3.2kbps MMBE声码器的研究  

Study on Modified Multi-Band Excitation Vocoder at 3.2 kbps

作　　者：胡剑凌[1] 徐盛[1] 陈健[1] 

机构地区：[1]上海交通大学电子工程系,上海200030

出　　处：《数据采集与处理》2000年第3期284-287,共4页Journal of Data Acquisition and Processing

摘　　要：提出了一种改进的多带激励 ( Modified multi- band excitation,MMBE)语音压缩编码算法以适用于低码率通信系统。作为一种多带激励 ( Multi- band excitation,MBE)编码器 ,MMBE根据重构信号谱与原始信号谱之间的相似程度来进行基音估计和浊清音判决 ,而其中基音参数的估计准确性将直接影响编码器的性能。文中提出的 MMBE算法采用了一种改进的基音估计算法以及基音轨迹跟踪方法 ,利用该方法既能保证基音周期的估计准确性 ,又能保证基音演变的平滑性。非正式主观测试表明 ,在相同码率下由 MMBE重建的语音质量明显优于 IMARSART- M标准IMBE,而在 3.2A modified multi-band excitation (MMBE) algorithm is p resented for low bit rate speech coding. As a kind of MBE codec,the MMBE estima tes the pitch period and determines the voiced/unvoiced speech according to the similarity between the reconstructed specturm and the original one,where the es timated error of pitch period would seriously degrade the speech quality. Here t he MMBE employs a modified pitch detection algorithm. Informal subjective test s hows that the quality of speech synthesized by the MMBE is superior to the IMARS AT-M MMBE coder at the same bit rates and is comparable with it at 3.2 kbps.

关 键 词：基音检测 语音编码 多带激励 声码器 

分 类 号：TN912.32[电子电信—通信与信息系统]