论文标题:基于声码器的900MHz数字对讲机研究
Research of 900MHz Digital Interphone Based on Vocoder
论文作者
论文导师 常义林,论文学位 硕士,论文专业 军事通信学
论文单位 西安电子科技大学,点击次数 547,论文页数 66页File Size1136K
2007-01-01论文网 http://www.lw23.com/lunwen_40554962/
Vocoder;G.723.1;CC1020;TDD
随着人们对移动通信需求的不断增加,具有即时沟通、一呼百应、经济实用等优点的对讲机越来越受到人们的青睐。目前市场上的对讲机主要工作在150MHz、400MHz和450MHz频段,传统的模拟对讲机由于其话音质量差、频带利用率低和保密性不高等固有缺点必将逐步退出市场。本文针对目前频率资源紧张、对讲机数字化程度低的实际情况,研究开发了一种新的基于声码器技术的900MHz频段数字对讲机。该对讲机采用先进的声码器技术实现了语音信号的低速率压缩编码、并依托无线数字收发芯片对编码数据进行数字调制、解调。并在此基础上,介绍了TDD(Time Division Duplex)时分双工技术,讨论了TDD协议的帧结构,并给出了时分双工通信的实现方法。最终实现的900MHz频段全双工数字对讲机具有广阔的应用前景。
With the increasing demand for mobile communication, interphone becomes more and more popular since it is instant, convenient and economical. At present, the Interphone available mainly works at 150MHz, 400MHz and 450MHz. The traditional analogue interphone will gradually withdraw from the market because of its inherent disadvantages such as poor speech quality, lower efficiency of bandwidth usage and lower security. With the current reality that the resource of frequency bandwidth is tensional and the extent of interphone digitization is low in mind, this paper presents a new 900MHz digital interphone on the basis of the technology of Vocoder. The advanced Vocoder technology is used in interphone to implement the low-rate speech signal coding, of which the digital modulation and demodulation is performed with the help of wireless digital transceiver chip. And on the basis of that, this paper introduces the TDD (Time Division Duplex), discusses the frame structure of the TDD protocol, and gives the way of realizing TDD. The 900 MHz full-duplex Digital Interphone invented has a promising prospect for broad application.
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