1、 International Telecommunication Union ITU-T J.83TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (12/2007) SERIES J: CABLE NETWORKS AND TRANSMISSION OF TELEVISION, SOUND PROGRAMME AND OTHER MULTIMEDIA SIGNALS Digital transmission of television signals Digital multi-programme systems for television,
2、sound and data services for cable distribution Recommendation ITU-T J.83 Rec. ITU-T J.83 (12/2007) i Recommendation ITU-T J.83 Digital multi-programme systems for television, sound and data services for cable distribution Summary Recommendation ITU-T J.83 covers the definition of the framing structu
3、re, channel coding and modulation for digital multi-programme signals for television, sound and data services distributed by cable networks. This Recommendation has four annexes (Annexes A, B, C and D) that provide the specifications for the four digital television cable systems submitted to the ITU
4、-T. This reflects the fact that a number of digital cable television systems had been developed and provisionally implemented before this standardization effort was undertaken by ITU. This Recommendation recommends that those implementing new digital multi-programme services on existing and future c
5、able networks should use one of the systems whose framing structure, channel coding and modulation are specified in Annexes A, B, C and D. Source Recommendation ITU-T J.83 was approved on 14 December 2007 by ITU-T Study Group 9 (2005-2008) under Recommendation ITU-T A.8 procedure. ii Rec. ITU-T J.83
6、 (12/2007) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsib
7、le for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU-T
8、 study groups which, in turn, produce Recommendations on these topics. The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. In some areas of information technology which fall within ITU-Ts purview, the necessary standards are prepared on a collaborative b
9、asis with ISO and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandato
10、ry provisions (to ensure e.g. interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words “shall“ or some other obligatory language such as “must“ and the negative equivalents are used to express requirements. The us
11、e of such words does not suggest that compliance with the Recommendation is required of any party. INTELLECTUAL PROPERTY RIGHTS ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Intellectual Property Right. ITU takes no
12、 position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. As of the date of approval of this Recommendation, ITU had received notice of intellectual property, prot
13、ected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database at http:/www.itu.int/ITU-T/ipr/. ITU 2009 All rights reserved. No part
14、of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. Rec. ITU-T J.83 (12/2007) iii CONTENTS Page 1 Scope 1 2 References. 1 3 Terms and definitions . 2 4 Symbols and abbreviations. 2 4.1 Symbols 2 4.2 Abbreviations . 3 5 Digital multi-programme
15、systems for cable distribution 4 Annex A Digital multi-programme System A 6 A.1 Introduction 6 A.2 Specification. 6 Annex B Digital multi-programme System B. 7 B.1 Introduction 7 B.2 Cable system concept . 7 B.3 MPEG-2 transport layer . 8 B.4 MPEG-2 transport framing. 8 B.5 Forward error correction.
16、 12 B.6 Modulation and demodulation 26 Annex C Digital multi-programme System C. 28 C.1 Introduction 28 C.2 Cable system concept . 28 C.3 MPEG-2 transport layer . 29 C.4 Framing structure 29 C.5 Channel coding. 30 C.6 Modulation . 32 Annex D Digital multi-programme System D 40 D.1 Introduction 40 D.
17、2 Cable system concept . 40 D.3 MPEG-2 transport layer . 41 D.4 Framing structure 41 D.5 Channel coding. 43 D.6 Modulation . 48 D.7 16-VSB cable receiver 49 D.8 Other VSB modes. 50 Bibliography. 58 iv Rec. ITU-T J.83 (12/2007) Introduction The development of new digital technologies is now reaching
18、the point at which it is evident that they enable digital systems to offer significant advantages, in comparison with conventional analogue techniques, in terms of vision and sound quality, spectrum and power efficiency, service flexibility, multimedia convergence and potentially lower equipment cos
19、ts. Moreover, the use of cable distribution for the delivery of video and audio signals to individual viewers and listeners is continually growing, and has already become the dominant form of distribution in many parts of the world. It is also evident that these potential benefits can best be achiev
20、ed through the economies of scale resulting from the widespread use of digital systems designed to be easily implementable on existing infrastructure and which take advantage of the many possible synergies with related audiovisual systems. Administrations and private operators planning the introduct
21、ion of digital cable television services are encouraged to consider the use of one of the systems described in Annexes A, B, C and D, and to seek opportunities for further convergence, rather than developing a different system based on the same technologies. The second edition (1997) of this Recomme
22、ndation incorporated Amendment 1 (10/1996), which brought the following changes with respect to the first edition of the Recommendation: a) Annex B includes a specification for 256-QAM; b) In Annex B, two distinct operating modes of interleaving capability are specified, called level 1 and level 2.
23、Level 1 is specified for 64-QAM transmission only and this mode already existed in the first edition of Annex B. Level 2 encompasses 64-QAM and 256-QAM transmission, and for both modulation schemes is capable of supporting variable interleaving. c) In the first edition of Annex D, 24 bits were ident
24、ified which determined the VSB mode for the data in the frame and two such modes were defined: 16-VSB Cable and 8-VSB Terrestrial (trellis coded). With the second edition, three other VSB modes are defined, i.e., 2-VSB, 4-VSB and 8-VSB. The third edition (2007) of this Recommendation enhanced the mo
25、dulation method by adding 128 QAM and 256 QAM in Annex A and 256 QAM in Annex C. Rec. ITU-T J.83 (12/2007) 1 Recommendation ITU-T J.83 Digital multi-programme systems for television, sound and data services for cable distribution 1 Scope The scope of this Recommendation is the definition of the fram
26、ing structure, channel coding and modulation for digital multi-programme television, sound and data signals distributed by cable networks (e.g., CATV systems) possibly in frequency-division multiplex. A separate Recommendation defines the transmission characteristics for digital multi-programme sign
27、als distributed through SMATV networks. NOTE 1 The system input is specified to be the MPEG-2 transport layer; this provides some ancillary data capacity in the forward channel, which can be used to accommodate the needs of interactive services (a description of the provision and characteristics of
28、the return channel is outside the scope of this Recommendation). Being highly flexible, the MPEG-2 transport layer can be configured to deliver any desired mix of television, sound and data signals (with sound either related or unrelated to the video signal content, and at various possible levels of
29、 quality). The transport layer can even be totally devoted to the delivery of sound programming, although it may not necessarily be optimized for this application. The specific case of the delivery of a multiplex only containing sound signals may be addressed in a future Recommendation. This Recomme
30、ndation is intended to ensure that the designers and operators of cable distribution (e.g., CATV) networks carrying multi-programme signals will have the information they need to be able to establish and maintain fully satisfactory networks. It also provides the information needed by the designers a
31、nd manufacturers of equipment (including receivers) for digital multi-programme signals distributed by cable networks. NOTE 2 The structure and content of this Recommendation have been organized for ease of use by those familiar with the original source material; as such, the usual style of ITU-T Re
32、commendations has not been applied. 2 References The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and oth
33、er references are subject to revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is published regularly. The re
34、ference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. 1 Recommendation ITU-R BO.1211 (1995), Digital multi-programme emission systems for television, sound and data services for satellites operating in the 11/12 GHz frequency ra
35、nge. 2 Recommendation ITU-T H.222.0 (1995) | ISO/IEC 13818-1:1996, Information technology Generic coding of moving pictures and associated audio information: Systems. 3 European Telecommunications Standards Institute (ETSI) EN 300 429 V1.2.1 (1998-04), Digital Video Broadcasting (DVB); Framing struc
36、ture, channel coding and modulation for cable systems. 2 Rec. ITU-T J.83 (12/2007) 3 Terms and definitions No unconventional terms or definitions are used in this Recommendation. 4 Symbols and abbreviations 4.1 Symbols This Recommendation uses the following symbols: Roll-off factor Ak, BkMost Signif
37、icant Bits at the output of the Byte to m-tuple converter byte Eight bits f0Channel centre frequency fNNyquist frequency g(x) RS code generator polynomial G(256) RS primitive field generator polynomial G(16) Randomizer generator polynomial I Interleaving depth (bytes) I, Q In-phase, Quadrature phase
38、 components of the modulated signal j Branch index k Number of bytes mapped into n symbols m Power of 2m-level QAM: 4,5,6 for 16-QAM, 32-QAM, 64-QAM, respectively M Convolutional interleaver branch depth for j = 1, M = N/I ms millisecond n Number of symbols mapped from k bytes N Error protected fram
39、e length (bytes) p(x) RS field generator polynomial PN(x) Pseudorandom sequence, identified by the number following the symbol q Number of bits: 2,3,4 for 16-QAM, 32-QAM, 64-QAM, respectively R Randomized sequence rmIn-band ripple (dB) RsSymbol rate corresponding to bilateral Nyquist bandwidth of mo
40、dulated signal RuUseful bit rate after MPEG-2 transport multiplexer RuBit rate after RS outer coder T Number of bytes which can be corrected in RS error-protected packet TsSymbol period Rec. ITU-T J.83 (12/2007) 3 4.2 Abbreviations This Recommendation uses the following abbreviations: ATM Asynchrono
41、us Transfer Mode BB BaseBand BER Bit Error Ratio bps Bits per second CATV Community Antenna Television C/N Carrier to Noise ratio DTVC Digital Television by Cable FEC Forward Error Correction FIFO First In First Out HEC Header Error Control HEX Hexadecimal IF Intermediate Frequency IRD Integrated Re
42、ceiver Decoder LSB Least Significant Bit MMDS Multichannel Multipoint Distribution System MPEG Moving Picture Experts Group MSB Most Significant Bit MUX Multiplex P Parity PDH Plesiochronous Digital Hierarchy PN Pseudorandom Noise ppm Parts per million PRBS PseudoRandom Binary Sequence QAM Quadratur
43、e Amplitude Modulation QEF Quasi Error Free RF Radio Frequency RS Reed-Solomon SMATV Satellite Master Antenna Television SNR Signal-to-Noise Ratio sps Symbols per second Sync Synchronizing signal TBD To Be Determined TDM Time Division Multiplex 4 Rec. ITU-T J.83 (12/2007) TS Transport Stream VLSI Ve
44、ry Large Scale Integration VSB Vestigial SideBand XOR Exclusive OR 2-VSB 2 level VSB 4-VSB 4 level VSB 8-VSB 8 level VSB 16-VSB 16 level VSB 5 Digital multi-programme systems for cable distribution It is recommended that those implementing new digital multi-programme services on existing and future
45、cable networks should use one of the systems whose framing structure, channel coding and modulation are specified in Annexes A, B, C and D. The specifications are compared in Table 1, indicating common features. Table 1 Comparison of specifications in summary form indicating common features Item Ann
46、ex B Annex A Annex C Annex D Input signals Modified MPEG-2 transport stream. A parity checksum is substituted for the sync byte, supplying improved packet delineation functionality, and error detection capability independent of the FEC layer. (See B.4.) MPEG-2 transport Stream (See Clause 5 in 3, C.
47、3, D.3.) Framing structure An FEC frame consists of a 42- or 40-bit sync trailer following 60 or 88 RS blocks, with each block containing 128 symbols. An RS symbol consists of 7 bits. Thus, there is a total of 53 802 or 78 888 bits in an FEC frame for 64- or 256-QAM respectively. (See B.5.3.) The fr
48、aming organization is based on the MPEG-2 transport packet structure. (See Clause 6 in 3, C.4, D.4.) Randomization The 3-word polynominal for the PRS: x3+ x + 3over GF 128. (See B.5.4.) The 15-bit polynominal for the PRBS: 1 + x14+ x15(See Clause 7.1 in 3, C.5.1.) The 16-bit poly-nominal for the PRB
49、S: 1 + x + x3+ x6+ x7+ x11+ x12+ x13+ x16.(See D.5.1.) Channel coding FEC Concatenated coding, RS (128, 122) GF 128 with convolutional coding. (See B.5.1.) RS (204, 188) GF 256 (See Clause 7.2 in 3, C.5.2.) RS (207, 187) GF 256 (See D.5.2.) Interleaving Convolutional interleaving depth: I = 128,64,32,16,8 J = 1,2,3,4,5,6,7,8,16. (See B.5.2.) Convolutional interleaving, depth: I = 12. (See Clause 7.3 in 3, C.5.3.) Convolutional interleaving, depth: I = 52. (See D.5.3.) Rec. ITU-T J.83 (12/2007) 5 Table 1 Comparison of specifications in summary form indi
