An Interactive Multimedia Introduction to Signal Processing
Springer-Verlag Berlin Heidelberg GmbH
U. Karrenberg An Interactive Multimedia Introduction to Signal Processing With 240 Figures Springer
Dipl.-Ing. Ulrich Karrenberg Mintarder Weg 90 40472 Düsseldorf Germany E-mail: ulrich.karrenberg@ t-online.de Additional material to this book can be downloaded from http:/lextra.springer.com. ISBN 978-3-540-43509-9 CIP data applied for Die Deutsche Bibliothek- CIP-Einheitsaufnahme Karrenberg, Ulrich: An interactive multimedia introduction to signal processing I Ulrich Karrenberg. ISBN 978-3-540-43509-9 ISBN 978-3-662-04949-5 (ebook) DOI 10.1007/978-3-662-04949-5 This work is subject to Copyright. All rights are reserved, whether the whole or part ofthe material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilm or in other ways, and storage in data banks. Duplication of this publication or parts thereof is permitted only under the provisions of the German Copyright Law of September 9, 1965, in its current version, and pennission for use must always be obtained from Springer-V erlag. Violations are liable for prosecution act under German Copyright Law. http://www.springer.de Springer-Verlag Berlin Heidelberg 2002 Originally published by Springer-Verlag Berlin Heidelberg New York in 2002 DASYLab isatrademarkofnationalinstrumentsservicesgmbh&co.kg Copyright 1993-2002 by National Instruments Services GmbH. All rights reserved. National Instruments Services GmbH & Co. KG, Postfach 401264, D-41182 Mönchengladbach, Germany The use of general descriptive names, registered names, trademarks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant proteelive laws and regulations and therefore free for general use. Multiple licenses for schools, university faculties, and institutions of further and higher education of industry and the public authorities can be acquired via the author. The author acts in the name and on behalf of National Instruments Services with regard to the DASYLab S pro gram. Typesetting: Dataconversion by author Cover-design: design & production, Heidelberg Printedon acid-free paper SPIN: 10876144 62 I 3020 hu -54 3 2 1 0-
This book is dedicated to Claude E. Shannon, a pioneer of modern communications technology. He died on 25 February 2001. Only few people know in depth the fundamental content of his 55-page book "Mathematical Theory of Communication" published in 1948. This, however, does not diminish his genius and the uniqueness of his findings. They have changed the world more than any other discovery because communication is now the keyword in our society and in life itself. His work will be accomplished once his theory has been integrated into modern physics thus leading to a greater understanding ofthe central principles ofnature. This is a... -".-& task which has not yet been fulfilled. Jf you want to build a ship, don 't round up people to proeure wood, don't allocate the different tasks andjobs, but arouse their longingfor the open sea which stretches to infinity! (Antoine de Saint-Exupery) The success of language in conveying information ist vastly overrated, especially in learned circles. Not only is language highly elleptical, but also nothing can supply the defect of first-hand experience of types cognate to the things explicitly mentioned.... First-hand knowledge is the ultimate basis of intellectuallife.... The second-handedness of learned world is the secret of its mediocrity. It is tarne because it never has been scared by facts. (Alfred North Whitehead) People ought to be ashamed who take the miracles of science and technology for granted without understanding more about them than a cow does about the botanical principles behind the plants it happily munches. (Albert Einstein at the Berlin Funkausstellung- telecommunications exhibition-in 1930) Realproblems ignore the fact that education has been arbitrarily divided into different school subjects. (the author) The purpose of computing is insight, not numbers I (R. W Hamming) Information and uncertainty find themselves to be partners. (Warren Weaver)
Table of contents Table of contents Introduction... 1 A science that people can understand... 1 Target groups.......................................................................................................... 2 Graphie programming............................................................................................ 3 The electronic document........................................................................................ 4 The Camtasia video player............................................................................... 10 Chapter 1 The concept: methods - content - objectives... 11 Everything und er one roof... 12 Hardware: Systems on a chip... 12 The software is the instrument............................................................................. 13 A case for up-to-date education... 14 On the unity of theory and practice...................................................................... 14 Multimedia and interactive leaming... 14 Science and Mathematics..................................................................................... 15 In search of other "tools"... 17 Physics as the point of departure.......................................................................... 22 Clarification of Objectives... 24 Preliminary conclusions: the concept takes on clearer contours... 28 Exercises on Chapter 1 :....................................................................................... 30 Chapter 2 Signals in the time and frequency domain... 33 The FOURIER Principle... 33 Periodic oscillations... 34 Our ear as a FOURIER-analyzer... 35 FOURIER-Transformation: from the time domain to the frequency domain and back... 42 Important periodic oscillations/signals................................................. 4 7 Comparison of signals in the time and frequency domain................................... 48 The confusing phase spectrum............................................................................. 50 Interference: nothing to be seen although everything is there... 50 Opposites which have a great deal in common: sine and d-pulse... 52 Non-periodie and one-off signals... 56 Pure randomness: stochastic noise... 57 Noise and information... 58 Exercises for Chapter 2:....................................................................................... 61 Chapter 3 The U ncertainty Principle... 65 A strange relationship between frequency and time and its practical consequences..................................................................... 65 Sinusoidal signal and d-pulse as a limiting case of the Uncertainty Principle..... 69 Why ideal filters cannot exist........................................................................... 70 Frequency measurements in the case ofnon-periodic signals... 74 Near-periodic signals... 80
Table of contents Tones, sounds and music... 81 Exercises on Chapter 3......................................................................................... 86 Chapter 4 Language as a carrier of information... 89 How speech, tones and sounds are generated and perceived............................... 97 Case study: a simple system for voice recognition............................................. 105 Refinement and optimisation phase... 110 Pattern recognition...... 113 Exercises on Chapter 4....................................................................................... 115 Chapter 5 The Symmetry Principle... 11 7 For reasons of symmetry: negative frequencies... 117 Proof of the physical existence of negative frequencies...... 117 Periodic spectra... 125 Inverse FOURIERtransformation and GAUSSian plane... 128 Exercises on Chapter 5....................................................................................... 140 Chapter 6 System analysis... 141 Sweep... 143 Modem test signals.............................................................................. 148 The d-pulse......................................................................................................... 149 The step function... 153 The GAUSSian pulse... 159 The GAUSSian oscihation pulse... 160 The Burst signal... 161 The Si-function and the Si-oscillation pulse... 162 Noise... 164 Transients in systems.......................................................................................... 168 Exercises on Chapter 6....................................................................................... 173 Chapter 7 Linear and non-linear processes... 17 5 Systemanalysis and system synthesis... 175 Measuring a process to reveal whether it is linear or non-linear... 175 Line and space.................................................................................................... 1 7 6 Inter-disciplinary significance... 176 Mirroring and projection... 177 A complex component: the transistor................................................................. 179 There are only few linear processes... 179 Multiplication of a si gnal by a constant................................................... 180 Addition of two or more signals......................................................................... 181 Delay... 181 Differentiation.................................................................................................... 183 Integration... 190 Malicious functions or signal curves.................................................................. 197 Filters... 199 Non-linear processes... 204
Table of contents Multiplication of two signals.............................................................................. 205 Formation ofthe absolute value... 209 Quantization....................................................................................................... 211 Windowing................................................................................................ 214 Exercises on Chapter 7....................................................................................... 215 Chapter 8 Classical modulation procedures... 217 Transmission media.......................................................................................... 217 Modulation with sinusoidal carriers................................................................... 21 7 Modulation and demodulation in the traditional sense... 218 Amplitude modulation and demodulation AM... 219 Wasting energy: double sideband AM with carrier.... 226 Single sideband modulation without a carrier... 227 Frequency multiplex... 235 Mixing... 238 Frequency modulation FM................................................................................. 240 Demodulation offm-signals... 250 The phase locked loop PLL................................................................................ 250 Phase modulation... 256 Immunity to interference of modulation processes... 258 Practical information theory....................................................................... 261 Exercises on Chapter 8....................................................................................... 262 Chapter 9 Digitalisation... 265 Digital technology does not always mean the same thing... 265 Digital processing of analog signals................................................................... 265 The gateway to the digital world: the A/D converter.................................... 267 Principle of a D/ A converter........................................................................... 269 Analog pulse modulation processes... 272 DASYLab and digital signal processing... 274 Digitalsignals in the time and frequency domain... 276 The period length of digital signals............................................................ 277 The periodic spectrum of digital signals....................................................... 286 The Sampling Principle... 288 Retrieval ofthe analog signal... 293 Non-synchronicity... 295 Signal distortion as a result of signal windowing... 298 Check Iist...................................................................................................... 299 Exercises on Chapter 9... 301 Chapter 10 Digital filters... 3 03 Hardware versus software.................................................................................. 303 How analog filters work... 303 FFT filters....................................................................................... 306 Digital filtering in the time domain................................................. 311 Convolution................................................ 315 Case study: Design and application of digital filters................................ 317
Table of contents A voiding ripple content in the conducting state region... 322 Exercises on Chapter l 0... 327 Chapter 11 Digitaltransmission technology 1: source encoding... 329 Encoding and decoding of digital signals and data... 331 Compression... 331 Low-loss and lossy compression... 333 RLE encoding... 334 Huffman encoding... 334 LZW encoding... 335 Source encoding of audio signals... 338 Delta encoding or delta modulation... 338 Sigma-deltamodulation or encoding (S-D-M)... 343 Noise shaping and decimation filter... 345 Exploiting psycho-acoustic effects (MPEG)... 345 Encoding and physics... 352 Exercises on Chapter 11... 353 Chapter 12 Digital transmission technology II: channel encoding... 355 Error protection encoding for the reduction ofbit error probability... 355 Distance... 356 Hamming codes and Hamming distance... 358 Convolutional encoding... 360 Viterbi decoding... 364 Hard and soft decision........................................................................................ 366 Channel capacity... 368 Exercises on Chapter 12... 370 Chapter 13 Digital Transmission Techniques 111: Modulation... 371 Keying of discrete states... 3 7 4 Amplitude Shift Keying (2-ASK)... 374 Phase Shift Keying (2-PSK)... 374 Frequency Shift Keying 2-FSK..................................................................... 3 7 6 Signal space........................................................................................................ 3 77 Quadrature Phase Shift Keying- QPSK... 380 Digital Quadrature Amplitude Modulation (QAM)... 383 Multiple Access... 387 Discrete Multitone... 390 Orthogonal Frequency division Multiplex (OFDM)... 395 Coded OFDM (COFDM) and Digital Audio Broadcasting (DAB)... 400 Global System for Mobile Communications (GSM)... 402 Asymmetrie Digital Subscriber Line (ADSL)... 402 Spread Spectrum... 405 Exercises on Chapter 13..................................................................................... 409 Bibliography... 411 Index... 419