Carrier wave

The frequency spectrum of a typical radio signal from an AM or FM radio transmitter. The horizontal axis is frequency; the vertical axis is signal amplitude or power. It consists of a signal (C) at the carrier wave frequency fC, with the modulation contained in narrow frequency bands called sidebands (SB) just above and below the carrier.

In telecommunications, a carrier wave, carrier signal, or just carrier, is a waveform (usually sinusoidal) that is modulated (modified) with an information-bearing signal (called the message signal or modulation signal) for the purpose of conveying information.[1]

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.[2]

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.[3]

  1. ^ "Carrier wave with no modulation transports no information". University Of Texas. Archived from the original on 2008-04-14. Retrieved 2008-05-30.
  2. ^ Federal Standard 1037C and MIL-STD-188
  3. ^ Rory PQ (May 8, 2019). "What Is Modulation and How Does It Improve Your Music". Icon Collective. Retrieved August 23, 2020.