11 Modulation and Demodulation of Biomedical Signals
In general, modulation is a process whereby a DC or low-frequency signal of interest is combined nonlinearly with a high-frequency carrier wave to form a modulated carrier suitable for transmission to a receiver/demodulator where the signal is recovered. Modulators and demodulators form essential components of most wire and wireless communication and other data transmission systems (e.g., fiber optic, ultrasound, light beam). Some modulation schemes involve multiplication of the carrier with a function of the modulating signal.
In biomedical engineering, recorded physiological ...