数字语音TDD对讲机的设计和实现.pdf

电子科技大学硕士论文 ABSTRACT Today,the resources of frequency bandwidth e more and more exiguous because of the high—speed have been doing the best press the transmission channel frequency bandwidth or to reduce channel data design of4Kb/s data rates,which the paper has depicted,has its applied can be appIied to many domains such as munications,VoIP,munications. This paper plishes the hardware design and implementation of a pression system and aTDD(Time Division Duplex) system adopts an advanced specific pression chip based on AMBE can achieve pression rate at4Kb/ system first performs A/D conversion on analog speech input to obtain PCM signal and the PCM signal was encoded by the pression FPGA is used as controller,performing the necessary processing such as the system head ofthe encoded data frame,adding channel frame head and storing the speech data into the receiving end,a inverse process is performed to restore the analog speech paper first introduces some pression ,some analysis of the structure and principles of the system are given,placing emphasis on introducing the pression these done,the control programme pi led and simulated. Moreover, some improvements are ,the hardware debug is achieyed and the analysis of conclusion also is given. Keywords:pression AMBE algorithm Manchester FPGA FIFO 独创性声明本人声明所呈交的学位论文是本人在导师指导下进行的研究工作及取得的研究成果。据我所知,除了文中特别加以标注和致谢的地方外,论文中不包含其他人已经发表或撰写过的研究成果,也不包含为获得电子科技大学或其它教育机构的学位或证书而使用过的材料。与我一同工作的同志对本研究所做的任何贡献均已在论文中作了明确的说明并表示谢意。签名:烈盎目期:湖lf年争月刁日关于论文使用授权的说明本学位论文作者完全了解电子科技大学有关保留、使用学位论文的规定,有权保留并向国家有关部门或机构送交论文的复印件和磁盘,允许论文被查阅和借阅。本人授权电子科技大学可以将学位论文的全部或部分内容编入有关数据库进行检索,可以采用影印、缩印或扫描等复制手段保存、汇编学位论文。(保密的学位论文在解密后应遵守此规定) 签名:童』叠圭导师签名:2訇!二至:兰日期:以年乒月j;日电子科技大学硕士论文 ,这反映在传输和存储语音信号的现代技术上,即语音信号的数字传输和数字存储技术上。, 有力地证明了数字语音通信的生命力。随着信息社会和通信技术的高速发展,特别是近10年来固定