题名 | 2400bps码率语音编码器的研究——基于波形内插语音编码算法 |
作者 | 徐金标 |
学位类别 | 博士 |
答辩日期 | 1999 |
授予单位 | 中国科学院声学研究所研究生部(北京) |
授予地点 | 中国科学院声学研究所研究生部(北京) |
关键词 | 语音编码 线性预测 矢量量化 波形内插 |
中文摘要 | 首先,全面系统地分析、介绍了Kleijn博士首先提出的典型波形内插语音编码算法(PWI)及其实现方法。同时,还详细介绍了Kleijn博士针对PWI编码算法的不足而首次提出的特征波形内插(CWI)语音编码算法。然后,在CWI的基础上,通过对CWI算法的研究,提出了一种新的线性预测语音编码模型,将线性预测残差基音周期波形分解为慢渐变基音周期波形(SEW)和快渐变基音周期波形(REW),这种分解方法通过对帧内的特征波形求均值得到慢渐变基音周期波形,特征波形与得到的均值之差就是快渐变基音周期波形。提出了一种简单而有效的谱矢量量化方法,即通过对特征波形填零的方式构造一个固定维数的通用码本对谐波矢量进行矢量量化,通用码本和结构化的矢量量化相结合减少了编码器的存储空间和计算复杂度,提高了量化效率。最后,对所提出的CWI语音编码器进行量化,得到2.4kbps码率的声码器,结果表明该声码器的语音质量明显高于LPC10e(FS1015),与4.8kbps的CELP(FS1016)算法接近。表明该CWI算法具有一定的实际应用。 |
英文摘要 | The current situation of the speech coding is summarized in this report. The principle and implementation method of the prototype waveform interpolation (PWI) speech coding are analyzed and introduced in detail. At the same time, the characteristic waveform interpolation (CWI) speech coding algorithm proposed by Kleijn first is also introduced specifically. Then, based on the CWI algorithm, through the research on CWI algorithm, a new linear predication speech coding model is presented. In this new model, we decompose the linear predictive residual pitch cycle waveform (CW) into the slowly evolving waveform (SEW) and quickly evolving waveform (REW). First, the extracted characteristic waveforms from residual signal are made DFT procedure, then, we obtain the mean of the DFT fourier coefficients of CW in one frame. The waveform of this mean DFT fourier coefficient vector represented is called as SEW, the fourier coefficient of the original CW subtracts this mean coefficient (or SEW), we obtain the fourier coefficient of REW. A simple and novel spectra vector quantization (VQ) method for SEW and REW is proposed in this report. Finally, the parameters of the proposed new CWI speech coding algorithm are quantized, spectively, the 2.4kps CWI speech codec is obtained. Listening tests shows the coded speech is better than that of LPC10e(FS1015), and is close to that of 4.8 kb/s CELP algorithms. The decoding speech of 2.4kbps shows it can deliver decoded speech of high communication quality. |
语种 | 中文 |
公开日期 | 2011-05-07 |
页码 | 57 |
内容类型 | 学位论文 |
源URL | [http://159.226.59.140/handle/311008/656] ![]() |
专题 | 声学研究所_声学所博硕士学位论文_1981-2009博硕士学位论文 |
推荐引用方式 GB/T 7714 | 徐金标. 2400bps码率语音编码器的研究——基于波形内插语音编码算法[D]. 中国科学院声学研究所研究生部(北京). 中国科学院声学研究所研究生部(北京). 1999. |
个性服务 |
查看访问统计 |
相关权益政策 |
暂无数据 |
收藏/分享 |
除非特别说明,本系统中所有内容都受版权保护,并保留所有权利。
修改评论