Attenuation is a telecommunications term that refers to a reduction in signal strength commonly occurring while transmitting analog or digital signals over long distances.
Attenuation is historically measured in dB but it can also be measured in terms of voltage.
Attenuation is a signal travels through a medium, it loses some of its energy due to resistance of the medium. This loss of energy is called Attenuation. This is the reason why a wire carrying electric signals gets warm. Some of the electrical energy in the signal is converted to heat. To overcome for this problem, amplifiers are used to amplify the signal.
Unit of the decibel is used to find out if a signal has lost or gained strength. The decibel (dB) measures the relative strengths of two signals or one signal at two different points. If decibel is negative then a signal is attenuated and if positive signal is amplified.
Distortion is the alteration of the original shape (or other characteristic) of something, such as an object, image, sound or waveform. Distortion is usually unwanted, and so engineers strive to eliminate distortion, or minimize it. In some situations, however, distortion may be desirable. The important signal processing operation of heterogeneity is based on nonlinear mixing of signals to cause inter modulation. Distortion is also used as a musical effect, particularly with electric guitars.
Distortion can occur in a composite signal, made up of different frequencies. Each signal component has its own propagation speed through a travelling medium and, therefore, its own delay in reaching at the final destination. Means signal components at the receiver have phases different from what they had at the sender.
Noise can be defined as an unwanted signal that interferes with the communication or measurement of another signal. A noise itself is a signal that conveys information regarding the source of the noise.Noise can cause transmission errors and may even disrupt a
communication process; hence noise processing is an important part of modern telecommunication and signal processing systems. The success of a noise processing method depends on its ability to characterize and model the noise process, and to use the noise characteristics advantageously to differentiate the signal from the noise.
**Types of noise**
Following types of noise are possible.