bit rate error (BER) Simulations and channel noise

Hi,

I wanted to know about these parameters in BER simuation in ADS.

I know Power_dBm it is transmitters output signal power

I know BitsPerSymbol it is 2 since it is QPSK modulation.

I know No_dBm is the noise power

There is a problem here:

EbN0 = 6 (It is swept to find BER)

No_dBm = Eb_dBm - EbN0

So basically we sweep the noise power

but why we have energy per bit here ?

No_dBm = Eb_dBm - EbN0 (It is swept)

Eb_dBm = Power_dBm - 10*log10( SymRate*BitsPerSymbol )

beats me. Maybe this will help

Thank you very much. It explains everything, I will real most of it :)

it is amazing tnx a lot :)

I think I understood what is happening in this tutorial.

Eb = C / R

Eb is energy per bit
C is carrier power
R is bit rate

in this tutorial, it seems Eb is calculated first

Eb_dBm = Power_dBm - 10*log10( SymRate*BitsPerSymbol )

Eb_dBm = Eb is energy per bit
Power_dBm = C is carrier power
10*log10( SymRate*BitsPerSymbol ) = R is bit rate

Here symrate = Bitrate/2 (QPSK) and bitspersymbol=2 so basically 10*log10( Bitrate )

now we want to find channel noise density

we cant write like this: No(noise density)=Eb/(Eb/No)

So
No_dBm = Eb_dBm - EbN0

and we sweep Eb/No from 0 to 10.