Discrete signal

Analogue (top left, non-discrete, non-quantized), Digital (bottom left, non-discrete, quantized) and Discrete signals (top right, non-quantized and bottom right, quantized)

Discrete signal ( lat. Discretus - “intermittent”, “divided”) - a signal that is intermittent (unlike analog ) and which changes in time and takes any value from the list of possible values. The list of possible values ​​can be continuous or quantized.

There is confusion between the concepts of discrete and digital signals. Often a digital signal is called discrete because it consists of discrete (separate) parts (samples), despite the fact that the digital signal is not an intermittent signal.

In English, the following concepts are used: discrete time , to consider the values ​​of variables at individual points in time; continuous time (continuous time), for considering the values ​​of variables at any time, and between any two points in time there are an infinite number of other points in time.

A digital signal is obtained by a sequence of two steps:

1. Sampling, which produces a continuous discrete time signal
2. Quantization, which replaces the value of each sample with an approximate value selected from a given discrete set (quantized levels).

Discreteness is used in computer technology for packet data transmission.