I'm new to telecomm and I was wondering how a SNR would be calculated if I knew the signal voltage and the noise power? Both the input and output signal is measured in voltage but the input and output noise is measured in watts. Also, this is through a 300ohm antenna amp (booster). Would the ratio be V^2/P or V^2*R/P? Or is there something I'm missing? I'm also looking for the noise figure in dB (so log10(SNRi/SNRo)). Thanks in advance if you can tell me if it's that simple above or if there is something else.