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additive white Gaussian noise
Posted:
Apr 5, 2013 8:02 PM


Hello all
please help me ; If I want to generate the following signal x= u*h ; y= x+ n ;
u=[1 1 1 1 1 1 1 1 ] ; h= random('rayl',1,8 ) ;
I want the signal to noise ration to be 5 dB ; I am generating 8 random Rayleigh fading envelopes and multiplying them by 1 or 1 according the the Hypothesis ( In wireless sensor Network ) ;
Will I have to use var(x) ... to calculate the signal power and after that calculating the required noise power ?
In some references they use the following formula : SNR= mean(x)/ std(n)
In the paper which I am trying to implement it ; they assumed Unity power fading envelopes ; E(h^2) = 1 ;
I am really confused ; between variance , mean , expectation .....
please help me



