File Name: modulation and types of modulation .zip
The term carrier is applied to the voltage whose characteristic is varied and the term modulating voltage signal is used for the voltage in accordance with which the variation is made. The modulation is the process of up shifting the message frequency to a range more useful for transmission. The carrier signal is a sine wave at the carrier frequency.
As we are living in an era of communication wherein we can easily transfer any form of information video, audio, and other data in the form of electrical signals to any other device or destined area. Although it is common in our perceptual experience that sending or receiving signals or data is simple, but it involves quite complex procedures, possibilities, and involved scenarios within the communication systems. So, in the scope of communication systems, modulation plays hold crucial responsibility in the communication system to encode information digitally in the analog world. It is very important to modulate the signals before sending them to the receiver section for larger distance transfer, accurate data transfer, and low-noise data reception. To be clear, let us dive into the detailed concept of knowing what is modulation, different types in it, and what are the types of modulation techniques used in communication systems. Modulation is a process of changing the characteristics of the wave to be transmitted by superimposing the message signal on the high-frequency signal. In this process video, voice and other data signals modify high-frequency signals — also known as the carrier wave.
In electronics and telecommunications , modulation is the process of varying one or more properties of a periodic waveform , called the carrier signal , with a separate signal called the modulation signal that typically contains information to be transmitted. For example, the modulation signal might be an audio signal representing sound from a microphone , a video signal representing moving images from a video camera , or a digital signal representing a sequence of binary digits, a bitstream from a computer. The carrier is higher in frequency than the modulation signal. The purpose of modulation is to impress the information on the carrier wave, which is used to carry the information to another location. In radio communication the modulated carrier is transmitted through space as a radio wave to a radio receiver.
A signal can be anything like a sound wave which comes out when you shout. This shout can be heard only up to a certain distance. A message carrying signal has to get transmitted over a distance and for it to establish a reliable communication, it needs to take the help of a high frequency signal which should not affect the original characteristics of the message signal. The characteristics of the message signal, if changed, the message contained in it also alters. Hence it is a must to take care of the message signal. A high frequency signal can travel up to a longer distance, without getting affected by external disturbances. We take the help of such high frequency signal which is called as a carrier signal to transmit our message signal.
Modulation is the process of converting data into electrical signals optimized for transmission. Modulation techniques are roughly divided into four types: Analog modulation, Digital modulation, Pulse modulation , and Spread spectrum method. This method is divided into single carrier modulation, by which the carrier occupies the entire bandwidth i. In addition, there is a pulse modulation technique used to change the pulse width and spread spectrum method that spreads the signal energy over a wide band. In wireless communication, information is transmitted by encoding voice and data on radio waves of certain frequencies. This technique utilizes the difference in the amplitude of analog signals to modulate digital signals by switching between low frequency and high frequency in order to represent 0 and 1. A digital modulation scheme that performs data transmission by phase-modulating a reference signal.
Modulation is the process by which information is encoded from a message source in order to optimize it for transmission. Frequency Modulation FM is the encoding of information in a carrier wave by changing the instantaneous frequency of the wave. FM technology is widely used in the fields of computing, telecommunications, and signal processing. Frequency Modulation is a modulation in which the frequency of the carrier wave is altered in accordance with the instantaneous amplitude of the modulating signal, keeping phase and amplitude constant.
RF communication is built upon a simple concept: by continually altering the characteristics of a sinusoid, we can use it to transfer information. At this point, we have covered a variety of important concepts that serve as a foundation for the successful design and analysis of real-world RF circuits and systems. We are now ready to explore a fundamental aspect of RF engineering: modulation. This high-frequency sinusoid that is used to carry information is called, appropriately, the carrier.
Modulation is a term that is going to be used very frequently in this book. So much in fact, that we could almost have renamed this book "Principles of Modulation", without having to delete too many chapters.
Note that once again, a composite M-ASK signal over many symbol durations does not have a constant amplitude. In the case of M-FSK, M different carrier.Reply
Modulation is the act of changing a signal to transmit useful data.Reply
Partes de un motor electrico de corriente directa pdf itil foundation exam reference book pdfReply