Pulse amplitude modulation pam, quadrature amplitude modulation qam 12. Sampling theorem and pulse amplitude modulation pam. A continuouswave goes on continuously without any intervals and it is the baseband message signal, which contains the information. The modulated waveform or signal which wants to demodulate is as above, this signal is provided to the demodulator circuit to recover the signal from it. It is a modulation system in which the signal is sampled at regular intervals and each sample is made proportional to the amplitude of the signal at the instant of sampling. The pulse may take any real voltage value that is proportional to the value of the original waveform. Digital pulsewidth modulation control in power electronic. To study sampling and reconstruction of pulse amplitude modulation system.
The continuous wave modulation techniques are further divided into amplitude modulation and angle modulation. Overmodulated am signals and its requirement for coherent detection are also considered. Amplitude modulation is defined as a process in which the amplitude of the carrier wave ct. How to simulate pam pulse amplitude modulation in matlab. Pulse amplitude modulated signal and demodulated signals are observed. Sampling theorem and pulse amplitude modulation pam reference stremler, communication systems, chapter 3. Cr1 is the input diode which allows capacitor c1 to charge to the peak value of the pam input pulse. Pulse amplitude modulation pam matlab tutorial behind.
Analog communication pulse modulation tutorialspoint. In pam the amplitude of the message or modulating signal is mapped to a series of pulses with two possible variant. The amplitude is more likely to be close to zero than to be at higher levels. Pulse amplitude modulation an overview sciencedirect. The simple pulse modulation technique called pulse amplitude modulation pam proved to be more power efficient than the pwm and consumes constant power for individual pulses like ppm. Pulse amplitude modulation pulse code modulation sampling. Pulse position modulation ppm is an analog modulation scheme in which, the amplitude and the width of the pulses are kept constant, while the position of each pulse, with reference to the position of a reference pulse varies according to the instantaneous sampled value of the message signal. Pulseamplitude modulation pam, is a form of signal modulation where the message information is encoded in the amplitude of a series of signal pulses. Pdf pulse amplitude modulation pam and discrete multitone.
The communication system lab is designed to help students understand the basic principles of communication techniques as well as giving them the insight. Pam is the simplest of all pulse modulation technique. This tutorial video teaches about simulating pulse amplitude modulation technique in matlab you can also download the code here at. To study and perform pulse position modulation and demodulation. Pdf experimental comparison of pulse amplitude modulation. Digital pulsewidth modulation control in power electronic circuits. There are two operations involved in the generation of the pulse amplitude modulation pam signal. To study pulse amplitude modulation and demodulation. The message signal must consist of integers between 0 and m1. The sampled analog data is changed to, and then represented by binary data. Amplitude modulation this experiment examines the characteristics of the amplitude modulation am process.
Before we study in detail about pam lets know the concepts of modulation. Pulse amplitude modulation sakshat remote triggered lab. The microprocessor hardware design and software routines are covered in detail. It is an analog pulse modulation scheme in which the amplitudes of a train of carrier pulses are varied according to the sample value of the message signal. Pcs lab manual page 1 laboratory manual principles of communication system lab ee226f ivth semester prepared by. Matlab program for pulse code modulation m file matlab. The purpose of this lab is to explore digital communications with a software radio to understand how each component works together. Pulse amplitude modulation is a technique in which the amplitude of each pulse is controlled by the instantaneous amplitude of the modulation signal. Pulse amplitude modulation theory pulse amplitude modulation.
In amplitude modulation, modulation depth refers to the ratio of the unmodulated carrier amplitude to the amplitude deviation for which the modulated carrier wave reaches its minimum value. In pam the amplitude of the individual pulses are varied according to the. The demodulation is performed by an envelope detector. Sampling theorem determines the necessary conditions which allow us to change an analog signal to a discrete one. Garg, yihchen wang, in the electrical engineering handbook, 2005. The lab will cover, analog to digital conversion, modulation, pulse shaping, and noise analysis 1. In this modulation, the signal is sampled at regular intervals and each sample is made proportional to the amplitude of the modulating signal. In this lab project, design of the transmitter and design of the receiver each present challenges and opportunities for investigation.
Figure 321 includes a simplified circuit view a for this demodulator and its waveforms views b and c. Pulse code modulation free download as powerpoint presentation. Pulse amplitude modulation has some applications, but it is not used by itself in data communication. Pdf analog communication system pdf notes ac notes sw.
Pulse amplitude modulation using matlab with waveforms. This report describes the design of a microprocessorcontrolled pulse amplitude modulation decommutator. To study and perform pulse width modulation and demodulation. Observation simulation of signal constellations of bpsk, qpsk and qam. Students will explore the mathematical theory behind amplitude modulation and use the analog discovery 2 to visualize the effects of amplitude modulation in the time and frequency domains. Simply put, the transmission of data takes place by the variation of the amplitude of pulse according to the modulating signal. To study the amplitude shift keying modulation and demodulation. The following safety and common symbols may be used in this manual and on the equipment. Delta modulation and demodulation lab manual read download systemsii. Pulse modulation timedivision multiplex tdm timedivision multiplexing is the method of combining several sampled signals in a definite time sequence. Rice, in academic press library in mobile and wireless communications, 2016. The transmitter part investigates creation of the ask signal and the effect of transmitted pulse shape on the bandwidth of the transmitted signal. It is the standard form of digital audio in computers, compact discs, digital telephony and other digital audio applications.
If you continue browsing the site, you agree to the use of cookies on this website. Complete notes download link ac notes analog communication pdf free download unit i introduction. To study and perform pulse amplitude modulation and demodulation. Pcm pulse code modulation quantized pam signal pcm modifies the pulses created by pam to create a completely digital signal. A modulation technique that allows variation in the position of the pulses according to the amplitude of the sampled modulating signal is known as pulse position modulation ppm. Apparatus delta modulation and demodulation matlab code.
Our modulation signal is going to be a continuous cosine. Analog communication lab viva questions and answers pdf analog communication lab viva questions with answers pdf ac interview questions jntu free download. Pulseamplitude demodulation peak detection is used to detect pam. Pulse amplitude modulation pam is one of several forms of single modulation in which data is transmitted through varying the amplitude of the pulses in regular timed sequence of electrical or electromagnetic pulses. Amplitude modulation a continuouswave goes on continuously without any intervals and it is the baseband message signal, which contains the information.
Pulse and digital circuits pdc lab manual download click the below link to download pdc lab manual. Theory and applications by angel vladimirov peterchev a. The original waveform amplitude is quantized with a resulting loss of information. Pulse width modulation and in position ppm, pulse position. It is another type of ptm, where the amplitude and width of the pulses are. In your lab write up compare this with what is expected for a modulation depth of m 1. In the case of analog pulse amplitude modulation signals, the number of pulse amplitudes can be infinite. Note that this is on the very low end of the recommended voltage range. The lab project is consequently divided into several parts. Dutton ee3 winter 2004 1 ee3 lab 1 amplitude modulation and demodulation 1 lab notes a word about power.
Consequently, the constellation points lie on the horizontal line. Modulation is a process by which characteristics of a highfrequency carrier signal are. Principles of communication systems 20022003 8 chapter 7. Pulse amplitude modulation is the basic form of pulse modulation. Introduction to communication system, need for modulation, frequency division multiplexing, amplitude modulation, definition, time domain and frequency domain description. Pulsecode modulation pcm is a method used to digitally represent sampled analog signals. The modulated signal has a minimum euclidean distance of 2.
A class d amplifier uses some form of pulsewidth modulation to control the output devices. Then, students will use labview to program an am demodulator and use it to explore and visualize the. To understand the theoretical foundations of analog communications as well as of doublesideband amplitude modulation and demodulation dsbam to design the simulink model of the dsbam to analyze each signal in time and frequency domains using time scope and spectrum analyzer. Among the types of modulation techniques, the main classification is continuouswave modulation and pulse modulation. Pulse amplitude modulation is the process by which the amplitude of the regularly spaced pulses varies according to the the amplitude of the modulating signal. In pulse amplitude modulation pam, the a m are purely real, that is im a m 0 for m 1, 2, m.
To study amplitude demodulation by linear diode detector 3. This lab introduces students to communications theory with amplitude modulation and demodulation. The receiver part investigates demodulation, matched. The title of the experiment should be written in the page in capital letters. Lab report introduction pulse code modulation pcm is a digital representation of an analog signal that takes samples of the amplitude of the analog signal at regular intervals.
T12 measure the peaktopeak amplitude of the am signal, with m 1, and confirm that this magnitude is as predicted, knowing the signal levels into the multiplier, and its k factor. A modulation technique in which the amplitude of the pulsed carrier signal is changed according to the amplitude of the message signal is known as pulse amplitude modulation pam. Commutator determines the synchronization and sequence of the channels signals to be sampled. Pulse amplitude modulation pam and demodulation is the process of converting an analog signal to a pulsetype signal in which the amplitude of the pulse denotes the analog information and then recovering the original signal from the pulse amplitude modulated. However, it is the first step in another very popular conversion method called pulse code modulation. No information is lost, but the energy is redistributed in the frequency domain. Download as pptx, pdf, txt or read online from scribd.
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