The signal shown above is an example of continuous time signal because we can get value of signal at each instant of time. Sine and cosine functions are the best example of Continuous time signal. These will have values at each instant of time.

This type of signal shows continuity both in amplitude and time. Continuous-time signals are often referred to as analog signals. Continuous Time SignalsĬontinuous-time signals are defined along a continuum of time and are thus, represented by a continuous independent variable. So, noise is also a signal but unwanted.Īccording to their representation and processing, signals can be classified into various categories details of which are discussed below. Note − Any unwanted signal interfering with the main signal is termed as noise. The process of operation in which the characteristics of a signal (Amplitude, shape, phase, frequency, etc.) undergoes a change is known as signal processing. It can also be defined as a physical quantity that varies with time, temperature, pressure or with any independent variables such as speech signal or video signal.

Digital Signal Processing - Signals-Definition DefinitionĪnything that carries information can be called as signal.