- 學位論文
AMR語音編碼檢測系統之製作
Implementation of a Conformance Test System for AMR speech codecs
摘要
語音傳輸是目前人際溝通最主要也是最普遍的通訊服務。近年來，多媒體無線通訊日益普及，目前已經有許多語音編碼系統被提出，其中有些更是被制定成為標準或規格。「第三代合作計畫」 (The Third Generation Partnership Project, 3GPP)為了在語音品質與通道容量之間提供一個最佳平衡而制定了一個稱為「適應性多重位元率」(Adaptive Multi-Rate, AMR) 的語音編碼標準。AMR speech codec是一種能在介於4.75至12.2kbit/s的範圍下，執行八種不同位元率的適應性多重位元率語音編碼系統，由於其優越的效能及廣泛的適用性，因此被3GPP採用為以WCDMA為核心網路 (core network) 的第三代行動通訊系統的語音編碼標準。 在本篇論文中，我們針對AMR語音編解碼系統建立一套標準的測試方法與驗證流程。在介紹AMR語音編碼系統所包含的概念與原則之後，我們接著詳述其符合性測試系統，包含其基本結構、測試方法、以及認證程序的理論。 實驗結果顯示，我們所發展的AMR符合性測試系統能夠提供標準的測試程序且其測試結果具有相當的可靠性。此測試系統同時能提供有益的技術支援可幫助發展AMR語音編碼系統的工程師們進行偵錯的程序。
並列摘要
Speech communication is the most dominant and common service in telecommunication. In recent years, the multimedia wireless communication has become more and more popular and many effective speech coding algorithms have been proposed and some of them have been standardized. The Third Generation Partnership Project (3GPP) defined a new speech coding scheme, namely the Adaptive Multi-Rate (AMR) speech codec, to supply the best balance between speech quality and channel capacity. The AMR standard is a speech coding algorithm operating at variable bit rates in the range of 4.75 to 12.2 kbit/s. Due to its toll quality performance and low complexity (below 20MIPS), the AMR has been adapted by the 3GPP as the mandatory codec for 3rd generation wireless systems based on the WCDMA core network. In this thesis, we realize the general AMR codec system and develop a standard test method and verification procedure for it. After introducing the principle of AMR speech codec, we describe the conformance test system for the AMR speech codec, including the structure of this system, the testing methods, and the methodology of the verification procedure. Our simulation results showed that our conformance test system can provide the standard conformance tests and reliable check results of an AMR codec system under test. This conformance test system also provides some useful technical supports to facilitate the AMR development engineers to do the debugging procedures.