高质量4～8kb/s变速率有限状态ACELP 语音编码算法研究  

4~8kb/s Variable Rate-Finite State-Algebraic Code Excited Linear Prediction Speech Coding Algorithm

作　　者：唐昆[1] 崔慧娟[1] 刘志勇 冯重熙[1] 

机构地区：[1]清华大学电子工程系

出　　处：《电子学报》2000年第1期21-25,共5页Acta Electronica Sinica

摘　　要：４～８ｋｂ／ｓ变速率有限状态代数码激励线性预测语音编码（ＶＲ－ＦＳ－ＡＣＥＬ）是一种具有延时较短、合成语音质量高、算法复杂度较低的语音编码算法．在线性预测（ＬＰ）参数量化上，使用预测式分裂式矢量量化，获得很高的量化效率．在自适应码本搜索上，采用了有限状态控制分数延时搜索的算法，有效地降低了运算量．对于随机码本，采用了具有多模结构的代数码本，提高语音合成质量．对于激励码序列的增益，采用了预测式矢量量化，有效地提高了量化精度．经非正式听音测试，其中４ｋｂ／ｓ的合成语音质量超过了北美 ８ｋｂ／ｓ ＶＳＥＬＰ，接近长途质量，而６ｋｂ／ｓ和 ８ｋｂ／ｓ合成语音质量达到了长途质量，与 Ｇ．７２９８ｋｂ／ｓ ＣＳＡＣＥＬＰ相当．4~8kb/s Variable Rate-Finite State-Algebraic Code Excited linear Prediction (VR-FS-ACELP) is a high -quality speech coding algorithm which has shorter time delay and low calculation burden. For line spectrum Pairs, this algorithm uses a highly efficient split vector quantizer based on intra-frame and inter-frame correlations. For adaptive codebook searching, it uses a finite state fractional delay adaptive codebook which has low calculation complexity and high performance. This algorithm also uses a state controlled multimode algebraic codebook and a predictive vector quantizer for gains to further improve the quality of synthesized speech. The non-formal tests show that the speech quality of 4kb/s algorithm is better than that of IS-54 8kb/s VSELP and near to toll quality and the speech quality Of 6kb/s and 8kb/s algorithms reaches toll quality.

关 键 词：变速率 有限状态 语音编码算法 ACELP 

分 类 号：TN912.32[电子电信—通信与信息系统]