1、 STD.ITU-R HDBK TSD-ENGL 1995 II 4855212 0540880 360 I INTERNATIONAL TELECOMMUNICATION UNION ITU-R SPECIAL PUBLICATION TERRESTRIAL AND SATELLITE DIGITAL SOUND BROADCASTING TO VEHICULAR, PORTABLE AND FIXED RECEIVERS IN THE VHFNHF BANDS RADIOCOMMUNICATION 6UREAU Geneva, 1995 STD-ITU-R HDBK TSD-ENGL 17
2、95 R4 4855232 054J8BL 2T7 II INTERNATIONAL TELECOMMUNICATION UNION ITU-R SPECIAL PUBLICATION TERRESTRIAL AND SATELLITE DIGITAL SOUND BROADCASTING TO VEHICULAR, PORTABLE AND FIXED RECEIVERS IN THE VHF/UHF BANDS RADIOCOMMUNICATION 6UREAU Geneva, 1995 STDJTU-R HDBK TSD-ENGL 1995 m YEMZLZ 0540a11z 133 m
3、 TERRESTRIAL AND SATELLITE DIGITAL SOUND BROADCASTING TO VEHICULAR. PORTABLE AND FIXED RECEIVERS IN THE VHF/UHF BANDS TABLE OF CONTENTS FOREWORD 5 EXECUTIVE SUMMARY 7 Chapter 1 INTRODUCTION 1 0 Chapter 2 REQUIREMENTS AND OBJECTIVES FOR DSB SERVICES 14 2.1 General requirements 14 2.2 Specific require
4、ments . 15 Chapter 3 SERVICE CONCEPTS 18 3.1 Terrestrial DSB . 18 3.1.1 Single transmitter coverage 19 3.1.2 Distributed emission using multiple transmitters . 20 3.1.2.1 Single frequency network (SFN) 21 3.1.2.2 Gap fillers 24 3.1.2.3 Coverage extenders . 25 3.2 Satellite DSB . 26 3.2.1 Satellite-o
5、nly DSB 26 3.2.2 Hybrid satellite/terrestrial DSB 26 3.3 Mixed satellite/terrestrial DSB . 32 Chapter 4 PROPAGATION CONSIDERATIONS IN THE FREQUENCY RANGE 30 - 3 O00 MHz 35 4.1 Propagation models . 35 4 .I . 1 Terrestrial paths 35 4.1.2 Space-to-Earth paths . 36 4.2 Time and frequency variation . 37
6、4.3 Local variation 39 4.3.1 Large area distribution function 39 4.3.2 Small area distribution functions 39 4.3.3 The combined propagation model 40 4.3.4 Frequency selectivity effects 41 i:textdsbhbkt-cqnt.doc STDmITU-R HDBK TSD-ENGL 1995 W 4855212 0540863 07T m -2- i:textdsbhbkt-cantdoc STD-ITU-R H
7、DBK TSD-ENGL L975 4855212 0540884 Tob m 8.1 8.1.1 8.1.1.1 8.1.1.2 8.1.1.3 8.1.2 8.1.3 8.1.4 8.1.5 8.1.6 8.1.6.1 8.1.6.2 8 . 1.7 8.2 8.3 8.3.1 8.3.2 8.3.3 8.3.4 8.3.4.5 8.3.4.6 8.3.5 8.3.6 8.4 8.4.1 8.4.2 8.4.3 -3- Chapter 8 DSB PLANNING CONSIDERATIONS . 72 Terrestrial dedicated-band systems . 72 Pol
8、arization . 72 Propagation factors influencing the choice of polarization 72 Practical aspects 72 Interference . 72 Receiving antennas . 73 Minimum usable field strength . 74 Propagation margins . 75 Transmitter power considerations . 78 Frequency reuse considerations 79 Transmitter separation dista
9、nces . 81 Re-use distance between two SFNs carrying different programmes 83 Computer planning methods . 84 Terrestrial FM overlaid systems . 85 Satellite DSB . 85 Polarization . 85 Carrier-to-noise ratio . 86 Characteristics of feeder links 86 Receiving antennas . 87 Mixed satellite/terrestriaI rece
10、ption 88 Low cost antennas for BSS (sound) 88 Propagation (link) margins . 93 Examples of link budgets 95 Mixed satellite/terrestrial DSB . 96 Coverage scenarios . 96 Frequency reuse considerations 100 Band segmentation versus use of the mixed concept . 103 BIBLIOGRAPHY 104 Chapter 9 SHARING FOR DSB
11、 SERVICES . 105 9.1 Protection ratios 105 9.1.1 Intra-service protection ratios . 105 9.1 . 1. 1 Terrestrial DSB . 105 i:textdsbhbkt-cont.doc 9 . 1 . 1.2 Satellite DSB 105 9.1.2 Inter-service protection ratios 106 9.1.2.1 Terrestrial DSB 106 9.1.2.2 Satellite DSB 106 9.2 Sharing cases 106 9.2.1 Band
12、 I . 106 i:textdsbhbkt-cont.doc STD-ITU-R HDBK TSD-ENGL L995 4855232 054088b 889 m -5- FOREWORD This Special Publication provides information on the studies relating to novel systems of sound broadcasting using modern digital techniques, normally referred to as “Digital Sound Broadcasting” (DSB). It
13、 provides information on technical characteristics of terrestrial and satellite digital sound broadcasting (DSB) systems for individual reception by vehicular, portable and fixed receivers in the frequency range 30 to 3 O00 MHz1. The document is primarily intended for those interested in the new sys
14、tems and for organizations or administrations intending to implement DSB services. Although not absolutely essential for an appreciation of the contents, a knowledge of radio broadcast engineering and basic digital techniques would be useful. ITU-R Working Parties 10-1 1 S and 10B have been involved
15、 in studies related to digital sound broadcasting (DSB) for satellite and terrestrial services, respectively, for several years. Working Party 10-1 IS has been studying satellite and complementary terrestrial sound broadcasting aimed at mobile, portable and fixed receivers. These studies are contain
16、ed in Report ITU-R B0.955-2. This Report includes information, inter alia, on digital systems characteristics, propagation conditions in the frequency bands considered, results of demonstrations and field tests, frequency planning aspects and sharing constraints. Working Party 10-1 1s revised Report
17、 955-2 at its meeting in October 1993 in order to take into account the decisions of WARC-92 and further technological developments. At the same time, Working Party 10-1 1s adopted a revision to Recommendation ITU-R B0.789 specifying a list of characteristics for digital sound broadcasting systems f
18、or BSS (sound) in the frequency range 500 - 3 O00 GHz. In addition, the Working Party adopted Recommendation ITU-R B0.1130 on a system for BSS (sound) in the frequency range 1 O00 - 3 O00 MHz. The latter document gives, in its Annex 1, a recommended process to seek consensus on a draft new Recommend
19、ation on digital sound broadcasting systems. In Autumn of 1994, Working Party 10-1 1 S agreed upon the draft revisions to Recommendation ITU-R B0.1130 in order to recommend that administrations which wish to implement BSS (sound) services meeting some or all the requirements as stated in ITU-R B0.78
20、9 in the near future, consider the use of Digital System A which is described in Annex l. A parallel process has been carried out within Working Party 10B on terrestrial sound broadcasting. Report ITU-R BS.1203 summarizes the studies in this area. Recommendation ITU-R BS.774, similar in form to Reco
21、mmendation ITU-R B0.789, has been adopted by Working Party 1 OB on the requirements for terrestrial digital sound broadcasting systems. In Autumn of 1994, Working Party 10B agreed to the draft revision of Recommendation ITU-R BS.1114 to recommend Digital System A to be used for terrestrial sound bro
22、adcasting services to vehicular, portable and fixed receivers in the frequency range 30 - 3 O00 MHz. Satellite sound broadcasting systems operating at 11/12 GHz, suitable for reception by fixed receivers, are described in Recommendation ITU-R B0.712. i:textdsbhbkpartle.doc STD-ITU-R HDBK TSD-ENGL In
23、 November 199 1 , Working Party 1 O- 1 1 1995 E 4855232 0540887 715 m -6- S appointed Mme. Giovacchini (France) as a Special Rapporteur, assisted by volunteers from various administrations, to prepare a handbook on satellite sound broadcasting to vehicular, portable and fixed receivers in the range
24、500 - 3 O00 MHz. This work was assisted by Messrs. E. Warren (Australia), F. Conway (Canada), M. Meilhoc (France), G. Towler (UK) and D. Messer (USA). At the same time, similar activity, aiming at converting Report ITU-R BS.1203 into a handbook was carried out within Working Party 1 OB. There is a n
25、eed to achieve maximum commonality between satellite and terrestrial systems and services. Furthermore, it is widely recognized that the benefits of complementary use of satellite and terrestrial systems may lead to a system convergence allowing a common receiver with common processing VLSI circuits
26、 and manufacturing of low cost receivers through mass production. Accordingly, the chairmen of Working Parties 10-1 1 S (R. Zeitoun, Canada), and 10B (A. Keller, France) and members of the Working Parties decided to join efforts in preparing one comprehensive handbook on digital sound broadcasting t
27、o vehicular, portable and fixed receivers in the frequency range 30 - 3000 MHz, describing both satellite and terrestrial DSB systems and services. Mr. Franc Kozamernik (EBU) was appointed as a Rapporteur to prepare this joint handbook. He was assisted by Mlle. Garnier (France) and Messrs. Ravanello
28、 (Australia), Assis (Brazil), Conway, Chouinard, Fortin, Trenholm and Zeitoun (Canada), Keller (France), Mgele and Petke (Germany), Messer (USA), Williams, Middleton and Towler (UK), OLeary (EBU), Nickelson and Rossi (ITU) and other members of Working Parties 10-1 1 S and 1 OB and the ITU-R Secretar
29、iat. During the preparation of the handbook, a decision to progress it in the form of a Special Publication was taken. The above group subsequently completed this Special Publication, after having held a meeting in June 1994 in Ottawa, Canada. The document was approved by Working Parties 1 O- 1 1 S
30、and 10B at a joint meeting held in November 1994 in Geneva, during which time the relevant Recommendations for DSB systems were also approved. This Special Publication was drawn up to reflect the latest state of technology and developments in the subject at the time of writing. It is based on the fo
31、llowing documents: - Report ITU-R B0.955-2, as revised in October 1993, - Draft BSS(sound) handbook (version October 1993) (Document 10- 1 1 S/I 29), - Report ITU-R BS.1203, as revised in OctoberiNovember 1993, - Recommendations ITU-R BS.774 and B0.789, - Draft new Recommendations ITU-R BS.1114 and
32、B0.1130, - other ITU-R Reports and Recommendations, and - new draft documents supplied by members of the Rapporteurs Group. An important source of information was the Proceedings of the Second International Symposium on Digital Audio Broadcasting held in March 1994 in Toronto. Most of the informatio
33、n included in this Special Publication is based on studies and tests undertaken in Canada, Germany, France, the Netherlands, the United Kingdom, Sweden, the United States and by the EBU in association with the Eureka- 147 Project. It is anticipated that revisions to this Special Publication will be
34、made in the future as experience is gained in service implementation and the technology developed further. STD-ITU-R HDBK TSD-ENGL 1475 m 4855212 0540888 b51 -7- EXECUTIVE SUMMARY This Special Publication describes the system and service requirements for digital sound broadcasting (DSB) to vehicular
35、, portable and fixed receivers, techniques employed in the digital sound broadcasting systems, and considers relevant planning parameters and sharing considerations. The Special Publication also makes reference to common system characteristics of the mixed satellite/terrestriaI digital sound broadca
36、sting service concept as well as the hybrid delivery concept. The mixed satellite/terrestriaI service concept is based on the use of the same frequency band by both satellite and terrestrial broadcasting services to the same receiver. The hybrid delivery concept is based on the use of low power terr
37、estrial “gap fillers” to improve the satellite coverage. The main text of the Special Publication includes the background engineering information that can be used by DSB system and service planners. An effort has been made to include generic information applicable generally to different digital syst
38、em approaches. More specific information, including the test and measurement results on Digital Systems A and B as well as the FM-overlaid system approach is given in the relevant Annexes. The Special Publication structure therefore permits future additions, as appropriate, as new experimental evide
39、nce becomes available or new system approaches may appear. Each chapter in this Special Publication is reasonably self-contained to enable readers seeking information on a particular topic. To assist Understanding, a glossary of terms and abbreviations is given at the end of the publication. Chapter
40、 1 introduces the topic of digital sound broadcasting and gives the main reasons why the use of new technology is required; it also provides a brief history of the subject. Chapter 2 outlines the principle requirements and objectives for DSB services in terms of sound quality, service availability a
41、nd coverage requirements. Some specific requirements which new technology is able to provide are also listed. In particular, some DSB systems are able to provide a range of sound reproduction qualities, including the highest when required, to a single receiver, whether mobile, stationary, or portabl
42、e from either a terrestrial or satellite source. Chapter 3 describes how the new DSB systems can be used to provide terrestrial and/or satellite services to national, sub-national and supra-national areas. For terrestrial wide area coverage, two methods are outlined. The first uses the conventional
43、method based on individual transmitters on different frequencies. The second method, only achievable using a specific version of the new technology, is based on the single frequency network concept (SFN). Here all transmitters in a given area utilize the same frequency block and carry the same progr
44、amme ensemble. Another application using digital technology consists of a system which overlays digital information with an existing FM transmission. This is termed the “in-band on-channel” (IBOC) system, a variation of this method is called the “in-band adjacent-channel” (IBAC) system. This concept
45、 appears to be attractive to those administrations unable to allocate new frequencies or to vacate currently used broadcasting bands for a DSB service. Further tests are being undertaken to verify the feasibility of such systems. i:textdsbhbkpartle.doc -8- Chapter 3 also describes the concept of usi
46、ng satellite delivery. The coverage from the satellite can be supplemented by low-powered terrestrial “fill-in” transmitters re-radiating the satellite signal; this is termed the hybrid system. Another satelliteherrestrial delivery system is termed the mixed concept whereby both the satellite and th
47、e terrestrial transmitter use the same frequency band, thereby maximizing spectrum efficiency. This is possible since any channels not allocated to the BSS for a service area could be used for terrestrial digital broadcasting, subject to co-channel re-use distances and sufficient adjacent-channel re
48、jection in the receiver. Chapter 4 supplies general background information on propagation models for terrestrial and satellite paths. These models may assist in planning DSB services; in addition, some consideration is given to the frequency-selective fading effects which are specifically relevant t
49、o digitally modulated signals. Chapter 5 outlines the use of diversity techniques which can improve the performance of a receiver when operating in a multipath environment. Frequency, time and spatial diversity are discussed. Chapter 6 describes the important elements of DSB systems, such as audio source coding, service multiplexing, channel coding and modulation, service information, ancillary data services and emission considerations. In audio source coding, reference is made to the studies undertaken by ISO/MPEG and relevant ITU working parties. Addi
