Modulation

• Modulation is a process of superposition carrier signal with high frequency and modulating signal by adjusting the properties of carrier signal according to the modulating signal.
• The modulating signal includes all information which is going to transmit from one place to another.

Types of Modulation

• The main classification of modulation is Analog modulation and Digital modulation
• In analog modulation, the modulating signal that is the signal containing the information is in the form of analog.
• But in the case of digital modulation, the signal is in the form of digital.

Analog Modulation

• Analog signal is super impose with a carrying signal and transmit from one place to another.
• Amplitude modulation, frequency modulation and phase modulation are the important analog modulations.

Amplitude Modulation

• In the case of amplitude modulation, amplitude of the carrier wave will change according to the signal wave. In this modulation, the amplitude of the carrier wave is not dependent.

Frequency Modulation

• In frequency modulation, the frequency of the carrier wave is changing according to the information wave or signal wave.

Phase Modulation

• Phase modulation is nothing but the changes in the phase of the carrier wave according to the signal while transmission.
• The modulating wave (blue) is modulating the carrier wave (brown), resulting the PM signal (green).

Digital Modulation

• In digital modulation, the signal wave is in the form of digital signal. The carrier signal is changing such a way that the phase matching with that of the modulating wave.
• Digital modulation is commonly seen in computers. The important digital modulation is pulse code modulation.

Pulse Modulation

• Pulse wave modulation is defined as the process of sampling the carrier signal according to the information signal.
• Mainly there are four types of pulse modulation. These are, pulse amplitude modulation (PAM), pulse position modulation (PPM), pulse width modulation (PDM) and pulse code modulation (PCM).