I have a fade margin for a RF bridge, but it only compares the sensitivity of the receiver to the received power - or alternatively calculates the Eb/N0 from the net received power divided by the thermal system noise. Intuitively I think I should subtract some dB from the power budget due to the transmitter's SNR, but removing 30dB SNR from the net power received kills everything so I find it hard to believe this is the right way.
Care to explain?
The first thought I had was to get the noise power from the radiated power and the SNR, then multiply this noise power by all gains of the chain, and at the receiver end convert both the resulting noise and the previously calculated received power (for infinite SNR at the transmitter's output) into µV into a 50Ohm load - then subtract the µV. Does that make sense?