地面数字声音广播(DAB)及其覆盖规划的考虑

Terrestrial Digital Sound Broadcasting(DAB) And Consideration in Coverage Network Planning

简要描述了近几年来研究开发的为移动、便携和固定接收服务的地面发射数字声音广播(DAB)系统总的特点、应达到的技术和运行要求。重点介绍了系统采用的最适合克服移动接收中出现的多径效应影响的先进源编码技术(MUSICAM)、信道编码技术(COFDM)等的基本原理、系统参数、并介绍了规划DAB业务时,在VHF/FM频段考虑的最佳频段及频谱利用改善情况,还提供了DAB单频网洛(SFN)覆盖的大体情况。其内容取材均来自1990～1992年EBU、CCIR等的最新文稿资料。

General characteristics, technical and operational requirements for trrestrial digital sound broadcasting system (DAB) for vehicular, portable and fixed reception, which has been developed in the recent years are described briefly in this article. Emphasis is laid on the basic principles and system parameters of the advanced source coding (MUSICAM) and channel coding (COFDM) techniques employed in DAB system, which are particularly suitable for overcoming multipath effects in mobile reception. The optimum frequency band for DAB in the VHF/FM broadcasting band and improved spectrum utilization for plannimg the DAB service are discussed. A general description of the coverage provided single-frequency network (SFN) is given. All the information included in the article are mainly taken from the newest documents of EBU and CCIR in 1990 to 1992. The use of complicated mathematical equations are avoided.