fsk modulation and demodulation lab manual

Connecting corApply the power to a motor for a veryThis is due to the inertia of the motor and theThe PWM technique is use in devices like DC motors, Loudspeakers, Class -D. Amplifiers, SMPS etc. They are also used in communication field as-well. The modulationAs in the case of the inertial loads mentioned previously, the PWM in a communication linkThe immunity of the PWM transmission against the inter-This article discusses the technique of generating a. PWM wave corresponding to a modulating sine wave.KHz.AIM: Study the Analog to Digital conversion and Digital to Analog conversion.As it is known,The group of n bits isThe range ofThis range can be used to indicate any range of voltage. The process of allocating theThe range of binary values used isMost systems use an 8 bit word length which is practically found most suitable toThe two major problems associated with quantizationThis leads to. Hence it is known as quantization noise. Quantization noise can be reduced by increasing the numberBut it can never be eliminated. Increasing the number of bits in aA digital-to-analog converter, or simply DAC, is a semiconductor device that is used to convert aDigital-to-analog conversion is the primary means by which digitalMost DAC's have several digitalSome DAC's,A simple DAC may be implemented using an op-amp circuit knownEach of its inputsWhere VR is the voltage to which the bit is connected when the digital input is '1'.Digital Transmission:-. There are two methods for sending digital data over a distance, namelyIn short distance communication like inside terminal equipment or two computerThis mode is faster.The two important parameters in serial signaling areThe signaling rate or modulation rate is defined as the maximum rate at which theThe other way of defining modulation rate is that it is the reciprocal of the shortestThe modulation rate is measured in. Baud which is equal to one unit signal element per second.AIM: Study of Delta Modulation and Demodulation.

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If you continue browsing the site, you agree to the use of cookies on this website. See our User Agreement and Privacy Policy.If you continue browsing the site, you agree to the use of cookies on this website. See our Privacy Policy and User Agreement for details.If you wish to opt out, please close your SlideShare account. Learn more. You can change your ad preferences anytime. Save so as not to loseHelpWriting.net is ready to help with any kind of academic writing!Modulation(PWM and PPM ).Analog conversion.Apparatus Required:-ST-2110 kit with power supply cord CRO with connecting probe,Theory: Most digital modulation systems are based on pulse modulation. It involves variationDepending upon the nature ofPulse amplitude modulation, pulse widthIn pulse amplitude modulation (PAM) the amplitude of the pulses areIn true sense, pulse amplitude modulation isThe pulse modulation systems require analog information to be sampled at predeterminedA sampled signal consists of a train of pulses,The signal sent to line is modulated in amplitude and hence the name Pulse Amplitude. Modulation (PAM). Block diagram:Time division multiplexing is the process of combining the samples from different informationThus every sample isThe time division multiplexing system can be simulated byEach signal is sampled over one sampling interval and transmitted one after the otherThus part of message 1 is transmitted first followed by partThe switches connect the transmitterIn effect eachA major problem in any. TDM system is the synchronization of the transmitter and receiver timing circuits. TheAlso SW1 must be in theIn a system that uses analogue modulation (PAM) the time slotsProcedure:Modulation output and try to locate them. RESULT: The Study of Pulse Amplitude Modulation and Time division multiplexingExperiment No-2Apparatus Required: ST-2110 Kit, power supply cord, CRO with connecting probe.

Note that, as the frequency of the analog signal increases, the low pass filter's outputCompare this with the output of integrator 1 (TP13), and note that theOutput waveforms at TP13 and TP43 respectivelyThe analog signal is now changing so quickly thatConsequently, changing the system clock frequencyProve this by changing the clock frequency selectorShould the level changer's positiveAIM: Study of Adaptive Delta Modulation and Demodulation. APPRATUS: ST-2105 kit with power supply cord CRO with connecting probe, connectingTHEORY: Theory of Adaptive Delta ModulationBoth these seriousThe delta modulator on-board can pass. This is possible on ST2105 boardThe inherent short coming ofIn delta sigmaThis simpleIt now responds to actual voltage levelsThe effect of the addition of integrator before theIf the voltage comparator is replaced by this circuit, the no. ofTherefore, these two blocks are redundant in. The system shown in the figure 12. Since the voltage comparator is highly non-linear device cannotInitial setup of ST 2155. Integrator (1) blocks switches position. Gain control switch position: Left-hand side. Integrator (2) blocks switches position. Gain control switch position:Right-hand side. Function Generator’s potentiometers position:Change the clockAt the receiver, move the slider of theAgain, it may be necessary to adjust slightly theOutput waveforms at TP13 and TP43 respectivelyNote that the demodulator's output signal is identical to theOutput waveforms at TP13 and TP43 respectivelyApplied Input OutputAIM: Study of Amplitude Shift Keying. APPRATUS: 1. ST2156 and ST2157 kit.These are related to the number ofFor a binary message sequence there are two levels, one of which is typically zero. Thus the modulated waveform consists of bursts of a sinusoid. There are sharp discontinuities shown at the transition points. These result in the signal having anBand limiting is generally introduced before transmission, in which.

APPRATUS: ST-2105 kit with power supply cord CRO with connecting probe, connectingTheory of Delta Modulation. As it has been seen, delta modulation system is unable to chase the rapidly changing information. This is knownThe problem can be overcome by increasing the integratorQuantization Noise:High quantization noise may play havoc on smallThe basic idea is to increase theIf still itThe integrator on boardThe integrator thusSee figure 8. 10. As it can be observed, the adaptive delta modulator is similar to the delta. The input to theThe counter is reset whenever 'high'When the output of counter is '00' the gain is lowest (standard)The Control Circuit Works as. Follows. The control circuit compares the preset data bit from D flip-flop with the previous two data bits. Its output to the counter is high when the three bits are identical, the control circuits output goesThis advancement continues till theSimilarly, the adaptive delta demodulator is a like delta demodulator except. They function in the same way as inInitial setup of ST2155. Integrator (1) blocks switchesGain control switch position: Left-hand side. Integrator (2) blocks switches position. Gain control switch position:Right-hand sideCase B: Bipolar output: Positive level The output from the transmitter's bistable circuit (TP 19)This should be aThis preset adjusts the relativeIf the receiver'sThis step size can be reduced by increasing the rate at which the system isThis is set by the A, B switches in the clock. While monitoring theOnce again, it may be necessary toOutput waveforms at TP13 and TP43 respectivelyKHz.

Scientech Technologies Pvt. Ltd. 48PLL, output of Divide by four (? 4) observe the wave forms.ST2157 and observe the waveforms.ST2157 and observe the waveforms. Data’ on ST2156 respectively.Phase Shifted signal as shown in the figure 6.2.Now customize the name of a clipboard to store your clips. Te invitamos a ingresar desde otro navegador o actualiza tu navegador haciendo click aqui We're Open. New Coronavirus Safety Procedures in Place View Policy 509-535-5946 Now Hiring Price Your Job in 60 Seconds MENU MENU About Us Why Gold Seal Plumbing. The page you are looking for was not found, it may be because the address is incorrect or the page no longer exists. All Rights Reserved. Call Us At 509-535-5946. So this website was intended for free download articles fromYou are self-liable for your download.You can learn how to disable cookie here. Get Latest Price from the seller These products are manufactured from high grade raw material in our well developed manufacturing division as per the international quality standards. Our product range is valued for its Quality standards, high Efficiency, Corrosion resistance and Tensile strength that enable us to create a huge client base across the Indian subcontinent.? Get Best Deal I agree to the terms and privacy policy All rights reserved. The ETT-101 is designed for introductory university courses and technical college labs where telecommunication is first introduced.Completely self contained within a single, low-profile case, the ETT-101 requires only a standard 12V DC plug-pack. Waveforms can be displayed on whatever equipment is available to the student, such as: a standard lab oscilloscope, or a PC-based scope. This dynamic visual approach helps students to see the relationship between modern telecoms methods and the math. When they explore more, they learn more. Each chapter includes background information which relates the experiment content to real-world applications.

The band limiting may be applied to the digitalThe data rate is often made a sub-multiple of the carrier frequency. This has been done in theOne of the disadvantages of ASK, compared with FSK and PSK, for example, is that it has not got aHowever, it does make for ease of demodulation with an envelopeA significant reduction can be accepted before errors at the receiver increase unacceptably. This canASK signal itself after generation.The shape, after band limiting, depends naturally enoughProcedure:Circuit (l) on ST2156 and observe the waveforms.ASK Waveform.Observations:AIM: Study of Frequency Shift Keying. APPRATUS: 1. ST2156 and ST2157 kit.THEORY: In Frequency shift keying, the carrier frequency is shifted (i.e. from one frequencyIf the higher frequency is used to. It is also represented as a sum of two ASK signals.The demodulation of FSK can be carried out by a PLL. As known. Thus the PLLTherefore to remove this, the signal is passed through. Low Pass Filter. The resulting wave is too rounded to be used for digital data processing. Also,As its name suggests, a frequency shift keyed transmitter has its frequency shifted by the message. Although there could be more than two frequencies involved in an FSK signal, in this experiment theProcedure:Observations:RESULT: The amplitude change in FSK waveform does not matter, therefore FSKAIM: Study of Phase Shift Keying. APPRATUS: 1. ST2156 and ST2157.THEORY: Phase shift keying involves the phase change of the carrier sine wave between 0 andPSK is also known as Phase reversalAt receiver, the square loop detectorThe demodulator is shown in figure 2.The phase adjust circuit allows the phase of the digital signalWhen the output is high the switch closes and the original PSK signal is switched through theModulator Circuit (l) on ST2156 and observe the waveforms.Result. The PSK modulator and demodulator circuit has been studied. Precautions:Experiment No 9ST2156 and observe the waveforms. ST2156 and observe the waveforms.

Digital data for the message is modeled by the Sequence Generator module. Students then recover the data using a simple envelope detector and observe its distortion. Finally, students use a comparator to restore the data. Digital data for the message is modeled by the Sequence Generator module. Students then recover the data by using a filter to pick-out one of the sinewaves in the FSK signal and demodulate it using an envelope detector. Finally, students observe the demodulated FSK signal’s distortion and use a comparator to restore the data. Digital data for the message is modeled by the Sequence Generator module. Students then recover the data using another Multiplier module and observe its distortion. Finally, students use a comparator to restore the data. Once generated, students examine the QPSK signal using the scope. Then, students examine how phase discrimination using a product detector can be used to pick-out the data on one BPSK signal or the other. Students then use a product detector (with a stolen carrier) to reproduce the message. Once done, students examine the importance of using the correct PN sequence for the local carrier and the difficulty of jamming DSSS signals. Students then use undersampling to demodulate the bandwidth limited signal and recover the message. Finally, students explore the effects on the recovered message of mismatches between the modulated carrier’s bandwidth and the frequency used for undersampling. After adding the carrier, students make necessary phase adjustments using the kiss test to turn the DSBSC signal into an AM signal. Then, students use the product detector to recover the message from the AM signal. Then, they set-up an envelope detector and product detector that receive the AM signal via a bandwidth limited and noisy channel and make SNR measurements for three levels of channel noise. Both SNR figures are compared for noise performance of the two demodulators.

Then, students activate the PCM Encoder and Decoder modules' TDM mode to transmit two sets of PCM data between the modules. Finally, students modify the set-up to transmit and reconstruct two signals to model a dual-channel TDMA telecommunication system. They will then adjust the inserted carrier for quadrature using the scope and hearing. Finally, the signal will be limited and filtered to convert it to PM. Once generated, students will examine the effect of phase division multiplexing on bandwidth. After this, they will examine how phase discrimination using a product detector can be used to pick-out one message or the other. The modulator is verified and observed in operation for an AC message signal. The DSBSC signal's upper sideband is removed by adjusting a low-pass filter to isolate the inverted message. The signal will then be band-limited to model the type of noise-affected signal that is possible at the output of a receiver. Students use this signal for determining signal-to-noise ratio figures for a variety of noise levels and observe the effects of noise and band-limiting using Eye Diagrams. Then, students complete the PCM system with the addition of a reconstruction filter and measure its SNDR. Digital data for the message is modeled by the Sequence Generator module. Students then recover the data using a product detector and investigate the importance of carrier synchronization in product detection. Digital data for the message is modeled by the Sequence Generator module. Students then recover the data by using a filter to pick-out one of the sinewaves in the FSK signal and demodulate it using an envelope detector. The NI ELVIS integrates 12 common lab instruments including an oscilloscope, function. If you continue to use this site we will assume that you are happy with it. Ok. The output sine-wave of the modulator is the direct or inverted (i.e. shifted of 180 ) input carrier, as function of the data signal.

Associated with each block diagram are detailed, step-by-step patching diagrams. Each chapter is carefully paced and constant use is made of questions to verify the student’s understanding and provide feedback to the teacher. The ETT-101 User Manual contains brief descriptions of each block function on the unit, its specifications and operating instructions. Students only need refer to this manual upon beginning a course, after which time using the system becomes easy and intuitive. The key to the ETT101’s versatility is it’s unique block diagram approach for building experiments. By working at the block diagram level, we are able to achieve many experiments in one system.All Rights Reserved. Based on your location, we recommend that you select:. Other MathWorks country sites are not optimized for visits from your location. To browse Academia.edu and the wider internet faster and more securely, please take a few seconds to upgrade your browser. Related Papers Communication Theory-1-Lab (15EC2205) Prepared by By Gupta Pandiri DIGITAL COMMUNICATION LAB Setting up a fiber optic analog link By towfiq bubt Laboratory ManuaL For DigitaL CoMMuniCation By Hector Al Ajad BTEC406 LAB Analog Communication Systems By Amit Halder ANALOG COMMUICATION LAB LABORATORY MANUAL DEPARTMENT OF ELECTRONICS AND COMMUNICATIONS ENGG MALLA REDDY COLLEGE OF ENGINEERING AND TECHNOLOGY By Arun Kumar READ PAPER Download pdf. The Emona DATEx Add-on Board combines with the NI ELVIS platform, providing a foundation to assist the student in visualizing and better understanding the concepts. DATEx allows the student to see the intermediate steps and associated signals in the implementation of different modulation schemes. Access to the complete volume of the Emona DATEx add-on board lab manual is provided upon purchase of the product.

Students will add a DC component to a pure sinewave to create a message signal then multiply it with another sinewave at a higher frequency (the carrier), then examine the AM signal using the scope and compare it to the original message. Students examine the DSBSC signal using the scope and compare it to the original message. Then students set-up an envelope detector using the Rectifier and RC LPF on the trainer’s Utilities module. Once done, students connect the AM signal to the envelope detector’s input and compare the demodulated output to the original message and the AM signal’s envelope. Students also observe the effect that an over-modulated AM signal has on the envelope detector’s output. Once done, students connect the DSBSC signal to the product detector’s input and compare the demodulated output to the original message and the DSBSC signal’s envelopes. Finally, students observe the effect that a distorted DSBSC signal due to overloading has on the product detector’s output. First students set up the VCO module to output an unmodulated carrier at a known frequency, then observe the effect of frequency modulating its output with a squarewave then speech. Finally students use the NI ELVIS Dynamic Signal Analyzer to observe the spectral composition of an FM signal in the frequency domain and examine the distribution of power between its carrier and sidebands for different levels of modulation. Students then examine the sampled message in the frequency domain using the NI ELVIS Dynamic Signal Analyzer. Finally, students reconstruct the message from the sampled signal and examine the effect of aliasing. In the process, students verify the operation of PCM encoding and investigate quantisation error. Students then recover the message using the Tuneable Low-pass filter module. Students observe the effect of bandwidth limiting on the PCM data using a scope. Finally, students use a comparator to restore a digital signal and observe its limitations.

Constellation Diagram The modulation states of the PSK Modulator are represented with points in a vectorial diagram. Each point is a modulation state, characterized by a phase and an amplitude. This representation is called constellation diagram, or more simply constellation. Main aspects The main aspects characterizing the 2-PSK are: use of digital radio transmission it requires circuits of average-high complexity high possibility of error but lower than the FSK if Fb is the bit transmission speed, the minimum spectrum Bw of the modulated signal is higher than Fb the transmission efficiency, defined as the ratio Fb and Bw, is lower than 1 the Baud or Baud rate, defined as the Modulation speed or symbol speed, is equal to the transmission speed Fb. 2 3 2-PSK Modulator The block diagram of the 2-PSK modulator is shown in fig.2. The sine carrier (1200 Hz) is applied to an input of the balanced modulator 1; a data signal (indicated with I) is applied to the other input. The circuit operates as balanced modulator, and multiplies the two signals applied to the inputs. The 6dB attenuator makes the signal amplitude half, and is activated only by the QAM. This must have the same frequency and phase of the one used in transmission (it must be coherent with the received signal), and is taken from the PSK signal as described further on. Mathematically, the demodulation process is developed as follows. Carrier regenerator with quadratic law The carrier regenerator circuit must extract a signal coherent (same frequency and phase) with the carrier from the PSK signal. A method used is the one of fig.

3: a squarer circuit removes the 180 phase shifts in the modulated carrier, to facilitate the same carrier regeneration by the next PLL circuit the PLL circuit generates a square-wave signal with double frequency than the PSK carrier a phase shifter circuit enables to properly adjust the phase of the regenerated carrier a frequency divider divides by 2 the square-wave supplied by the PLL, and provides the regenerated carrier in this way. Demodulator circuit The block diagram of the 2-PSK demodulator with coherent detector is shown in fig.4. It includes the following circuits: the carrier regenerator, which supplies a signal coherent (same frequency and phase) with the carrier of the PSK signal. It consists of: a double squarer, which purpose is to remove the 180 phase shifts in the modulated carrier, to facilitate the same carrier regeneration by the next PLL circuit a PLL circuit, which generates a square-wave signal with frequency four times the one of the PSK carrier a frequency divider by 4, to obtain the regenerated carrier. The double squarer and the frequency divider by 4 enables the use of the same circuit for carrier regeneration in the 4-PSK systems too. The 2-PSK demodulator (shown in the diagram as DEM I), consists in a double sampler. If the regenerated carrier phase is correct, the sampler output will contain only positive half-waves when the 2- PSK signal has a certain phase, only negative half-waves when the phase is reversed a low pass filter a squarer circuit (with output in TP29 in case of asynchronous data, which are not re-timed) a clock extraction and data re-timing circuit, in case of synchronous data (data output on TP31, clock on TP33). Adjust the phase (PHASE) to invert the phase of the carrier in correspondence to 0 0. Q1 Examine the carrier at the input TP12 and the output (TP 16) of the modulator. As the communication channel is limited band, the phase transitions of the output PSK signal are slightly beveled.

The sampling clock consists in the carrier regenerated by the Carrier Recovery Section Across TP21 you can note a rectangular signal which samples the negative half-wave of the PSK signal. Q2 What kind of signal can you observe on the demodulator output (TP23). The signal supplied by the PSK demodulator passes a low filter, which eliminates the residuals of the 1200 Hz carrier. Across the filter s output (TP24, Fig. 5) you get the wave-form of the detected data signal. It can happen that the received signals are inverted in respect to the transmitted one. This can be understood as the demodulator does not know which of the coming phases is 0 0 or 180 0, and this ambiguity can take to the inversion of the demodulated data. The ambiguity is overcome by carrying out a data differential coding before the modulation. In case push Phase Sync to obtain data with proper sign. The squared data signal can be detected across TP31. See on the oscilloscope the correspondence between the transmitted data (TP6) and the received ones (TP31) Across TP32 see the reception clock (rectangular wave at 600 Hz), reconstructed starting from the data signal and used to re-time the same data. 7 8 Figure 5: 2-PSK Waveforms SIS1 - Turn ON switch S24 Q3 The data received on TP29 is not correct. Why? 8 9 SKETCH THE GRAPHS FROM THE OSCILOSCOPE: SIS1 - Turn OFF switch S24 Set now a data sequence with few alternation, e.g. all 1 and a single 0, and push START Examine the signal across TP4 (transmitted data), TP31 (received data), TP32 (reception clock). Eventually push Phase Sync to obtain the data with proper sign across TP31. It can happen that the reception clock (TP32) is not stable, and that the received data (TP31) has some time different from the transmitted (TP4). This is due to a bad operation of the PLL which regenerates the reception clock. Q4 What can you observed at TP4, TP31 and TP32.

The Manchester coding of the data to be transmitted ensures there are always alternates in the transmitted signal, facilitating in this way the clock extraction by the PLL. Supply the 2-PSK modulator with the Manchester coded data (disconnect J1c and connect J1-d) The Received Data and the Reception Clock are now available after the Manchester coder (TP9 and TP10) Keep the same data sequence of the last case and see that: - The clock is now regenerated properly - The received data is equal to the transmitted ones Q5 What can you observed at TP4, TP9, TP3 and TP10? 9 EE3723: Digital Communications. Synchronization. Carrier Phase Recovery. Carrier Phase Synchronization Techniques. This means we must have a way to perform (1) Bit or symbol synchronization (2) Frame synchronization These are related PSK digital modulation Digital communication has demonstrated CS3282: Digital Communications 06.CME 313-Lab Anas Al-ashqar Dr. Ala' Khalifeh Advanced Communication System Communication Laboratory.Review of phase ambiguity Dr. Hasan Huseyin BALIK (5 th Week) 5. Signal Encoding Techniques 5.Outline An overview of the basic methods of encoding digital data into a digital signal An overview of Prof, Dept The particular encoding Review Passband Modulation. Constellations ASK, FSK, PSK. Principles of Communication Systems ELEN E3701. Spring Semester May Final Examination Surendra Prasad Department of Electrical Engineering Indian Institute of Technology, Delhi Surendra Prasad Department of Electrical Engineering Indian Institute of Technology, Delhi Lecture - 10 Single Sideband Modulation We will discuss, now we will continue Phase ambiguity DISCUSSION Good news: No complicated mathematics and calculations. Concepts: Understanding and remember. Homework: review Question Exam Marks Question Exam Marks 1 Draw the block diagram of the basic digital communication system. State the function of each block in detail. W 2015 6 2 State General project hints. Behavioral Model.

General project hints, cont. Lecture 5. Required documents Modulation, cont. Requirement specification Channel coding Design specification Bandpass Modulation. Page 1 Digital modulation formats: Study the generation of differential binary signal.! Study the differential PSK modulation.! Study the differential PSK demodulation. Lab Exercises Theory Carrier and All rights reserved. 1 Modulation The process of varying one signal, called carrier, according Communication Laboratory OSI Protocol Model Mythili Vutukuru CS 653 Spring 2014 Jan 13, Monday Total Number of Questions: To use this website, you must agree to our Privacy Policy, including cookie policy.