Demodulaator

Demodulaator (Estonian for demodulator) is a device that extracts the original information-bearing signal from a modulated carrier wave. It is the counterpart to a modulator and is essential in many communication systems, including radio receivers, television receivers, and data links. The goal of demodulation is to recover the baseband signal with minimal distortion and noise.

There are several demodulation methods, depending on the modulation scheme. Analog demodulation includes envelope detection for amplitude modulation (AM), discriminators for frequency modulation (FM) or phase-sensitive detectors for PM. For digital communication, demodulation refers to recovering transmitted symbols from modulated carriers such as PSK, QAM, or FSK, often using coherent detection with a reference carrier and digital signal processing.

Key considerations in demodulation include carrier recovery, synchronization, bandwidth, and noise performance. A demodulator must handle channel impairments and may incorporate automatic gain control, equalization, or error-correcting features to improve reliability of the recovered signal.

In practice, demodulaator implementations vary. They appear as integrated circuits in radio front-ends, as separate modules in receivers, or as software components in software-defined radios. Regardless of form, the demodulator is a critical element for converting modulated signals into usable audio, data, or video content.