Modulation
Modulation is the process of varying some characteristic of a periodic wave with external signals.
Modulation is utilized to send an information bearing signal over long distances.
Radio communication superimposes this information bearing signal onto a carrier signal.
These high frequency carrier signals can be transmitted over the air easily and are capable of traveling long distances.
The characteristics (amplitude, frequency, or phase) of the carrier signal are varied in accordance with the information bearing signal.
In the field of communication engineering, the information bearing signal is also known as the modulating signal.
The modulating signal is a slowly varying signal, as opposed to the rapidly varying carrier frequency.
Types of Modulation
Types of modulation include:
- Amplitude Modulation
- Frequency Modulation
- Phase Modulation
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- Frequency Modulation
Frequency modulation is a type of modulation where the frequency of the carrier is varied in accordance with the modulating signal. The amplitude of the carrier remains constant. The information-bearing signal (the modulating signal) changes the instantaneous frequency of the carrier. Since the amplitude is kept constant, FM modulation is a low-noise process and provides [...]...
- Quadrature Amplitude Modulation
Quadrature Amplitude Modulation (QAM) is a complicated name for a simple technique. In the simplest of terms, Quadrature amplitude modulation is the combination of amplitude modulation and phase shift keying. More technically, quadrature amplitude modulation is a system of modulation in which data is transferred by modulating the amplitude of two separate carrier waves, mostly [...]...
- Pulse Width Modulation
Pulse Width Modulation, abbreviated as PWM, is a method of transmitting information on a series of pulses. The data that is being transmitted is encoded on the width of these pulses to control the amount of power being sent to a load. In other words, pulse width modulation is a modulation technique for generating variable [...]...
- Pulse Position Modulation
Pulse position modulation is a signal modulation technique that allows computers to share data by measuring the time each data packet takes to reach the computer. It is often used in optical communication, such as fiber optics, in which there is little multi-pathway interference. Pulse position modulation exclusively transfers digital signals and cannot be used [...]...
- PSK (Phased Shift Keying)
Digital modulation is no new concept. Programmers and people working in today’s technological field know it for sure, as they have been using certain modulation techniques to transmit data digitally. However, several techniques are available for techies to choose from, and out of three popular digital modulation options, the PSK or Phase Shift Keying tops [...]...