See frequency shift.

See signals intelligence.

In a communications system, the signal power or intensity at a specified point and with respect to a specified reference level, e.g., 1 mW.

In communications systems, a message, i.e., an assembly of signaling information, that (a) includes associated message alignment and service indications, (b) pertains to a call, and (c) is transferred via the message transfer part.

The processing--such as detection, shaping, converting, coding, and time positioning--of signals, that results in their transformation into other forms, such as other waveshapes, power levels, and coding arrangements.

1. The ratio of (a) the signal-to-noise ratio of a processed signal to (b) the signal-to-noise ratio of the unprocessed signal.
Note: Signal processing gain is usually expressed in dB.
2. In a spread-spectrum communications system, the signal gain, signal-to-noise ratio, signal shape, or other signal improvement obtained by coherent band spreading, remapping, and reconstitution of the desired signal.

The portion of a facility grounding system that (a) provides reference planes, such as ground-return circuits, for all of the signal paths in the facility and (b) is isolated from other circuits, especially isolated from circuits that carry fault, lightning discharge, and power distribution currents.

Signal processing that restores a signal so that it conforms to its original characteristics.

The value of a particular characteristic of a signal at a chosen instant.

The process of obtaining a sequence of instantaneous values of a particular signal characteristic, usually at regular time intervals.