM,_______ employs multiple closely spaced subcarriers,but the subcarriers are divided into groups of subcarriers.

With ________ it is possible to simultaneously transmit either from or to different users by allocating the subcarriers during any one-time interval to multiple users.

The two types of MIMO transmission schemes are spatial diversity and __________ .

For the IEEE 802.11a LAN standard,the OFDM scheme consists of a set of ______ subcarriers with a base frequency of 0.3125 MHz.

_______ is a multiplexing technique used with spread spectrum.

The ________ scheme uses advance digital signal processing techniques to distribute the data over multiple carriers at precise frequencies.

Spread spectrum is an important form of encoding for wireless communications.

There are two applications of MU-MIMO: Uplink--Multiple Access Channel,MAC and __________.

In a MIMO scheme the transmitter employs a single antenna.

MIMO-MAC systems outperform point-to-point MIMO.

Subchannels are further grouped into ________,which can be allocated to wireless users.

A disadvantage of MU-MIMO is that the available capacity cannot be shared to meet time-varying demands.

_________ antenna architecture has become a key technology in evolving high-speed wireless networks,including IEEE 802.11 Wi-Fi LANs and WiMAX.

With __________ ,each bit in the original signal is represented by multiple bits in the transmitted signal,using a spreading code.

__________ is when a source data stream is divided among the transmitting antennas.

The ________ is an algorithm that converts a set of uniformly spaced data points from the time domain to the frequency domain.

Spatial diversity can be used when transmitting conditions are favorable and for relatively short distances compared to spatial multiplexing.

________ defines subchannels that can be allocated to subscriber stations depending on their channel conditions and data requirements.