代数码书分级分段优化搜索方法研究  

Study on the Algebraic Codebook Optimization Search Method based on Grade and Subsection

作　　者：李凤莲[1] 张雪英[1] 李红春[2] 李静[1] 

机构地区：[1]太原理工大学信息工程学院,太原030024 [2]中国人民解放军驻631所军事代表室,西安710119

出　　处：《信号处理》2013年第2期279-283,共5页Journal of Signal Processing

基　　金：山西省自然科学基金2012011014-1

摘　　要：代数码书作为一种流行的固定码书结构,其搜索方法直接影响解码语音质量及计算复杂度。本文提出了一种代数码书分级分段优化搜索GSOS(Graded and Subsection Optimization Search)方法。GSOS方法融合了脉冲替代法、分段搜索及分级优化方法的优点,通过创建优质的初始码书,达到提高初始码书质量的目的,并将码书矢量的乘法运算用分段子码书的加法运算替代,同时将脉冲按贡献不同进行分级,由此提高脉冲替代优化的搜索效率;将该方法用于自适应多速率宽带语音编码器AMR-WB固定码书搜索阶段,实验结果表明,所提出的搜索方法可使固定码书搜索计算量降为深度优先树搜索方法的13.75%,但解码语音质量只降低了4.01%,主观听觉感受基本感觉不出差异。Algebraic codebook is a popular fixed codebook structure; its searching method directly influences decoding speech quality and computational complexity. The paper puts forward a kind of algebraic codebook GSOS （ Graded and Subsection Optimization Search） Method. The method luses the advantages of pulse replacement, subsection searching and grade optimization method. It first creates good initial codebooks ; then proceeds codebook searching by subsection for replacing multiplication by the operation of addition; at the same time, the pulses are graded according to contribution degrees for improving the efficiencies of pulses replacement optimization . By using the proposed method to fixed codebook searching stage of AMR-WB （Adaptive Multi-Rate Wideband Speech Codec） , the experiment results showed that the proposed method can make the computational complexities of fixed codebook searching down to 13.75% of depth -first tree search procedure, but the decoding speech qualifies were only reduced by 4.01% . The subjective auditory almost did not feel the difference.

关 键 词：脉冲取代法 分段搜索方法 分级优化方法 深度优先树搜索方法 AMR-WB 

分 类 号：TN912.3[电子电信—通信与信息系统]