1、DEUTSCHE NORM Oktober 1998 D i g it ale r Fe rnse h ru n ci f u n k ( DVB) Rahmenstruktur, Kanalcodierung und Modulation bei Kabelsystemen Englische Fassung EN 300429 Vi .2.1 (1998-04) I EN 300429 ICs 33.060.40 Ersatz fr Deskriptoren: Fernsehrundfunk, Kabelfernsehanlage, Rahmenstruktur, Modulation,
2、DIN ETS 300429 : 1995-06 Kanalcodierung Digital Video Broadcasting (DVB) - Framing structure, channel coding and modulation for cable systems; English version EN 300429 V1.2.1 (1998-04) Die Europische Telekommunikationsnorm EN 300429 : 1998 hat den Status einer Deutschen Norm. Nationales Vorwort Die
3、 vorliegende Norm enthlt die vom Europischen Institut fr Telekommunikationsnormen (ETSI) heraus- gegebene Europische Norm (Telekommunikationsserie) EN 300429 V1.2.1 (1998-04) ,Digital Video Broad- casting (DVB) - Framing structure, channel coding and modulation for cable systems“. Diese Norm enthlt
4、unter Bercksichtigung des DIN-Prsidialbeschlusses 13/1983 den englischen Originaltext der vom ,Joint Technical Committee (JTC)“ des ETSI und der EBU erarbeiteten EN 300429. Fachlich zustndig in Deutsch- land ist das Unterkomitee 742.4 ,Rundfunk-Empfangsgerte und verwandte Gerte und Systeme der Unter
5、- haltungselektronik der Deutschen Elektrotechnischen Kommission im DIN und VDE (DKE). nderungen Gegenber DIN ETS 300429 : 1995-06 wurden folgende nderungen vorgenommen: - EN 300429: 1998 (zweite Ausgabe) bernommen. Frhere Ausgaben DIN ETS 300429: 199506 Fortsetzung 20 Seiten EN-Original Deutsche El
6、ektrotechnische Kommission im DIN und VDE (DKE) Q DIN Deutsches Institut fr Normung e.V. .Jede Ait der Vervielfltigung. auch auszugsweise, Alleinverkauf der Normen durch Beuth Verlag GmbH, 10772 Berlin nur mit Genehmigung des DIN Deutsches Institut fr Normung e.V., Berlin, gestattet. Ref. Nr. DIN EN
7、 300429: 1998-10 Preisgr. O9 Verir.-Nr. 1709 - Leerseite - EN 300 429 1.2.1 (1998-04) European Standard (Telecommunications series) Digital Video Broadcasting (DVB); Framing structure, channel coding and modulation for cable systems European Broadcasting Un nion Digira! Video Broadcasting Europenne
8、2 EN 300 429 V1.2.1 (1 998-04) Reference RENIJTC-DVB-71 (3000ioo.PDF) Keywords DVB, digital, video, broadcasting, cable, MPEG, Tv ETSI Postal address F-O6921 Sophia Antipolis Cedex - FRANCE Office address 650 Route des Lucioles - Sophia Antipolis Valbonne - FRANCE Tel.: +33 4 92 94 42 O0 Fax: +33 4
9、93 65 47 16 Siret N“ 348 623 562 O001 7 - NAF 742 C Association but non lucratif enregistre la Sous-Prfecture de Grasse (06) No 7803/88 Internet secretariat etsi.fr http:/www.etsi.fr http:/www.etsi.org COD vriuht No tifca fion No part may be reproduced except as authorized by written permission. The
10、 copyright and the foregoing restriction extend to reproduction in all media. O European Telecommunications Standards Institute 1998. O European Broadcasting Union 1998. All rights rcserved. ETSI 3 EN 300 429 V1.2.1 (1998-04) Contents Intellectual Property Rights . 4 Foreword .,4 1 2 3 3.1 3.2 4 4.
11、I 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 5 6 7 7.1 7.2 7.3 8 9 Scope . 5 References ._ . 5 Symbols . . 5 Symbols and abbreviations . 5 6 Cable System concept . 6 Abbreviations. . . . . . . . . . . Sync 1 inversion and randomization Reed-Solomon (RS) coder . . 8 Baseband shaping . 8 Cable receiver ._._ Rand
12、omization for spectrum shaping Reed-Solomon codin Essential. or potentially Essential, IPRs riotijed to ETSI iit respect of ETSI standards“, which is available free of charge from the ETSI Secretariat. Latest updates are available on the ETSI Web server (http:/www.etsi.fr/ipr). Pursuant to the ETSI
13、Interim IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee can be given as to the existence of other IPRs not referenced in ETR 314 (or the updates on http:/www.etsi.fr/ipr) which are, or may be, or may become, essential to the present document. Foreword
14、 This European Standard (Telecommunications series) has been produced by the Joint Technical Committee (JTC) of the European Broadcasting Union (EBU), Comit Europen de Normalisation ELECtrotechnique (CENELEC) and the European Telecommunications Standards Institute (ETSI). NOTE: The EBUETSI JTC was e
15、stablished in 1990 to Co-ordinate the drafting of standards in the specific field of broadcasting and related Fields. Since 1995 the JTC became a tripartite body by including in the Memorandum of Understanding also CENELEC, which is responsible for the standardization of radio and television receive
16、rs. The EBU is a professional association of broadcasting organizaions whose work includes the Co-ordination of its members activities in the technical, legal, prograiiiiiie-making and programme-exchange domains. The EBU has active members in about 60 countries in the European broadcasting area; its
17、 headquarters is in Geneva *. * European Broadcasting Union CH- 1218 GRAND SACONNEX (Geneva) Switzerland Tel: +41 22 717 21 I I Fax: +41227172481 Digital Video Broadcasting (DVB) Project Founded in September 1993, the DVB Project is a market-led consortium of public and private sector organizations
18、in the television industry. Its aim is to establish the framework for the introduction of MPEG-2 based digital television services. Now comprising over 200 organizations from more than 25 countries around the world, DVB fosters market- led systems, which meet the real needs, and economic circumstanc
19、es, of the consumer electronics and the broadcast industry. I National transposition dates I Date of adoption of this EN: Date of latest announcement of this EN (doa): Date of latest publication of new National Standard or endorsement of this EN (dop/e): Date of withdrawal of any conflicting Nationa
20、l Standard (dow): 17 April 1998 3 1 July 1998 31 January 1999 31 January 1999 ETSI 5 EN 300 429 V1.2.1 (1 998-04) 1 Scope The present document only adds 128 and 256 QAM to the specification The present document describes the framing structure, channel coding and modulation (denoted “the System“ for
21、the purposes of the present document) for a digital multi-programme television distribution by cable. The aim of the present document is to present a harmonized transmission standard for cable aiid satellite, based on the MPEG-2 System Layer ISO/IEC 1381 8-1 i J, with the addition of appropriate For
22、ward Error Correction (FEC) technique. This System can be used transparently with the modulation/channel coding system used for digital multi-programme television by satellite (see EN 300 421 3). The System is based on Quadrature Amplitude Modulation (QAM). It allows for 16,32, 64, 128 or 256-QAhf c
23、onstellations. The System FEC is designed to irriprove Bit Error Ratio (BER) from Error Free“ (QEF) operation with approximately one uncorrected error event per transmission hour. to a range, to lo-“, ensuring “Quasi 2 References References may be made to: a) specific versions of publications (ident
24、ified by date of publication, edition number, version number, etc.), in which case, subsequent revisions to the referenced document do not apply; or b) all versions up to and including the identified version (identified by “up to and including“ before the version identity); or c) all versions subseq
25、uent to and including the identified version (identified by “onwards“ following the version identity); or d) publications without mention of a specific version, in which case the latest version applies. A non-specific reference to an ETS shall also be taken to refer to later versions published as an
26、 EN with the same number. il u1 ISOIIEC 138 18-1: “Coding of moving pictures and associated audio“. IEEE Trans. Comm. Tech., COM-19, pp. 772-781, (October 1971) Foriiey, G.D : “Burst- correcting codes for the classic bursty channel“. EN 300 421 : “Digital Video Broadcasting (DVB); Framing structure,
27、 channel coding and modulation for 11/12 GHz satellite services“. 31 3 Symbols and abbreviations 3.1 Symbols For the purposes of the present document, the following symbols apply: Roll-off factor Most Significant Bits at the output of the Byte to m-tuple converter Channel centre frequency Nyquist fr
28、equency RS code generator polynomial Hexadecimal Interleaving depth (bytes) In-phase, Quadrature phase components of the modulated signal Branch index Number of bytes mapped into n symbols 6 EN 300 429 V1.2.1 (1 998-04) Power of 2Vevel QAM: 4,5,6,7,8 for 16-QAM, 32-QAM, 64-QAM, 128-QAM, 256-QAM resp
29、ectively Convolutional interleaver branch depth for j = 1, M = N/I Number of symbols mapped from k bytes Error protected frame length bytes RS field generator polynomial In-band ripple (dB) Randomized sequence Symbol rate corresponding to the bilateral Nyquist bandwidth of the modulated signal Usefu
30、l bit rate after MPEG-2 transport multiplexer Bit rate after RS outer coder Number of bits: 2,3,4,5,6 for 16-QAM, 32-QAM, 64-QAM, 128-QAM, 256-QAM respectively Number of bytes which can be corrected in RS error protected packet Symbol period Abbreviations .- . For the purposes of . BB BER DTVC FEC F
31、IFO IF IRD LSB MPEG MSB MUX PDH PRBS QAM QEF RF RS SMATV TDM TV the present document. the ioiiowing abbreviations apply: Baseband Bi1 Error Ratio Digital Television by Cable Forward Error Correction First In First Out Intermediate Frequency Integrated Receiver Decoder Least Significant Bit Moving Pi
32、ctures Experts Group Most Significant Bit Multiplex Plesiochronous Digital Hierarchy Pseudo Random Binary Sequence Quadrature Amplitude Modulation Quasi Error Free Radio Frequency Reed-Solomon Satellite Master Antenna Television Time Division Multiplex Television 4 Cable System concept The cable Sys
33、tem shall be defined as the functional block of equipment performing the adaptation of the baseband TV signals to the cable channel characteristics (see figure 1). In the cable head-end, the following TV baseband signal sources can be considered: - satellite signal(s); - contribution link(s); - loca
34、l program source(s). The processes in the following subclauses shall be applied as shown in figure 1. ETSI 7 U c U Cu al I n o a, Cu - E E pl LT o *- .,“E v) -I J 7 1 2 3 4 5 6 7 8 9 10U 12 13 :14 15 - Channel coding - To achieve the appropriate level of error protection required for cable transmiss
35、ion of digital data, a FEC based on Reed-Solomon encoding shall be used. In contrast to the Baseline System for satellite described in ETS-300 421 3, no convolutional coding shall be applied to cable transmission. Protection against burst errors shall be achieved by the use of byte interleaving. 7.1
36、 Randomization for spectrum shaping DatainputWSBfirst): 10111000 xxxxx xxx PRBS sequence : o o oio o o 1 1 Figure 3: Scrambler/deccrambler schematic diagram The first bit at the output of the PRBS generator shall be applied to the first bit of the first byte following the inverted MPEG-2 sync byte (
37、.BHEx). To aid other synchronization functions, during the MPEG-2 sync bytes of the subsequent 7 transport packets, the PRBS generation continues, but its output shall be disabled, leaving these bytes unrandomized. The period of the PRBS sequence shall therefore be 1 503 bytes. The randomization pro
38、cess shall be activc also when the modulator input bit-stream is non-existant, or when it is non- compliant with the MPEG-2 transport stream format (.e. 1 sync byte + 187 packet bytes). This is to avoid the emission of an uninodulated carrier from the modulator. E TSJ 11 EN 300 429 V1.2.1 (1998-04)
39、7.2 Reed-Solomon coding Following the energy dispersal randomization process, systematic shoriened Reed-Solomon encoding shall be performed on each randomized MPEG-2 transport packet, with T = 8. This means that 8 erroneous bytes per transport packet can be corrected. This process adds 16 parity byt
40、es to the MPEG-2 transport packet to give a codeword (204,188). NOTE RS coding shall also be applied to the packet sync byte, either non-inverted (Le. 47HEx) or inverted (1.e. B*HEx). Code Generator Polynomial: g(x) = (x+li0)(x+h)(x+h2) . (+h), where 1 = 02HEx Field Generator Polynomial: p(x) = x8 +
41、 x4 + x3 + x2 + 1 The shortened Reed-Solomon code shall be implemented by appending 51 bytes, all set to zero, before the information bytes at the input of a (255,239) encoder: after the coding procedure these bytes are discarded. 7.3 Convo I ut io n al i n t e rleavi n g Following the scheme of fig
42、ure 4, convolutional interleaving with depth I = 12 shall be applied to the error protected packets (see figure 2c). This results in an interleaved frame (see figure 2d). The convolutional interleaving process shall be based on the Forney approach (see Burst-correcting codes for the classic bursty c
43、hannel in IEEE Trans. Coinin. Tech., COM-19 2) which is compatible with the Rainsey type III approach, with I = 12. The Interleaved Frame shall be composed of overlapping error protcctcd packets and shall be delimited by MPEG-2 sync bytes (preserving the periodicity of 204 bytes). The interleaver ma
44、y be composed of I = 12 branches, cyclically connected to the input byte-stream by the input switch. Each branch shall be a First In First Out (FIFO) shift register, with depth (Mj) cells (where M = 17 = NO, N = 204 = error protected frame length, I = 12 = interleaving depth, j = branch index). The
45、cells of the FIFO shall contain 1 byte, and the input and output switches shall be synchronized. For synchronization purposes, the sync bytes and the inverted sync bytes shall be always routed into the branch “O“ of the interleaver (corresponding to a null delay). NOTE: The deinterleaver is similar,
46、 in principle, to the interleaver, but the branch indexes are reversed (i.e. j = O corresponds to the largest delay). The deinterleaver synchronization can be carried out by routeing the first recognized sync byte into the “O“ branch. I Sync word route 2 3 a -a I Interleaver Li2 I Sync word route I
47、- 11=1-1 Figure 4: Conceptual diagram of the convolutional interleaver and de-interleaver 12 EN 300 429 V1.2.1 (1 998-04) From interleaver output 8 Byte to symbol mapping After convolutional interleaving, an exact mapping of bytes into symbols shall be performed. The mapping shall rely on the use of
48、 byte boundaries in the modulation system. In each case, the MSB of symbol 2 shall be taken from the MSB of byte V. Correspondingly, the next significant bit of the symbol shall be taken from the next significant bit of the byte. For the case of 2“-QAM modulation, the process shall map k bytes into
49、n symbols, such that: 8k=nxm The process is illustrated for the case of 64-QAM (where ni = 6, k = 3 and n = 4) in figure 5: b7 b6 b5 b4 b3 b2 bi bO b7b6 b5 b4 b3 b2 bl bO b7b6 b5 b4 b3 b2 bl bO NOTE I: bo shall be understood as being the Least Significant Bit (LSB) of each byte or m-tuple. NOTE 2: In this conversion, each byte results in more than one m-tuple, labelled Z, Z+l, etc. with Z being transmitted before Z+1. Figure 5: Byte to rn-tuple conversion for 64-QAM The two most significant bits of each symbol shall then
