plural of ring modulation

A component on a SIM card that stores information to identify a mobile phone user.

plural of Subscriber Identity Module

(radio) A modification of amplitude modulation that modulates the output signal on a single sideband only, as opposed to both sidebands.

(radio) A modulation scheme that conveys data by applying amplitude modulation to two carrier waves at once. These two waves, usually sinusoids, are out of phase with each other by 90° and are thus called quadrature carriers. Commonly abbreviated QAM.

plural of quadrature amplitude modulation

plural of single-sideband modulation

The "mother ship" of the spacecraft that carried astronauts to the Moon in the Apollo missions.