【作者】 李长春；

【导师】 陈向东；

【作者基本信息】 西南交通大学 ， 通信与信息系统， 2006， 硕士

【摘要】 无线电对讲机是移动通信中一个重要的分支,应用非常广泛,无线电对讲机和其它无线通信工具(如手机)其市场定位各不相同,难以互相取代,还将长期使用下去。在3G标准制定过程中,国际上对无线通信中的TDD方式第一次给予了高度重视,CDMA,TDMA系统中都制定了TDD的标准。TDD技术近年来在国际上受到越来越多的重视,但是基于TDD方式的数字对讲机在国内目前的应用中还很少。 本文分析了TDD双工方式的原理与技术特点。TDD技术具有节省频谱资源、适合不对称业务、设备成本低且便于实现等优势,能为无线通信系统提供一个低成本的解决方案。本文结合现有的无线通信技术、单片机技术以及语音编码调制技术等,研究和探讨了数字对讲机系统的TDD通信协议方案和整体结构。接着对微处理器、语音处理器和射频芯片进行了选型;并根据要求对数字对讲机的硬件电路进行了设计;然后对系统的软件进行了设计。最后将程序下载到电路中,对系统进行了调试和实验,并对结果进行了分析。实验证明,基于TDD双工方式的数字对讲机在技术上是可行的。 本文所研究的TDD数字对讲机,它为无绳电话、集群通信系统提供了另一种基于TDD方式的选择方案。另外,若系统以低成本、低功耗为出发点,完善系统的功能,达到应用简单、可靠,性能好,满足日常的语音通话等需求,则系统还可以在更多的地方进行推广。更多还原

【Abstract】 Wireless handset, an important offset in mobile communication, is applied at large. Wireless handset would be used in the future because it differ with other wireless communication devices such as mobile telephone on market orientation and they can’ t be substituted each other. TDD mode in wireless communication is firstly highly regarded in the world during constituting 3G standard, TDD standard is constituted in both CDMA and TDMA system. TDD technology is more and more regarded lately, but few of mobile communication systems based on TDD double mode are applied.The principle and characteristic of TDD double mode is analyzed in this thesis. TDD double mode has many advantages, such as less wireless resource to be occupied, supporting asymmetry services, lower cost equipment relatively, easier to be implemented, and so on. So that TDD technology can provide an economical resolvent for wireless communication systems. The TDD communication protocol and structure of the digital handset system is studied in this thesis, which is combined with the technologies of wireless communication, microcontroller and voice coding, etc. Then the element models such as microprocessor, voice processor and RF chip are chosen. Hardware of digital handset is designed according to its demand, and software of this system is designed then. In the end, program is downloaded to hardware, system is debugged and experimented, and the result of experimentation is analyzed. Experimentation proved that TDD digital handset is feasible in technology.The digital handset studied in this thesis can provide another resolvent based on TDD for the Trunked communication system and cordless phone system. Moreover, if taking low cost, low power as a starting point, the system, which function has been perfected, is wieldy, reliable, and has well performance enough to satisfy demand on daily telephone conversation, the system also may be generalized in more areas.更多还原