What is Modulation? Last Updated : 27 May, 2024 Comments Improve Suggest changes Like Article Like Report Modulation can be digital or analog, the input wave of the analog signal varies continuously like a sine wave. Modulation can be defined as the process of converting data into waves by adding information to a carrier signal. Such a signal can be transmitted electronically or optically, but it must have a consistent waveform. What is Modulation?The process by which data is converted into electrical/digital signals for transferring that signal over a medium is called modulation. It increases strength for maximum reach of the signals. The process of extracting data from the transmitted signal is called demodulation. A Modem is a device that performs both modulation and demodulation processes. The various forms of modulation are designed to alter the characteristics of carrier waves. The most commonly altered characteristics of modulation include amplitude, frequency, and phase. Carrier signal: The signals that contain no information but have a certain phase, frequency, and amplitude are called carrier signals.Modulated signals: The signals which are the combination of the carrier signals and modulation signals are modulated signals. The modulated signal is obtained after the modulation of the signals.Types of ModulationAmplitude Modulation: It is a type of modulation in which only the amplitude of the carrier signal is varied to represent the data being added to the signals whereas the phase and the frequency of the signal are kept unchanged. Frequency Modulation: It is a type of modulation in which only the frequency of the carrier signal is varied to represent the frequency of the data whereas the phase and the amplitude of the signals are kept unchanged. Phase Modulation: It is a type of modulation in which the phase of the carrier signal is varied to represent the data being added to the signal. Different information values are represented by different phases. For example: '1' may be represented by 0° while '0' by 180°. Polarisation Modulation: Polarisation modulation involves varying the angle of rotation of an optical carrier signal to reflect transmitted data. Pulse-Code Modulation: An analog signal is sampled to generate a data stream, which is then utilized to modulate a digital carrier signal. Quadrature Amplitude Modulation (QAM): Quadrature amplitude modulation employs two AM carriers to encode two or more bits in a single transmission.What is the Need of Modulation?Size of Antenna: As we know that the size of the antenna is inversely proportional to the frequency of the radiated signal and antenna size must be 1/10th of the wavelength. If the frequency signals are more than 5KHz in that case it is quite impossible to set up an antenna of that size. So, by using the modulation technique the size of the antenna is reduced.Wireless Communication: Modulation provides a wireless connection to transmit the signals to a longer distance. Earlier we used wire systems (like the telephone) to transfer information with the help of telephonic wires but it was not possible to spread the wires all over the world for communication. By using the modulation technique, the cost of wire is saved and even information can be transferred to longer distances faster. Working of Modulation Data can be added to the carrier signal by varying its amplitude, frequency, and phase. Basically, modulation is applied to electromagnetic signals like radio waves, optics, and computer networks. It can also be applied to direct current that can be treated as a degenerate carrier wave with a fixed amplitude and frequency of 0 Hz by turning it off and on as in a digital current loop and in Morse code telegraphy. Why use Modulation in Communication? Multiple carriers of various frequencies can frequently be sent across the same medium, with each carrier modulated by a separate signal. For Example Wi-Fi employs individual channels to transmit and receive data from several customers at the same time. A carrier signal is used to decrease the wavelength for more effective transmission and reception. Because the ideal antenna size is one-half or one-quarter of a wavelength, an audio frequency of 3000 Hz needs a wavelength of 100 kilometers and a 25-kilometer antenna. Instead, with a 100 MHz FM carrier and a wavelength of 3 meters, the antenna would only need to be 80 cm long. Advantages of ModulationIt reduces the size of the antenna.It reduces the cost of wires.It prohibits the mixing of signals.It increases the range of communication.It improves the reception quality.It easily multiplexes the signals.It also allows the adjustment of the bandwidth.Disadvantages of ModulationThe cost of the equipment is higher.The receiver and the transmitter are very complicated.For better communication, the antennas for the FM system must be kept closed.It is not efficient for large bandwidth. Power wastage takes place.Define Duty CycleIn wireless communications, the duty cycle is the percentage of time the wireless network emits RF signals. As a result, the duty cycle is an important factor when measuring a person's exposure to electromagnetic radiation. The actual duty cycle differs based on the network's data load and speed. As a result, the duty cycle can be changed by whether the network is used for Voice Over Internet Protocol(VoIP), streaming videos, or videos. What is Demodulation?The Demodulation is the process of extracting the original information from a modulated carrier wave. It is an important function used in the communication systems which allows the recovery of transmitted data at the receiver end. Demodulation is the technique to recover the original signal from the modulated signal. The demodulation is done with the help of a demodulator. A demodulator will convert the carrier variation of amplitude, frequency, or phase back to the message signal. There are three different types of demodulators for converting the AM (amplitude modulation), FM (frequency modulation), and PM (phase modulation) modulation schemes. Difference Between Modulation and DemodulationModulation Demodulation The process by which data is converted into electrical/digital signals for transferring that signal over a medium is called modulation. The process of extracting data from the transmitted signal is called demodulation. Modulation is connected from transmitting end. Demodulation is connected from Receiving end. Modulation converts digital signal to analog signal. Demodulation converts analog signal to digital signal. The transmission of frequency in modulation goes low to high. The transmission of frequency in demodulation goes high to low. In modulation, the circuit used is modulator. In demodulation, the circuit used is demodulator. Comment More infoAdvertise with us Next Article Multiplexing (Channel Sharing) in Computer Network 69406930ravi Follow Improve Article Tags : Computer Subject Computer Networks Similar Reads Data Communication Tutorial Data communication plays an important role in today's interconnected world and enables the exchange of information between devices and networks. Whether you're sending an email, making a video call, or browsing the web, data communication ensures that information flows smoothly. 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These all data are store 2 min read Analog to Digital ConversionDigital Signal: A digital signal is a signal that represents data as a sequence of discrete values; at any given time it can only take on one of a finite number of values. Analog Signal: An analog signal is any continuous signal for which the time varying feature of the signal is a representation of 6 min read Digital to Analog ConversionDigital Signal - A digital signal is a signal that represents data as a sequence of discrete values; at any given time it can only take on one of a finite number of values. Analog Signal - An analog signal is any continuous signal for which the time varying feature of the signal is a representation 3 min read Quadrature Amplitude ModulationQuadrature Amplitude Modulation (QAM) is a modulation technique that can be utilized in Analog modulation concepts and digital modulation concepts. It is a combination of ASK and PSK. So, in this article, we will discuss QAM, Analog QAM, Digital QAM, and many more. Quadrature Amplitude Modulation:Qu 5 min read Analog to Analog Conversion (Modulation)Analog Signal: An analog signal is any continuous signal for which the time varying feature of the signal is a representation of some other time varying quantity i.e., analogous to another time varying Signal. Analog to Analog Conversion - Analog-to-analog conversion, or modulation, is the represent 3 min read What is Modulation?Modulation can be digital or analog, the input wave of the analog signal varies continuously like a sine wave. Modulation can be defined as the process of converting data into waves by adding information to a carrier signal. Such a signal can be transmitted electronically or optically, but it must h 6 min read MultiplexingMultiplexing (Channel Sharing) in Computer NetworkMultiplexing means multiple sources but one link. An alternative approach is a Direct point-to-point connection, but it has several problems as it requires an I/O port for each device, a need line for each device, and also a large amount of wiring needed if on different floors. Instead, if we use a 9 min read Types of Multiplexing in Data CommunicationsImagine you have several friends who all want to send letters to the same person at the same time. Instead of sending each letter individually, which would take a lot of time and effort, you put all the letters into one big envelope and send that. When the big envelope arrives, the letters are taken 6 min read Frequency Division and Time division multiplexingMultiplexing is used in cases where the signals of lower bandwidth and the transmitting media is having higher bandwidth. In this case, the possibility of sending a number of signals is more. 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Its installation and implementation are easy but it is less efficient than optical fiber also it provides moderately low bandwidth in compar 6 min read Fiber Optics and TypesFiber Optics or Optical Fiber is a technology that transmits data as a light pulse along a glass or plastic fiber. An Optical Fiber is a cylindrical fiber of glass that is hair-thin in size or any transparent dielectric medium. The fiber which is used for optical communication is waveguides made of 6 min read Difference between Twisted pair cable, Co-axial cable and Optical fiber cableA computer cable is a medium used to transmit data between devices such as computers, servers, routers, and switches. Cables physically connect these devices, enabling them to communicate within a network. In computer networking, it is very important to know the distinctions between the different ty 8 min read Radio WavesRadio waves are a special type of energy that travels through space, carrying information without needing wires. They have the longest wavelengths in the electromagnetic spectrum, meaning they stretch out much farther than other waves like visible light or X-rays. These waves can be incredibly long, 9 min read Infrared light for TransmissionInfrared light for Transmission :Infrared is the frequency of light that is not visible to the eyes .The frequency of the waves lies between three hundred gigacycles to four hundred THz. In this, the radiation is in the region of the electromagnetic spectrum . Infrared could be a communication mediu 3 min read Difference between Guided and Unguided MediaNetwork media or transmission media refer to the physical pathways through which data is transmitted from one device to another within a network. These ways can be wired or wireless. The selection of media depends on factors like distance, speed, and interference. In this article, we will discuss th 4 min read Error Detection and CorrectionError Detection in Computer NetworksError is a condition when the receiver's information does not match the sender's. Digital signals suffer from noise during transmission that can introduce errors in the binary bits traveling from sender to receiver. That means a 0 bit may change to 1 or a 1 bit may change to 0. Data (Implemented eit 7 min read Forward Error Correction in Computer NetworksForward Error Correction (FEC) is a technique used to minimize errors in data transmission over communication channels. In real-time multimedia transmission, re-transmission of corrupted and lost packets is not useful because it creates an unacceptable delay in reproducing : one needs to wait until 3 min read Vertical Redundancy Check (VRC) or Parity CheckVertical Redundancy Check is also known as Parity Check. In this method, a redundant bit also called parity bit is added to each data unit. This method includes even parity and odd parity. Even parity means the total number of 1s in data is to be even and odd parity means the total number of 1s in d 3 min read Longitudinal Redundancy Check (LRC)/2-D Parity CheckLongitudinal Redundancy Check (LRC) is also known as 2-D parity check. In this method, data which the user want to send is organised into tables of rows and columns. A block of bit is divided into table or matrix of rows and columns. In order to detect an error, a redundant bit is added to the whole 2 min read Hamming Code in Computer NetworkHamming code is an error-correcting code used to ensure data accuracy during transmission or storage. Hamming code detects and corrects the errors that can occur when the data is moved or stored from the sender to the receiver. This simple and effective method helps improve the reliability of commun 10 min read Concepts of hamming distanceHamming Distance Problem: In general, it is assumed that it is more likely to have fewer errors than more errors. This “worst-case†approach to coding is intuitively appealing within itself. Nevertheless, it is closely connected to a simple probabilistic model where errors are introduced into the me 2 min read Error Detection Code - ChecksumChecksum is the error detection method used by upper-layer protocols and is considered to be more reliable than Longitudinal Redundancy Check (LRC), Vertical Redundancy Check (VRC), and Cyclic Redundancy Check (CRC). This method uses a Checksum Generator on the sender side and a Checksum Checker on 4 min read ChannelizationFrequency Division Multiple Access (FDMA) TechniquesIn Frequency-Division Multiple Access the channel bandwidth is subdivided into a variety of sub-channels. FDMA is used for voice and data transmission. During this method the general channel bandwidth is shared by multiple users, therefore a variety of users can transmit their data simultaneously. N 5 min read CDMA Full FormCDMA stands for Code Division Multiple Access. It is basically a channel access method and is also an example of multiple access. Multiple access basically means that information by several transmitters can be sent simultaneously onto a single communication channel. There are multiple users which ar 4 min read What is Ethernet?A LAN is a data communication network connecting various terminals or computers within a building or limited geographical area. The connection between the devices could be wired or wireless. Ethernet, Token rings, and Wireless LAN using IEEE 802.11 are examples of standard LAN technologies.In this a 9 min read Bridges (local Internetworking device)Prerequisites - Network Devices, Types of switches Bridge is a local internetworking device that is used to connect two or more network segments together. A bridge operates at the Data Link Layer (Layer 2) of the OSI model and uses the MAC addresses of devices to make forwarding decisions. Bridges w 6 min read Introduction of Gigabit EthernetThe committee began working on a faster Ethernet, quickly dubbed gigabit Ethernet. The goal was to increase performance while maintaining all Ethernet standards. Gigabit Ethernet had to provide service with both unicast and broadcast using the same 48-bit address scheme and also maintaining the same 3 min read Like