Multiple choice questions and answers on amplitude modulation. This ocw supplemental resource provides material from outside the official mit curriculum. Modulation index is the ratio of amplitude of modulating signal em to amplitude. The output modulated signal from an am modulator is. Amplitude modulation chapter 3 objectives at the conclusion of this chapter, the reader will be able to. Doublesideband reduced carrier transmission dsbrc this type of modulation uses full power of both sidebands but reduces the carrier level amplitude. Problems and solutions in fiberoptic amplitudemodulated sensors. In this problem you will know how to do power calculations and how to apply power formula in amplitude modulation. Would 16qam be more or less susceptible to noise than this type of modulation.
Calculate the frequency deviation, modulation index, and bandwidth. Video solution to gate ece2006 problem amplitude modulation common data type problem. Physical layer mac layer network layer transport layer question 12 which of the following is not a common network topology. A sinusoidal modulating waveform of amplitude 5 v and a frequency of 2 khz is applied to fm generator, which has a frequency sensitivity of 40 hzvolt. Amplitude modulation early radio ee 442 spring semester.
As illustrated in figure 5, the amplifier is biased class c and the output rf signal amplitude is modulated by causing the collector supply voltage to vary with the modulation voltage. View test prep am and fm modulation and demodulation, dsb modulation and demodulation problems solutions from eel 4512c at university of south florida. In general, amplitude modulation definition is given as a type of modulation where the amplitude of the carrier wave is varied in some proportion with respect to the modulating data or the signal. Am and fm modulation and demodulation, dsb modulation and. Mar 14, 2018 venkatesha m jrf,research scholar and adjunct faculty department of ece sai vidya institute of technology, bangalore560064. Frequency modulation examplesproblems 1 a music signal with frequency components from 50 hz to 2 hz is frequency modulated. Question 11 amplitude modulation is in which layer. Modulation 2 the reverse process of modulation where the received signals are.
Solutions to some sampled questions of previous finals. These can be sketched as an electrooptic module connected to the sensing tip by means of a multimode fiberoptic link. Effectively it is formed by having two carriers 90 out of phase. Modulation and demodulation this chapter describes the essential principles behind modulation and demodulation, which. By using those formulas, we can find the respective parameter values. The amplitude of the analog signal is sampled at uniform intervals and each sample is quantized to its nearest. Vsb modulation with envelope detection is used to modulate image in analog tv signals. The concluding part will be spent looking at the more popular form of high level modulation known as collector modulation or heising, named after its inventor. This ezed video explains the solution to the following university problem the modulating signal of 20 cos2 pi 103 t is used to. 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. The bandwidth of the message signal mt is w and the transfer function of the bandpass filter is shown in the fig.
Bpsk, qpsk, msk frequency shift keying, fsk quadrature amplitude modulation, qam. What is digital modulation and state various techniques. Question 11 amplitude modulation is in which layer of communication network. At the point in time when the modulating cosine wave is zero, the total signal is a 2, so ka 0.
The continuous wave modulation techniques are further divided into amplitude modulation and angle modulation. Chapter 4 amplitude modulation transmission items definitions terms 1 the process of impressing lowfrequency information signals onto a highfrequency carrier signal. What is amplitude modulation, am electronics notes. Assignments signals and systems mit opencourseware. The pdf of r is equal to the convolution of the pdfs of s and n. A continuouswave goes on continuously without any intervals and it is the baseband message signal, which contains the information. Principles of communications, 7th edition communication. Heres our standard modulationdemodulation system diagram. Pdf chapter 4 amplitude modulation anne jung academia. Amplitude modulation am is a modulation technique used in electronic communication, most commonly for transmitting information via a radio carrier wave. Ask is similar to standard amplitude modulation except there are only two output amplitudes possible.
Ziemer and tranter provide a thorough treatment of the principles of communications at the physical layer suitable for college seniors, beginning graduate students, and practicing engineers. Fiberoptic sensors based on the amplitude modulation of the light guided by the fiber are considered. In am radio broadcasts, is the audio signal being transmitted usually bandlimited to less than 10 khz, and is the channel center frequency that one dials up on a radio receiver. Of all the methods of impressing information onto a carrier signal, am is the oldest. Amplitude modulation an overview sciencedirect topics. You can publish your book online for free in a few minutes. Make the modulation frequency 110 of the carrier frequency.
Dec 11, 2017 solved problems on amplitude modulation. Change in amplitude of the carrier according to modulating signal frequency. Sketch the time variation and frequency spectrum of an rf signal with 75 percent amplitude modulation. The transmitter just uses the information signal, v m t to vary the amplitude of the carrier, v co to produce a modulated signal, v am t. It is easy to see that we can represent st as the following. Among the types of modulation techniques, the main classification is continuouswave modulation and pulse modulation.
Amplitude modulation a continuouswave goes on continuously without any intervals and it is the baseband message signal, which contains the information. 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. Problem 1 fm versus pm waveforms 20 points sketch the phase modulation pm and frequency modulation fm signals that are. Am is widely used for the transmission of data in everything from short range wireless links such as wifi to cellular telecommunications and much more. The transmitted signal contains the carrier, and a pair of sidebands for each tone in the information signal, so the frequencies present are. Vsb signals are generated using standard am or dsbsc modulation, then passing modulated signal through a sideband shaping.
Change in frequency of the carrier according to modulating signal c. In amplitude modulation, the amplitude signal strength of the carrier wave is varied in proportion to that of the message signal being transmitted. Basic concept of modulation the information source typically a low frequency signal referred to as the baseband signal carrier a higher frequency sinusoid example. Solved problem amplitude modulation find modulation. Demodulation uses either standard am or dsbsc demodulation, depending on whether a carrier tone is transmitted. Example problem 34 page 394 nbfm hin ts for solution consider a narro wband fm w a v e. With no modulation, the am carrier is transmitted by itself. Video solution to gate ece2006 problemamplitude modulation.
Modulation is a process by which some characteristics of high frequency carrier signal is varied in accordance with the instantaneous value of the modulating signal. Hsu analog and digital communication summary equation message general mt monotone am cos. The use of amplitude modulated analog carriers to transport digital information is a relatively lowquality, lowcost type of digital modulation and, therefore, is seldom used except for very lowspeed telemetry circuits. In this chapter, let us solve a few problems based on the concept of frequency modulation. This gives rise to several types of amplitude modulation. Jan 09, 2020 multiple choice questions and answers on amplitude modulation. Why frequency modulation is better than amplitude modulation. It is the standard form of digital audio in computers, cds, digital telephony and other digital audio applications. As given is the problem the modulation is sinusoidal this is also called tone modulation. Amplitude modulation ang man shun october 30, 2012 reference hwei p. When the modulating information signal a sine wave is applied, the carrier amplitude. The solution to this problem is to suppress the carrier, one of the sidebands, or both.
Uniti amplitude modulation 2 marks questions and answers. Amplitude modulation definition, types, solved examples. In this chapter, let us solve a few problems based on the concept of amplitude modulation. Linear modulation techniques university of colorado. Change in amplitude of the modulating signal according to carrier signal d. This is accomplished by providing overviews of the necessary background in signal, system, probability, and random process theory required for the analog and digital communications topics covered in the. The problems related to the optical system and light propagation and those related to the referencing system and probe manufacturing. These form some of the main uses of amplitude modulation. Dec 11, 2017 solved numerical problems on common emitter configuration of bjt in hindi duration. Problems and solutions in fiberoptic amplitudemodulated. Find the modulation index, the carrier power, and the power required for transmitting am wave. Amplitude modulation 2 marks questions and answers 1.
In amplitude modulation, it is the voltage level of the signal to be transmitted that changes the amplitude of the carrier in proportion, see figure 63. What is analog modulation and state various techniques. Amplitude modulation additional problems eel306 communication engineering. 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. Amplitude modulation numerical problems with solution svit15ec45 march 14, 2018 problems 6 comments. There is no over modulation means that modulation index is less than or equal to 1. As for the mechanism, when amplitude modulation is used there is a variation in the amplitude of the carrier.
Rutgersthe state university of new jersey college of engineering department of electrical and computer engineering 332. Next topic pulse code modulation pulsecode modulation pcm is used to digitally represent sampled analog signals. Although its old technology, it is still widely used in the following applications. Amplitude modulation electronic engineering mcq questions.
Solutions to some sampled questions of previous finals first exam. If correctly designed, 16 qam should in general less susceptible to noise because the symbols would be be. If the maximum allowed frequency deviation is 50 khz. The idea is simple, though the notion that it can be used to modulate signals for transmission was hardly obvious before its discovery.
Amplitude modulation is the simplest of the three to understand. Ssb modulation and am wave systems problems solutions what students are saying as a current student on this bumpy collegiate pathway, i stumbled upon course hero, where i can find study resources for nearly all my courses, get online help from tutors 247, and even share my old projects, papers, and lecture notes with other students. Modulated carrier amplitude reach value greater than. The idea is simple, though the notion that it can be used to modulate signals. Bus ring rectangle mesh question which of the followings is wireless transmission media. The dominant noise limiting performance of communication systems in the. Each of the chimes has an amplitude of 10v, and the carriers amplitude is 20v. But we are getting ahead of ourselves, as we have not yet even defined what am is. Amplitude modulation based solved problems are covered in this video lecture.
Sinusoidal amplitude modulation am mathematics of the dft. Amplitude modulation problems solutions i amplueude. Change in amplitude of the carrier according to modulating signal b. Amplitude modulation reception by wayne tomasi as part of communications engineering topic. In the previous chapter, we have discussed the parameters used in amplitude modulation. Discovered angle modulation a signal st is measured and found to be described by st acos2. A vestigial sideband modulation system is shown in fig.
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