White noise and Autocorrelation

Question

Define the following term:

a) White noise

b) Autocorrelation

Answer 1

White noise :

A stationary random process is known as white noise in case its power density spectrum remains constant. Thus, the white noise has the flat frequency response spectrum.

Autocorrelation :

The autocorrelation of the sequence refers to the correlation of the sequence having its shifted version, and this signify how fast the signal changes.
SX (w) = σx2, -π ≤ wπ