COMPUTER NETWORKING

Detailed explanation-1: -Modulation is used to condition a signal to suit the characteristics of the channel. The reverse process of modulation is called demodulation. Both modulation and demodulation (aka modem) are ISO/OSI Layer 1 (i.e., physical layer) techniques. Information transfer over communications networks cannot work without modem.

Detailed explanation-2: -Based on this nonlinearity, the demodulation methods can be broadly classified as methods using rectification (non-synchronous detection) and methods using mixing with a reference oscillator signal (synchronous detection).

Detailed explanation-3: -Demodulation. The process of separating the original information or SIGNAL from the MODULATED CARRIER. In the case of AMPLITUDE or FREQUENCY MODULATION it involves a device, called a demodulator or detector, which produces a signal corresponding to the instantaneous changes in amplitude or frequency, respectively.