【作者】 袁帅；

【导师】 归琳；

【作者基本信息】 上海交通大学 ， 电子与通信工程， 2011， 硕士

【摘要】 随着移动通信技术的迅速发展,移动多媒体已经成为一个新兴的研究和利用领域。同时伴随着手机产品全面进入了智能手机时代,移动多媒体系统在智能手机终端上的研究和开发也已成为最为热门的发展方向。其中CMMB技术,作为中国移动多媒体广播的行业标准,得到了越来越多的关注。在这一背景下,本文针对CMMB在智能移动终端上的设计与实现进行了研究,从系统架构,硬件设计,以及软件设计的角度全面剖析了CMMB系统,提出了了一种全新的基于Android平台的CMMB系统的解决方案。该方案遵循CMMB规范,提供了完整的硬件设计,和基于Android的分层次模块化的软件设计,实现了CMMB移动手机电视的接收和播放,并且经过了测试,在性能上基本达到了商用的标准。本文首先介绍了该解决方案的系统架构,从软硬件相结合角度作了系统化的设计方案,结合CMMB标准描述了该解决方案中所涉及的硬件平台和软件架构。然后介绍了CMMB软件设计,本文设计一种与Android分层结构对应的模块化软件架构,给出了CMMB Service,Play Engine,以及Linux驱动三个软件模块的具体设计与实现方案。在Android的应用程序框架层,设计了CMMB Service模块,实现了抽象解调器,解复用,以及向上层提供编程接口的功能。针对解码MFS流的要求,设计了Play Engine模块,在Android的系统库层实现了多媒体框架“Stagefright”的CMMB插件,实现了解码音视频的功能。针对真实硬件解调器芯片,在Android操作系统内核层设计了解调器芯片的驱动程序。接着介绍了CMMB硬件电路设计,围绕射频外围电路,解调器芯片,以及应用处理器这三个主要硬件子系统,以及它们之间的互联设计了CMMB的硬件系统。对TD信号的干扰,静电干扰进行了优化,引入SAW滤波器和ESD二极管,同时通过应用处理器和解调器芯片的通讯接口实现了互联,实现了硬件系统的正常工作。通过测试表明,该CMMB硬件系统工作正常,功能与设计预期完全一致,在接收灵敏度测试中达到了良好的接收性能。最后,介绍了课题在工程实践中的具体工作任务和完成情况,给出了成果的展示。同时介绍了CMMB系统在整机情况下的接收性能测试,给出了测试数据,并对测试结果进行了分析。实践证明,本文论述的方案在设计流程与实现方法上能够在Android系统上有效地实现CMMB功能,是一种很好的实现方法。本文可以为诸如移动多媒体和智能移动系统,嵌入式系统的适配,移植等相关课题的研究和开发提供参考和借鉴,同时也为进一步的深度研究奠定了基础。更多还原

【Abstract】 With the rapid development of mobile communication technology, mobile multimedia has become a new field of research and utilization. In the meantime, with the mobile phone to enter the Smartphone era, research and development of mobile communication on Smartphone terminals has become the hot spot of the mobile development. CMMB technology, as China’s mobile multimedia broadcasting industry standard, gets more and more attention.In this context, this paper researches the design and implementation of CMMB system on smart mobile terminals. From aspect of system architecture, hardware design and software design, a new solution of design and implementation for CMMB system based on Android Platform is presented. This solution follows CMMB specifications, provides complete hardware design, and software design based on the Android system, realize receiving and playback function of CMMB mobile TV. Test results show that this solution’s performance meets commercial standards.This paper, firstly, introduces an overview of system architecture. From the aspect of hardware and software, this solution’s hardware platform and software architecture are described combined with CMMB specifications.Then this paper introduces software design, which is a modular software architecture with the corresponding layered structure in Android architecture, describes design and implementation of three modules in software system: CMMB Service, Play Engine, and Linux driver. In Android application framework layer, CMMB Service module is designed, realize the abstraction of demodulator, demux function and application programming interface for upper layer. For decoding MFS stream, Play Engine module is designed as a CMMB plug-in for Android multimedia architecture“Stagefright”in Android system libraries layer to realize the function of decoding audio and video. In Android operating system kernel layer, demodulator chip’s Linux driver is designed.Then hardware design is introduced, mainly describes three main hardware subsystems: RF circuit, CMMB demodulator, and Application processor, along with their interconnection. In order to optimize the interference of TD signal and ESD, SAW filter and ESD diode are introduced. Test results show that CMMB hardware works well, consistent with expected, and achieve good result in receiving sensitivity test.Finally, this paper introduces specific tasks and their completion in engineering practice. Some demonstrations are provided. Meanwhile, this paper introduces CMMB overall machine’s conductive and radiated sensitivity test, test data are provided along with their analysis.Practice proves, this paper’s solution is a good one which can effectively achieve CMMB function on Android platform in design process and implement method. This paper can be used as a reference for relevant subject research and development such as mobile multimedia, smart mobile system, embedded system adaption and porting. This paper also lay the foundation of further in-depth research.更多还原