Experiment 03: Amplitude Modulation With Noise

Size: px
Start display at page:

Download "Experiment 03: Amplitude Modulation With Noise"

Transcription

1 ECE363, Experiment 03, 2015 Communications Lab, University of Toronto Experiment 03: Amplitude Modulation With Noise Bruno Korst - bkf@comm.utoronto.ca Abstract In this third laboratory experiment, you will see Amplitude Modulation (AM) and will study its demodulation free of noise and in the presence of noise. The simplest form of AM is accomplished by the multiplication between a bandlimited message signal and a cosine (called carrier), whose frequency is located at a much higher place in the spectrum. This multiplication will cause a shift of the bandlimited message spectrum to where the carrier is located. In the time domain, the envelope of the carrier signal will change (i.e. will be modulated in amplitude) proportionally to the voltage of the message signal. The presence of noise in the transmission will set a limit after which the demodulation can no longer occur and the message is lost. Keywords Modulation Amplitude Carrier Demodulation Noise Contents Introduction 1 1 Some Theory 2 2 Experiment Designing and Simulating an AM Modulator Designing and Simulating an AM Demodulator Implementing an AM Modulator and Demodulator Modulator Demodulator 3 Accomplishments 6 Acknowledgments 6 References 6 Introduction Amplitude modulation (AM), still used in commercial radio today, is one of the simplest ways that a message signal can modulate a sinusoidal carrier wave. The purpose of this lab is for you to gain familiarity with the concepts of amplitude modulation and demodulation. This will be done in three main steps: First, an amplitude modulation system will be created and simulated using Simulink; Second, you will implement an AM modulator or an AM demodulator on a DSP platform; Finally, you will pair up with a neighbouring group assess AM demodulation in the presence of noise. Before coming to the lab, you must complete the preparation sheet. The preparation work should lead you to identify the equation for an AM-modulated signal, to understand the concept of overmodulation, to understand the time domain and frequency domain representation of an AM-modulated signal with (AM-DSB) and without (AM-DSB-SC) and to have a clear high-level picture of an AM modulator and demodulator. Note that the preparation is to be done individually, whereas the lab answer sheet is to be done in groups of a maximum of two students. You should print the preparation and the answer sheet, fill out the preparation and bring them both to the lab. In the lab you will follow this procedure online and record your answers in the answer sheet.

2 Experiment 03: Amplitude Modulation With Noise 2/6 1. Some Theory Your measurements will be done on four variables: the noiseless modulated signal input to the demodulator (Si), the input signal plus channel noise (SNi), the demodulated signal without noise (So) and the signal plus noise level measured at the output (SNo). You will monitor these variables using Code Composer Studio and will record their values for different noise scenarios. Your objective is to populate the SNR input/output tables given and use the values you calculate to draw graphs for each scenario. Figure 1 below shows the points where the variables are measured by the program. (SN i ) Input ADC + (S i ) BPF Demod (SN o ) (S o ) DAC Output noise Figure 1. At the receiver, the program implements the systems contained in the main block. In order to measure the noise component (both for input and output), you must recall that signal and noise are uncorrelated. Therefore, you can measure the combined signal plus noise and subtract from that value the signal without noise, as shown below for the input measurements. SN i = E {[s i (t) + n i (t)][s i (t) + n i (t)]} { = E s i (t) 2} { + E n i (t) 2} + E {s i (t)n i (t)} + E {s i (t)n i (t)} { = E s i (t) 2} + E { n i (t) 2} = S i + N i therefore N i = SN i S i Every time you measure SNi or SNo, you are actually measuring noise added to signal. Therefore, you must subtract the signal-only component from that value in order to obtain the noise component. So your input and output SNR(dB) will be calculated as follows: (1) S i SNR i = 10log (SN i S i ) (2) likewise S o SNR o = 10log (SN o S o ) There are many books and resources online to explain amplitude modulation. If your preference is to read from a (real) book, you can take a look at [1], [2] and [3], among others. The advantage you have in seeking for information online as well is that you can try to find out practical information about AM. For instances, where are the stations located in our area (example: 680News) and what kind of equipment do they use? Also, you may find interesting to read about Citizen Band (CB) radio, which is a very accessible form of communication to everyone and uses plain-old AM. 2. Experiment It is expected that at this point you are familiar with the basic blocks of Simulink as well as the procedure to compile and run programs on the target DSP hardware. The pictures provided below should also guide you as to what is expected in the simulation. (3)

3 Experiment 03: Amplitude Modulation With Noise 3/6 2.1 Designing and Simulating an AM Modulator The purpose of a simulation is to better understand what is expected from a system when it is actually implemented. You will simulate things first and then move to implementing them on the DSP hardware. Start, then, by building your AM modulator in Simulink. It should look like Figure 2 below. Figure 2. Amplitude Modulator For the initial simulation, use a DSP Sine generator as input, and for output use one time scope and put together your own frequency domain scope, as you did in the previous experiment. For your message signal, use a 1.5KHz, 0.5 peak Voltage (that is 1V pp ) sinusoid. Use 48KHz as your sampling rate, and make sure you define the sampling rate for all blocks that need it. As the block diagram shows, the input signal must be added to a DC component (use 1 as your DC component) and the signal resulting from this addition will be multiplied by the carrier frequency. The carrier frequency is generated by another discrete-time sine wave generator, with an amplitude of 1 (peak value) and 12KHz. Remember that you are multiplying your baseband signal by a carrier in order to shift it up in the spectrum. Run your simulation, and observe the result on the Simulink scopes. Adjust the setting of your scopes appropriately (i.e, should you really start displaying your signal at -150dB?). At this point, the scopes should allow you to observe an AM signal similar to the one you drafted on your lab preparation sheet. The pictures below shows a time-domain and frequency domain amplitude modulated signal similar to what you should observe. Your numbers may differ. (a) Time Domain Display (b) Frequency Domain Display Figure 3. Simulated Time Domain and Frequency Domain Display for AM

4 Experiment 03: Amplitude Modulation With Noise 4/6 2.2 Designing and Simulating an AM Demodulator Your modulator runs fine, but your objective is really to receive the message after it goes through modulator, amplifiers, antenna, channel and receiving antenna. You must then demodulate this received signal to extract the modulating signal, which is the signal containing the information you want. In your case, this information is a 1KHz, 1V pp sine wave, or a single tone. In this part of the experiment, you will utilize your previously tested AM modulator and implement a demodulator by adding a filter to the signal path, after the multiplication with the carrier. As you have seen in the theory, by multiplying the incoming (received) signal by the carrier frequency, one will have as a result the desired baseband signal as well as DC and other higher frequency components. If you remove the higher frequency components with a low-pass filter, you retrieve the original message signal which was transmitted, plus a DC component, as the model in 4. Since you do not have a capacitor to put in series and remove the DC, your option in software (firmware) is to create a bandpass filter. Design one now and run it. It should be similar to the one presented below, except for the filter. Figure 4. Simulating Modulation and Demodulation 2.3 Implementing an AM Modulator and Demodulator Modulator You will now run a program on the DSP platform to implement the system(s) you have just simulated. Start by opening CCS. The program you are looking for is located on the left pane, and it is called ECE363 Exp02a AM MOD. All files related to the project should appear under the project tree. Inspect the files, identifying the most relevant routines, such as carrier generation, sample handling, adding DC, etc. When you click on it, the message [Active - Debug] should appear next to the project name. Right-click on it and select Build Project. Now click on the green bug (see below) and select Debug As -- Code Composer Debug Session. Figure 5. Bug This should connect to the target, load the executable and put everything ready to run. Make all the physical connections and make the system run (press play ). Answer the questions below, pertaining to the system you are running. Use a 3KHz, 0.5V pp sine wave as input. Make sure your signal generators are adjusted to see a high-impedance load at the output. Also, take a good look at the code and make sure you understand what is going on. You will be required to change it. One interesting point: when you run your modulator on the target hardware, you will notice that the modulated signal will not have the amplitude you read from your signal generator. This is due to a few reasons. One comes from the numerical values used in the code, that upon being translated back to volts will be scaled. For instance, if you use 0.7V pp or more, the signal will be overmodulated. Take a look at the code to see what is being done to each input sample as it makes its way to the output. Also, there is an analog filter at the input of the CODEC, which starts to roll off at approximately 10KHz. Since your modulated signal presents a carrier at 12KHz, you can expect your output amplitude to be off by a certain margin (question for thinking only: how would you determine this margin?). The other detail that you will notice on the code is the presence of a DC blocking filter, applied to both channels. This is due to a spurious DC value that is passed to the DSP by the CODEC even without any input present. It is there and it must be removed right after the samples are passed to the program.

5 Experiment 03: Amplitude Modulation With Noise 5/6 As a simple exercise to familiarize yourself with the code, make it implement AM-DSB-SC, and use as input a 1KHz, 0.5V pp square wave. Now when you look at your results, think of it this way: you have mixed a carrier with a stream of bits. Remember that in communications, mixing is the multiplication between two signals, whereas in audio it is their addition. The 1KHz square wave message mimics alternating bits at 2Kbps. Notice how much bandwidth this signal is taking. After you put it to run, move on to answer some questions on the answer sheet Demodulator Click on ECE363 Exp02b AM DEMOD, which should make it active. Build the project and create a CCS debugging session (i.e., connect to the target and load the executable). Remember that now you are implementing a demodulator, which means that you will need an amplitude modulated signal to serve as input to your system. You will test your demodulator first by using an AM signal coming from the signal generator. Assuming you have now a sinusoid on your signal generator, you will proceed as follows: Set the existing sinusoid to 12KHz, 1.8V pp. This will be your sinusoidal carrier. Press Modulation on your signal generator (top buttons). Set the message, or modulating signal to be a 3KHz sinusoid. You want sine modulating sine. Set the modulation index (or depth) to be less than 100% (say, 80%). Test to see which of the two input channels is the input to the demodulator. You can also try to change the input to a triangle or a square wave to see what happens. Now that you have tested both modulator and demodulator, pair up with the group next to you and have one group run the modulator and the other run the demodulator. Initially, your input to the modulator will be a 3KHz, 1V pp sine. Set the system up, connect everything appropriately and run it, making sure it works for a sinusoid. There are three controllable parameters in the whole experiment (modulator and demodulator): the modulation depth (in the modulator), the output gain (also in the modulator), and the AWGN (this is the noise in the demodulator). Note that the output gain of the demodulator is not relevant to this part of the experiment. You will draw an SNR Input vs SNR Output graph using the process below. It is obtained by assessing how the output signal s SNR changes while the channel s SNR decreases. The channel s SNR can be affected (or changed) in different ways: a) by changing the input signal amplitude; b) by changing the Additive White Gaussian Noise (AWGN) amplitude; and c) by changing the modulator output gain. For this part of the experiment, you will change the channel SNR by varying the modulator output gain. This would be the Input on Figure 1. Proceed as follows. Power up and run the modulator and demodulator in each board. Make sure that the demodulator receives the message sent by the modulator; Set the function generator to output a sine wave of 1 khz and 1.8 Vpp (this amplitude should cover the whole dynamic range of the ADC in the modulator). On the demodulator side, go to the Script menu in Code Composer Studio (make sure you are on Debug mode) then select Input->noise level. Use the slider to set gain of the AWGN. A level of 10 should be enough. This is required because the natural noise level of the transmission is too low. By doing this, we increase the noise floor, making the changes more apparent. Set the continuous refresh interval to a value between 1.5 and 2.0 seconds. If you hit the continuous refresh button now you can see the values of the variables changing in real time. At the CCS of the demodulator, while on Debug mode, select the top menu Tools->Graph->Dual Time. At Graph Properties set: Acquisition buffer = 1; Dsp Data Type = 32 bit floating point; Start Address A = &Si; Start Address B = &So. Leave the rest as their default values.

6 Experiment 03: Amplitude Modulation With Noise 6/6 At the CCS of the modulator, while on Debug mode, go to Script top menu, then select Modulation->Depth. Use the slider to set the depth. At the CCS of the modulator, while on Debug mode, go to Script top menu, then select Output->Output Amp. Use the slider to set demodulator output gain be 2 (20 in the slider). Reset the graphs data and enable the continuous refresh of the graphs at the demodulator. Slowly reduce the Output Amp slider at the modulator. At this point you should see the signal strength dropping in the oscilloscope and each graph being filled point by point. Make sure that the graphs have at least one point for each notch in the slider two or three should be enough. When the slider reaches 0, stop the auto refresh. Export the data from the graphs, right click the graph; Go to data->export all. Data1 will be Si and Data2 So. Repeat steps 8 through 11 for different modulation depth values. Now draw your graph on the answer sheet for three different modulation indexes: 10%, 50% and 100%. 3. Accomplishments In this experiment, you were presented with the key issues involved in designing, simulating and implementing an AM modulator and demodulator. This was done by using a simulation model, a DSP platform in which modulator and demodulator were implemented. You tried a software-defined and possibly an envelope detector as well for the demodulation of the AM signal. The experiment intended to guide you through the steps necessary to achieve a practical understanding of the concepts studied in the theory of Amplitude Modulation. Acknowledgments Thanks for all the students who have provided input on the previous versions of this experiment. [1] S. Haykin. Communication Systems, 4th Ed References [2] S. Haykin and M. Moher. Introduction to Analog and Digital Communications, 2nd. Ed [3] B.P. Lathi. Modern Digital and Analog Communication Systems, 3rd Ed

Department of Electrical and Computer Engineering Ben-Gurion University of the Negev. LAB 1 - Introduction to USRP

Department of Electrical and Computer Engineering Ben-Gurion University of the Negev. LAB 1 - Introduction to USRP Department of Electrical and Computer Engineering Ben-Gurion University of the Negev LAB 1 - Introduction to USRP - 1-1 Introduction In this lab you will use software reconfigurable RF hardware from National

More information

AM Receiver. Prelab. baseband

AM Receiver. Prelab. baseband AM Receiver Prelab In this experiment you will use what you learned in your previous lab sessions to make an AM receiver circuit. You will construct an envelope detector AM receiver. P1) Introduction One

More information

EXPERIMENT NUMBER 5 BASIC OSCILLOSCOPE OPERATIONS

EXPERIMENT NUMBER 5 BASIC OSCILLOSCOPE OPERATIONS 1 EXPERIMENT NUMBER 5 BASIC OSCILLOSCOPE OPERATIONS The oscilloscope is the most versatile and most important tool in this lab and is probably the best tool an electrical engineer uses. This outline guides

More information

Lock - in Amplifier and Applications

Lock - in Amplifier and Applications Lock - in Amplifier and Applications What is a Lock in Amplifier? In a nut shell, what a lock-in amplifier does is measure the amplitude V o of a sinusoidal voltage, V in (t) = V o cos(ω o t) where ω o

More information

Implementation of Digital Signal Processing: Some Background on GFSK Modulation

Implementation of Digital Signal Processing: Some Background on GFSK Modulation Implementation of Digital Signal Processing: Some Background on GFSK Modulation Sabih H. Gerez University of Twente, Department of Electrical Engineering s.h.gerez@utwente.nl Version 4 (February 7, 2013)

More information

The front end of the receiver performs the frequency translation, channel selection and amplification of the signal.

The front end of the receiver performs the frequency translation, channel selection and amplification of the signal. Many receivers must be capable of handling a very wide range of signal powers at the input while still producing the correct output. This must be done in the presence of noise and interference which occasionally

More information

Experiment # (4) AM Demodulator

Experiment # (4) AM Demodulator Islamic University of Gaza Faculty of Engineering Electrical Department Experiment # (4) AM Demodulator Communications Engineering I (Lab.) Prepared by: Eng. Omar A. Qarmout Eng. Mohammed K. Abu Foul Experiment

More information

AM TRANSMITTERS & RECEIVERS

AM TRANSMITTERS & RECEIVERS Reading 30 Ron Bertrand VK2DQ http://www.radioelectronicschool.com AM TRANSMITTERS & RECEIVERS Revision: our definition of amplitude modulation. Amplitude modulation is when the modulating audio is combined

More information

Experiment 3: Double Sideband Modulation (DSB)

Experiment 3: Double Sideband Modulation (DSB) Experiment 3: Double Sideband Modulation (DSB) This experiment examines the characteristics of the double-sideband (DSB) linear modulation process. The demodulation is performed coherently and its strict

More information

PCM Encoding and Decoding:

PCM Encoding and Decoding: PCM Encoding and Decoding: Aim: Introduction to PCM encoding and decoding. Introduction: PCM Encoding: The input to the PCM ENCODER module is an analog message. This must be constrained to a defined bandwidth

More information

RF Measurements Using a Modular Digitizer

RF Measurements Using a Modular Digitizer RF Measurements Using a Modular Digitizer Modern modular digitizers, like the Spectrum M4i series PCIe digitizers, offer greater bandwidth and higher resolution at any given bandwidth than ever before.

More information

MATRIX TECHNICAL NOTES

MATRIX TECHNICAL NOTES 200 WOOD AVENUE, MIDDLESEX, NJ 08846 PHONE (732) 469-9510 FAX (732) 469-0418 MATRIX TECHNICAL NOTES MTN-107 TEST SETUP FOR THE MEASUREMENT OF X-MOD, CTB, AND CSO USING A MEAN SQUARE CIRCUIT AS A DETECTOR

More information

Modification Details.

Modification Details. Front end receiver modification for DRM: AKD Target Communications receiver. Model HF3. Summary. The receiver was modified and capable of receiving DRM, but performance was limited by the phase noise from

More information

SIGNAL GENERATORS and OSCILLOSCOPE CALIBRATION

SIGNAL GENERATORS and OSCILLOSCOPE CALIBRATION 1 SIGNAL GENERATORS and OSCILLOSCOPE CALIBRATION By Lannes S. Purnell FLUKE CORPORATION 2 This paper shows how standard signal generators can be used as leveled sine wave sources for calibrating oscilloscopes.

More information

Software Defined Radio

Software Defined Radio Software Defined Radio GNU Radio and the USRP Overview What is Software Defined Radio? Advantages of Software Defined Radio Traditional versus SDR Receivers SDR and the USRP Using GNU Radio Introduction

More information

Non-Data Aided Carrier Offset Compensation for SDR Implementation

Non-Data Aided Carrier Offset Compensation for SDR Implementation Non-Data Aided Carrier Offset Compensation for SDR Implementation Anders Riis Jensen 1, Niels Terp Kjeldgaard Jørgensen 1 Kim Laugesen 1, Yannick Le Moullec 1,2 1 Department of Electronic Systems, 2 Center

More information

Lab 3: Introduction to Data Acquisition Cards

Lab 3: Introduction to Data Acquisition Cards Lab 3: Introduction to Data Acquisition Cards INTRODUCTION: In this lab, you will be building a VI to display the input measured on a channel. However, within your own VI you will use LabVIEW supplied

More information

Building a Simulink model for real-time analysis V1.15.00. Copyright g.tec medical engineering GmbH

Building a Simulink model for real-time analysis V1.15.00. Copyright g.tec medical engineering GmbH g.tec medical engineering GmbH Sierningstrasse 14, A-4521 Schiedlberg Austria - Europe Tel.: (43)-7251-22240-0 Fax: (43)-7251-22240-39 office@gtec.at, http://www.gtec.at Building a Simulink model for real-time

More information

SIGNAL PROCESSING & SIMULATION NEWSLETTER

SIGNAL PROCESSING & SIMULATION NEWSLETTER 1 of 10 1/25/2008 3:38 AM SIGNAL PROCESSING & SIMULATION NEWSLETTER Note: This is not a particularly interesting topic for anyone other than those who ar e involved in simulation. So if you have difficulty

More information

Lab #9: AC Steady State Analysis

Lab #9: AC Steady State Analysis Theory & Introduction Lab #9: AC Steady State Analysis Goals for Lab #9 The main goal for lab 9 is to make the students familar with AC steady state analysis, db scale and the NI ELVIS frequency analyzer.

More information

Tektronix RSA306 USB Spectrum Analyzer

Tektronix RSA306 USB Spectrum Analyzer Tektronix RSA306 USB Spectrum Analyzer Simple Demos The Demo of the RSA306 is easy. Even you do not have signal generators, devices under test, or demo boards, using the whip antenna provided in box, you

More information

Simple SDR Receiver. Looking for some hardware to learn about SDR? This project may be just what you need to explore this hot topic!

Simple SDR Receiver. Looking for some hardware to learn about SDR? This project may be just what you need to explore this hot topic! Michael Hightower, KF6SJ 13620 White Rock Station Rd, Poway, CA 92064; kf6sj@arrl.net Simple SDR Receiver Looking for some hardware to learn about SDR? This project may be just what you need to explore

More information

Spectrum analyzer with USRP, GNU Radio and MATLAB

Spectrum analyzer with USRP, GNU Radio and MATLAB Spectrum analyzer with USRP, GNU Radio and MATLAB António José Costa, João Lima, Lúcia Antunes, Nuno Borges de Carvalho {antoniocosta, jflima, a30423, nbcarvalho}@ua.pt January 23, 2009 Abstract In this

More information

Voice---is analog in character and moves in the form of waves. 3-important wave-characteristics:

Voice---is analog in character and moves in the form of waves. 3-important wave-characteristics: Voice Transmission --Basic Concepts-- Voice---is analog in character and moves in the form of waves. 3-important wave-characteristics: Amplitude Frequency Phase Voice Digitization in the POTS Traditional

More information

RF Communication System. EE 172 Systems Group Presentation

RF Communication System. EE 172 Systems Group Presentation RF Communication System EE 172 Systems Group Presentation RF System Outline Transmitter Components Receiver Components Noise Figure Link Budget Test Equipment System Success Design Remedy Transmitter Components

More information

Introduction to Receivers

Introduction to Receivers Introduction to Receivers Purpose: translate RF signals to baseband Shift frequency Amplify Filter Demodulate Why is this a challenge? Interference (selectivity, images and distortion) Large dynamic range

More information

LEVERAGING FPGA AND CPLD DIGITAL LOGIC TO IMPLEMENT ANALOG TO DIGITAL CONVERTERS

LEVERAGING FPGA AND CPLD DIGITAL LOGIC TO IMPLEMENT ANALOG TO DIGITAL CONVERTERS LEVERAGING FPGA AND CPLD DIGITAL LOGIC TO IMPLEMENT ANALOG TO DIGITAL CONVERTERS March 2010 Lattice Semiconductor 5555 Northeast Moore Ct. Hillsboro, Oregon 97124 USA Telephone: (503) 268-8000 www.latticesemi.com

More information

Timing Errors and Jitter

Timing Errors and Jitter Timing Errors and Jitter Background Mike Story In a sampled (digital) system, samples have to be accurate in level and time. The digital system uses the two bits of information the signal was this big

More information

Sampling Theorem Notes. Recall: That a time sampled signal is like taking a snap shot or picture of signal periodically.

Sampling Theorem Notes. Recall: That a time sampled signal is like taking a snap shot or picture of signal periodically. Sampling Theorem We will show that a band limited signal can be reconstructed exactly from its discrete time samples. Recall: That a time sampled signal is like taking a snap shot or picture of signal

More information

A WEB BASED TRAINING MODULE FOR TEACHING DIGITAL COMMUNICATIONS

A WEB BASED TRAINING MODULE FOR TEACHING DIGITAL COMMUNICATIONS A WEB BASED TRAINING MODULE FOR TEACHING DIGITAL COMMUNICATIONS Ali Kara 1, Cihangir Erdem 1, Mehmet Efe Ozbek 1, Nergiz Cagiltay 2, Elif Aydin 1 (1) Department of Electrical and Electronics Engineering,

More information

ELAD FDM-SW1 USER MANUAL. Ver. 1.0

ELAD FDM-SW1 USER MANUAL. Ver. 1.0 ELAD FDM-SW1 USER MANUAL Ver. 1.0 Index 1 FDM-SW1 Overview... 4 2 Graphical User Interface (GUI)... 5 2.1 Display Window... 6 2.1.1 Filter Spectrum... 6 2.1.2 Click Options... 7 2.1.3 Graphics Settings...

More information

DDX 7000 & 8003. Digital Partial Discharge Detectors FEATURES APPLICATIONS

DDX 7000 & 8003. Digital Partial Discharge Detectors FEATURES APPLICATIONS DDX 7000 & 8003 Digital Partial Discharge Detectors The HAEFELY HIPOTRONICS DDX Digital Partial Discharge Detector offers the high accuracy and flexibility of digital technology, plus the real-time display

More information

Wireless Communication and RF System Design Using MATLAB and Simulink Giorgia Zucchelli Technical Marketing RF & Mixed-Signal

Wireless Communication and RF System Design Using MATLAB and Simulink Giorgia Zucchelli Technical Marketing RF & Mixed-Signal Wireless Communication and RF System Design Using MATLAB and Simulink Giorgia Zucchelli Technical Marketing RF & Mixed-Signal 2013 The MathWorks, Inc. 1 Outline of Today s Presentation Introduction to

More information

The Phase Modulator In NBFM Voice Communication Systems

The Phase Modulator In NBFM Voice Communication Systems The Phase Modulator In NBFM Voice Communication Systems Virgil Leenerts 8 March 5 The phase modulator has been a point of discussion as to why it is used and not a frequency modulator in what are called

More information

MODULATION Systems (part 1)

MODULATION Systems (part 1) Technologies and Services on Digital Broadcasting (8) MODULATION Systems (part ) "Technologies and Services of Digital Broadcasting" (in Japanese, ISBN4-339-62-2) is published by CORONA publishing co.,

More information

DDX 7000 & 8003. Digital Partial Discharge Detectors FEATURES APPLICATIONS

DDX 7000 & 8003. Digital Partial Discharge Detectors FEATURES APPLICATIONS DDX 7000 & 8003 Digital Partial Discharge Detectors The HAEFELY HIPOTRONICS DDX Digital Partial Discharge Detector offers the high accuracy and flexibility of digital technology, plus the real-time display

More information

Application Note Receiving HF Signals with a USRP Device Ettus Research

Application Note Receiving HF Signals with a USRP Device Ettus Research Application Note Receiving HF Signals with a USRP Device Ettus Research Introduction The electromagnetic (EM) spectrum between 3 and 30 MHz is commonly referred to as the HF band. Due to the propagation

More information

T = 1 f. Phase. Measure of relative position in time within a single period of a signal For a periodic signal f(t), phase is fractional part t p

T = 1 f. Phase. Measure of relative position in time within a single period of a signal For a periodic signal f(t), phase is fractional part t p Data Transmission Concepts and terminology Transmission terminology Transmission from transmitter to receiver goes over some transmission medium using electromagnetic waves Guided media. Waves are guided

More information

Electrical Resonance

Electrical Resonance Electrical Resonance (R-L-C series circuit) APPARATUS 1. R-L-C Circuit board 2. Signal generator 3. Oscilloscope Tektronix TDS1002 with two sets of leads (see Introduction to the Oscilloscope ) INTRODUCTION

More information

Frequency Response of Filters

Frequency Response of Filters School of Engineering Department of Electrical and Computer Engineering 332:224 Principles of Electrical Engineering II Laboratory Experiment 2 Frequency Response of Filters 1 Introduction Objectives To

More information

BER Performance Analysis of SSB-QPSK over AWGN and Rayleigh Channel

BER Performance Analysis of SSB-QPSK over AWGN and Rayleigh Channel Performance Analysis of SSB-QPSK over AWGN and Rayleigh Channel Rahul Taware ME Student EXTC Department, DJSCOE Vile-Parle (W) Mumbai 056 T. D Biradar Associate Professor EXTC Department, DJSCOE Vile-Parle

More information

Analog and Digital Signals, Time and Frequency Representation of Signals

Analog and Digital Signals, Time and Frequency Representation of Signals 1 Analog and Digital Signals, Time and Frequency Representation of Signals Required reading: Garcia 3.1, 3.2 CSE 3213, Fall 2010 Instructor: N. Vlajic 2 Data vs. Signal Analog vs. Digital Analog Signals

More information

Analog Representations of Sound

Analog Representations of Sound Analog Representations of Sound Magnified phonograph grooves, viewed from above: The shape of the grooves encodes the continuously varying audio signal. Analog to Digital Recording Chain ADC Microphone

More information

25. AM radio receiver

25. AM radio receiver 1 25. AM radio receiver The chapter describes the programming of a microcontroller to demodulate a signal from a local radio station. To keep the circuit simple the signal from the local amplitude modulated

More information

RF Network Analyzer Basics

RF Network Analyzer Basics RF Network Analyzer Basics A tutorial, information and overview about the basics of the RF Network Analyzer. What is a Network Analyzer and how to use them, to include the Scalar Network Analyzer (SNA),

More information

Digital Transmission of Analog Data: PCM and Delta Modulation

Digital Transmission of Analog Data: PCM and Delta Modulation Digital Transmission of Analog Data: PCM and Delta Modulation Required reading: Garcia 3.3.2 and 3.3.3 CSE 323, Fall 200 Instructor: N. Vlajic Digital Transmission of Analog Data 2 Digitization process

More information

Measurement of Adjacent Channel Leakage Power on 3GPP W-CDMA Signals with the FSP

Measurement of Adjacent Channel Leakage Power on 3GPP W-CDMA Signals with the FSP Products: Spectrum Analyzer FSP Measurement of Adjacent Channel Leakage Power on 3GPP W-CDMA Signals with the FSP This application note explains the concept of Adjacent Channel Leakage Ratio (ACLR) measurement

More information

Engineering Sciences 151. Electromagnetic Communication Laboratory Assignment 3 Fall Term 1998-99

Engineering Sciences 151. Electromagnetic Communication Laboratory Assignment 3 Fall Term 1998-99 Engineering Sciences 151 Electromagnetic Communication Laboratory Assignment 3 Fall Term 1998-99 WAVE PROPAGATION II: HIGH FREQUENCY SLOTTED LINE AND REFLECTOMETER MEASUREMENTS OBJECTIVES: To build greater

More information

Lab 1: The Digital Oscilloscope

Lab 1: The Digital Oscilloscope PHYSICS 220 Physical Electronics Lab 1: The Digital Oscilloscope Object: To become familiar with the oscilloscope, a ubiquitous instrument for observing and measuring electronic signals. Apparatus: Tektronix

More information

Ultrasound Distance Measurement

Ultrasound Distance Measurement Final Project Report E3390 Electronic Circuits Design Lab Ultrasound Distance Measurement Yiting Feng Izel Niyage Asif Quyyum Submitted in partial fulfillment of the requirements for the Bachelor of Science

More information

FREQUENCY RESPONSE OF AN AUDIO AMPLIFIER

FREQUENCY RESPONSE OF AN AUDIO AMPLIFIER 2014 Amplifier - 1 FREQUENCY RESPONSE OF AN AUDIO AMPLIFIER The objectives of this experiment are: To understand the concept of HI-FI audio equipment To generate a frequency response curve for an audio

More information

Voltage. Oscillator. Voltage. Oscillator

Voltage. Oscillator. Voltage. Oscillator fpa 147 Week 6 Synthesis Basics In the early 1960s, inventors & entrepreneurs (Robert Moog, Don Buchla, Harold Bode, etc.) began assembling various modules into a single chassis, coupled with a user interface

More information

AC Measurements Using the Oscilloscope and Multimeter by Mr. David Fritz

AC Measurements Using the Oscilloscope and Multimeter by Mr. David Fritz AC Measurements Using the Oscilloscope and Multimeter by Mr. David Fritz 1 Sine wave with a DC offset f = frequency in Hz A = DC offset voltage (average voltage) B = Sine amplitude Vpp = 2B Vmax = A +

More information

Radio Interface Setup

Radio Interface Setup For getting started with Ham Radio Sound Card digital modes. Jeffrey Kopcak K8JTK Table of Contents Introduction... 3 Program versions... 3 Resources... 3 SignaLink... 3 Rigblaster... 3 Configuration...

More information

QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 956 24-BIT DIFFERENTIAL ADC WITH I2C LTC2485 DESCRIPTION

QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 956 24-BIT DIFFERENTIAL ADC WITH I2C LTC2485 DESCRIPTION LTC2485 DESCRIPTION Demonstration circuit 956 features the LTC2485, a 24-Bit high performance Σ analog-to-digital converter (ADC). The LTC2485 features 2ppm linearity, 0.5µV offset, and 600nV RMS noise.

More information

RFSPACE CLOUD-IQ #CONNECTED SOFTWARE DEFINED RADIO

RFSPACE CLOUD-IQ #CONNECTED SOFTWARE DEFINED RADIO CLOUD-IQ #CONNECTED SOFTWARE DEFINED RADIO 1 - SPECIFICATIONS Cloud-IQ INTRODUCTION The Cloud-IQ is a high performance, direct sampling software radio with an ethernet interface. It offers outstanding

More information

Amplitude Modulation Fundamentals

Amplitude Modulation Fundamentals 3 chapter Amplitude Modulation Fundamentals In the modulation process, the baseband voice, video, or digital signal modifies another, higher-frequency signal called the carrier, which is usually a sine

More information

Germanium Diode AM Radio

Germanium Diode AM Radio Germanium Diode AM Radio LAB 3 3.1 Introduction In this laboratory exercise you will build a germanium diode based AM (Medium Wave) radio. Earliest radios used simple diode detector circuits. The diodes

More information

Making Accurate Voltage Noise and Current Noise Measurements on Operational Amplifiers Down to 0.1Hz

Making Accurate Voltage Noise and Current Noise Measurements on Operational Amplifiers Down to 0.1Hz Author: Don LaFontaine Making Accurate Voltage Noise and Current Noise Measurements on Operational Amplifiers Down to 0.1Hz Abstract Making accurate voltage and current noise measurements on op amps in

More information

Lecture 1-6: Noise and Filters

Lecture 1-6: Noise and Filters Lecture 1-6: Noise and Filters Overview 1. Periodic and Aperiodic Signals Review: by periodic signals, we mean signals that have a waveform shape that repeats. The time taken for the waveform to repeat

More information

Manual for the sound card oscilloscope V1.24 C. Zeitnitz english translation by P. van Gemmeren and K. Grady

Manual for the sound card oscilloscope V1.24 C. Zeitnitz english translation by P. van Gemmeren and K. Grady Manual for the sound card oscilloscope V1.24 C. Zeitnitz english translation by P. van Gemmeren and K. Grady C. Zeitnitz 04/2008 This Software and all previous versions are NO Freeware! The use of the

More information

EE289 Lab Fall 2009. LAB 4. Ambient Noise Reduction. 1 Introduction. 2 Simulation in Matlab Simulink

EE289 Lab Fall 2009. LAB 4. Ambient Noise Reduction. 1 Introduction. 2 Simulation in Matlab Simulink EE289 Lab Fall 2009 LAB 4. Ambient Noise Reduction 1 Introduction Noise canceling devices reduce unwanted ambient noise (acoustic noise) by means of active noise control. Among these devices are noise-canceling

More information

1. (Ungraded) A noiseless 2-kHz channel is sampled every 5 ms. What is the maximum data rate?

1. (Ungraded) A noiseless 2-kHz channel is sampled every 5 ms. What is the maximum data rate? Homework 2 Solution Guidelines CSC 401, Fall, 2011 1. (Ungraded) A noiseless 2-kHz channel is sampled every 5 ms. What is the maximum data rate? 1. In this problem, the channel being sampled gives us the

More information

Introduction to FM-Stereo-RDS Modulation

Introduction to FM-Stereo-RDS Modulation Introduction to FM-Stereo-RDS Modulation Ge, Liang Tan, EK Kelly, Joe Verigy, China Verigy, Singapore Verigy US 1. Introduction Frequency modulation (FM) has a long history of its application and is widely

More information

Audio processing and ALC in the FT-897D

Audio processing and ALC in the FT-897D Audio processing and ALC in the FT-897D I recently bought an FT-897D, and after a period of operation noticed problems with what I perceived to be a low average level of output power and reports of muffled

More information

Massachusetts Institute of Technology Department of Electrical Engineering and Computer Science. 6.002 Electronic Circuits Spring 2007

Massachusetts Institute of Technology Department of Electrical Engineering and Computer Science. 6.002 Electronic Circuits Spring 2007 Massachusetts Institute of Technology Department of Electrical Engineering and Computer Science 6.002 Electronic Circuits Spring 2007 Lab 4: Audio Playback System Introduction In this lab, you will construct,

More information

Keysight Technologies 8 Hints for Better Spectrum Analysis. Application Note

Keysight Technologies 8 Hints for Better Spectrum Analysis. Application Note Keysight Technologies 8 Hints for Better Spectrum Analysis Application Note The Spectrum Analyzer The spectrum analyzer, like an oscilloscope, is a basic tool used for observing signals. Where the oscilloscope

More information

CIRCUITS AND SYSTEMS Circuits and Systems for Radiofrequency and Telecommunications Dente Del Corso

CIRCUITS AND SYSTEMS Circuits and Systems for Radiofrequency and Telecommunications Dente Del Corso CIRCUITS AND SYSTEMS FOR RADIOFREQUENCY AND TELECOMMUNICATIONS Dante Del Corso Politecnico di Torino, Torino, Italy. Keywords: Heterodyne, direct conversion, ZIF, image frequency, mixer, SDR, LNA, PA,

More information

Propagation Channel Emulator ECP_V3

Propagation Channel Emulator ECP_V3 Navigation simulators Propagation Channel Emulator ECP_V3 1 Product Description The ECP (Propagation Channel Emulator V3) synthesizes the principal phenomena of propagation occurring on RF signal links

More information

Analog Filters. A common instrumentation filter application is the attenuation of high frequencies to avoid frequency aliasing in the sampled data.

Analog Filters. A common instrumentation filter application is the attenuation of high frequencies to avoid frequency aliasing in the sampled data. Analog Filters Filters can be used to attenuate unwanted signals such as interference or noise or to isolate desired signals from unwanted. They use the frequency response of a measuring system to alter

More information

THE IMPLEMENTATION OF A DTV RF ANALYSIS AND REGENERATION SYSTEM

THE IMPLEMENTATION OF A DTV RF ANALYSIS AND REGENERATION SYSTEM THE IMPLEMENTATION OF A DTV RF ANALYSIS AND REGENERATION SYSTEM Tae-Hoon Kwon, Ha-Kyun Mok, Young-Woo Suh, and Young-Min Kim KBS(Korean Broadcasting System), Seoul, Korea ABSTRACT In this paper, we developed

More information

Digital Guitar Effects Pedal

Digital Guitar Effects Pedal Digital Guitar Effects Pedal 01001000100000110000001000001100 010010001000 Jonathan Fong John Shefchik Advisor: Dr. Brian Nutter SPRP499 Texas Tech University jonathan.fong@ttu.edu Presentation Outline

More information

QAM Demodulation. Performance Conclusion. o o o o o. (Nyquist shaping, Clock & Carrier Recovery, AGC, Adaptive Equaliser) o o. Wireless Communications

QAM Demodulation. Performance Conclusion. o o o o o. (Nyquist shaping, Clock & Carrier Recovery, AGC, Adaptive Equaliser) o o. Wireless Communications 0 QAM Demodulation o o o o o Application area What is QAM? What are QAM Demodulation Functions? General block diagram of QAM demodulator Explanation of the main function (Nyquist shaping, Clock & Carrier

More information

DSPDemo. By Moe Wheatley MoeTronix.

DSPDemo. By Moe Wheatley MoeTronix. DSPDemo By Moe Wheatley MoeTronix www.moetronix.com Sept. 10, 2004 Table of Contents 1 Introduction... 3 1.1 The Idea... 3 1.2 Hardware... 3 1.2.1 Block Diagram... 3 1.3 Software... 4 1.3.1 Basic Modules...

More information

Signal Processing in So.ware and Electric Field Sensing

Signal Processing in So.ware and Electric Field Sensing Signal Processing in So.ware and Electric Field Sensing CSE 466: So.ware for Embedded Systems Winter 2009 B. Mayton University of Washington CSE & Intel Research SeaMle CSE

More information

EECC694 - Shaaban. Transmission Channel

EECC694 - Shaaban. Transmission Channel The Physical Layer: Data Transmission Basics Encode data as energy at the data (information) source and transmit the encoded energy using transmitter hardware: Possible Energy Forms: Electrical, light,

More information

Digital Modulation. David Tipper. Department of Information Science and Telecommunications University of Pittsburgh. Typical Communication System

Digital Modulation. David Tipper. Department of Information Science and Telecommunications University of Pittsburgh. Typical Communication System Digital Modulation David Tipper Associate Professor Department of Information Science and Telecommunications University of Pittsburgh http://www.tele.pitt.edu/tipper.html Typical Communication System Source

More information

Hideo Okawara s Mixed Signal Lecture Series. DSP-Based Testing Fundamentals 46 Per-pin Signal Generator

Hideo Okawara s Mixed Signal Lecture Series. DSP-Based Testing Fundamentals 46 Per-pin Signal Generator Hideo Okawara s Mixed Signal Lecture Series DSP-Based Testing Fundamentals 46 Per-pin Signal Generator Advantest Corporation, Tokyo Japan August 2012 Preface to the Series ADC and DAC are the most typical

More information

Transistor Amplifiers

Transistor Amplifiers Physics 3330 Experiment #7 Fall 1999 Transistor Amplifiers Purpose The aim of this experiment is to develop a bipolar transistor amplifier with a voltage gain of minus 25. The amplifier must accept input

More information

Clock Recovery in Serial-Data Systems Ransom Stephens, Ph.D.

Clock Recovery in Serial-Data Systems Ransom Stephens, Ph.D. Clock Recovery in Serial-Data Systems Ransom Stephens, Ph.D. Abstract: The definition of a bit period, or unit interval, is much more complicated than it looks. If it were just the reciprocal of the data

More information

Vector Signal Analyzer FSQ-K70

Vector Signal Analyzer FSQ-K70 Product brochure Version 02.00 Vector Signal Analyzer FSQ-K70 July 2004 Universal demodulation, analysis and documentation of digital radio signals For all major mobile radio communication standards: GSM

More information

The Effective Number of Bits (ENOB) of my R&S Digital Oscilloscope Technical Paper

The Effective Number of Bits (ENOB) of my R&S Digital Oscilloscope Technical Paper The Effective Number of Bits (ENOB) of my R&S Digital Oscilloscope Technical Paper Products: R&S RTO1012 R&S RTO1014 R&S RTO1022 R&S RTO1024 This technical paper provides an introduction to the signal

More information

Bipolar Transistor Amplifiers

Bipolar Transistor Amplifiers Physics 3330 Experiment #7 Fall 2005 Bipolar Transistor Amplifiers Purpose The aim of this experiment is to construct a bipolar transistor amplifier with a voltage gain of minus 25. The amplifier must

More information

RADIO FREQUENCY INTERFERENCE AND CAPACITY REDUCTION IN DSL

RADIO FREQUENCY INTERFERENCE AND CAPACITY REDUCTION IN DSL RADIO FREQUENCY INTERFERENCE AND CAPACITY REDUCTION IN DSL Padmabala Venugopal, Michael J. Carter*, Scott A. Valcourt, InterOperability Laboratory, Technology Drive Suite, University of New Hampshire,

More information

ANALYZER BASICS WHAT IS AN FFT SPECTRUM ANALYZER? 2-1

ANALYZER BASICS WHAT IS AN FFT SPECTRUM ANALYZER? 2-1 WHAT IS AN FFT SPECTRUM ANALYZER? ANALYZER BASICS The SR760 FFT Spectrum Analyzer takes a time varying input signal, like you would see on an oscilloscope trace, and computes its frequency spectrum. Fourier's

More information

AN1200.04. Application Note: FCC Regulations for ISM Band Devices: 902-928 MHz. FCC Regulations for ISM Band Devices: 902-928 MHz

AN1200.04. Application Note: FCC Regulations for ISM Band Devices: 902-928 MHz. FCC Regulations for ISM Band Devices: 902-928 MHz AN1200.04 Application Note: FCC Regulations for ISM Band Devices: Copyright Semtech 2006 1 of 15 www.semtech.com 1 Table of Contents 1 Table of Contents...2 1.1 Index of Figures...2 1.2 Index of Tables...2

More information

Appendix C GSM System and Modulation Description

Appendix C GSM System and Modulation Description C1 Appendix C GSM System and Modulation Description C1. Parameters included in the modelling In the modelling the number of mobiles and their positioning with respect to the wired device needs to be taken

More information

Lab 1. The Fourier Transform

Lab 1. The Fourier Transform Lab 1. The Fourier Transform Introduction In the Communication Labs you will be given the opportunity to apply the theory learned in Communication Systems. Since this is your first time to work in the

More information

Lab 4 - Data Acquisition

Lab 4 - Data Acquisition Spring 11 Lab 4 - Data Acquisition Lab 4-1 Lab 4 - Data Acquisition Format This lab will be conducted during your regularly scheduled lab time in a group format. Each student is responsible for learning

More information

SR2000 FREQUENCY MONITOR

SR2000 FREQUENCY MONITOR SR2000 FREQUENCY MONITOR THE FFT SEARCH FUNCTION IN DETAILS FFT Search is a signal search using FFT (Fast Fourier Transform) technology. The FFT search function first appeared with the SR2000 Frequency

More information

Maximizing Receiver Dynamic Range for Spectrum Monitoring

Maximizing Receiver Dynamic Range for Spectrum Monitoring Home Maximizing Receiver Dynamic Range for Spectrum Monitoring Brian Avenell, National Instruments Corp., Austin, TX October 15, 2012 As consumers continue to demand more data wirelessly through mobile

More information

LAB 12: ACTIVE FILTERS

LAB 12: ACTIVE FILTERS A. INTRODUCTION LAB 12: ACTIVE FILTERS After last week s encounter with op- amps we will use them to build active filters. B. ABOUT FILTERS An electric filter is a frequency-selecting circuit designed

More information

Radio Transmission Performance of EPCglobal Gen-2 RFID System

Radio Transmission Performance of EPCglobal Gen-2 RFID System Radio Transmission Performance of EPCglobal Gen-2 RFID System Manar Mohaisen, HeeSeok Yoon, and KyungHi Chang The Graduate School of Information Technology & Telecommunications INHA University Incheon,

More information

Introduction to IQ-demodulation of RF-data

Introduction to IQ-demodulation of RF-data Introduction to IQ-demodulation of RF-data by Johan Kirkhorn, IFBT, NTNU September 15, 1999 Table of Contents 1 INTRODUCTION...3 1.1 Abstract...3 1.2 Definitions/Abbreviations/Nomenclature...3 1.3 Referenced

More information

Objectives. Lecture 4. How do computers communicate? How do computers communicate? Local asynchronous communication. How do computers communicate?

Objectives. Lecture 4. How do computers communicate? How do computers communicate? Local asynchronous communication. How do computers communicate? Lecture 4 Continuation of transmission basics Chapter 3, pages 75-96 Dave Novak School of Business University of Vermont Objectives Line coding Modulation AM, FM, Phase Shift Multiplexing FDM, TDM, WDM

More information

INTRODUCTION TO COMMUNICATION SYSTEMS AND TRANSMISSION MEDIA

INTRODUCTION TO COMMUNICATION SYSTEMS AND TRANSMISSION MEDIA COMM.ENG INTRODUCTION TO COMMUNICATION SYSTEMS AND TRANSMISSION MEDIA 9/6/2014 LECTURES 1 Objectives To give a background on Communication system components and channels (media) A distinction between analogue

More information

Lock-in amplifiers. A short tutorial by R. Scholten

Lock-in amplifiers. A short tutorial by R. Scholten Lock-in amplifiers A short tutorial by R. cholten Measuring something Common task: measure light intensity, e.g. absorption spectrum Need very low intensity to reduce broadening Noise becomes a problem

More information

Experiment #11: LRC Circuit (Power Amplifier, Voltage Sensor)

Experiment #11: LRC Circuit (Power Amplifier, Voltage Sensor) Experiment #11: LRC Circuit (Power Amplifier, Voltage Sensor) Concept: circuits Time: 30 m SW Interface: 750 Windows file: RLC.SWS EQUIPMENT NEEDED Science Workshop Interface Power Amplifier (2) Voltage

More information

PIEZO FILTERS INTRODUCTION

PIEZO FILTERS INTRODUCTION For more than two decades, ceramic filter technology has been instrumental in the proliferation of solid state electronics. A view of the future reveals that even greater expectations will be placed on

More information

Loop Bandwidth and Clock Data Recovery (CDR) in Oscilloscope Measurements. Application Note 1304-6

Loop Bandwidth and Clock Data Recovery (CDR) in Oscilloscope Measurements. Application Note 1304-6 Loop Bandwidth and Clock Data Recovery (CDR) in Oscilloscope Measurements Application Note 1304-6 Abstract Time domain measurements are only as accurate as the trigger signal used to acquire them. Often

More information