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1、| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS EN 50248:1998 The Euro
2、pean Standard EN 50248:1997 has the status of a British Standard ICS 33.160.20 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Characteristics of DAB receivers Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 06 08:06:32 GMT+00:00 2006, Uncontrolled Copy, (c) BSI This Briti
3、sh Standard, having been prepared under the direction of the Electrotechnical Sector Board, was published under the authority of the Standards Board and comes into effect on 15 June 1998 BSI 1998 ISBN 0 580 29714 4 BS EN 50248:1998 Amendments issued since publication Amd. No.DateText affected Nation
4、al foreword This British Standard is the English language version of EN 50248:1997. The UK participation in its preparation was entrusted by Technical Committee EPL/100, Audio, video and multimedia systems and equipment, to Subcommittee EPL/100/1, Receiving equipment, which has the responsibility to
5、: aid enquirers to understand the text; present to the responsible European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. A list of organizations repre
6、sented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled International Standards Corresponden
7、ce Index, or by using the Find facility of the BSI Standards Electronic Catalogue. A British Standard does 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 itsel
8、f confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 18, an inside back cover and a back cover. Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 06 08:06:32 GMT+00:00 2006, Uncontrolled Copy, (c) BSI
9、 CENELEC European Committee for Electrotechnical Standardization Comite Europe en de Normalisation Electrotechnique Europa isches Komitee fu r Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B-1050 Brussels 1997 CENELEC All rights of exploitation in any form and by any means reser
10、ved worldwide for CENELEC Members. Ref. No. EN 50248:1997 E EUROPEAN STANDARDEN 50248 NORME EUROPE ENNE EUROPA ISCHE NORM December 1997 ICS 33.160.20 Descriptors: Sound broadcasting, television broadcasting, satellite broadcasting, digital technics, receivers, characteristics, performance evaluation
11、, measurements, parasitic signals, test results, presentation English version Characteristics of DAB receivers Caracte ristiques du re cepteur DABEigenschaften von DAB-Empfa ngern This European Standard was approved by CENELEC on 1997-10-01. CENELEC members are bound to comply with the CEN/CENELEC I
12、nternal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CENELE
13、C member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation 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. C
14、ENELEC members are the national electrotechnical committees of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland,Italy,Luxembourg,Netherlands,Norway,Portugal,Spain,Sweden, Switzerland and United Kingdom. Licensed Copy: sheffieldun sheffieldun, na, Mon Nov
15、06 08:06:32 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Page 2 EN 50248:1997 BSI 1998 Foreword This European Standard was prepared by the Technical Committee CENELEC TC 206, Broadcast receiving equipment. The text of the draft was submitted to the formal vote and was approved by CENELEC as EN 50248 o
16、n 1997-10-01. The following dates were fixed: lastest date by which the EN has to be implemented at national level by publication of an identical national standard or by endorsement(dop) 1998-09-01 latest date by which the national standards conflicting with the EN have to be withdrawn(dow) 1998-09-
17、01 Annexes designated normative are part of the body of the standard. Annexes designated informative are given for information only. In this standard, annex B is normative and annex A is informative. Contents Page Foreword2 1Scope3 2Definitions, abbreviations, symbols and block diagram3 3References3
18、 3.1Normative references3 3.2Informative references3 4Basic implementation and functional performance requirements5 4.1Audio decoder5 4.2Automatic mode selection5 4.3Frequency bands5 4.4Programme service selection5 4.5Receiver reactions to a multiplex re-configuration5 4.6Automatic switching to anot
19、her ensemble5 4.7Response to conditional access (CA) services5 4.8Output for audio and other services6 4.9Transparency for copy protection6 4.10 Coding profiles (Minimum implementation of specified coding profiles)6 5Interfaces:6 5.1RF input6 5.2Analogue audio interface IEC 268-156 5.3Digital audio
20、interface IEC 9586 5.4Coded audio interface6 5.5General digital interface ( F in figure 1)6 5.6Conditional access interface6 6Options6 6.1Receiver display:6 6.2Other features6 7Reference performance levels and measuring methods:7 7.1General conditions7 7.2Audio part8 7.3R. F. part8 Annex A (informat
21、ive) Recommended centre frequencies for DAB13 Annex B (normative) Characteristics of a Rayleigh channel15 Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 06 08:06:32 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Page 3 EN 50248: 1997 BSI 1998 1 Scope This standard describes the DAB (Digital Audio B
22、roadcasting) receiver characteristics for consumer equipment intended for terrestrial and cable reception operating in band III and L-band and for satellite reception in L-band. Dedicated receivers for specific applications are not within the scope of this standard. 2 Definitions, abbreviations, sym
23、bols and block diagram Receivers which are intended to receive and decode programmes transmitted according to the DAB system specification ETSI ETS 300 401 are called DAB receivers. In this document A typical value is an average value that can be used as a basis for planning, whereas Minimum require
24、ment is the lowest value that a DAB receiver should fulfil in order to be called a DAB receiver. Minimum requirements take into account low cost receivers. Other definitions, abbreviations and symbols are solely related to DAB unless stated otherwise. Example of a Functional Block Diagram of a DAB R
25、eceiver (see Figure 1 for information only) 3 References The following documents include provisions which, through reference in this text, constitute provisions of this standard. If the reference standard is subject to revision, the latest version will apply. 3.1 Normative references ETSI ETS 300 40
26、1, Digital Audio Broadcasting to mobile, portable and fixed receivers. (DAB system standard). ISO/IEC 11172-3, Coding of moving pictures and associated audio for digital storage media at up to 1.5 Mbit/s Part 3: Audio. ISO/IEC 11172-4, Coding of moving pictures and associated audio for digital stora
27、ge media at up to 1.5 Mbit/s Part 4: Compliance testing. ISO/IEC 13818-3, Generic coding of moving pictures and associated audio information Part 3: Audio. ISO/IEC 13818-4, Generic coding of moving pictures and associated audio information Part 4: Compliance testing. IEC 268-15, Preferred matching v
28、alues for the inter-connection of sound system components. IEC 958, Digital Audio Interface. IEC 1606, Basic methods of measurement of the audio characteristic of the digital audio part of audio and audio-visual equipment. IEC 315-1, Methods of measurement on radio receivers for various classes of e
29、mission. Part 1: General considerations and methods of measurement, including audio-frequency measurement. IEC 581-11, High fidelity systems for use in vehicles. EN 50255, Digital Audio Broadcasting system Specification of the Receiver Data Interface (RDI). 3.2 Informative references EN 50067, Speci
30、fication of Radio Data Systems (RDS). prEN 12313, Traffic and Traveller Information (TTI) TTI Messages via Traffic Message Coding Coding Protocol for Radio Data System-Traffic Message Channel (RDS-TMC). IEC 68-1, Environmental testing Part 1: General and guidance. IEC 721-1, Environmental parameters
31、 and their severities. IEC Guide 106, Guide for specifying environmental conditions for equipment performance rating. CCITT Rec.O.151, Error performance measuring equipment operating at a primary bit-rate and above. Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 06 08:06:32 GMT+00:00 2006, Unco
32、ntrolled Copy, (c) BSI BSI 1998 Page 4 EN 50248:1997 Figure 1 Example of a Functional Block Diagram of a DAB Receiver (Block 8 is optional, block 9 is not part of the DAB receiver) Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 06 08:06:32 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Page 5 EN 50
33、248:1997 BSI 1998 4 Basic implementation and functional performance requirements 4.1 Audio decoder The audio decoder function of a DAB receiver shall conform to the subset of ISO/IEC 11172-3 as defined in ETSI ETS 300 401. The conformity is described in ISO/IEC 11172-4. The audio decoder should incl
34、ude an error concealment method which may be based on the ScF-CRC (Scale Factor-Cyclic Redundancy Check) as defined within ETSI ETS 300 401. If for any reason the data stream cannot be decoded, the receiver shall mute. The audio part shall be able to decode DAB bit streams corresponding to both 24 a
35、nd 48 kHz sampling frequencies. It shall comply with ISO/IEC 11172-3 and ISO/IEC 13818-3 (bit-rates above 256 kHz/sec are optional). 4.2 Automatic mode selection 4.2.1 Introduction Four different transmission modes are defined: modes I, II, III the time when the receiver has to switch according to t
36、he MCI (Multiplex Configuration Information); next MCI. The receiver shall follow the multiplex reconfiguration. In cases where the position and size of the service is unchanged by the reconfiguration, reception of that service should continue without any adverse effect. 4.6 Automatic switching to a
37、nother ensemble In order to allow seamless reception of a particular service component the ability of a DAB receiver to switch automatically to an other ensemble is mandatory for mobile receivers. 4.7 Response to conditional access (CA) services 4.7.1 Introduction In DAB some Service Components belo
38、nging to a Service may be individually scrambled to make these components incomprehensible for unauthorised users. 4.7.2 Requirements for DAB receivers without CA capabilities These receivers shall either make scrambled Service Components unavailable for selection or indicate their presence together
39、 with the fact that they are scrambled and thus not accessible. Special care has to be taken in the transition from unscrambled to scrambled. When this occurs on one of the selected Service Components, the receiver shall mute the audio and give an appropriate indication. NOTEFor DAB receivers with C
40、A capabilities, see clause 6.2. Licensed Copy: sheffieldun sheffieldun, na, Mon Nov 06 08:06:32 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Page 6 EN 50248:1997 BSI 1998 4.8 Output for audio and other services 4.8.1 Introduction The DAB system provides both Programme and Data Services. Programme Serv
41、ices comprise of an audio Primary Service Component and (optionally) additional Secondary Service Components. Each audio Service Component can also contain PAD (Programme Associated Data) which is used to convey information intimately linked to the sound programme in terms of content and synchroniza
42、tion. DRC (Dynamic Range Control) is an example of a PAD application. Data Services comprise of non-audio Primary Service Components and may optionally have additional Secondary Service Components. Two types of data services are defined: a) General Data Service Component types such as: paging TMC Tr
43、affic Message Channel EWS Emergency Warning Systems ITTS Interactive Text Transmission Systems non interactive point to multipoint data services b) Specific Service Component types for Closed User Groups 4.8.2 Requirements The DAB receiver shall output the audio signal to e.g. loudspeakers and/or pr
44、ovide other outputs via one of the interfaces specified in chapter 5. 4.9 Transparency for copy protection The DAB system allows transmission of copy protection information within the header of the ISO/IEC-coded audio bit stream. The information shall be transferred, together with the complete heade
45、r, to the digital audio output as described in 5.3, 5.4 or 5.5. 4.10 Coding profiles (Minimum implementation of specified coding profiles) The channel decoder shall support all protection profiles and shall be able to decode at least one stereo audio programme with a bit rate of up to 256 kbit/sec.
46、5 Interfaces If any of the following interfaces are applied, the described standardized versions should be used. Alternative and dedicated solutions may be used for in-car or similar systems. 5.1 RF input Home and portable DAB receiver 75 Vaccording Car DAB receiver50 Vto IEC 169-2 (A in Figure 1)no
47、t fixed yet 5.2 Analogue audio interface (IEC 268-15) (I, J and H in Figure 1) 5.3 Digital audio interface (IEC 958) (D in Figure 1) 5.4 Coded audio interface The DAB receiver may (optionally) provide an interface/output of the error-corrected but source-coded bit stream of one audio sub-channel. Th
48、e audio coding is based on ISO/IEC 11172-3. (G in Figure 1). An interface description is under consideration (IEC 1937). 5.5 General digital interface (F in Figure 1) See EN 50255. 5.6 Conditional access interface The conditional access interface is under consideration. 6 Options The following featu
49、res are not mandatory for a basic receiver, but are recommended. 6.1 Receiver display It is recommended that at least 8 characters be used, and the following information be displayed: service label service component label programme type language ensemble label dynamic label segment copy protection status for conditional access local flag region label information on reception quality time and date 6.2 Other features national character sets switching to alternative FM frequencies and linkin