Timedomain description, frequencydomain description, generation of am wave. The goal of this experiment is to become familiar with fm modulation and demodulation. Pulse modulation may be used to transmitting analog information, such as continuous speech signal or data. The pulse position modulation ppm is a modulation technique designed to achieve the goals like simple transmitter and receiver circuitry, noise performance, constant bandwidth and the power efficiency and constant transmitter power. Pulse position modulationppm advantages disadvantage. To study amplitude demodulation by linear diode detector 3. Modulation and demodulation of pulse position modulation with. Pulse position modulation ppm digital modulation is classified as. This method is widely used for optical communication systems such as optic fiber and ir remote controls, where efficiency is required and little or no external interference occurs.
Here, we consider imdd signaling based on m ary pulseamplitude modulation m pam 8, where ook is its simplest form with m 2. The word pulse in the term pulse code modulation refers to the pulses to be found in the transmission line. The simulation for the same was carried out using ngspice. It is another type of ptm, where the amplitude and width of the pulses are kept constant and only. 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. Pulseposition modulation ppm is a signal modulation used for both analog and digital signal transmissions. As an alternative to rf, a pulse position modulation ppm guided. It is proven by theoretical studies that the signal strength. The ppm can be demodulated both synchronously and asynchronously. Digital communication using chaoticpulseposition modulation.
Demodulation is extracting the original informationbearing signal from a carrier wave. Pulse amplitude modulation using matlab with waveforms %pam clc. The pam modulator and demodulator circuits simple compared to other kind of modulation and. Pulse position modulation, sometimes known as pulse phase modulation is used for digital signal transition. Analog communication pulse modulation tutorialspoint. The obtained simulation and experimental results confirm well with the given analysis. Fig2 shows the spectrum of pulse amplitude modulated signal along with the message signal and the sampling signal which is the carrier train of pulses with the help of the waveform plotted in time domain. Ppm pulse position modulation basics, circuit, working. Abstract this document gives an overview of how pulse width modulation and demodulation can be performed using bipolar junction transistors and operational amplifiers. Modulation pwm, pulse position modulation ppm and pulse density modulation. No information is lost, but the energy is redistributed in the frequency domain. Jun, 2011 pulse position modulation ppm is a form of signal modulation in which m message bits are encoded by transmitting a single pulse in one of 2 m possible timeshifts. To study frequency modulation and determine its modulation factor 4.
Identify the demodulation circuits for pwm and ppm signals. Explain generation and demodulation of pam, ppm and pwm with. Pulse position modulation ppm is a signal modulation used for both analog and digital signal transmissions. The ppmwc signal is generated by summing the ppm signal and the pll reference signal. This is repeated every t seconds, such that the transmitted bit rate is m t \\displaystyle mt bits per second. Ppm uses the relative position of pulses for modulation, of which pulse amplitude and width remain unchanged, thus facilitating modulation and demodulation. Pulse position modulation ppm is a form of signal modulation in which m message bits are encoded by transmitting a single pulse in one of. There are different types of modulation and so are demodulators. Lets start the seminar from analog pulse modulation 4. A time to digital converter tdc is then used to demodulate the data from the differential pulse position modulated signal. The other characteristics amplitude and position of the pulse are constants. An enhanced pulse position modulation ppm uni scholarworks. Pulseposition modulation wikimili, the free encyclopedia. Demodulation is defined as extracting the original informationcarrying signal from a modulated carrier wave.
Pulse position modulation definition of pulse position. The original waveform amplitude is quantized with a resulting loss of information. To download switching theory and logic design provides mathematical foundations and tools. Pulse amplitude modulation, pulse width modulation, pulse. Double sideband suppressed carrier modulation dsbsc. Indeed, it is well known that ppm is optimal in terms of energy. It is used in fibre optics and ir infrared remote controls where there is a lack of interference, it is a technique that uses pulses of the same breath and height but is displaced in time from some base position according to the. Pulse modulation systems represent a messagebearing signal by. There are many types of modulation so there are many. This is repeated every t seconds, such that the transmitted bit rate is. Frequency modulation fm is a process in which the carrier frequency is varied by the amplitude of the modulating signal i. In singlechannel efield sensing, the carrier we transmit is m, the sensed value is a, and the noise is n vectors. Pulse position modulation ppm is a form of signal modulation in which m message bits are.
The operation theory of pcm modulation pcm modulation is a kind of source coding. This kit has been designed keeping students in mind so its very easy to understand and use. Pulse amplitude modulation pam theory of and its applications. Index terms ultra wideband, pulse position modulation, on off key modulation. Everything is available on board and no external function generator is required. Pulse amplitude modulation pulse width modulation pulse position modulation pulse code modulation pulse modulation the process of transmitting signals in the form of pulses discontinuous signals by using special techniques. Aug 06, 2018 in this video, i have explained ppm pulse position modulation by following outlines. The pulse may take any real voltage value that is proportional to the value of the original waveform. This is repeated every t seconds, such that the transmitted bit rate is bit. In analog modulation technique, if the amplitude, duration or position of a pulse is varied in accordance with the instantaneous values of the baseband modulating signal, then such a technique is called as pulse amplitude modulation pam or pulse durationwidth modulation pdmpwm, or pulse position modulation ppm. It is primarily useful for optical communications systems, where tends to be.
The meaning of source coding is the conversion from analog. In this video, i have explained ppm pulse position modulation by following outlines. To study and perform pulse width modulation and demodulation. Pulse position modulation using matlab with waveforms. 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 position modulation definition is modulation of a radio wave or signal in which the intelligence is conveyed by varying the time relationship of the pulses of the wave.
The theoretical background of ppm communication systems was established around 50 years ago as it. This is repeated every t seconds, such that the transmitted bit rate is mt bits per second. Principles of communication modulation tutorialspoint. Each channel sharing scheme a set of basis vectors. The proposed scheme is examined by using computer simulation and experiment. This paper presents the modulation and demodulation of pulse position modulation with carrier. This pulse position modulated signal ensembles the modulating signal and hence easily recovered by a simple low pass filter. It is the extent of modulation denoted in percentage, and is denoted by m. To study sampling and reconstruction of pulse amplitude modulation system 6. For a perfect modulation, the value of modulation index should be 1, which means the modulation depth should be 100%.
The pulse position modulation ppm can be actually easily generated from a pwm waveform which has been modulated according to the input signal waveform. Pulse amplitude modulation is widely used in modulating signal transmission of digital data, with nonbaseband applications having been largely replaced by pulse code modulation, and, more recently, by pulse position modulation. Pulse amplitude modulation is a technique in which the amplitude of each pulse is controlled by the instantaneous amplitude of the modulation signal. It is another type of ptm, where the amplitude and width of the pulses are kept constant and only the position of the pulses is varied. It is often used in optical communication, such as fiber optics, in which there is little multipathway interference. Capacityapproaching codes demodulation line coding modem anm pom pam pcm pdm pwm m ofdm fdm multiplexing v t e. We can also get back our analog signal by demodulation. This perhaps is a natural consequence of this technique having evolved alongside two analog methods, pulse width modulation and pulse position modulation, in which the information to be encoded is represented by discrete signal pulses. In pam the amplitude of the individual pulses are varied according to the amplitude of the modulating signals. It is primarily useful for optical communications systems, which tend to have little or no multipath interference.
Ook modulation, in the article an energy adaptive demodulation for high data rates with impulse. To study and perform pulse position 6 to study and perform pulse code modulation and demodulation. Pulse position modulation ppm is a form of signal modulation in which m message bits are encoded by transmitting a single pulse in one of possible required time shifts. The synchronous demodulation is complex as it requires synchronization of the receiver with the transmitter. A demodulator is an electronic circuit or computer program in a softwaredefined radio that is used to recover the information content from the modulated carrier wave. User manual for pulse position modulation and demodulation trainer. In pulse position modulation the amplitude of the pulse is kept constant as in the case of the fm and pwm to avoid noise interference. Dec 18, 2019 pulse position modulation ppm is a form of signal modulation in which m message bits are encoded by transmitting a single pulse in one of possible required time shifts. Jul 12, 2018 pulse modulation techniques pam, pwm, ppm, pcm pulse amplitude, pulse width, pulse position, code duration. Pulse position modulation is a signal modulation technique that allows computers to share data by measuring the time each data packet takes to reach the computer. 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. Jan 15, 2018 modulation is the process of changing the characteristics of the carrier signal in accordance with the instantaneous values of the modulating signal message signal. Pulse code modulation is a method that is used to convert an analog signal into a digital signal, so that modified analog signal can be transmitted through the digital communication network. Pulse amplitude modulation pam pulse duration modulation pdm pulse position modulation ppm pulse code modulation pcm dpcm, dm,adm analog pulse modulation digital pulse modulation 3.
In particular, all telephone modems faster than 300 bits use quadrature amplitude modulation qam. The results obtained have been presented at the end of this document. It is a modulation system in which the signal is sampled at regular intervals and each sample is made. A brief discussion about pulse code modulation and demodulation. In this paper, we combine all the optimal and nearoptimal optical demodulation receivers that have been found to date under one general class of structured receiversthe conditional pulse nulling cpn. Pulse modulation by herin gala keval mamaniya keval gada dattaprasad shenoy 2.
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. Pulseposition modulation ppm is a form of signal modulation in which m message bits are. A demodulator is an electronic circuit that is mainly used to recover the information content from the modulated carrier wave. In this pulse position modulation system, the amplitude and width of pulses is kept constant, while the position of each pulse, in relation to the position of a recurrent reference pulse, is varied by each instantaneous sampled value of the modulating wave.
Pulseposition modulation wikipedia republished wiki 2. Pcm is in binary form,so there will be only two possible states high and low 0 and 1. This is repeated every t seconds, such that the transmitted bit rate is bits per second. Pulse position modulation ppm is a form of signal modulation in which m message bits are encoded by transmitting a single pulse in one of 2 m \\displaystyle 2m possible required time shifts.
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