1、BRITISH STANDARD BS EN 50080:1991 Specification for RF characteristics of MAC AM-VSB cable receivers This European Standard EN 50080:1991 has the status of a British StandardBSEN50080:1991 This British Standard, was published under the authority ofthe Standards Board and comesinto effect on 20Decemb
2、er1991 BSI 03-2000 The following BSI references relate to the work on this standard: Committee reference EEL/25 Draft announced in BSI News, October 1991 ISBN 0 580 20304 2 Cooperating organizations The European Committee for Electrotechnical Standardization (CENELEC), under whose supervision this E
3、uropean Standard was prepared, comprises the national standards organizations of the following Western European countries. Austria Italy Belgium Luxembourg Denmark Netherlands Finland Norway France Portugal Germany Spain Greece Sweden Iceland Switzerland Ireland United Kingdom Amendments issued sinc
4、e publication Amd. No. Date CommentsBSEN50080:1991 BSI 03-2000 i Contents Page Cooperating organizations Inside front cover National foreword ii Foreword 2 Text of EN 50080 3 National appendix NA (informative) Inside back coverBSEN50080:1991 ii BSI 03-2000 National foreword This British Standard has
5、 been prepared under the direction of the Electronic Equipment Standards Policy Committee and is the English language version of EN50080:1991 “RF characteristics of MAC AM-VSB cable receivers”, published by the European Committee for Electrotechnical Standardization (CENELEC). A British Standard doe
6、s not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an insi
7、de front cover, pages i and ii, theEN title page, pages 2 to 8, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.EUROPEAN STANDARD NORME EUROPEN
8、NE EUROPISCHE NORM EN 50080 May 1991 UDC 621.397.743:621.397.63 Descriptors: Telecommunication, cabled television, receiver, demodulator, signal, characteristic English version RF characteristics of MAC AM-VSB cable receivers Caractristiques RF des rcepteurs MAC en MA/BLR pour tlvision par cbles RF
9、Merkmale von MAC AM-RSB Kabel-Empfngern This European Standard was approved by CENELEC on 15 March 1991. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any altera
10、tion. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CENELEC member. This European Standard exists in three official versions (English, French, German). A version in any other language made by tra
11、nslation under the responsibility of a CENELEC member into its own language and notified to the Central Secretariat has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Irel
12、and, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart
13、35, B-1050 Brussels 1991 Copyright reserved to CENELEC members Ref. No. EN 50080:1991 EEN50080:1991 BSI 03-2000 2 Foreword This European Standard has been prepared by CENELEC Technical Committee TC106, MAC receiving equipment. The text was submitted to the CENELEC Unique Acceptance Procedure (UAP) i
14、n July1990. The text of the draft was approved by all CENELEC members with the exception of Finland as EN50080 on 15March1991. The following dates were fixed: Annexes designated “normative” are part of the body of the standard. In this standard, Annex A is normative. Contents Page Foreword 2 Introdu
15、ction 3 1 Scope 3 2 RF Characteristics of MAC AM-VSB cable receivers 3 3 Characteristics of the modulated signal 3 Annex A (normative) 6 Figure 1 Filter characteristics of the receiver 4 Figure 2 Carrier levels 5 Figure A.1 Filter characteristics of the modulator 7 latest date of publication ofan id
16、entical national standard (dop) 1992-03-01 latest date of withdrawal of conflicting national standards (dow) 1992-03-01EN50080:1991 BSI 03-2000 3 Introduction The introduction of MAC transmission standards and the need to provide a possibility to introduce HDMAC signals at a later stage, gave rise f
17、or the need to standardize the RF characteristics of MAC AM-VSB cable receivers. This standard is so far restricted to the use of MAC signals in the hyperband, some countries are however envisaging additional transmissions outside this band. The most notable difference with the RF characteristics in
18、 case of conventional transmissions is the location of the vision Nyquist slope, which is the transmitter. This is done to improve the noise properties of the whole transmission chain. Optimized behaviour of the complete AM-VSB CATV system will be attained only by correctly matching both RF receiver
19、 characteristics as well as RF transmitter characteristics. Therefore the RF transmitter characteristics described inAnnex A are normative. 1 Scope This standard specifies the RF characteristics for MAC AM-VSB cable receivers and defines the behaviour of the receiver demodulator by referring to the
20、characteristics of the modulated signal. It takes into account the development of the HDMAC specification and ensures compatibility with the HDMAC transmission parameters. 2 RF Characteristics of MAC AM-VSB cable receivers 3 Characteristics of the modulated signal NOTE 112MHz channel spacing is requ
21、ired for DMAC and HDMAC and the bandwidth available for D2MAC signals received by satellite can be maintained. Unless special measures likee.g.scrambling of the wanted channel and/or frequency offsetting are taken, the lower adjacent channel shall not be a system B/G/I or system L signal, because th
22、e sound carrier will give rise to interference. NOTE 2The receiver filter is a so called window filter. Frequency band: Hyperband 300470 MHz Signal level: 70 dB 4V range 6084 dB 4V Channel spacing: 12 MHz (note 1) Receiver filter characteristic: see Figure 1 (note 2) Group delay characteristic: flat
23、 (linear phase characteristic) Modulation polarity: negative Amplitude at black level: 100% Residual carrier level: 10% (see Figure 2)EN 50080:1991 4 BSI 03-2000 Figure 1 Filter characteristics of the receiverEN50080:1991 BSI 03-2000 5 Figure 2 Carrier levelsEN50080:1991 6 BSI 03-2000 Annex A (norma
24、tive) CORRESPONDING CABLE PARAMETERS The following essential cable parameters are assumed to ensure a good performance of the receiver. They are given here as far they are not clear from clause2. A complete cable specification will be defined by CLC/TC109. SIGNALS RECEIVED FROM SATELLITE SERVICES: A
25、ny energy dispersal waveform added to the MAC/packet signal shall be removed prior to transmission in cable systems. The linear pre-emphasis specified in the MAC packet specification for the FM transmission shall be removed prior to transmission in cable systems. MAC/packet systems may use maximum a
26、mplitude colour-difference signals. For broadcasting via satellites, some systems may also use nominal data amplitudes for D-MAC which have been increased in order to optimize bit-error-rate performance. For both these cases over-modulation of the VSB/AM/MAC packet signal will occur if the simplest
27、types of remodulation schemes are used. NOTE 1For HDMAC the so called HDMAC Nyquist slope around 10.125MHz is not yet fully determined. NOTE 2For HDMAC the value is still under consideration. Maximum level difference between adjacent channels: 3 dB Filter characteristics of the modulator: see Figure
28、 A.1 (note 1) Minimum C/N olevel: 50 dB at 1 MHz bandwidth (note 2)EN 50080:1991 BSI 03-2000 7 Figure A.1 Filter characteristics of the modulator8 blankBSEN50080:1991 BSI 03-2000 National appendix NA (informative) The United Kingdom participation in the preparation of this British Standard was entru
29、sted by the Electronic Equipment Standards Policy Committee (EEL/-) to Technical Committee EEL/25, upon which the following bodies were represented: British Broadcasting Corporation British Radio and Electronic Equipment Manufacturers Association British Telecommunications plc Independent Television
30、 Commission Institution of Electrical Engineers Radio Electrical and Television Retailers Association Radiocommunications Agency The following bodies were also represented in the drafting of the standard, through subcommittees and panels: Association for Consumer Research (ACRe) British Educational
31、Equipment Association Consumer Policy Committee of BSI International Consumer Electronics Association (ICEA) National Television Rental AssociationBS EN 50080:1991 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI is the independent national body responsible for preparing B
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