Carriersignalen

Carriersignalen, commonly referred to in English as the carrier signal, is a high-frequency waveform that is modulated to convey information in communication systems. It is typically a stable, periodic signal, often sinusoidal, that provides the reference for modulation and transmission.

Information is impressed on the carrier by modulation. In amplitude modulation (AM), the carrier’s amplitude varies with the information signal. In frequency modulation (FM) and phase modulation (PM), the instantaneous frequency or phase of the carrier is altered. Digital communications use more complex schemes (such as QAM or PSK) that modify the carrier’s phase and amplitude to represent symbols. In some cases, the carrier is suppressed (suppressed-carrier modulation) to improve efficiency.

Spectrum and bandwidth are tied to the carrier and the modulation method. The carrier occupies the center frequency, with sidebands carrying the information. The required bandwidth depends on the modulation type and the message signal. For AM, the bandwidth is roughly twice the baseband bandwidth. For FM and PM, bandwidth is commonly estimated using Carson’s rule, B ≈ 2(Δf + fm), where Δf is frequency deviation and fm is the maximum baseband frequency.

Generation and reception are core to its use. Carriersignalen is produced by a local oscillator or transmitter and transmitted via an antenna or medium. At the receiver, a local oscillator and demodulator recover the baseband signal from the carrier. The carrier signal underpins many applications, including radio broadcasting, telecommunications, satellite links, and data networks, where stable frequency and coherent demodulation enable reliable communication.