Importance of Modulation in Communication System
It is one of the important techniques in which the addition of signal is done to an optical signal carrier or electronic wave carrier. It is very important as it uses the properties of a periodic waveform the most. It is used in communication just to pass the signal which bears information from one source to other destination.
Here, a transmitter is used which is normally present to modify the message signal. In this process, the message signal is modified in a suitable form and it is transmitted over various communication channels. This whole process of modification of message and carrier signals is termed as modulation.
The need of Modulation Process in CommunicationIt is necessary for a communication system to make a message and carrier signal ready for the transmission of communication channels. Another reason for its use is because of the multiplexing properties.
During modulation, the size of the antenna matters the most. The size of the antenna depends upon the wavelength of the signal. Therefore, the practicality of an antenna is achieved with the help of modulation. Also, to remove the interference in the communication channel the modulation is preferred.
The modulation process is also needed to reduce the quantity of noise present in the communication band.
What Is Demodulation?The opposite of modulation is defined as demodulation. It is the process where the impressed message signal is recovered. Here, the conversion of a modulating carrier signal is done into the required signal which is equivalent to the original signal. In simple words, we can define demodulation techniques as the process of extracting the original information holding signal from a modulated signal wave.
Types of ModulationThere are various types of modulation. They are defined as amplitude modulation, frequency modulation, and phase modulation. In amplitude modulation, the amplitude of the high-frequency carrier signal is changed. The amplitude of the carrier signal contains all the needed information. It depends upon the intensity of the signal.
Similarly, in frequency modulation, the frequency of the carrier signal is changed and it does not depend on the amplitude or phase. The frequency of the carrier signal contains all the needed information. It uses the information signal for varying the carrier frequency within a desired range. And, in phase modulation, the phase of the carrier signal is changed.
Vestigial side-band modulation (VSB-AM)One of the examples of modulation is vestigial sideband modulation. It is the type of Amplitude modulation technique and also called VSB-AM.
Here, the VSB-AM stands for Vestigial Side Band Modulation- Amplitude Modulation where the encoding of the information is carried out by creating wide variations in amplitude of a Signal. In this type of modulation process, the very low-frequency parts play an important role at the receiving end. Here, in vestigial sideband modulation along with the desired sideband, another part of the sideband is also transmitted.