1、 ETSI TS 102 386 V1.2.1 (2006-03)Technical Specification Digital Radio Mondiale (DRM);AM signalling system (AMSS)European Broadcasting Union Union Europenne de Radio-Tlvision EBUUER ETSI ETSI TS 102 386 V1.2.1 (2006-03) 2 Reference RTS/JTC-DRM-16 Keywords broadcasting, digital, DRM, radio, AM ETSI 6
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6、The copyright and the foregoing restriction extend to reproduction in all media. European Telecommunications Standards Institute 2006. European Broadcasting Union 2006. All rights reserved. DECTTM, PLUGTESTSTM and UMTSTM are Trade Marks of ETSI registered for the benefit of its Members. TIPHONTMand
7、the TIPHON logo are Trade Marks currently being registered by ETSI for the benefit of its Members. 3GPPTM is a Trade Mark of ETSI registered for the benefit of its Members and of the 3GPP Organizational Partners. ETSI ETSI TS 102 386 V1.2.1 (2006-03) 3 Contents Intellectual Property Rights4 Foreword
8、.4 Introduction 4 1 Scope 6 2 References 6 3 Definitions and abbreviations.6 3.1 Definitions6 3.2 Abbreviations .7 4 General .7 5 Service information7 5.1 Introduction 7 5.2 Use of SDC data entities 7 5.2.1 Permitted SDC data entities8 5.2.2 Usage rules for SDC data entities .8 5.3 Structure .8 5.3.
9、1 Segmentation 8 5.3.2 Block 1 coding9 5.3.3 Block 2 coding9 5.4 Repetition and decoding issues 10 6 Baseband coding 10 6.1 Structure of baseband coding .10 6.2 Features of data transmission .11 6.3 Error protection 11 6.4 Block and group synchronization.12 7 Modulation .12 History 14 ETSI ETSI TS 1
10、02 386 V1.2.1 (2006-03) 4 Intellectual Property Rights IPRs essential or potentially essential to the present 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 ETSI SR 000 3
11、14: “Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in respect of ETSI standards“, which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web server (http:/webapp.etsi.org/IPR/home.asp). Pursuant to the ETSI IPR Policy,
12、 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 ETSI SR 000 314 (or the updates on the ETSI Web server) which are, or may be, or may become, essential to the present document. Foreword This Technic
13、al Specification (TS) has been produced by Joint Technical Committee (JTC) Broadcast of the European Broadcasting Union (EBU), Comit Europen de Normalisation ELECtrotechnique (CENELEC) and the European Telecommunications Standards Institute (ETSI). NOTE: The EBU/ETSI JTC Broadcast was established in
14、 1990 to co-ordinate the drafting of standards in the specific field of broadcasting and related fields. Since 1995 the JTC Broadcast became a tripartite body by including in the Memorandum of Understanding also CENELEC, which is responsible for the standardization of radio and television receivers.
15、 The EBU is a professional association of broadcasting organizations whose work includes the co-ordination 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 headq
16、uarters is in Geneva. European Broadcasting Union CH-1218 GRAND SACONNEX (Geneva) Switzerland Tel: +41 22 717 21 11 Fax: +41 22 717 24 81 Introduction The frequency bands used for broadcasting below 30 MHz are: Low Frequency (LF) band: from 148,5 kHz to 283,5 kHz, in ITU Region 1 1 only; Medium Freq
17、uency (MF) band: from 526,5 kHz to 1 606,5 kHz, in ITU Regions 1 1 and 3 1 and from 525 kHz to 1 705 kHz in ITU Region 2 1; High Frequency (HF) bands: a set of individual broadcasting bands in the frequency range 2,3 MHz to 27 MHz, generally available on a Worldwide basis. These bands offer unique p
18、ropagation capabilities that permit the achievement of: large coverage areas, whose size and location may be dependent upon the time of day, season of the year or period in the (approximately) 11 year sunspot cycle; portable and mobile reception with relatively little impairment caused by the enviro
19、nment surrounding the receiver. There is thus a desire to continue broadcasting in these bands, perhaps especially in the case of international broadcasting where the HF bands offer the only reception possibilities which do not also involve the use of local repeater stations. ETSI ETSI TS 102 386 V1
20、.2.1 (2006-03) 5 However, broadcasting services in these bands: use analogue techniques; are subject to limited quality; are subject to considerable interference as a result of the long-distance propagation mechanisms which prevail in this part of the frequency spectrum and the large number of users
21、. As a direct result of the above considerations, there is a desire to effect a transfer to digital transmission and reception techniques in order to provide the increase in quality which is needed to retain listeners who, increasingly, have a wide variety of other programme reception media possibil
22、ities, usually already offering higher quality and reliability. In order to meet the need for a digital transmission system suitable for use in all of the bands below 30 MHz, the Digital Radio Mondiale (DRM) consortium was formed in early 1998. The DRM consortium is a non-profit making body which se
23、eks to develop and promote the use of the DRM system worldwide. Its members include broadcasters, network providers, receiver and transmitter manufacturers and research institutes. More information is available from their website (http:/www.drm.org/). ETSI ETSI TS 102 386 V1.2.1 (2006-03) 6 1 Scope
24、The present document defines a system for adding a limited amount of service information to analogue broadcasts in the frequency bands below 30 MHz in a complementary way to the Digital Radio Mondiale (DRM) system. It is intended to be used by broadcasters in the transition to all digital transmissi
25、on by providing labelling and frequency information for a better user experience. 2 References The following documents contain provisions which, through reference in this text, constitute provisions of the present document. References are either specific (identified by date of publication and/or edi
26、tion number or version number) or non-specific. For a specific reference, subsequent revisions do not apply. For a non-specific reference, the latest version applies. Referenced documents which are not found to be publicly available in the expected location might be found at http:/docbox.etsi.org/Re
27、ference. 1 ETSI ES 201 980: “Digital Radio Mondiale (DRM); System specification“. 2 ITU-R Recommendation BS.706: “Data system in monophonic AM sound broadcasting: (AMDS)“. 3 CENELEC EN 62106: “Specification of the radio data system (RDS) for VHF/FM sound broadcasting in the frequency range from 87,5
28、 to 108,0 MHz“. 3 Definitions and abbreviations 3.1 Definitions For the purposes of the present document, the following terms and definitions apply: reserved for future addition (rfa): bits with this designation shall be set to zero NOTE: Receivers shall ignore these bits. reserved for future use (r
29、fu): bits with this designation shall be set to zero NOTE: Receivers shall check that these bits are zero in order to determine the valid status of the other fields in the same scope. Service Description Channel (SDC): channel of the multiplex data stream which gives information to decode the servic
30、es included in the multiplex NOTE: The SDC also provides additional information to enable a receiver to find alternative sources of the same data. ETSI ETSI TS 102 386 V1.2.1 (2006-03) 7 3.2 Abbreviations For the purposes of the present document, the following abbreviations apply: AM Amplitude Modul
31、ation AMDS Amplitude Modulation Data System AMSS AM Signalling System CRC Cyclic Redundancy Check DRM Digital Radio Mondiale FAC Fast Access Channel HF High Frequency LF Low FrequencyLSb Least Significant bit MF Medium Frequency MSb Most Significant bit rfa reserved for future addition rfu reserved
32、for future use SDC Service Description Channel 4 General Digital Radio Mondiale (DRM) provides a system for digital transmission in the broadcasting bands below 30 MHz. These bands are also used globally for analogue broadcasting and many hundreds of millions of listeners regularly tune in. The tran
33、sition from the analogue to the digital world requires careful planning by broadcasters so as to move at the speed of their audiences. The AM signalling system specified in the present document provides a tool for easing the transition from analogue to digital. It allows limited additional service i
34、nformation features to be provided to analogue listeners (for example, assisted re-tuning) in order to give them a taste of the full enhancements provided by digital broadcasting (for example, greatly improved audio quality). Further, it assists DRM receivers equipped with AM decoders with AMSS to f
35、ind DRM transmissions of the same service in the same area or when the receiver is moved to a new area. The AM signalling system makes use of the service information signalling from DRMs SDC to reduce the complexity of the database management in combined DRM/AM receivers and the coding and modulatio
36、n basis of the AMDS system specified in ITU-R Recommendation BS.706 2. The AM signalling system uses phase modulation of the AM carrier to provide a low data rate digital signal path from broadcaster to receiver. The modulation scheme parameters are chosen so as to provide this data path without cau
37、sing obtrusive impairment to the audio. Error control mechanisms are included in the baseband coding scheme. 5 Service information 5.1 Introduction This clause describes the format and content of the service information provided by the system. To allow simple decoding of data in a combined DRM/AM re
38、ceiver, the DRM SDC 1 is used as the coding mechanism, although certain restrictions apply. Two data blocks are transmitted alternately to provide fast identification of the broadcast and service information to enhance the listeners experience. Each data block has a payload of 36 data bits. 5.2 Use
39、of SDC data entities The SDC data entities specified for DRM (see ES 201 980 1, clause 6.3) provide many features. Some of these are not required for AM services. Furthermore, DRM can transport up to four services in a multiplex (audio or data), whereas AM carries only one audio service. The followi
40、ng restrictions and rules apply to the use of the SDC data entities. ETSI ETSI TS 102 386 V1.2.1 (2006-03) 8 5.2.1 Permitted SDC data entities Table 1 lists the data entities that are permitted to be carried. Table 1: SDC data entity usage Data entity Name Permitted? 0 Multiplex description No 1 Lab
41、el Yes 2 Conditional Access Parameters No 3 AFS - Multiple frequency network information No 4 AFS - Schedule definition Yes 5 Application information No 6 Announcement support and switching Yes 7 AFS - Region definition Yes 8 Time and date information Yes 9 Audio information No 10 FAC channel parame
42、ters No 11 AFS - Other services Yes 12 Language and country Yes 5.2.2 Usage rules for SDC data entities The Short Id field shall always be set to “00“ and refers to the service identifier carried in each AM signalling group. 5.3 Structure To allow fast identification of the broadcast, the service id
43、entifier is provided in every AM signalling group. In addition, service information, coded as SDC data entities, can be transported using an addressed segmentation system that permits an efficient error control mechanism. The AM signalling group is divided into two blocks, called block 1 and block 2
44、 (see clause 6). 5.3.1 Segmentation SDC data entities may be sent singly or aggregated together. Padding bytes are added if the overall data length is not a multiple of four bytes minus two. A CRC is calculated over the SDC data entities and padding (if present) and appended to form the data entity
45、group (see ES 201 980 1, annex D). The maximum overall length of the data entity group is 64 bytes. The data entity group is divided into a series of 4-byte segments. Figure 1 shows this process. SDC data entity k Data entity group . SDC data entity v CRC pad- ding segment 1 segment 2 segment n-1 se
46、gment n . SDC data entity p Figure 1: Segmentation scheme ETSI ETSI TS 102 386 V1.2.1 (2006-03) 9 The SDC data entity fields shall contain one of the permitted SDC data entities given in table 1. The padding field shall be of length 0 bytes to 3 bytes and shall contain bytes of value 0x00. The CRC (
47、Cyclic Redundancy Check) field shall contain a 16-bit CRC calculated over the SDC data entities fields and the padding field. It shall use the generator polynomial G16(x) = x16+ x12+ x5+ 1. See ES 201 980 1, annex D. NOTE: The calculation of the CRC differs from DRM because the AFS index is not incl
48、uded and padding could be required. The data entity group is divided into a number of segments (between 1 and 16), each 4 bytes long. 5.3.2 Block 1 coding This block allows for identification of the service and indicates the size of the data entity group transported in block 2. The information is as
49、 follows: - Version flag 1 bit. - AM carrier mode 3 bits. - Number of segments 4 bits. - Language 4 bits. - Service identifier 24 bits. The following definitions apply: Version flag: this flag changes state whenever the contents of the data entity group carried in block 2 changes. It indicates to the receiver that new information is available. AM carrier mode: this field shall be used to signal any dynamic carrier processing which is being applied to the transmission currently received according to table 2. Number of seg
