G.726语音编解码系统的研究和实现

发布时间：2018-07-03 02:31

本文选题：G.726标准 + ADPCM　；参考：《华中科技大学》2014年硕士论文

【摘要】：随着通信和移动互联网的发展，语音编码的发展速度越来越快，国际电信联盟也在不断的更新编码方案，G.726是国际电信联盟建议的一种波形编码方式，其特点是编码语音质量高，延时短，稳定性好。G.726是基于ADPCM(自适应差分脉冲编码调制)算法的，将标准的G.711输出信号进行再压缩。G.726是一种非常有效的语音波形编码方案，本文就旨在设计一个G.726编码系统，实现语音的采集、编解码、播放、存储、传输等功能。本文重点研究建议中的各个算法模块在DSP上的实现。该设计将编码算法从整体上划分为自适应量化和自适应预测两个模块：在自适应量化模块中，，分别实现了输入PCM格式转换、差分信号计算、量化定标因子自适应、自适应速度控制、单音信号和转移（瞬变）检测以及自适应量化6个子算法；在自适应预测模块中，实现了反向自适应量化、自适应预测和重建信号子算法。文中详细叙述了算法的硬件实现方案，并从成本，可靠性上都做了考虑，力争朝产品化和商业化上发展。本文严格遵循ITUG.726标准，按照标准的建议用MATLAB验证了每一编码模块，并创新地对算法进行了优化，满足编码算法MOS得分，算法验证符合要求后将其移植到DSP系统中，同时在一个系统中实现多种速率编码，很好的完成了一个G.726编码系统。
[Abstract]:With the development of communication and mobile Internet, speech coding is developing more and more rapidly, and the International Telecommunication Union (ITU) is constantly updating its coding scheme (G.726), which is a waveform coding method recommended by the International Telecommunication Union (ITU), which is characterized by the high quality of encoded speech. The delay is short, the stability is good. G. 726 is based on ADPCM (Adaptive differential Pulse Code Modulation) algorithm. Recompressing the standard G.711 output signal. G. 726 is a very effective speech waveform coding scheme. The purpose of this paper is to design a G.726 coding system. Achieve voice acquisition, codec, play, storage, transmission and other functions. This paper focuses on the implementation of the proposed algorithm modules on DSP. In this design, the coding algorithm is divided into two modules: adaptive quantization and adaptive prediction. In the adaptive quantization module, the input PCM format conversion, the difference signal calculation, the quantization scaling factor adaptation are realized, respectively. Adaptive speed control, single tone signal and transfer (transient) detection and adaptive quantization are 6 subalgorithms. In the adaptive prediction module, reverse adaptive quantization, adaptive prediction and reconstruction signal subalgorithms are implemented. In this paper, the hardware implementation scheme of the algorithm is described in detail, and the cost and reliability are considered in order to develop towards production and commercialization. According to the standard ITUG.726, this paper verifies every coding module with MATLAB, and innovatively optimizes the algorithm to satisfy the MOS score of the coding algorithm. The algorithm is transplanted to DSP system after the verification of the algorithm meets the requirements. At the same time, in a system to achieve a variety of rate coding, a good completion of a G.726 coding system.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN912.3

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