DMR系统转发模型的研究及中转台软件设计与开发

发布时间：2019-06-19 03:23

【摘要】：随着移动通信的发展,移动通信发展至现在的4G阶段并正在向5G迈进,专用无线通信也到了从模拟通信过渡到数字通信的阶段。数字专业无线通信系统能够提供更清晰的语音质量、更远的通信覆盖、更快的接通速度、更灵活的产品功能。目前,比较成熟的技术有TETRA系统和iDEN系统,但这两项技术的实现成本比较高,且专利比较多,直接对其开发比较麻烦。2005年欧洲电信标准协会(ETSI)提出了DMR标准。DMR标准主要适用于中低端的专用数字无线通信,技术实现简单,能兼容专用无线通信的模拟设备。近些年来DMR标准受到了越来越多的关注,目前市场上已经出现了采用DMR标准的数字对讲机产品。本文中首先介绍了数字对讲机在我国的发展近况,对市面上出现的各种数字对讲机的产品进行了对比及分析,得出其中最具发展潜力、且得到国内大多企业认可的就是DMR数字对讲机。之后本文详细介绍了DMR协议的基本内容,简单的描述了本文涉及到的DMR空中接口协议中的帧格式、信令、信道、与其他网络的通信等内容。对于只有一个中转设备的小型专业无线系统,本文对其性能进行了分析,得出了呼损率,话务量等性能之间的关系。最后对4个单工信道和2个双工信道的情况分别进行了爱尔兰呼损率的仿真。本文重点研究了DMR转发阶段中中转台的软件设计开发。详细分析了各个信令在中转台中的处理流程,中转台高层状态的转换,中转台中缓存的设计方案及可行性分析,最终设计出了中转台上DMR呼叫控制层协议的完整方案。然后在linux操作系统下,运行设计并编写好的软件,分单工和双工2种情况分别对实验过程中得出的结果进行分析,发现设计出的中转发程序能正确的将源对讲机端机发送的消息转发给目的对讲机端机,且语音清晰。最后,本文对本次项目中第一阶段的工作做了简单的总结。简单介绍了在DMR第一阶段中所做的工作内容,然后分别对键盘,LCD显示屏和写频软件进行了介绍,并展示了其实验结果。
[Abstract]:With the development of mobile communication, mobile communication has developed to 4G stage and is moving towards 5G, and private wireless communication has also reached the stage of transition from analog communication to digital communication. Digital professional wireless communication system can provide clearer voice quality, farther communication coverage, faster connection speed and more flexible product functions. At present, the more mature technologies are TETRA system and iDEN system, but the implementation cost of these two technologies is relatively high, and there are many patents, so it is troublesome to develop them directly. In 2005, the European Telecommunications Standards Association (ETSI) put forward the DMR standard. DMR standard is mainly suitable for special digital wireless communication at the middle and low end, and the technology implementation is simple and compatible with the analog equipment of special wireless communication. In recent years, more and more attention has been paid to DMR standard. At present, digital interphone products using DMR standard have appeared in the market. In this paper, the development of digital interphone in China is introduced, and the products of all kinds of digital interphone in the market are compared and analyzed, and it is concluded that DMR digital interphone is the most potential and recognized by most domestic enterprises. Then this paper introduces the basic content of DMR protocol in detail, and briefly describes the frame format, signaling, channel, communication with other networks and so on in the DMR air interface protocol involved in this paper. For a small professional wireless system with only one transit device, the performance of the system is analyzed in this paper, and the relationship between call loss rate, traffic volume and other performance is obtained. Finally, the Irish call loss rates are simulated for four single channels and two duplex channels, respectively. This paper focuses on the software design and development of DMR forwarding stage transit platform. The processing flow of each signaling in the transit platform, the transition of the high level state of the transit station, the design scheme and feasibility analysis of the cache in the transit platform are analyzed in detail. Finally, the complete scheme of DMR call control layer protocol on the transit platform is designed. Then, under the linux operating system, the designed software is run and written, and the results obtained in the experimental process are analyzed in two cases: simplex and duplex. It is found that the designed middle forwarding program can correctly forward the message sent by the source intercom to the target intercom, and the voice is clear. Finally, this paper makes a brief summary of the first stage of the project. This paper briefly introduces the work done in the first stage of DMR, then introduces the keyboard, LCD display screen and writing frequency software respectively, and shows the experimental results.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN929.5

【相似文献】