demodulatory

Demodulatory is an adjective relating to demodulation, the process of extracting the original information-bearing signal from a modulated carrier. Demodulatory techniques are fundamental to many communication systems, broadcasting, radar, and telemetry, where a received modulated signal must be converted back to its baseband or digital form for use.

In analog communications, demodulation recovers the modulating signal using a demodulator specific to the modulation scheme. Common examples include envelope detection for amplitude modulation (AM), which recovers the envelope of the carrier, and frequency demodulation using discriminators for FM, or phase demodulation for PM.

In digital communications, demodulation refers to recovering a discrete symbol sequence from a modulated waveform. Techniques include coherent (synchronous) and non-coherent demodulation, depending on whether a reference carrier is used. Popular schemes include quadrature amplitude modulation (QAM), phase-shift keying (PSK), and frequency-shift keying (FSK). Demodulation can be performed in hardware or software, as in software-defined radios.

Demodulatory components appear in receivers, transceivers, and data links, and may be implemented as analog circuits, digital signal processing blocks, or mixed-signal modules. Performance depends on synchronization, noise, distortion, and channel conditions. Accurate demodulation requires proper filtering, timing recovery, and carrier recovery where appropriate.

See also: demodulation, modulation. The term emphasizes the function of extracting information from a modulated signal, rather than the modulation process itself.