Types of modulation 6 flynnkatz 7810 analog modulation amplitude modulation, am frequency modulation, fm double and single sideband, dsb and ssb digital modulation phase shift keying. Application to microwave links covers the theoretical principles of microwave beam technique. Amplitude modulation a1 49 you will see in this experiment, and in others to follow, that there is no problem in generating an am signal with a depth of modulation exceeding 100%, and without any rf distortion whatsoever. Ssb modulation by dsbscam and filtering in singlesidebandssb modulation only the. Amplitude modulation or am is a method to transmit signals via electromagnetic transmission. But we are getting ahead of ourselves, as we have not yet even defined what am is. Click download or read online button to get frequency modulation book now. However if st is sinusoidal, then the instantaneous frequency deviation of the anglemodulated signal is. Scribd is the worlds largest social reading and publishing site. Its still used in radio systems to transmit audio signals although it has lesser in popularity compared to fm due to its lower signal to noise ratio. Introduction to modulation and demodulation free download as powerpoint presentation.
Pdf analog communication system pdf notes ac notes sw. Fm signals are used in technology such as radars, telemeters, eeg, radio broadcasting, satellite communication and magnetic tape recording systems. Frequency modulation download ebook pdf, epub, tuebl, mobi. After passing the modulated signal over a band limited channel the data is demodulated using either. Frequency modulation fm is a process in which the carrier frequency is varied by the amplitude of the modulating signal i. Ee and ece important mcq pdfmodulation and demodulation 1. Modulation and demodulation in communication engineering 1. Frequency and phase modulation sharlene katz james flynn overview history why fm. Modulation and demodulation based interview questions. In telecommunications and signal processing, frequency modulation fm is the encoding of information in a carrier wave by varying the instantaneous frequency of the wave in analog frequency modulation, such as fm radio broadcasting of an audio signal representing voice or music, the instantaneous frequency deviation, the difference between the frequency of the carrier and its center. Modulation and demodulation in communication engineering. Frequency modulation keeps constant the amplitude of the highfrequency oscillation that is used as a signal and to vary the instantaneous frequency for presenting the information. A similar approach is then taken for developing models for multiple phase shift keying mpsk, minimum shift keying msk, and frequency shift.
Scientech techbook 2203 frequency modulation and demodulation techniques is a comprehensive learning solution specifically designed to study basic operation as well as to provide conceptual and step by step understanding of frequency modulation and demodulation techniques through observation of waveforms at various test points. Chapter amplitude modulation and demodulation, ppt, adc. Apr, 2020 chapter amplitude modulation and demodulation, ppt, adc, semester, engineering computer science engineering cse notes edurev is made by best teachers of computer science engineering cse. In this chapter the basic theory of fm modulation and demodulation will be presented and you will implement two types of demodulators, the frequency discriminator and the phaselocked loop. The goal of this experiment is to become familiar with fm modulation and demodulation. To study and perform pulse amplitude modulation and demodulation. Frequency modulation is widely used for radio transmission due to the fact that the signaltonoise ratio snr is large in this method of modulation and hence radio frequency interference is minimized. Modulation is the process of influencing data information on the carrier, while demodulation is the recovery of original information at the distant end from the carrier. Download ac unit 3 unit iv angle modulation concepts. Theory shows that in order to transmit a wave effectively, the length of the. In addition to commercial radio, it is used as a component of television signals, for satellite and microwave communications, and for digital data transmission. Bpsk modulation and demodulationreal time experiment.
This chapter describes the essential principles behind modulation and demodulation, which we introduced briefly in chapter 10. Theoretical description of frequency modulation osa publishing we present a comprehensive theory for heterodyne absorption spectroscopy with. Modulation and demodulation based interview questions and. Hapter modulation and demodulation mit opencourseware. Introduction to modulation and demodulation modulation. Radio waves can carry audio, video, and digital information over great distances by using changes in a carrier waves amplitude, frequency, or phase to represent the information being transmitted. Example commercial fm signals use a peak frequency deviation of. For example, the signal in a cell phone is a voice signal with a. I n this experiment a digital communication system employing bpsk is studied. Frequency modulation and phase modulation is a system in which the amplitude of the modulated carrier is kept constant, while its frequency and rate of change are varied by the modulating signal.
Carrier frequency chan ges not those due to frequency modulation andor. Digital phase modulation and demodulation request pdf. What we do in am, very roughly,is to throw away the frequency content of. From the above information, finally, we can conclude that, in frequency modulation, both efficiencies as well as bandwidth depends on the maximum the modulation index and modulating frequency. This site is like a library, use search box in the widget to get ebook that you want. Essentially an amplitude modulated wave consists of a radio frequency carrier a sine wave at one frequency, typically in the radio frequency portion of the spectrum. The output signal via demodulator may describe the sound, images or binary data. The basic theory and equations behind amplitude modulation are relatively straightforward and can be handled using straightforward trigonometric calculations and manipulation.
This fivechapter text particularly discusses the propagation of the waves used, frequency modulation, and noise and sundry distortions liable. Changing the amplitude of the carrier am modulation is one type of modulation easy, cheap, lowquality used for am receiver and cbs citizen bands generally high carrier frequency is used to modulate the voice signal. Modulation and demodulation pdf on the various aspects of modulation and demodulation. Modulation is the process of altering the characteristics of the amplitude, frequency, or phase angle of the highfrequency signal in accordance with the instantaneous value of the modulating wave.
In frequency modulation, the amplitude of the carrier. Theory of frequency modulation and phase modulation. Meaning, pronunciation, translations and examples log in. The simplest method for representing this kind of modulation is fresnels vectorial representation with. This document is highly rated by computer science engineering cse students and has been viewed 2848 times. Then, students will use labview to program an am demodulator and use it to explore and visualize the. Amplitude modulation am, demodulation and their circuit. Modulation and demo dulation 66c h a p t e r learning objectives what is a carrier wave.
Request pdf digital phase modulation and demodulation digital phase modulation is a class of power and bandwidthefficient modulations widely used in telecommunications. A standard approach to solving this problem is to add a small sinusoidal component called a pilottonewhose frequency is not in the ssb signal band and has a known relationship to the carrier frequency. Laboratory manual principles of communication system lab ee226f ivth semester. Chapter 7 singlesidebandmodulationssb andfrequency. Bpsk, qpsk, msk frequency shift keying, fsk quadrature amplitude modulation, qam.
To study and perform pulse width modulation and demodulation. Pm and digital modulation s p where 2 is the pkpk phase change in one symbol duration, t for digital signals the modulation index. Frequency shift keying demodulation matlab fskdemod. Radio frequency spectrum sound need for modulation radio broadcasting modulation methods of modulation amplitude modulation percent modulation upper and lower sidebands mathematical analysis of a modulated. The spectrum of an fm signal is quite complicated and is dependent on mf. Random data for transmission is generated and it is tranmitted using bpsk modulation. Fm signals have the same peak frequency deviation, then when mt is a sinusoidal signal set such that the pm and note. Frequency modulation definition and meaning collins. This lab introduces students to communications theory with amplitude modulation and demodulation.
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