What is Modulation, Definitions & Types

Authored By: Ankita Prajapati

Modulation is the process of changing the frequency, phase, or amplitude of a signal. It is often used in communications to transmit messages over long distances. Modulation can be used to encode information into a signal, allowing it to be sent over a variety of media, such as radio waves and optical fibers.

Modulation can be used to reduce the amount of noise that is present in a signal, allowing it to be heard more clearly.

The amplitude, frequency, and phase of the signal can all be changed in order to make the transmission of the message more efficient. Modulation is an essential part of communication systems and is used in a variety of applications, such as radio communications and data transmission.

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Types

Their are four type of modulation techniques are there. These are:-

Amplitude modulation
Frequency modulation
Phase modulation
Quadrature amplitude modulation

The most common types of modulation are amplitude modulation (AM) and frequency modulation (FM).

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Amplitude Modulation

Amplitude modulation (AM) is the process of varying the amplitude of a carrier signal in proportion to the waveform of the modulating signal. The amplitude of the carrier is increased and decreased according to the amplitude of the modulating signal, resulting in a waveform that is the sum of the carrier and the modulating signal. This is the most common form of modulation used in radio broadcasting.

Frequency Modulation

Frequency modulation (FM) is the process of varying the frequency of a carrier signal in proportion to the waveform of the modulating signal. The frequency of the carrier is increased and decreased according to the amplitude of the modulating signal, resulting in a waveform that is the sum of the carrier and the modulating signal. This is the most common form of modulation used in radio broadcasting.

Phase Modulation

Phase modulation (PM) is the process of varying the phase of a carrier signal in proportion to the waveform of the modulating signal. The phase of the carrier is shifted according to the amplitude of the modulating signal, resulting in a waveform that is the sum of the carrier and the modulating signal. PM is used in some digital communication systems, such as spread-spectrum technology.

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Quadrature Amplitude Modulation

Quadrature amplitude modulation (QAM) is the process of varying both the amplitude and the phase of a carrier signal in proportion to the waveform of the modulating signal. The amplitude and phase of the carrier are changed according to the amplitude and phase of the modulating signal, resulting in a waveform that is the sum of the carrier and the modulating signal. QAM is used in some digital communication systems, such as digital television and cable modems.

Conclusion

Modulation is used in many communication systems, such as radio and television broadcasting, radar, two-way radio communication, and data transmission for telecommunications.

Modulation provides the ability to transmit multiple types of data on the same channel, as well as the ability to separate multiple channels.