carrier to noise ratio (CNR)
Carrier to Noise (CNR or C/N) is the ratio of a high- frequency carrier frequency to a noise signal, which is expressed in the reception quality.
If the CNR value is low, interference in the form of noise becomes noticeable. The carrier-to-noise ratio is measured in decibels( dB) and must be above a specified threshold at the receiving end.
InRF receiving equipment, carrier-to-noise 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.