A novel frame error concealment scheme is proposed to improve the decoded audio quality of the receiver for transform coded excitation（TCX）audio codec.This scheme,which is a gain control approach based on the stabil...A novel frame error concealment scheme is proposed to improve the decoded audio quality of the receiver for transform coded excitation（TCX）audio codec.This scheme,which is a gain control approach based on the stability of linear predictive coding（LPC）filter,predicts the lost frames by utilizing the linear spectrum frequency and different continuous attenuation factor of different kinds of lost frames.Signal noise ratio（SNR）test and multiple stimuli with hidden reference and anchor（MUSHRA）test are conducted to evaluate the performance of this approach in adaptive multi-rate wideband plus（AMR-WB＋）audio codec.Compared with the original frame error concealment scheme,our scheme achieves better audio recovery quality in AMR-WB＋audio codec.展开更多
世界数字广播(Digital Radio Mondiale,DRM)是数字调幅广播的国际标准,其信息媒介为音频信号。介绍DRM系统中广泛采用的MPEG-4高级音频编解码(Advanced Audio Coding,AAC)标准及相关算法,包括心理声学模型、滤波、量化、无噪声编码及时...世界数字广播(Digital Radio Mondiale,DRM)是数字调幅广播的国际标准,其信息媒介为音频信号。介绍DRM系统中广泛采用的MPEG-4高级音频编解码(Advanced Audio Coding,AAC)标准及相关算法,包括心理声学模型、滤波、量化、无噪声编码及时域噪声整形的实现原理,分析音频解码的基本流程。在工程应用阶段,为了优化硬件接收器的设计方法,利用C++语言编写接收器软件,用于模拟硬件设备的功能。经测试,该软件工具能够有效解码DRM音频信息。展开更多
针对超声波微弱信号接收和处理问题,进行了基于DSP(digital signal processor)开发板的采集前端分析与优化设计。采用下变频技术,充分利用了开发板上的音频编译码器实现微弱超声波信号采集。通过与普通ADC(analog-to-digital converter...针对超声波微弱信号接收和处理问题,进行了基于DSP(digital signal processor)开发板的采集前端分析与优化设计。采用下变频技术,充分利用了开发板上的音频编译码器实现微弱超声波信号采集。通过与普通ADC(analog-to-digital converter)采集方案的噪声系数进行对比,表明系统在微弱信号情况下,仍然可以获得较高的信噪比。该方案应用于一种便携式的超声波接收系统,使用户随时可以进行超声波信号的接收与处理工作。展开更多
基金Supported by the National High Technology Research and Development Program of China(863 Program)(2015AA016306)the Foundation of Outstanding Middle-aged and Young Scientific and Technological Innovation Team Program of Department of Education of Hubei Province(T201516)the Foundation of Department of Education of Hubei Province(Q20132207)
文摘A novel frame error concealment scheme is proposed to improve the decoded audio quality of the receiver for transform coded excitation（TCX）audio codec.This scheme,which is a gain control approach based on the stability of linear predictive coding（LPC）filter,predicts the lost frames by utilizing the linear spectrum frequency and different continuous attenuation factor of different kinds of lost frames.Signal noise ratio（SNR）test and multiple stimuli with hidden reference and anchor（MUSHRA）test are conducted to evaluate the performance of this approach in adaptive multi-rate wideband plus（AMR-WB＋）audio codec.Compared with the original frame error concealment scheme,our scheme achieves better audio recovery quality in AMR-WB＋audio codec.
文摘世界数字广播(Digital Radio Mondiale,DRM)是数字调幅广播的国际标准,其信息媒介为音频信号。介绍DRM系统中广泛采用的MPEG-4高级音频编解码(Advanced Audio Coding,AAC)标准及相关算法,包括心理声学模型、滤波、量化、无噪声编码及时域噪声整形的实现原理,分析音频解码的基本流程。在工程应用阶段,为了优化硬件接收器的设计方法,利用C++语言编写接收器软件,用于模拟硬件设备的功能。经测试,该软件工具能够有效解码DRM音频信息。
文摘针对超声波微弱信号接收和处理问题,进行了基于DSP(digital signal processor)开发板的采集前端分析与优化设计。采用下变频技术,充分利用了开发板上的音频编译码器实现微弱超声波信号采集。通过与普通ADC(analog-to-digital converter)采集方案的噪声系数进行对比,表明系统在微弱信号情况下,仍然可以获得较高的信噪比。该方案应用于一种便携式的超声波接收系统,使用户随时可以进行超声波信号的接收与处理工作。
