Modulaatiomäärän

Modulaatiomäärän, often translated as modulation index or degree of modulation, is a concept used in signal processing, particularly in the context of amplitude modulation (AM) and frequency modulation (FM). It quantifies the extent to which a carrier signal is modified by a message signal.

In amplitude modulation, the modulation index is defined as the ratio of the amplitude of the modulating signal to the amplitude of the carrier signal. A modulation index of 1 (or 100%) signifies that the amplitude of the carrier signal varies by its full original amplitude. If the index is less than 1, the carrier's amplitude variation is less than its full amplitude, and if it exceeds 1, overmodulation occurs, leading to distortion in the demodulated signal.

In frequency modulation, the concept is analogous but relates to the frequency deviation. The modulation index represents the ratio of the maximum frequency deviation of the carrier signal to the frequency of the modulating signal. A higher modulation index in FM can lead to wider bandwidth requirements but often results in better signal-to-noise ratio.

Understanding modulaatiomäärän is crucial for designing and analyzing communication systems to ensure efficient and distortion-free transmission and reception of information. It directly impacts the power efficiency, bandwidth usage, and fidelity of the modulated signal.