In modulation, the message signal changes the amplitude, frequency. Intelligence plus character that is the goal of true education. Prof mist mist, hyderabad ece department page 1 index page no. Advanced modulation formats, such as pulseamplitude modu lation and quadrature. Cr1 is the input diode which allows capacitor c1 to charge to the peak value of the pam input pulse. Pulse width modulation and in position ppm, pulse position.
Pulse amplitude modulation pam, quadrature amplitude modulation qam 12. Oscilloscope fundamentals case school of engineering. Pulse amplitude modulation has some applications, but it is not used by itself in data communication. Sampling theorem and pulse amplitude modulation pam reference stremler, communication systems, chapter 3.
Rough record and fair record are needed to record the experiments conducted in the laboratory. What happens when messages signal is combine with a carrier signal through a mixer. Analog communication pulse modulation tutorialspoint. T1 time division multiplexing lab university of pittsburgh. Here we will discuss in details, pulse modulation and pulse modulation techniques like pulse amplitude modulation pam, pulse width modulation pwm, pulse position modulation ppm and pulse code.
It is deserved to pay attention that pcm modulation is a real digital signal that can be processed. The original waveform amplitude is quantized with a resulting loss of information. Observation simulation of signal constellations of bpsk, qpsk and qam. To study and perform pulse amplitude modulation and demodulation. Amplitude modulation is defined as the process in which is the amplitude of the carrier wave. Pam pulse amplitude modulated modulation ve demodulation sample and hold flat top mode hacettepe university ee telecommunication lab. 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. Pdf this tutorial discusses analogmodulation techniques with the. Hence balanced amplitude modulation can be described as. Thus the amplitude modulation and demodulation operation has been. The ideal modulated signal should have a minimum euclidean distance of 2. A sinusoidal message signal modulated the amplitude of a carrier.
Pam pulse amplitude modulated modulation ve demodulation. The instructional modules offer handson training in the following digital communications techniques. Overmodulated am signals and its requirement for coherent detection are also considered. Pdf simulation of analog modulation and demodulation. In your lab write up compare this with what is expected for a modulation depth of m 1. Sampling theorem determines the necessary conditions which allow us to change an analog signal to a discrete one.
To study sampling and reconstruction of pulse amplitude modulation system. To study and perform pulse width modulation and demodulation. However, it is the first step in another very popular conversion method called pulse code modulation. By varying the amplitude of the pulses the carrier signal in proportion to the instantaneous values of. After you convert your signal of interest to bits, you will group those bits in. The vicom t1 uses a twostage approach to producing a digital multiplexed signal. An eye diagram for a pam4 signal is unusual, with three eye openings and four levels stacked vertically as shown in the figure. Telecommunications pulse modulation and sampling pam. Comparison of linear frequency and amplitude modulation for. We additionally pay for variant types and after that type of the books to browse. This contrasts with amplitude modulation, in which the amplitude. In the case where the coefficients fn are real we can combine these two plots into one plot. Pdf a labviewbased analog modulation tool for virtual and.
Pulse amplitude modulation using matlab with waveforms. 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. Pcm pulse code modulation quantized pam signal pcm modifies the pulses created by pam to create a completely digital signal. In this modulation, the signal is sampled at regular intervals and each sample is made proportional to the amplitude of the modulating signal. Pam, pwm, and ppm modulations belong to analog modulation and the pcm modulation belongs to the digital modulation.
Pulse modulation and sampling pam pwm ppm courseware sample 39862f0. Pam pulse amplitude modulation signal generation for qam transmission mp1800a s eries. Pulse amplitude modulated pam fluorometry is a useful technique for identifying the amount of energy that is not used in photosynthesis but is reemitted as fluorescence or dissipated as heat in. To study sampling and reconstruction of pulse amplitude modulation system 6.
A carrier is used to make the wavelength smaller for practical. Quadrature amplitude modulation qam pam signals occupy twice the bandwidth required for the baseband transmit two pam signals using carriers of the same frequency but in. File type pdf lab 6 pam pulse amplitude modulation demodulation on lab 6 pam pulse amplitude modulation demodulation on right here, we have countless books lab 6 pam pulse amplitude modulation demodulation on and collections to check out. In this study, manipulating pulse train frequency and amplitude had. 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. In this experiment, a carrier signal and an audio modulating signal are applied to the modulator ic mc 1496 and the produced modulated waveform is observed. Figure 321 includes a simplified circuit view a for this demodulator and its waveforms views b and c.
Pulseamplitude modulation pam, is a form of signal modulation where the message information is encoded in the amplitude of a series of signal pulses. The transition between the virtual and the real world is accomplished via data acquisition cards, installed. In radio communications, cable tv systems or the public switched. Any periodic signal can be represented mathematically as the basic pulse shape. Before we study in detail about pam lets know the concepts of modulation. Analog communication lab manual, prepared by nakka. For the frequency modulation, the pulse amplitude was fixed at the perceptual threshold value, and the pulse frequency was modulated between. The digital communications training system consists of thirteen instructional modules supported by sixteen instrumentation modules. The main difference in generating balanced amplitude modulation to standard amplitude modulation is the missing offset of the 1 offset in the modulating signal. Ultrafast pulseamplitude modulation with a femtojoule. A continuouswave goes on continuously without any intervals and it is the baseband message signal, which contains the information.
Note that this is on the very low end of the recommended voltage range. Quadrature amplitude modulation qam pam signals occupy. The manual provided with your oscilloscope will give you more specific. Application note of pam pulse amplitude modulation signal generation for qam transmission. Pulse modulation timedivision multiplex tdm timedivision multiplexing is the method of combining several sampled signals in a definite time sequence.
In the first stage, the 24 analog input channels are sampled and multiplexed to produce a single analog pam signal. In pam the amplitude of the individual pulses are varied according to the. The function of website is to teach one to think intensively and to think critically. The pulse amplitude modulated signal, will follow the amplitude of the original signal, as. We therefore began by performing a control experiment with tactile. Before going to discuss the difference between pam, pwm, and ppm, let us discuss individually each. Dutton ee3 winter 2004 1 ee3 lab 1 amplitude modulation and demodulation 1 lab notes a word about power. A class d amplifier uses some form of pulse width modulation to control the output devices. Techniques in virtual instrumentation and remote lab. Application note of pampulse amplitude modulation signal. Pdf an analog method to modulate and demodulate signals is presented in this short paper. The pulse amplitude modulated signal, will follow the amplitude of the original signal, as the signal traces out the path of the whole wave. Additionally, software packages like national instruments lab view and.
Pulse amplitude modulation pulse code modulation sampling. 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. Pam4 indicates pulse amplitude modulation, with the 4 indicating four levels of pulse modulation. A pulse indicates sudden changes in voltage, similar to the voltage changes. Laboratory exercise on demodulation of pam signal asee peer logo. An application of this is the simulation of a communication system that uses pulse amplitude modulation pam to transmit text messages over a bandlimited channel, such. 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 pam is used extensively in telecommunications as an intermediate step.
Frequency and amplitude modulation have different effects on the. The pulse may take any real voltage value that is proportional to the value of the original waveform. Lab 6 pam pulse amplitude modulation demodulation on. In pulse amplitude modulation system the amplitude of a carrier pulse train is varied in accordance with the instantaneous level of the modulating signal. Among the types of modulation techniques, the main classification is continuouswave modulation and pulse modulation. This amplitude modulation is tested in ni usrp rio 2920 as transmitter.
Principles of communication systems 20022003 8 chapter 7. Pulse amplitude modulation pam pulse width modulation pwm pulse position modulation ppm pulse code modulation pcm differential pulse. Pulse amplitude modulation pam the actual amplitude of the pulse represents the number being transmitted. The lab will cover, analog to digital conversion, modulation, pulse shaping, and noise analysis 1. 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. Amplitude modulation this experiment examines the characteristics of the amplitude modulation am process. If you continue browsing the site, you agree to the use of cookies on this website. The purpose of this lab is to explore digital communications with a software radio to understand how each component works together. To study and perform pulse position modulation and demodulation. The continuous wave modulation techniques are further divided into amplitude modulation and angle modulation. Pulse amplitude modulation is the basic form of pulse modulation. Sampling theorem and pulse amplitude modulation pam.