Carrier to Noise (CNR) is the ratio of a high-frequency carrier frequency to an interference signal
, which is expressed in the reception quality. If the CNR value is low, interference noise becomes noticeable in the form of hiss
. Thecarrier-to-noise ratio is measured in decibels
(dB) and must be above a specified threshold on the receiving side. In RF receiving equipment, the carrier-to-noise value is the noise ratio present in the IF amplifier before it amplifies the carrier signal with its nonlinear processes such as amplitude limiting and detection.