Research and Implementation of the Internet Telephone Based on a Digital Signal Processor

[[abstract]]隨著寬頻網路的快速發展，使用網際網路來進行語音通訊已成為未來的趨勢。基於德洲儀器TMS320 C6000系列DSP的強大運算能力，本論文設計並實現了一套以C6711 DSP為核心的嵌入式網路電話雛型系統，具備了獨立化，處理速度快以及使用方便等優點。 本系統在硬體中設計了一塊可供C6711 DSK開發板使用的電話介面子卡，可以讓使用者把一般的電話機連接上網路電話系統，進而降低使用上的學習門檻。在軟體方面，我們結合了ITU G.729A語音壓縮演算法及網路運作核心，使用即時多工作業系統DSP/BIOS來開發網路電話的系統程式。在開發過程中，我們利用C6711 DSP的硬體特性來有效的降低G.729A所耗用的運算量，並且使系統程式能穩定地達到即時多工運作的效果。系統在設計時採模組化設計，未來如果要更換更佳的語音演算法，都只要更新部份程式即可。[[abstract]]With the rapid development of the board band networking, it becomes the upcoming trend to communication over the Internet. Due to the powerful computation ability of Texas Instruments TMS320 C6000 DSP, an embedded VoIP prototype was designed to perform in it. Our system has several advantages especially it is a stand-alone system. In this system, we design a telephone interface daughter card for C6711 DSK. It can provide the users to connect the regular phone to our system, this will reduce their learning curve when using. In terms of the software, we combine ITU G.729A speech coder and the codes of network function, with using the real time operation system DSP/BIOS to provide task scheduling. Our system utilized the property of C6711 DSP well to efficiently reduce the computation time. Moreover, our system is designed in modules, and it can be easily renewed by loading additional codes if Programmer wants to upgrade it