# RF_Noise in "Com_Sys/BlueTooth_prj"

Question asked by TNAKA on Mar 20, 2006
Latest reply on Mar 24, 2006 by SIMUMAN
Hi.

In the example of "EEsof Knowledge Center>Examples>Application Examples>ADS>2005A>Com_Sys>BlueTooth_prj", using two baseband Gaussian Noise sources(Noise_I, Noise_Q), Noise_RF are created via QAM_MOD.

Here parameters of QAM_MOD are Power=dbmtow(10) and Vref=1.414.

So Noise_RF is created like following.
Noise_RF=A*Real{(Noise_I+j*Noise_Q)*exp(j*wc*t)},
A=sqrt(2*50*dbmtow(10))/1.414=1/sqrt(2)

Then consider average noise power.
<Noise_RF**2>=(A**2)*0.5*{<Noise_I**2>+<Noise_Q**2>}=(A**2)*<Noise_I**2>=(A**2)*<Noise_Q**2>
Here <> means average.

From the above average noise power equatios, I think A should be 1.0 not 1/sqrt(2).

On the other hand we can create Noise_RF using just one Gaussian Noise source with FCarrier=2.4GHz.

Two baseband Gaussian Noise sources with QAM_MOD of A=1.0 can give same result as single Gaussian Noise source with FCarrier=2.4GHz.

How do you think ?