SNR - please explain how it works

[matlab1983]

just_read

hi all

i have a problem for the meaning of S/N ratio

now if we work on BPSK the Eb=1 since once we send 1 or -1 the energy is 1

and if we work in AWGN channel with zero mean and unit variance in other word

N0=variance, since the mean=0.

so the overall will be S/N=1/1=1

can any one help me what is the wrong?

 

[ring0]

Re: just_read

S/N doesn't equal Eb/N0.

 

[matlab1983]

Re: just_read

hi this is good work

but still the idea not clear

in other words i see in papers and in matlab help that the varience = 0.5/(s/n)

and s/n is a vector form like from [5:30] db so the varience also will be a vector

so the question is the varience is it a scalar when we talk uint varience (=1) or is it

a vector for each s/n there are different varience ?

thanks for all

 

[matlab1983]

Re: just_read

hi
i dont know where i read

but i want toas k always the varience is scalar?