In current OFDM systems, only a single user can transmit on all of the subcarriers at any given time, and time division or frequency division multiple access is employed to support multiple users.

在目前的OFDM系统中，在任何一个特定的时间，只有一个用户可以在所有副载波上进行传送；利用时分或者频分多路访问机制来支持多个用户。

youdao

Today,VOA broadcasts to satellites in space that send the signal back to stations on the ground that transmit programs with a clear signal.

VOA: special.2010.12.08

An account on the AeroVironment website (the company MacCready went on to found) details how Allen reported, not long into the journey, that the transmit button on his radios malfunctioned, meaning he could hear his colleagues below him on the boats, but only respond with nods and gestures.

ENGADGET: The Highs and Lows of Human-Powered Flight Alt

The station had to go off public airwaves and transmit solely on cable.

CNN: March 6, 2013 -- Updated 0055 GMT (0855 HKT)

It also taught the participants how to use information and communication technologies (ICT) as instruments for searching and producing new content that would transmit messages on preventing violence in their communities.

UNESCO: MEDIA SERVICES