Design And Implementation Of CMMB System On ANDROID Platform

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.