SINAD

Signal-to-noise and distortion ratio (SINAD) is a measure of the quality of a signal from a communications device, often defined as:

where is the average power of the signal, noise and distortion components. SINAD is usually expressed in dB and is quoted alongside the receiver RF sensitivity, to give a quantitative evaluation of the receiver sensitivity. Note that with this definition, unlike SNR, a SINAD reading can never be less than 1 (i.e. it is always positive when quoted in dB).