【作者】 范锦秀；

【导师】 赵欢；

【作者基本信息】 湖南大学 ， 计算机科学与技术， 2009， 硕士

【摘要】 高速发展的DSP技术为语音信号处理提供了强有力的工具,使实时实现各种复杂算法成为可能。针对不同应用,国际标准组织制定了一系列语音压缩编码标准,其中AMR-WB语音编码是3GPP组织于2001年3月制定的自适应变速率宽带语音编码标准,并被国际电信联盟电信标准部ITU-T选定为有线通信的宽带编码标准,其编码方法采用的是代数码本激励线性预测技术。与其他语音编码标准相比,AMR-WB语音编码器的重建语音具有更高的自然度和可懂度,可广泛应用于移动通信、ISDN宽带电话、ISDN可视电话和电视会议等领域,但其较高的计算复杂度限制了其在计算资源有限的某些领域的应用。本文的目标是在维持合成语音质量的前提下降低AMR-WB语音编码算法计算复杂度,并在TMS320C6416 DSP上实现AMR-WB语音编码的实时处理。本文对AMR-WB语音编码算法的时间复杂度、空间复杂度及合成语音质量进行了评估。评估测试表明:固定码本搜索算法的计算复杂度为674.13MIPS,占整个AMR-WB语音编码算法的40%左右。这是导致整个语音编码算法复杂度偏高的主要原因。针对上述问题,本文在充分研究了ACELP固定码本搜索方法的基础上,提出了一种基于AMR-WB固定码本结构的快速搜索方法,实验结果表明,与AMR-WB中深度优先树搜索方法相比,新方法不仅能够维持合成语音质量,更使固定码本搜索模块的计算复杂度降低了53.6%,整个语音编码算法的计算复杂度降低了21.2%;最后,对AMR-WB语音编码算法进行了基于TMS320C6416平台的移植和优化,完成了关键模块的C代码优化,实时实现了AMR-WB语音编码算法。更多还原

【Abstract】 With the rapid development of DSP technology, it becomes a powerful tool in the speech signal processing, which makes it possible to implement all kinds of complex algorithms in real time. Based on different applications, many standards of speech compress coding have been established by different international standardization organizations. The AMR-WB speech codec based on ACELP was approved by 3GPP in March 2001 and selected for wideband speech coding by ITU-T.Compared with other speech coding standards, AMR-WB is much more natural and intelligible, so it is widely used in Mobile Communications, ISDN wideband telephone, ISDN video telephone and video conferencing. But its high complexity limits its application in the area with critical hardware platform. The purpose of the thesis is to lower the complexity of AMR-WB, ensure the coding quality and implement the AMR-WB speech coding algorithm in real time on the platform of TMS320C6416.This thesis evaluated the computing complexity, memory space complexity and coding quality of AMR-WB coding algorithm. The results show that the computing complexity of fixed codebook search algorithm is 674.13MIPS, occupying 40% of the whole AMR-WB coding algorithm. This results in the high computing complexity of AMR-WB coding algorithm. In order to reducing the computing complexity of AMR-WB coding algorithm, this thesis proposed a fast fixed codebook search algorithm for AMR-WB coding algorithm on the basis of studying the methods of ACELP fixed codebook search. The results show that the computing complexity of the new algorithm reduces by 53.6% compared with deep first tree search algorithm in AMR-WB,not only reduces the computing complexity of the whole coding algorithm significantly, but also ensures the coding quality. Lastly, this thesis transported and optimized the AMR-WB coding algorithm with improved algorithm based on the platform of TMS320C6416 DSP, completed the optimization of kernal algorithms at the C code level and real-time implementation of the AMR-WB speech coding algorithm.更多还原