1、STD-ETSI TR LO1 198-ENGL 1997 3400855 0225000 T5T 1$1 TR 1 O1 198 1.1.1 (1997-09) Technical Repon Digital Video Broadcasting (DVB); Implementation of Binary Phase Shift Keying (BPSK) modulation in DVB satellite transmission systems 2 TR 101 198 Vl.l.1 (1997-09) Reference DTWJTC-00DVB-63 (b3cOOics.PD
2、F) Keywords DVB, broadcasting, digital, video, MPEG, TV ETSI Secretariat Postai address F-O6921 Sophia Antipolis Cedex - FRANCE Office address 650 Route des Lucioles - Sophia Antipolis Valbonne - FRANCE Siret No 348 623 562 00017 - NAF 742 C Association but non lucratif enregistre la Sous-Prfecture
3、de Grasse (06) No 7803/88 Tel.: +33 4 92 94 42 O0 Fax: +33 4 93 65 47 16 X.400 c= fr; a=atlas; p=etsi; s=secretariat Internet secretariat Q etsi.fr http:/w. etsi .fr Copyright Notification No part may be reproduced except as authorized by written permission. The copyright and the foregoing restricti
4、on extend to reproduction in ail media. O European Telecommunications Standards Institute 1997. O European Broadcasting Union 1997. All rights reserved. STD-ETSI TR LO1 19-ENGL 1797 a 3400855 022SOO2 822 81 3 TR 101 198 Vl.l.1 (1997-09) Contents Intellectual Property Rights 4 Foreword 4 1 Scope 5 2
5、References 5 3 Definitions and abbreviations 5 3.1 Definitions . 5 3.2 Abbreviations . 5 4 Background 6 5 BPSK implementation 6 History 7 STD-ETSI TR LO1 178-ENGL 1777 3400855 0225003 7b7 H 4 TR 101 198 Vl.l.1 (1997-09) Intellectual Property Rights iPRs essential or potentially essential to the pres
6、ent document may have been declared to ETSI. The information pertaining to these essential iPRs, if any, is publicly available for ETSI members and non-members , and can be found in ETR 3 14: “intellectual Propeq Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in respect of
7、 ETSI standards“, which is available free of charge from the ETSI Secretariat. Latest updates are available on the ETSI Web server (http:/www.etsi.i/ipr). hirsuant to the ETSI Interim IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee can be given as to
8、the existence of other PRs not referenced in ETR 314 (or the updates on http:/www.etsi.fi/ipr) which are, or may be, or may become, essential to the present document. Foreword This Technical Report (TR) has been produced by the DVB Project and submitted for publication to the Joint Technical Committ
9、ee (JTC) of the European Broadcasting Union (EBU), Comit Europen de Normalisation ELECtrotechnique (CENELEC) and the European Telecommunications Standards Institute (ETSI). NOTE: The EBUBTSI JTC was established in 1990 to co-ordinate the drafting of standards in the specific field of broadcasting an
10、d 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 receivers. The EBU is a professional association of broadcasting organizations whose work includes the co-o
11、rdination of its members activities in the technical, legal, programme-making and programme-exchange domains. The EBU has active members in about 60 countries in the European broadcasting area; its headquarters is in Geneva *. * European Broadcasting Union Case Postale 67 CH-1218 GRAND SACONNEX (Gen
12、eva) Switzerland Tel: +41 22 717 21 11 Fax: +41 22 717 24 81 Digital Video Broadcasting (DVB) Project Founded in September 1993, the DVB Project is a market-led consortium of public and private sector organizations in the television industry. Its aim is to establish the framework for the introductio
13、n 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 circumstances, of the consumer electronics and the broadcast industry. 5 TR 101 198 Vl.l.1 (1997-
14、09) 1 Scope The present document supplements EN 300 421 i which describes the transmission of MPEG-2/DVB Transport Stream (TS) via satellite. The present document covers a special case, where the use of Binary Phase Shift Keying (BPSK) modulation is required, rather than that specified in EN 300 421
15、 i. 2 Ref e re n ces References may be made to: a) specific versions of publications (identified 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 (
16、identified by “up to and including“ before the version identity); or c) all versions subsequent 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-
17、specific reference to an ETS shall also be taken to refer to later versions published as an EN with the same number. Because of the rapid development of specifications and standards it is recommended to verify in each case whether the following documents have been replaced by more recent versions. T
18、he following list was compiled in August 1997. il EN 300 421: “Digital Video Broadcasting (DVB); Framing structure, channel coding and modulation for 11/12 GHz satellite services“. 3 Definitions and abbreviations 3.1 Definitions For the purposes of the present document, the definitions given in EN 3
19、00 421 il apply. 3.2 Abbreviations For the purposes of the present document, the following abbreviations apply: BPSK C/N DVB DTH Eb/No I 1, Q MPEG-2 N QPSK TS R, Binary Phase Shift Keying signal to noise ratio Digital Video Broadcasting Direc t-To-Home ratio between the Energy per useful bit and twi
20、ce the Noise power spectral density Interference In-phase, Quadrature phase components of the modulated signal Moving Picture Experts Group additive white Gaussian Noise Quaternary Phase Shift Keying useful bit-rate after RS outer coder Transport Stream STD-ETSI TR 101 L98-ENGL 1777 m 3400855 022500
21、5 531 I 6 TR 101 198 Vl.l.1 (1997-09) 4 Background Under typical conditions for Direct-To-Home (DTH) emissions by satellite, the Quaternary Phase Shift Keying (QPSK) modulation adopted in EN 300 421 11 achieves an optimum trade-off between spectrum and power efficiencies, Compared to BPSK, QPSK offe
22、rs a double spectrum efficiency and a comparable power efficiency at the same useful bit-rate Ru, in the presence of additive white Gaussian Noise (N) and Interference (I). In general, the best system performance by satellite is met by adopting QPSK at the maximum symbol rate compatible with the tra
23、nsponder bandwidth (see EN 300 421 i, annex C). This configuration is indicated in the present document as “full-band transmission, in contrast with a “reduced-band transmission, where part of the transponder bandwidth is not exploited by the signal. The maximization of the useful bit-rate Ru compat
24、ible with the available C/N + I is achieved by considering full-band QPSK associated with progressively decreasing coding rates (from 7/8 to 1/2). if a configuration is found which meets the C/N + I requirements, there is no BPSK scheme with comparable or better performance in terms of Ru or in term
25、s of generated interference power density affecting other services. For example, comparing full-band QPSK 1/2 with full-band BPSK 7/8 (Le. at the same symbol rate), the latter shows a 12,5 % loss in terms of Ru and at the same time a power loss of about 1,3 dB, while the generated interference power
26、 density affecting other services is similar. Only under exceptionally critical transmission conditions, full-band BPSK can out-perform reduced-band QPSK 1/2 at the same Ru. This can happen when the available C/N + I ratio can not even support the bit-rate R u of full-band QPSK 1/2, and in the prese
27、nce of strong narrow-band Co-channel interference (I). For example, assuming a narrow-band interference at C/I = 10 dB, and taking as a reference reduced-band QPSK 1/2 at the same Ru, full-band BPSK 2/3 requires similarEb/No, but generates an interference power density 1,7 dB lower. Under the same c
28、onditions but at even smaller bit-rates Ru, full-band BPSK 1/2 offers reductions of about 0,s dB in terms of required Eb/No, and of 3 dB in terms of generated interference power density. On the other hand, in some cases the lower spectrum occupation of QPSK can allow to avoid Co-channel interference
29、, by shifting the signal within the transponder bandwidth. The present document describes a preferred implementation of BPSK for those applications which do not conform to EN 300 421 11 in the modulation format only. 5 BPSK implementation The inner code puncturing conforms to table 2 of EN 300 421 i
30、 (relevant to QPSK modulation), to generate the I and Q parallel signals. By means of a parallel-to-serial conversion, these two signals I and Q are merged in a single signal R, at double rate, following the rule: R = I, Q. This results in the puncturing scheme summarized in table 1. Table 1: Punctu
31、ring scheme for BPSK Code 1 12 213 314 516 710 Rates X: 1 10 101 10101 1 O001 o1 Y: 1 11 110 11010 1111010 R= XlYl XlYlY2 x3y3y4 XlYlY2 x3 XlYlY2 x3y4x5 1 1 2 3 4 56 7 The mapping of signal R into the BPSK constellation is absolute (no differential coding). Baseband filtering for spectrum shaping conforms to the QPSK specification. 7 TR 101 198 V1.l.l (1997-09) v. 1.1.1 History September 1997 Publication I Document history I ISBN 2-7437-1736-X Dpt lgal : Septembre 1997
