SNR = Psignal - Pnoise (dB). Higher is better.
SINAD = Psignal / (Pnoise + Pdistortion). Accounts for harmonic distortion.
Eb/N0 = SNR − 10·log₁₀(bits/symbol). Normalised per-bit SNR.
Shannon = log₂(1 + SNRlinear) [bit/s/Hz]. Theoretical maximum spectral efficiency.
Thermal noise = kTB = −174 dBm/Hz + 10·log₁₀(BW)