To install click the Add extension button. That's it.


Kelly Slayton
Congratulations on this excellent venture… what a great idea!
Alexander Grigorievskiy
Live Statistics
English Articles
Improved in 24 Hours
Added in 24 Hours
Show all languages

Carrier-to-noise ratio

From Wikipedia, the free encyclopedia

In telecommunications, the carrier-to-noise ratio, often written CNR or C/N, is the signal-to-noise ratio (SNR) of a modulated signal. The term is used to distinguish the CNR of the radio frequency passband signal from the SNR of an analog base band message signal after demodulation, for example an audio frequency analog message signal. If this distinction is not necessary, the term SNR is often used instead of CNR, with the same definition.








where and are the root mean square (RMS) voltage levels of the carrier signal and noise respectively.


or in term of voltage:

Measurements and estimation



C/N estimators are needed to optimize the receiver performance.[1] Typically, it is easier to measure the total power than the ratio of signal power to noise power (or noise power spectral density), and that is why CNR estimation techniques are timely and important.

Carrier-to-noise density ratio

In satellite communications, carrier-to-noise-density ratio (C/N0) is the ratio of the carrier power C to the noise power density N0, expressed in dB-Hz. When considering only the receiver as a source of noise, it is called carrier-to-receiver-noise-density ratio.

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 noise power density, N0=kT, is the receiver noise power per hertz, which can be written in terms of the Boltzmann constant k (in joules per kelvin) and the noise temperature T (in kelvins).

See also


  1. ^ Islam, A. K. M. Najmul; Lohan, E. S.; Renfors, M. (Mar 2008). "Moment based CNR estimators for BOC/BPSK modulated signal for Galileo/GPS". 2008 5th Workshop on Positioning, Navigation and Communication. pp. 129–136. doi:10.1109/WPNC.2008.4510366. ISBN 978-1-4244-1798-8.


Further reading

This page was last edited on 22 September 2020, at 12:49