Radio communication
= Radio communication
Radio communication conveys information using <radio waves> coupled into and out of space by <antennas>. <Amplitude modulation> and <frequency modulation> vary a <carrier wave>; <wireless telegraphy> can instead encode symbols in transmission intervals. The useful separation is between the rapid electrical <oscillation> and the slower message timing. A receiver needs both <frequency> selection and a way to turn its selected <signal> into a readable output.