Modulation Types

Modulation is the process of varying one or more properties of a periodic waveform, called the carrier signal, with a separate signal called the modulating signal that contains information to be transmitted.

Analog Modulation

Amplitude Modulation (AM)

The amplitude of the carrier wave varies in proportion to the message signal.

Frequency Modulation (FM)

The frequency of the carrier wave is varied.

Digital Modulation

Phase Shift Keying (PSK)

Data is conveyed by changing (modulating) the phase of a constant frequency reference signal.

Quadrature Amplitude Modulation (QAM)

Combines both amplitude and phase modulation.

[!TIP] Higher order modulations (like 256-QAM) allow for higher data rates but require a better Signal-to-Noise Ratio (SNR).