In facsimile, the ratio of the level of the white signal to the level of the black signal.
Note: Signal contrast is usually expressed in dB.

Synonym modem.

1. A measure of the difference between a given signal and a reference signal.
Note: For analog signals, the signal distance is the root mean square difference between the given signal and a reference signal over a symbol period.
2. Synonym Hamming distance.

See distortion.

In an otherwise essentially flat-topped rectangular pulse, distortion characterized by a decline of the pulse top.

A multifrequency (MF) or dual-tone multifrequency (DTMF) signal timing interval during which the signal is being transmitted. For MF signals the signal duration interval begins when the last tone of the MF tone pair exceeds 90% of its steady-state value and ends when either tone of the MF tone pair falls below 90% of its respective steady-state value. For DTMF… (Read More →)

A part of a signal, distinguished by its nature, magnitude, duration, transition, or relative position.
Note: Examples of signal elements include signal transitions, significant conditions, significant instants, and binary digits (bits).

Restoration of the dynamic range of a compressed signal.

See frequency shift.

See signals intelligence.