Additive white Gaussian noise

As additive white Gaussian noise, short AWGN or AWGN (English additive white Gaussian noise ), a channel model is referred to, in which the influence of the channel on the useful signal by a noise signal with gaußverteilter signal amplitude and constant spectral noise density is modeled, which is the useful signal superimposed.

In communication engineering, the simple mathematical model of an AWGN channel has gained importance. A signal is sent to S ( t), through this channel, we obtain at the receiver the signal g ( t) by additive interference n (t):

Here, n ( t) is a realization of a WGR process. However, this simple model provides many real-world effects of message transmission as interference, multipath propagation or dispersion not expire.

In contrast to white noise is important to note that white noise is not always Gaussian distributed. Also may be inferred from Gaussian distribution is not the presence of a WGR process.

Examples of white Gaussian noise

Noise voltage of an electrical resistance

Thermal noise in electronic components - such as a resistor - can be approximated by an additive white Gaussian noise process ( WGR ) process model: the instantaneous voltage is Gaussian distributed in this model at any time and the voltage at different points in time is completely uncorrelated. Very small noise voltages ( in a practical example in the range of nV, uV ) occur with a very high probability. However, the probability that noise amplitudes in the range of volts or kilovolts does occur is very low.