【作者】 张健；

【导师】 吴乐南；

【作者基本信息】 东南大学 ， 信号与信息处理， 2006， 硕士

【摘要】 在数字化的大趋势下,在2G、3G对多媒体服务支持不力的情况下,数字广播成了多媒体服务的最佳载体。世界上各个国家和地区都在制订、或者已经制订了数字广播的标准,有些已经成功商业化。中国正处于标准制订时期,对现有数字广播系统的研究和学习,具有重要的借鉴意义,也有助于标准的加速制订,运营拥有更多的商机。现有的数字广播系统包括(已成标准或即将成为标准)DAB、DVB-C、DVB-H、MediaFLO、DRM、ISDB-T、T-DMB等。这些系统可以分成两大部分:传输部分和服务、应用部分。传输部分主要负责可靠地传输服务、应用的内容,主要采用COFDM技术来保证传输的可靠性;服务、应用部分主要是系统所承载的商业化服务内容,主要提供音频、视频和其他增值数据服务。在数字广播系统的传输部分,主要介绍了OFDM技术的参数设计理论,广播系统中所涉及各种关键技术,以及接收机的OFDM信号同步技术;在数字广播系统的应用、服务部分,主要介绍了商业化的应用类型,介绍了流行的音视频编码方案,以及结合IP的数据广播技术。本文对数字广播系统的两大部分都有所涉及:传输部分在仿真的基础上,总结了OFDM的同步方法,对有些数字广播系统提出完整的同步方案;应用、服务部分在DSP实现,软硬件实现的基础上,开发并验证了两类服务类型,并且保证服务的广播系统独立性,对现有的商业化服务做了积极的探索和有益的补充。最后还结合当前流行的技术,对数字广播系统作出预测和展望,以期对中国的数字广播标准有微薄的借鉴意义。更多还原

【Abstract】 Following the trend of digitalization, digital broadcasting is the best carrier for multi-medium since 2G and 3G can’t manage it. Many countries have been involved in making the standards for digital broadcasting, and some have finished and even commercialized the results successfully. However, China is still under the establishment of the standards. We maintain that the study on current digital broadcasting system brings some reference to this topic and advances the process. Definitely, it can help with more commercial opportunities.The present digital broadcasting system includes (standardized or to be standardized) DAB、DVB-C、DVB-H、MediaFLO、DRM、ISDB-T、T-DMB and so on, which are mainly divided into two categories, transporting, as well as severing and application. The transporting part, mainly adopting COFDM, is in charge of transporting service and the content of application. While the severing and application part are the commercialized service, such as audio、video and data services .For the transporting part, the paper introduces the theory of parameter design in OFDM, the key technologies in broadcasting system, and the synchronization in OFDM receivers .As for the other part, it introduces the varieties of commercialization, the popular standard of audio and video, and the digital broadcasting technology combined with IP.Based on simulation, the transporting part summarizes the synchronization algorithms of OFDM and offers a complete set of synchronization scheme for relative digital broadcasting systems. Besides, based on the implementation of DSP and software as well as hardware, the application and severing part develops and testifies two service patterns and ensures the independence of services, which are the effective exploration and useful supplement for commercialization.What’s more, the thesis gives some predictions on the development of digital broadcasting with the reference of current prevailing technologies, hoping to be beneficial to the growth of digital broadcasting of China.更多还原