Modulasjonsprinsipp

Modulasjonsprinsipp is a concept in signal processing and telecommunications related to how information is encoded onto a carrier signal. Essentially, it involves altering certain properties of a carrier wave, such as its amplitude, frequency, or phase, in accordance with the characteristics of the information signal to be transmitted. This process is crucial for transmitting information over a communication channel, as it allows the signal to travel efficiently and be distinguished from other signals.

There are several common types of modulation. Amplitude modulation (AM) involves changing the amplitude of the carrier wave. Frequency modulation (FM) varies the frequency of the carrier. Phase modulation (PM) alters the phase of the carrier wave. Digital modulation techniques, such as amplitude-shift keying (ASK), frequency-shift keying (FSK), and phase-shift keying (PSK), encode digital data by changing these properties in discrete steps.

The primary purpose of modulation is to adapt a baseband signal, which often has a limited frequency range, to a form suitable for transmission. This can involve shifting the signal's spectrum to a higher frequency band for efficient radiation by an antenna, allowing multiple signals to share the same transmission medium without interference (multiplexing), and improving the signal's robustness against noise and distortion during transmission. Demodulation, the reverse process, is then performed at the receiver to extract the original information signal from the modulated carrier.