Noise

simple question
Why noise devided by two (N0/2) ? is it average value of noise +ve and
-ve.

gaussian channel consider zero or white?

"Almas_Uddin_Ahmed" <almas.mmu@gmail.com> writes:

> simple question
> Why noise devided by two (N0/2) ? is it average value of noise +ve and
> -ve.

I think it's just a convenience factor due to the way we normally
think about bandwidth. 

Normally, if we say a signal has bandwidth B Hz, what we mean is
it is a) real, and b) non-zero from 0 to B Hz. 

When working with the "complex baseband signal," such a signal has
non-zero energy from -B to +B. Thus if you have white noise PSD of
N0/2, and you integrate over -B to +B, you get the nice result that
the toal noise power is B*N0 watts.
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