White noise in communication system :

White noise take the shape of impulse function in time domain;

and its F.T is a constant so it takes all the range in frequency domain , and we need an infinite power to generate it and this is impossible in real live but we can use it to know the transfer function in a system that we don't know what is the transfer function for it by applying an impulse response to it .

White noise take the shape of impulse function in time domain;

and its F.T is a constant so it takes all the range in frequency domain , and we need an infinite power to generate it and this is impossible in real live but we can use it to know the transfer function in a system that we don't know what is the transfer function for it by applying an impulse response to it .