In satellite communications, carrier-to-receiver noise density (C/kT) is the ratio of the power by received carrier to the densityof the noise power of the receiver. It determines whether a receiver can lock on to the carrier and if the information encoded in the signal can be retrieved, given the amount of noise present in the received signal. The carrier-to-receiver noise density ratio is usually expressed in dBHz.

The carrier-to-receiver noise density is given by

$\frac{C}{k T},$

where C is the received carrier power in watts, k is Boltzmann constant in joules per kelvin, and T is the receiver system noise temperature in kelvins. The receiver noise power density, kT, is the receiver noise power per hertz.