Sampling theorem and pulse amplitude modulation pam. Sampling theorem determines the necessary conditions which allow us to change an analog signal to a discrete one. An am wave may thus be dscribed, in the most general form, as a function. This lab introduces students to communications theory with amplitude modulation and demodulation. In your lab write up compare this with what is expected for a modulation depth of m 1. It is often called as am and is commonly used in transmitting a piece of information through a radio carrier wave. 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. Collector modulation method is the example of high level amplitude modulation. By varying the amplitude of the pulses the carrier signal in proportion to the instantaneous values of. Amplitude modulation definition, types, solved examples.
Pulse amplitude modulation sakshat remote triggered lab for. The sampled analog data is changed to, and then represented by binary data. It is an analog pulse modulation scheme in which the amplitude of train of carrier pulse are varied according to the sample value of the message signal. To study and perform amplitude modulation and demodulation. The possible number of amplitudes can be infinite, but mostly it is some power of two. Pulse amplitude modulation pam is an analog modulating scheme in which the amplitude of the pulse carrier varies proportional to the instantaneous amplitude of the message signal. Pulse amplitude modulation is defined as the data transmission by altering the amplitudes power levels or voltage of every pulse in a regular time sequence of electromagnetic pulses. In pulse amplitude modulation the amplitude of the carrier pulses varies in accordance. Explanation of pulse amplitude modulation frequency modulation. To study and perform pulse amplitude modulation and demodulation.
Pulse amplitude modulation circuit, definition, advantages. Pulse amplitude demodulation matlab pamdemod mathworks france. Pulse amplitude modulation is the simplest form of modulation. The pulse amplitude modulation is the simplest form of the pulse modulation. Configure the mcr, ccr and set initial values for the data. Pulse amplitude modulation has some applications, but it is not used by itself in data communication. In the case of analog pulse amplitude modulation signals, the number of pulse amplitudes can be infinite. Pulse modulation modulation digital signal free 30day. Pulse amplitude modulation is a technique in which the amplitude of each pulse is controlled by the instantaneous amplitude of the modulation signal. 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. Pulsecode modulation pcm is a method used to digitally represent sampled analog signals. The number of samples per second, ranging from 8,000 to 192,000, is usually several times the maximum. Padm symbol structure and other specifications were. Use emios to generate pulse width modulation pwm signal to the motor.
Pulse amplitude demodulation peak detection is used to detect pam. The ideal modulated signal should have a minimum euclidean distance of 2. The simulation of modulation schemes such as amplitude modulation and frequency modulation are designed using vi models are used as reference for designing fire rescue system 14. Amplitude modulation is a process by which the wave signal is transmitted by modulating the amplitude of the signal. Pulse amplitude modulation sakshat remote triggered lab. Pulse modulation modulation digital signal free 30. To study frequency modulation and determine its modulation factor 4. System in which pulseamplitudemodulated subcarriers are used to frequencymodulate a second carrier. The uniform sampling takes place in multiplier to generate pam signal. Pulse amplitude modulation pam, is a form of signal modulation where the message information is encoded in the amplitude of a series of signal pulses. For the love of physics walter lewin may 16, 2011 duration. Analog communication pulse modulation tutorialspoint. Pulse amplitude modulation article about pulse amplitude. Modulation is defined as the process by which some characteristics of a carrier signal is varied in accordance with a modulating signal.
Pulse amplitude modulation pam theory of and its applications. The particular form of pulse amplitude modulation is referred to as natural pam, because the tops of the pulses follow the shape of the modulating signal. An am wave may thus be dscribed, in the most general form, as a function of time. Then, students will use labview to program an am demodulator and use it to explore and visualize the. Electromagnetic theory and transmission lines emtl notes and textbook download click the below links to download ec05214anotes1. Pulseamplitude demodulation peak detection is used to detect pam. Pulse amplitude and delay modulation technique padm for power efficient indoor optical wireless communications is proposed in this paper. Pdf pulse amplitude modulation pam and discrete multitone dmt.
Pulseamplitude modulation, acronym pam, is a form of signal modulation where the message information is encoded in the amplitude of a series of signal pulses. In amplitude and angle modulation, some characteristic of the carrier amplitude, frequency, or phase is continuously varied in. This form of modulation is essentially derived from two carriers that are 90 out of phase and adding information, either analogue or digital. To perform the amplitude modulation and demodulation using am kit. 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. Pulse amplitude modulation using simulink matlab and simulink. The possible number of amplitudes can be infinite, but mostly it is some power of two so that the final output signal can be digital. Feb 23, 20 pulse amplitude modulation, acronym pam, is a form of signal modulation where the message information is encoded in the amplitude of a series of signal pulses. The main difference in generating balanced amplitude modulation to standard amplitude modulation is the missing offset of the 1 offset in the modulating signal. Vestigial sideband amplitude modulation vsbam is a modulation that improves the spectral e. Before going to discuss the difference between pam, pwm, and ppm, let us discuss individually each.
To study amplitude demodulation by linear diode detector 3. Use emios to generate pulse width modulation pwm signal to the motor 24 channels with many different operating modes see chapter 17 mpc5553rm emios operation modes timer mode input channel modes single action input capture input pulse width measurement input period measurement. Figure 321 includes a simplified circuit view a for this demodulator and its waveforms views b and c. Analog communication lab viva questions and answers pdf analog communication lab viva questions with answers pdf ac interview questions jntu free download. Pulse amplitude modulation using simulink matlab and. The pulse train acts as a periodic switching signal to the modulator, which when switched on allows samples of. The original waveform amplitude is quantized with a resulting loss of information. The pulse amplitude modulated signal, will follow the amplitude of the original signal, as the signal traces out the path of the whole wave. Therefore, the signal that samples is, generally, a sequence of pulses which amplitudes are proportional to the instantaneous values of the information signal.
The pulse may take any real voltage value that is proportional to the value of the original waveform. Ee3 lab 1 amplitude modulation and demodulation broadcast analog television tv signals have a bandwidth of approximately 6mhz and this is achieved with a quadrature modulation. Pulse amplitude modulation is one of the kinds of modulation techniques used in signal transmission. Matlab program for pulse code modulation m file matlab. Pulse amplitude modulation frequency modulation article. To study the effect of pam for varying width of carrier pulse train. Pulse amplitude modulation the carrier is in the form of narrow pulses having frequency fs. By varying the amplitude of the pulses the carrier signal in proportion to the instantaneous values of the analog signal the message signal. However, it is the first step in another very popular conversion method called pulse code modulation. Connect frequency counter across the fm out sockets and measure free run span by rotating v r control to. In high level amplitude modulation system, modulation is done at high power of carrier and modulating signals so power amplifiers are used to boost the carrier and modulating signals before modulation. To study sampling and reconstruction of pulse amplitude modulation system.
Pulse amplitude modulated signal and demodulated signals are observed. These signals carry the information through modulation. Then as the audio signal amplitude is changed to 150 mvpp, the percentage modulation dropped to around 30%. Today communication is the heart of the technology. To construct and study the pulse amplitude modulation technique. No information is lost, but the energy is redistributed in the frequency domain. Mar 19, 2016 amplitude, frequency, pulse code modulation and demodulation. Pam pulse amplitude modulated modulation ve demodulation. The pulse amplitude modulated signal, will follow the amplitude of the original signal, as.
Amplitude modulation is defined as the process in which the amplitude of the carrier wave ct is varied about a mean value, linearly with the baseband signal. Quadrature amplitude modulation is widely used for carrying many digital signals, everything from wifi to mobile phone communications and very much more. Pulse amplitude modulation pulse code modulation sampling. Amplitude, frequency, pulse code modulation and demodulation. Pulse code modulation pcm is a method used to digitally represent sampled analog signals. Click the below links to download cds lab manual 1. Connect frequency counter across the fm out sockets and measure free run span by. 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. This conforms to the expectation as the maximum and minimum peak of the modulated signal waveform varies proportional to the amplitude of the modulating signal. 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.
In amplitude and angle modulation, some characteristic of the carrier amplitude, frequency, or phase is continuously varied in accordance with the modulating information. Pdf experimental comparison of pulse amplitude modulation. Dec 07, 2016 for the love of physics walter lewin may 16, 2011 duration. Ensure that your work environment is clear and free of debris before starting your work. Pcm pulse code modulation quantized pam signal pcm modifies the pulses created by pam to create a completely digital signal. It is the standard form of digital audio in computers, compact discs, digital telephony and other digital audio applications. Pulse width modulation and introduction to simple virtual worlds pwm 2. What is amplitude modulation, am electronics notes. Since the amplitude of the pulses varies therefore the peak power of the modulating sg is much greater.
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. Pcs lab manual page 1 laboratory manual principles of communication system lab ee226f ivth semester. 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. Pulse width modulation and in position ppm, pulse position. Digital data transmission by baseband pulse amplitude modulation pam laboratory home page. To study and perform pulse width modulation and demodulation. In am, the amplitude of carrier signal will be varied with amplitude of message signal. Pam pulse amplitude modulated modulation ve demodulation sample and hold flat top mode hacettepe university ee telecommunication lab. In this experiment, you will learn the basics concepts of digital communications like pulse shaping filters, nyquist criterion, eye diagram, intersymbol interference and clock recovery. Pulse amplitude modulation using matlab with waveforms.
Oct 22, 2017 pam pulse amplitude modulated modulation ve demodulation sample and hold flat top mode hacettepe university ee telecommunication lab. In the positive half cycle of pam signal, diode conducts and current flows through r, whereas in negative half cycle, the diode is reversed biased and. Find out information about pulse amplitude modulation frequency modulation. The following safety and common symbols may be used in this manual and on the equipment. This project shows how amplitude, frequency and pulse code modulation and demodulation is done through matlab code. Pdf pulse amplitude and delay modulation for indoor. Pam is a pulse modulation system is which the signal is sampled at regular intervals. Communication is achieved over a transmitter and a receiver through signals. Amplitude modulation is mostly used in the form of electronic communication. Sampling theorem and pulse amplitude modulation pam reference stremler, communication systems, chapter 3. The pulse train acts as a periodic switching signal to the modulator, which when switched on allows samples of the modulating signal to pass through to the output. Pulse amplitude modulation and demodulation objectives. Pdf simulation of analog modulation and demodulation.
To study sampling and reconstruction of pulse amplitude modulation system 6. Application note of pampulse amplitude modulation signal. Cr1 is the input diode which allows capacitor c1 to charge to the peak value of the pam input pulse. Consist essentially of sampling analog information signals and then converting those samples into discrete pulses and transmitting the pulse from a source to a destination over a physical transmission medium pulse modulation includes many different methods of converting information into pulse form for transferring pulses from a source to destination. 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. Hence balanced amplitude modulation can be described as.