Ulrich Reimers DVB. The Family of International Standards for Digital Video Broadcasting. Second Edition. With 261 Figures.

Transcription

1 Ulrich Reimers DVB

2 Ulrich Reimers DVB The Family of International Standards for Digital Video Broadcasting Second Edition With 261 Figures ~Springer

3 Professor Dr.-Ing. Ulrich Reimers Professor Dr.-Ing. Frank Fechter Dipl.-Ing. Heiko Foellscher Dr.-Ing. Dirk Jaeger Dipl.-Ing. Christian Johansen Dipl.-Ing. Frank Klinkenberg Dr.-Ing. Uwe Ladebusch Dipl.-Ing. Volker Leisse Dipl.-Ing. Claudia Liss Dr.-Ing. Martin Piastowski Professor Dr.-Ing. Christof Rieken Dr.-Ing.Alexander Roy Dipl.-Ing. Ulrich Schiek Dr.-Ing. Markus Traub erg Dipl.-Ing. Andreas Verse Technische Universitat Braunschweig Institut fiir Nachrichtentechnik (Braunschweig Technical University Institute for Communications Technology) Schleinitzstr. 22 D Braunschweig u. Originally published as a monograph Library of Congress Control Number: ISBN ISBN (ebook) DOI / This work is subject to copyright. All rights are reserved, whether the whole or part of the 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 permission for use must always be obtained from Springer-Verlag Berlin Heidelberg GmbH. Violations are liable for prosecution under German Copyright Law. springeronline.com Springer-Verlag Berlin Heidelberg 2005 Originally published by Springer-Verlag Berlin Heidelberg New York in 2005 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 protective laws and regulations and therefore free for general use. Typesetting: Camera ready copy from author Cover-Design: Design & Production, Heidelberg Printed on acid-free paper 62/3020 Rw

4 Preface of the 2"d Edition The first English edition of the book "Digital Video Broadcasting (DVB)" was published at the end of the year It was based upon the second German edition and reflected the developments in the world of DVB as of the end of Only a year after the sales of the first English edition began, Springer publishers asked for a new, completely updated version of the book. This request was a result of the very favourable acceptance of the book by its readers. The revision provided me with the opportunity to incorporate those reports of the many new developments in the world of DVB which could not be reflected in the first English edition. A new team of authors gathered to add new sections to the book. Again they all are or once were researchers working with me at the Institute for Communications Technology (Institut fur Nachrichtentechnik - IfN) at Braunschweig Technical University (Technische Universitiit Braunschweig) in Germany. They contributed to the work of the relevant ad-hoc groups of the Technical Module of the DVB Project, of which I am the chairman, and therefore were able to provide highly informed insider reports about the most recent results of the developments in the world of DVB. In preparing the second English edition we decided to update chapter 1, the introduction to the DVB world (Reimers) and to considerably enlarge section 5 4 dealing with Service Information (Foellscher). In Chapter u, which describes DVB-T the standard for terrestrial transmission, we added the latest results of chip and receiver implementations and describe in some detail the capabilities of DVB-T when used by mobile receivers (Liss, Dr. Roy). A new chapter 12 was added in order to describe the use of DVB for data broadcasting (Foellscher). Among the most recent additions to the set of DVB standards are those enabling the offering of interactive services. These are now described in chapter 13 (Leisse, Dr.Piastowski). Chapter 14 deals with the Multimedia Home Platform (MHP) (Klinkenberg, Schiek). The MHP is a software platform to be used in all kinds ofterminal devices. It is specified by the most complex of all DVB standards so far and promises to become a real global success. The previous section on Measurement Techniques has now become chapter 15.

5 vi Preface of the 2"d Edition I wish to thank Springer publishers, for their support in producing the book and in particular Dr. Dieter Merkle and Ms. Heather King. I very much hope that this completely revised and amended edition will be received well by its readers. Braunschweig, Summer 2004 Prof. Dr.-Ing. Ulrich Reimers

6 Preface Digital Television ("Digital TeleVision Broadcasting" [DTVB] or "Digital Video Broadcasting" [DVB]) has become one of the most exciting developments in the area of consumer electronics at the end of the twentieth century. The term digital television is not typically used either to describe the digitisation of the production studio or to indicate the advent of digital signal processing in the integrated circuits used in television receivers. Rather, digital television refers to the source coding of audio, data and video signals, the channel coding and the methods for the transport of DVB signals via all kinds of transmission media. The term normally also embraces the technologies used for the return path from the consumer back to the programme provider, techniques for scrambling and conditional access, the concepts of data broadcasting, the software platforms used in the terminal devices, as well as the user interfaces providing easy access to DVB services. The aim of this book is to describe the technologies of digital television. The description refers to a point in time at which much of the technical development work had taken place. No doubt, in the future there will inevitably be a considerable number of modifications and additions to the list of technical documents describing the technologies used for DVB. The performance data of the DVB systems, specifically of the one used for terrestrial transmission, are still in the process of being evaluated in many countries throughout the world. In some respects this book must therefore be regarded as a report on the present intermediate stage of the development of digital television and of the practical experience gained so far. I nevertheless consider it timely to present such a report, since at the date of its publication DVB will have become a market reality in many countries. The focus is on the developments within, and the achievements of, the "Moving Pictures Experts Group (MPEG)" in the area of source coding of audio and video signals, followed by an extended description of the work and the results of the "DVB Project", the international body dealing with the design of all the other technical solutions required for the successful operation of digital television. The combination of the specifications designed by MPEG and those designed by the DVB Project has led to the overall system that we can now call digital television. The system for the

7 viii Preface terrestrial transmission of MPEG signals presented by the ''Advanced Television Systems Committee (ATSC)" will not be described in detail in this book. This system will be used in the United States of America, in Canada, Mexico and some other parts of the world. It uses vestigial side-band modulation (VSB) of a single carrier per channel, and sound coding called Dolby AC-3. VSB will be explained in the chapter dealing with modulation techniques. The book addresses readers who wish to gain an in-depth understanding of the techniques used for digital television. They should already have a good knowledge of the existing analogue television systems and should know the properties of analogue audio and video signals. They should also have some understanding of the techniques used in digital signal origination and digital signal processing. Chapter 1 is an introduction to the DVB world. It presents an overview of the whole DVB scenario and answers the very fundamental questions concerning the goals of the development of digital television. It describes the state of technical developments and tries to evaluate several scenarios for the introduction of services using the different transmission media. Chapter 2 recapitulates the fundamentals of the digitisation of audio and video signals. It explains the parameters chosen for the digitisation, such as the quantisation scales and the sampling frequencies, and derives the resulting data rates. On the basis of the figures presented in chapter 2 the fundamentals of source coding of audio and video signals are described in chapters 3 and 4, respectively. The primary goal of source coding is to reduce the data rate for the representation of audio and video signals in such a way that no deterioration of the perceptual quality results or, at most, only a well-defined one. In this way the resources required for the transmission and/or storage of the signals can be limited. Before the data-reduced signals can actually be transmitted they have to be amalgamated into a system multiplex. Tools for the synchronisation of audio and video, auxiliary data needed for the description of the multiplex and of the programme content conveyed by that multiplex, teletext data, and a great deal of other information need to be added. Chapter 5 explains the multiplexing and the structure of the auxiliary data. One of the special features of digital signals is that they can be protected against the effects of unavoidable errors occurring during transmission by adding forward error correction before the signals are sent. Chapter 6 describes methods of forward error correction (FEC) in general. It then concentrates on the two methods used in the DVB world, namely, Reed-Solomon coding and convolutional coding. Digital modulation is dealt with in chapter 7 Here again we highlight those methods which are used in DVB (QPSK, QAM, OFDM, VSB).

8 Preface ix The techniques used for the scrambling of digital signals are presented in chapter 8. Owing to the very nature of this topic it is impossible to describe in detail the specific methods which are used for DVB. The three standards for the transmission of DVB signals via satellite, on cable and via terrestrial networks are described in chapters 9, 10 and n, respectively. In addition to merely explaining the specific details of the standards, we give the performance data and further information regarding the hardware implementation in the receivers. Finally, the methods of measuring and evaluating DVB signals as well as audio and video quality are explained in chapter 12. This book is the result of the joint effort of several researchers working at the Institute for Communications Technology (Institut fiir Nachrichtentechnik - IfN) at Braunschweig Technical University (Technische Universitat Braunschweig) in Germany. The contents are based upon a series of seminars held for interested European industrial professionals since the beginning of To date, over 250 participants have attended such seminars, in which we not only present the theoretical background of the DVB systems but demonstrate the possibilities of DVB and the existing DVB systems and services. In nearly all cases the authors report about areas in which they themselves have carried out research work. Amongst other things, this work has already generated four doctoral theses. Several of the researchers are - or have been - members of either ad-hoc groups of the DVB Project or of the Moving Pictures Experts Group (MPEG). I wish to thank the authors for their competency and co-operation in meeting deadlines for the various manuscripts. Ms. Boguslawa Brandt and Ms. Simone Sengpiel prepared a large number of the drawings used in this book and Dipl.-Ing. Christian Johansen was responsible for the final co-ordinating and editing of the whole text. I extend my thanks to all three of them. The first German edition of this book was published in It was followed by a revised second edition in The English version is based upon that second German edition. Of course, several amendments portraying developments between 1997 and 1998 have been included. The translation from German into English was done by Ms. Vivienne Bruns and Ms. Anne Kampendonk. I am most grateful to both ladies for having taken on this very difficult job. Dr. George Waters, the former Director of Engineering of the European Broadcasting Union (EBU), undertook the final proofreading of the English version. I am especially indebted to him for his invaluable contribution to the quality of the book. Springer publishers, and in particular Dipl.-Ing. Thomas Lehnert, were competent and active partners in producing the book. My thanks go to them for their guidance and assistance during the publication process of the English version.

9 x Preface Digital television, based on the specifications developed by the DVB Project, would most certainly have remained a dream without the co-operation of countless researchers and engineers in Europe, North America and Asia who were highly enthusiastic about the creation of the digital television paradigm. I have the pleasure of being chairman of the Technical Module of the DVB Project and I wish to join the other authors of this book in thanking all the DVB colleagues and friends for such a great achievement. Braunschweig, December 1998 Prof. Dr.-Ing. Ulrich Reimers

10 Table of Contents Digital Television- a First Summary (REIMERS)... Definitions and Range of Application The Genesis of Recommendations for Digital Television. Work in the United States of America. Work in Europe Work in Japan.... Objectives in the Development of Digital Television. Data Reduction as the Key to Success Possible Means of Transmission for Digital Television. Standards and Norms in the World of Digital Television. The New DVB-Project Digitisation and Representation of Audio and Video Signals (JOHANSEN) Sampling and Quantising... Digitising Video Signals..... ADCs and DACs for Video Signals. Representation of Video Signals. Digitising Audio Signals Representation of Audio Signals.. ADCs and DACs for Audio Signals. MPEG Source Coding of Audio Signals (FECHTER). Basics of Bit-rate Reduction.... Psychoacoustic Basics Threshold of Audibility and Auditory Sensation Area. Masking.... Source Coding of Audio Signals Utilising the Masking Qualities of the Human Ear Basic Structure of the MPEG Coding Technique. Coding in Accordance with Layer 1 Coding in Accordance with Layer 2 Coding in Accordance with Layer 3 Decoding

11 xii Preface The Parameters of MPEG Audio.. MPEG-2 Audio Coding. Summary.... JPEG and MPEG Source Coding of Video Signals (RieKEN) Coding in Accordance with JPEG.... Block Diagram of Encoder and Decoder Discrete Cosine Transform. Quantisation Redundancy Reduction. Specific Modes..... Interchange Format.. Coding in Accordance with the MPEG Standards. Block Diagrams of Encoder and Decoder. Motion Estimation.. Reordering of Pictures... Data-rate Control Special Features ofmpeg-1. Special Features ofmpeg-2. Summary o MPEG-2 Systems and Multiplexing (FOELLSCHER, RICKEN) Differences between Programme Multiplex and Transport Multiplex.... Positioning of Systems in the ISO/OSI Layer Model. End-to-end Synchronisation Service Information PSI/SI Tables and their Insertion into the MPEG-2 Transport Stream Section and Table Structure Examples of Table Usage: NIT and SDT Network Information Table (NIT) Service Description Table (SDT) Forward Error Correction (FE C) in Digital Television Transmission (RoY). m 6.1 Basic Observations Reed-Solomon Codes Introduction to the Arithmetic of the Galois Field Definition of the RS Code and the Encoding/Decoding in the Frequency Domain

12 Preface xiii Error Correction Using the RS Code Examples of Encoding/Decoding in the Frequency Domain Encoding and Decoding in the Time Domain Efficiency of the RS Code Convolutional Codes Basics of the Convolutional Codes Examples of Convolutional Encoding and Decoding Construction of a Model Encoder State Diagram and Trellis Diagram of the Model Encoder Example of Encoding with Subsequent (Viterbi) Decoding Hard Decision and Soft Decision Puncturing of Convolutional Codes Performance of Convolutional Codes 6.4 Code Concatenation Block-Code Concatenation Interleaving Error Correction in DVB 6.5 Further Reading Digital Modulation Techniques (JAEGER) NRZ Baseband Signal Principles of the Digital Modulation of a Sinusoidal Carrier Signal Amplitude Shift Keying (2-ASK) Frequency Shift Keying (2-FSK) Phase Shift Keying (2-PSK) Quadrature Phase Shift Keying (QPSK) Higher-level Amplitude Shift Keying (ASK) and Vestigial- Sideband Modulation (VSB) Digital Quadrature Amplitude Modulation (QAM) Orthogonal Frequency Division Multiplex (OFDM) Conditional Access for Digital Television (VERSE). The Satellite Standard and Its Decoding Technique (VERSE) The Basics of Satellite Transmission. Transmission Distance.... Processing on Board a Satellite Polarisation Decoupling. Energy Dispersal Signal Reception Reference Data of a Television Satellite with Astra 1D as an Example Requirements of the Satellite Standard

13 xiv Preface 9 3 Signal Processing at the Encoder System Overview Energy Dispersal Error-protection Coding Filtering Modulation Decoding Technique Demodulator Filtering and Clock Recovery Viterbi Decoder Sync-byte Detector De-interleaver and RS Decoder Energy-dispersal Remover Baseband Interface Performance Characteristics of the Standard Useful Bit Rates Required Carrier-to-noise Ratio in the Transmission Channel Antenna Diameter Local Terrestrial Transmission The Cable Standard and Its Decoding Technique (JAEGER) Cable Transmission Based on the Example of a German CATV Network Intermodulation Thermal Noise..... Reflections User Requirements of the Cable Standard. Signal Processing at the Encoder... Conversion of Bytes to Symbol Words Differential Coding of MSBs Modulation.... Decoding Technique. Cable Tuner IF Interface Recovery of the Carrier Signal Generating the Clock Signal Demodulation of the QAM Signal Differential Decoding of MSBs Conversion of Symbol Words to Bytes Detection of MPEG Sync Bytes Performance Details of the Standard. Determination of Useful Data Rates Carrier-to-noise Ratio Required in the Transmission Channel 232

14 Preface xv 10.6 DVB Utilisation in Master Antenna Television Networks Local Terrestrial Transmission (MMDS) n The Standard for Terrestrial Transmission and Its Decoding Technique (LISS, REIMERS, ROY) Basics of Terrestrial Television Transmission User Requirements for a System for Terrestrial Transmission of DVB Signals Encoder Signal Processing Inner Interleaver and Symbol Mapping Choosing the OFDM Parameters Arrangement of the Transmission Frame Decoding Technique Receiver Classes Straight Forward Technology- the Classical Approach Antenna Tuner IF Processing DVB-T Decoder Chip Enhanced Technologies for DVB-T Reception Antenna Pre-Amplifiers for DVB-T One-Chip Silicon Tuner Network Interface Module (NIM) Technology Antenna Diversity Hierarchical Modulation Features of the Standard Determination of Useful Data Rates Required Carrier-to-noise Ratio in the Transmission Channel Features Relevant for Mobile Reception DVB Data Broadcasting (FOELLSCHER) Basics of Data Broadcasting Data Piping Data Streaming Asynchronous Data Streaming Synchronous Data Streaming Synchronised Data Streaming Data/Object Carousel Data Carousel Object Carousel Multiprotocol Encapsulation IP over DVB System Software Update

15 xvi Preface 13 DVB Solutions for Interactive Services (LEISSE, PIASTOWSKI) 13.1 Interactive Services Network-Independent Protocols for DVB Interactive Services Protocol Stack System Model Higher Layer Protocols Network-Dependent Solutions for PSTN, ISDN, DECT, GSM Interaction Channel through PSTN/ISDN Interaction Channel through DECT Interaction Channel through GSM Network-Dependent Solutions for DVB-C, DVB-S and DVB-T Interaction Channel for Cable TV Distribution Systems Interaction Channel for LMDS Interaction Channel for Satellite Distribution Systems Interaction Channel for Satellite Master Antenna TV Interaction Channel for Digital Terrestrial Television The Multimedia Home Platform (MHP) (KLINGENBERG, SCHIEK) The Role of Software Platforms in the Receiver Some Non-MHP Solutions ATVEF Betanova Liberate Mediahighway MHEG OpenTV Migration Concepts MHP Basic Architecture Transport Protocols Broadcast Channel Protocols Interaction Channel Protocols Application Model and Signalling Content Formats Graphics Model User Interface Security Architecture Minimum Platform Capabilities 14.4 MHP Enhancements in MHP The Future ofmhp Ongoing Developments Aspects of a mobile MHP The MHP Test Suite The Globally Executable MHP

16 Preface xvii Other Java-Based Software Platforms OSGi.... DAB Java Specification.... Mobile Information Device Profile - MIDP Measurement Techniques for Digital Television (JOHANSEN, LADEBUSCH, TRAUBERG) Measurement Techniques for Source-Signal Processing in the Baseband Quality Evaluation of Video Source Coding... Checking Compressed Audio and Video Signals. Checking the MPEG-2 Transport Stream.... Checking the Functionality of the Decoder... Measurements for Digital Transmission Technology. Representation of the Eye Diagram Measurements Carried out at Modulators and Demodulators Measurement of Error Rate. Bibliography Acronyms and Abbreviations. Index