In telecommunications, a carrier wave, carrier signal, or just carrier, is a periodic waveform (usually sinusoidal) that carries no information that has one or more of its properties modified (the called modulation) by an information-bearing signal (called the message signal or modulation signal) for the purpose of conveying information.[1][2]
This carrier wave usually has a much higher frequency than the message signal does. This is because it is impractical to transmit signals with low frequencies.
The purpose of the carrier is usually either to transmit the information through space as an electromagnetic wave (as in radio communication), or to allow several carriers at different frequencies to share a common physical transmission medium by frequency division multiplexing (as in a cable television system).
The term originated in radio communication, where the carrier wave creates the waves which carry the information (modulation) through the air from the transmitter to the receiver. The term is also used for an unmodulated emission in the absence of any modulating signal.[3]
In music production, carrier signals can be controlled by a modulating signal to change the sound property of an audio recording and add a sense of depth and movement.[4]
- ^ "Carrier wave with no modulation transports no information". University Of Texas. Archived from the original on 2008-04-14. Retrieved 2008-05-30.
- ^ "How does modulation work? | Tait Radio Academy". Tait Radio Academy. 2014-10-22. Retrieved 2024-06-17.
- ^ Federal Standard 1037C and MIL-STD-188
- ^ Rory PQ (May 8, 2019). "What Is Modulation and How Does It Improve Your Music". Icon Collective. Retrieved August 23, 2020.