EE5713 : Advanced Digital Communications
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Shahabi-Adib-Masc-ECE-August
A New Line Code for a Digital Communication System by Adib Shahabi Submitted in partial fulfilment of the requirements for the degree of Master of Applied Science at Dalhousie University Halifax, Nova Scotia August 2019 © Copyright by Adib Shahabi, 2019 To my wife Shahideh ii TABLE OF CONTENTS LIST OF TABLES ............................................................................................................ v LIST OF FIGURES .......................................................................................................... vi ABSTRACT ....................................................................................................................viii LIST OF ABBREVIATIONS USED ............................................................................... ix ACKNOWLEDGEMENTS ............................................................................................... x CHAPTER 1 INTRODUCTION ....................................................................................... 1 1.1 BACKGROUND ........................................................................................... 1 1.2 THESIS SYNOPSIS ...................................................................................... 4 1.3 ORGANIZATION OF THE THESIS ............................................................ 5 CHAPTER 2 MODELLING THE LINE CHANNEL ....................................................... 7 2.1 CABLE MODELLING .................................................................................. 7 2.2 TRANSFORMER COUPLING .................................................................. -
A Guide to Making RF Measurements for Signal Integrity Applications
White Paper A Guide to Making RF Measurements for Signal Integrity Applications Introduction Designing a system for Signal Integrity requires a great deal of knowledge and tremendous effort from all disciplines involved. Higher data rates and more complex modulation schemes are requiring digital engineers to take into account the analog and RF performance of the channels to a much greater degree than in the past. Moreover, increasing performance demands are requiring digital engineers move from oscilloscopes and TDRs to vector network analyzers (VNAs), with which they may be less familiar. Correspondingly, RF measurement groups within companies are being called on by their digital colleagues to help them with making VNA measurements. This paper is intended to review signal integrity-based VNA measurements for digital engineers and correlate VNA measurements to key signal integrity parameters for RF engineers. Contents The Driving Need for RF Measurements ...........................................................................................................3 Understanding Signal Integrity Terms and Measurements ...........................................................................4 Eye Diagrams .................................................................................................................................................4 Dispersion .......................................................................................................................................................4 High Frequency Loss /Attenuation -
Revision of Wireless Channel
ELEC6214 Advanced Wireless Communications Networks and Systems S Chen Revision of Wireless Channel • Quick recap system block diagram Wireless CODEC MODEM Channel • Previous three lectures looked into wireless mobile channels – To understand mobile communication technologies, one needs a deep understand of mobile communication media – Two main sources of hostility in mobile media are Doppler spread and multipath – Many techniques developed are counter measures for fading and frequency selective – How spatial/angular dimension fits into wireless mobile landscape • Front end of transceiver is Modem, which faces hostile (fading and frequency selective) communication media – Next eight lectures we will have a close look into Modem 57 ELEC6214 Advanced Wireless Communications Networks and Systems S Chen Digital Modulation Overview In Digital Coding and Transmission, we learn schematic of MODEM (modulation and demodulation) • with its basic components: clock carrier pulse b(k) x(k) x(t) s(t) pulse Tx filter bits to modulat. symbols generator GT (f) clock carrier channel recovery recovery GC (f) ^ b(k) x(k)^x(t) ^s(t) ^ symbols sampler/ Rx filter AWGN demodul. + to bits decision GR (f) n(t) The purpose of MODEM: transfer the bit stream at required rate over the communication medium • reliably – Given system bandwidth and power resource 58 ELEC6214 Advanced Wireless Communications Networks and Systems S Chen Constellation Diagram • Digital modulation signal has finite states. This manifests in symbol (message) set: M = {m1, m2, ··· , mM }, where each symbol contains log2 M bits • Or in modulation signal set: S = {s1(t),s2(t), ··· sM (t)}. There is one-to-one relationship between two sets: modulation scheme M S ←→ Q • Example: BPSK, M = 2. -
Design and Performance Evaluation of QPSK Modulation And
International Conference on Applied Science and Engineering Innovation (ASEI 2015) Design and Performance Evaluation of QPSK Modulation and Demodulation in SS mode Based on Systemview Sheng LIANGa, Gaofeng PANb, Youxing WU, Yong XIEc China Satellite Maritime Tracking and Control Department, Jiangyin, Jiangsu, 214431,China a [email protected], b [email protected], c [email protected] Keywords: SS; QPSK; Eye Diagram. Abstract. Because the modulation and demodulation method in SS (Spread Spectrum) mode is different with sub-carrier TT&C system, so it is necessary to realize its performance evaluation based on software simulation. This paper makes use of Systemview to simulate the single target measurement in SS system and evaluate its anti-noise performance by eye diagram and BER. Results show the simulation model designed in this paper is feasible and Systemview can visualize abstract communication simulation. Introduction The present SS TT&C system has two kinds, which are coherent and non-coherent SS modes. In coherent mode, telecommand message is embedded in branch I of QPSK modulation after encoded with short PN code (period 210-1), distance measure message is embedded in branch Q after encoded with long PN code (period (210-1)×256) and the two branch signals with different powers compose UQPSK signal. In non-coherent mode, two branch messages encoded with short PN code are BPSK modulated respectively, which will be transmitted to the satellite after up-conversion and power amplification. This paper sets conditions to unitize the two modes and designs the modulation & demodulation simulation model based on Systemview to evaluate performance of SS mode. -
Pulse Shape Filtering in Wireless Communication-A Critical Analysis
(IJACSA) International Journal of Advanced Computer Science and Applications, Vol. 2, No.3, March 2011 Pulse Shape Filtering in Wireless Communication-A Critical Analysis A. S Kang Vishal Sharma Assistant Professor, Deptt of Electronics and Assistant Professor, Deptt of Electronics and Communication Engg Communication Engg SSG Panjab University Regional Centre University Institute of Engineering and Technology Hoshiarpur, Punjab, INDIA Panjab University Chandigarh - 160014, INDIA [email protected] [email protected] Abstract—The goal for the Third Generation (3G) of mobile networks. The standard that has emerged is based on ETSI's communications system is to seamlessly integrate a wide variety Universal Mobile Telecommunication System (UMTS) and is of communication services. The rapidly increasing popularity of commonly known as UMTS Terrestrial Radio Access (UTRA) mobile radio services has created a series of technological [1]. The access scheme for UTRA is Direct Sequence Code challenges. One of this is the need for power and spectrally Division Multiple Access (DSCDMA). The information is efficient modulation schemes to meet the spectral requirements of spread over a band of approximately 5 MHz. This wide mobile communications. Pulse shaping plays a crucial role in bandwidth has given rise to the name Wideband CDMA or spectral shaping in the modern wireless communication to reduce WCDMA.[8-9] the spectral bandwidth. Pulse shaping is a spectral processing technique by which fractional out of band power is reduced for The future mobile systems should support multimedia low cost, reliable , power and spectrally efficient mobile radio services. WCDMA systems have higher capacity, better communication systems. It is clear that the pulse shaping filter properties for combating multipath fading, and greater not only reduces inter-symbol interference (ISI), but it also flexibility in providing multimedia services with defferent reduces adjacent channel interference. -
Digital Baseband Modulation Outline • Later Baseband & Bandpass Waveforms Baseband & Bandpass Waveforms, Modulation
Digital Baseband Modulation Outline • Later Baseband & Bandpass Waveforms Baseband & Bandpass Waveforms, Modulation A Communication System Dig. Baseband Modulators (Line Coders) • Sequence of bits are modulated into waveforms before transmission • à Digital transmission system consists of: • The modulator is based on: • The symbol mapper takes bits and converts them into symbols an) – this is done based on a given table • Pulse Shaping Filter generates the Gaussian pulse or waveform ready to be transmitted (Baseband signal) Waveform; Sampled at T Pulse Amplitude Modulation (PAM) Example: Binary PAM Example: Quaternary PAN PAM Randomness • Since the amplitude level is uniquely determined by k bits of random data it represents, the pulse amplitude during the nth symbol interval (an) is a discrete random variable • s(t) is a random process because pulse amplitudes {an} are discrete random variables assuming values from the set AM • The bit period Tb is the time required to send a single data bit • Rb = 1/ Tb is the equivalent bit rate of the system PAM T= Symbol period D= Symbol or pulse rate Example • Amplitude pulse modulation • If binary signaling & pulse rate is 9600 find bit rate • If quaternary signaling & pulse rate is 9600 find bit rate Example • Amplitude pulse modulation • If binary signaling & pulse rate is 9600 find bit rate M=2à k=1à bite rate Rb=1/Tb=k.D = 9600 • If quaternary signaling & pulse rate is 9600 find bit rate M=2à k=1à bite rate Rb=1/Tb=k.D = 9600 Binary Line Coding Techniques • Line coding - Mapping of binary information sequence into the digital signal that enters the baseband channel • Symbol mapping – Unipolar - Binary 1 is represented by +A volts pulse and binary 0 by no pulse during a bit period – Polar - Binary 1 is represented by +A volts pulse and binary 0 by –A volts pulse. -
ECE 463 Lab 3: Pulse Shaping and Matched Filtering
UIUC ECE 463 Digital Communication Laboratory Fall 2018 ECE 463 Lab 3: Pulse Shaping and Matched Filtering 1. Introduction The objective of this lab session is to introduce the basic concepts of pulse shaping, matched filter and pulse alignment. In digital communication, the message in digital must be converted into an analog signal to be transmitted. This conversion is done by the pulse shaping filter, which changes each symbol into a suitable analog pulse. Designing the pulse shape is important because the spectrum of the pulse dictates the spectrum of the whole transmission. However, to confine the spectrum, we have to smooth the pulse with slow transition. This requires the pulse extending beyond a symbol time, which introduces inter- symbol interference (ISI). Thus, there is a trade-off between the bandwidth and the ISI of the pulse shape. After transmission, the matched filter helps to recapture the symbols from the received pulses. The matched filter is aimed at reducing the sensitivity of noise by maximizing the signal-to-noise ratio (SNR) and minimizing the ISI at the receiver. In a more realistic channel model, the receiver never knows the precise arrival time of the pulse. Therefore, the receiver must know the exact symbol timing in order to correctly demodulate the transmitted symbols from the transmitter. 1.1. Contents 1. Introduction 2. Pulse Shaping 3. Matched Filtering 4. Pulse Alignment (Symbol Timing Recovery) 1.2. Report Submit the answers, figures and the discussions on all the questions. The report is due as a hard copy at the beginning of the next lab. -
AN-808 Long Transmission Lines and Data Signal Quality
Application Report SNLA028–May 2004 AN-808 Long Transmission Lines and Data Signal Quality ..................................................................................................................................................... ABSTRACT This application note explores another important transmission line characteristic, the reflection coefficient. This concept is combined with the material in AN-806 to present graphical and analytical methods for determining the voltages and currents at any point on a line with respect to distance and time. The effects of various source resistances and line termination methods on the transmitted signal are also discussed. This application note is a revised reprint of section four of the Fairchild Line Driver and Receiver Handbook. This application note, the third of a three part series (See AN-806 and AN-807), covers the following topics: Contents 1 Overview ..................................................................................................................... 3 2 Introduction .................................................................................................................. 3 3 Factors Causing Signal Wave Shape Changes ......................................................................... 4 4 Influence of Loss Effects on Primary Line Parameters ................................................................ 5 5 Variations in Z0, α(ω), and Propagation Velocity ........................................................................ 6 6 Signal Quality—Terms .................................................................................................... -
Creating Eye Diagrams Using Vectorstar Snp Files and AWR
Application Note Creating Eye Diagrams using VectorStar™ SnP files and AWR Microwave Office® MS4640B Series Vector Network Analyzer 1 Introduction As data rates and design complexity continues to increase, signal integrity becomes an integral part of the design and verification process. At first glance, one might assume that because digital signals are represented by discrete voltage (or current) levels, signal integrity may not be of major concern to digital designers. However, digital signals are fundamentally analog in nature, and all signals are subject to effects such as noise, distortion, and loss. Over short distances and at low bit rates, a simple conductor can transmit digital signals reliably without much distortion, but at high bit rates and over longer distances or through various media, various effects can degrade the electrical signal to the point where errors occur and the system or device fails. Today, it is common to see devices and systems operating at multi-GHz data rates. Digital signals being transmitted over relatively long transmission lines or through differing materials also present signal integrity challenges. Because of these challenges, a host of variables can affect the integrity of signals, including transmission-line effects, impedance mismatches, signal routing, termination schemes, and grounding schemes. One tool used to characterize these effects is the eye diagram. With eye diagrams, engineers can quickly evaluate system performance and gain insight into the nature of channel imperfections that can lead to errors when a receiver tries to interpret the value of a transmitted data bit. This application note reviews basic eye diagram definitions and terminologies. It will include a measurement example showing how to import a S-Paramater File of a device measured by an Anritsu VectorStar VNA into AWR’s Microwave Office application to generate an Eye Diagram. -
Enabling Precision EYE Pattern Analysis Extinction Ratio, Jitter, Mask Margin
Technical Note Enabling Precision EYE Pattern Analysis Extinction Ratio, Jitter, Mask Margin MP2100A Series BERTWave Contents 1 Introduction ..................................................................................................................................................... 2 2 EYE Pattern Fundamentals............................................................................................................................. 3 2.1 Analyzing EYE Pattern.................................................................................................................................... 3 2.2 Amplitude Definitions for Vertical Eye Patterns ............................................................................................... 4 2.3 Time Definitions for Horizontal EYE Pattern.................................................................................................... 4 3. Main Measurement Items for EYE Pattern Analysis........................................................................................ 5 3.1 Extinction Ratio ............................................................................................................................................... 5 3.2 Jitter (RMS, Peak-to-Peak) ............................................................................................................................. 5 3.3 Compliance Mask Test .................................................................................................................................... 6 3.4 Mask Margin Test ........................................................................................................................................... -
Root Raised Cosine (RRC) Filters and Pulse Shaping in Communication Systems
Root Raised Cosine (RRC) Filters and Pulse Shaping in Communication Systems Erkin Cubukcu Abstract This presentation briefly discusses application of the Root Raised Cosine (RRC) pulse shaping in the space telecommunication. Use of the RRC filtering (i.e., pulse shaping) is adopted in commercial communications, such as cellular technology, and used extensively. However, its use in space communication is still relatively new. This will possibly change as the crowding of the frequency spectrum used in the space communication becomes a problem. The two conflicting requirements in telecommunication are the demand for high data rates per channel (or user) and need for more channels, i.e., more users. Theoretically as the channel bandwidth is increased to provide higher data rates the number of channels allocated in a fixed spectrum must be reduced. Tackling these two conflicting requirements at the same time led to the development of the RRC filters. More channels with wider bandwidth might be tightly packed in the frequency spectrum achieving the desired goals. A link model with the RRC filters has been developed and simulated. Using 90% power Bandwidth (BW) measurement definition showed that the RRC filtering might improve spectrum efficiency by more than 75%. Furthermore using the matching RRC filters both in the transmitter and receiver provides the improved Bit Error Rate (BER) performance. In this presentation the theory of three related concepts, namely pulse shaping, Inter Symbol Interference (ISI), and Bandwidth (BW) will be touched -
Digital Phase Modulation: a Review of Basic Concepts
Digital Phase Modulation: A Review of Basic Concepts James E. Gilley Chief Scientist Transcrypt International, Inc. [email protected] August , Introduction The fundamental concept of digital communication is to move digital information from one point to another over an analog channel. More specifically, passband dig- ital communication involves modulating the amplitude, phase or frequency of an analog carrier signal with a baseband information-bearing signal. By definition, fre- quency is the time derivative of phase; therefore, we may generalize phase modula- tion to include frequency modulation. Ordinarily, the carrier frequency is much greater than the symbol rate of the modulation, though this is not always so. In many digital communications systems, the analog carrier is at a radio frequency (RF), hundreds or thousands of MHz, with information symbol rates of many megabaud. In other systems, the carrier may be at an audio frequency, with symbol rates of a few hundred to a few thousand baud. Although this paper primarily relies on examples from the latter case, the concepts are applicable to the former case as well. Given a sinusoidal carrier with frequency: fc , we may express a digitally-modulated passband signal, S(t), as: S(t) A(t)cos(2πf t θ(t)), () = c + where A(t) is a time-varying amplitude modulation and θ(t) is a time-varying phase modulation. For digital phase modulation, we only modulate the phase of the car- rier, θ(t), leaving the amplitude, A(t), constant. BPSK We will begin our discussion of digital phase modulation with a review of the fun- damentals of binary phase shift keying (BPSK), the simplest form of digital phase modulation.