Operations on Signals

Basic operations which can be performed on any signal are given below:

• Amplification: Amplification in electric signal is a process in which amplitude or strength of a signal is increased. A device named amplifier is used to perform the operation of amplification. This operation is mainly used for effective transmission of a signal because intensity of a signal decreases during transmission, so to regain that amplitude the process of amplification is required.
• Attenuation: Attenuation in an electric signal is a process in which there is decrease in amplitude or strength of a signal. During transmission, a signal may be subjected to various disturbances like noise, echo or dispersion which results in decrease in amplitude and thus, attenuation takes place.
• Modulation: Modulation is an operational technique which is performed on a signal in which various characteristics of a signal is changed so that it could be transmitted to a longer distance without any loss of information which is to be carried by a signal.
• Encoding: Encoding refers to a technique in which a special code is applied on any signal’s information, and it gets converted to a particular format so as to shield it from noise and distortion and to provide privacy and security during transmission of a signal.
• Decoding: Decoding of an electrical signal is a process in which encoded signal is converted back into its original form. It’s purpose is to provide receiver the original data which was transmitted by the sender.

An electrical signal is a physical quantity that varies with time. It varies with any dependent or independent quantity. A signal can either be one-dimensional or multi-dimensional. When the function which varies with time depends only on a single variable then that type of signal is referred to as a one-dimensional signal. Examples of such signals are audio signals, biometrics like pulse or heartbeat, light wave signals, etc. On the other hand, a signal that is dependent on more than one time-dependent variable, then that type of signal is known as a multi-dimensional signal. Examples of two-dimensional signals are electromagnetic signals, video signals, etc. A signal is a mathematical representation of energy.

Thus, signal is a time-dependent function that can be dependent on one or more than one physical quantity for the transference of data and information with or without the presence of the medium. Electromagnetic wave signals can travel in a vacuum whereas sound and electrical signals require a medium for their propagation.