1、QUESTION ITU-R 56-1/6 Characteristics of terrestrial digital sound broadcasting systems for reception by vehicular, portable and fixed receivers (1993-2006) The ITU Radiocommunication Assembly, considering a) that there is an increasing requirement by some countries for suitable means of broadcastin
2、g high quality stereo/multi-channel sound to vehicular, portable and fixed receivers; b) that significant progress has been made in technical studies on digital sound broadcasting systems and that some systems have been demonstrated with success; c) that it has been demonstrated that advanced digita
3、l sound broadcasting systems can lead to greater spectrum and power efficiency and immunity to multipath compared with conventional analogue sound broadcasting systems; d) that digital sound broadcasting systems can be designed to allow common signal processing in receivers for various broadcasting
4、bands; e) that digital sound broadcasting systems can provide national, regional and local terrestrial services; f) that it would be advantageous for a digital sound broadcasting system if a common receiver, capable of receiving terrestrial and satellite services, could be designed; g) that digital
5、sound broadcasting systems may be configured to transmit programmes with lower bit rates in order to trade quality against the number of sound channels; h) that new digital sound broadcasting systems will be able to provide additional facilities for programme-related and non programme-related data;
6、j) that the World Administrative Radio Conference (Malaga-Torremolinos, 1992) (WARC-92) asked the former CCIR to undertake as a matter of urgency the technical studies associated with terrestrial digital audio broadcasting, decides that the following Question should be studied 1 What are the technic
7、al characteristics of digital sound broadcasting systems for reception by vehicular, portable and fixed receivers? 2 What are the most suitable VHF/UHF bands, technically, economically and from a sharing and programme capacity point of view, for the implementation of a terrestrial digital sound broa
8、dcasting service? 3 What are the system and service requirements for a digital sound broadcasting service? C:DOCUMENTS AND SETTINGSQGV33745MY DOCUMENTSDOWNLOADSR-QUE-SG06.56-1-2006-MSW-E.DOC 4 What are the most appropriate source coding, channel coding, multiplexing and modulation systems for a digi
9、tal sound broadcasting service? 5 What are the effects of normal, abnormal and very abnormal propagation, including multipath on digital sound broadcasting systems? 6 What protection ratios are required to prevent mutual interference between different digital sound broadcasting services and other se
10、rvices using the same and adjacent frequency bands? 7 What are the necessary planning criteria for national, regional and local area coverage for vehicular, portable and fixed reception? 8 What advantages can be obtained by the combined use of satellite and terrestrial services operating in the same
11、 frequency band? 9 What influence to the increase of the efficiency of utilization of digital broadcasting systems in moving transport can cause the utilization of diversity reception? 10 What is the efficiency of utilization of hierarchically modulated signals? NOTE 1 See Recommendations ITU-R BS.774 and ITU-R BS.1114, further decides 1 that the results of the above studies should be included in (a) Recommendation(s); 2 that the above studies should be completed by 2008. Category: S1
