The 4.0 kbit/s speech codec described in this paper is based on a Frequency Domain Interpolative (FDI) coding technique, which belongs to the class of prototype waveform Interpolation (PWI) coding techniques. The codec also has an integrated voice activity detector (VAD) and a noise reduction capability. The input signal is subjected to LPC analysis and the prediction residual is separated into a slowly evolving waveform (SEW) and a rapidly evolving waveform (REW) components. The SEW magnitude component is quantized using a hierarchical predictive vector quantization approach. The REW magnitude is quantized using a gain and a sub-band based shape. SEW and REW phases are derived at the decoder using a phase model, based on a transmitted measure of voice periodicity. The spectral (LSP) parameters are quantized using a combination of scalar and vector quantizers. The 4.0 kbits/s coder has an algorithmic delay of 60 ms and an estimated floating point complexity of 21.5 MIPS. The performance of this coder has been evaluated using in-house MOS tests under various conditions such as background noise. channel errors, self-tandem. and DTX mode of operation, and has been shown to be statistically equivalent to ITU-T (3.729 8 kbps codec across all conditions tested.
标签： frequency-domain interpolation performance Design kbit_s speech coder based and of
上传时间： 2018-04-08
上传用户：kilohorse
css美化有序列表，贴出部分css代码 <ol > <li>先涂粉底再涂防晒</li> <li>先涂防晒再涂粉底</li> </ol> <!doctype html> <html> <head> <title>CSS3 ordered list styles - demo</title> <style> body{ margin: 40px auto; width: 500px; } /* -------------------------------------- */ ol{ counter-reset: li; list-style: none; *list-style: decimal; font: 15px 'trebuchet MS', 'lucida sans'; padding: 0; margin-bottom: 4em; text-shadow: 0 1px 0 rgba(255,255,255,.5); } ol ol{ margin: 0 0 0 2em; } /* -------------------------------------- */
上传时间： 2018-08-22
上传用户：53660542
projcet2007模板内容丰富，项目计划的编辑习惯，界面布局，时间计算的规则，任务的依赖关系等都和MS Project非常接近，用户会用MS Project，就会用我们的计划编辑功能。
上传时间： 2019-02-19
上传用户：自由自在xc
关于晶习预测，各种立场优化与结构文件的优化与分析
标签： 软件教学 帮助掌握软件的操作与运行！！！！！！！！！！！！！
上传时间： 2019-04-23
上传用户：caicai123
MS8XF系列单片机常见问题解决办法，仿真器常见问题 ，烧录器及烧录器软件常见问题 等
标签： MS 常见问题
上传时间： 2019-06-11
上传用户：jdz8888
%========================开始提取加噪信号的各类特征值================================ for n=1:1:50; m=n*Ns; x=(n-1)*Ns; for i=x+1:m; %提取加噪信号'signal_with_noise=y+noise'的前256个元素，抽取50次 y0(i)=signal_with_noise(i); end Y=fft(y0); %对调制信号进行快速傅里叶算法（离散） y1=hilbert(y0) ; %调制信号实部的解析式 factor=0; %开始求零中心归一化瞬时幅度谱密度的最大值gamma_max for i=x+1:m; factor=factor+y0(i); end ms=factor/(m-x); an_i=y0./ms; acn_i=an_i-1; end gamma_max=max(fft(acn_i.*acn_i))/Ns
上传时间： 2020-04-07
上传用户：如拷贝般复制
%========================开始提取加噪信号的各类特征值================================ for n=1:1:50; m=n*Ns; x=(n-1)*Ns; for i=x+1:m; %提取加噪信号'signal_with_noise=y+noise'的前256个元素，抽取50次 y0(i)=signal_with_noise(i); end Y=fft(y0); %对调制信号进行快速傅里叶算法（离散） y1=hilbert(y0) ; %调制信号实部的解析式 factor=0; %开始求零中心归一化瞬时幅度谱密度的最大值gamma_max for i=x+1:m; factor=factor+y0(i); end ms=factor/(m-x); an_i=y0./ms; acn_i=an_i-1; end gamma_max=max(fft(acn_i.*acn_i))/Ns
上传时间： 2020-04-07
上传用户：如拷贝般复制
The General Packet Radio Service (GPRS) allows an end user to send and receive data in packet transfer mode within a public land mobile network (PLMN) without using a permanent connection between the mobile station (MS) and the external network during data transfer. This way, GPRS opti- mizes the use of network and radio resources (RRs) since, unlike circuit- switched mode, no connection between the MS and the external network is established when there is no data flow in progress. Thus, this RR optimiza- tion makes it possible for the operator to offer more attractive fees.
上传时间： 2020-05-27
上传用户：shancjb
接触Silvaco TCAD仿真软件已经有很长时间了，这期间还熟悉了一下ISE TCAD。学习的过程中，老师、师兄姐和同学给了我极大的帮助。这本书的主旨就是希望提供一些对于Silvaco仿真的可资借鉴的经验。学习和使用Silvaco的时候各人的视角会不一样，虽然这本书只是介绍一些常用的仿真，例句也有限，但因为流程控制和语法都有相通的地方，完全可以参照本书和手册的说明灵活地建立仿真以及仿真一些本书未提及的特性。写本书的另一个动力是想体验一下IAT在排版书籍上和word的不同。经过这次编排觉得各有优缺点。IZTX对排图片和表格这些浮动元素很费力。我在排此书的时候经常遇到图片和表格按照自动方式排的位置很差，和文字内容脱节很远，为此不得不处理图片，有时还将表格拆开等。如果各位遇到很脱节的地方还请见谅。LTX的使用需要有很强的耐心和探索精神，也可以说是牺牲精神。不管是MS Office还是ITEX，总的目的是想内容通顺，阅读起来舒服，用什么工具就是“八仙过海，各显神通”了。
上传时间： 2021-11-27
上传用户：qingfengchizhu
MSxxxxE系列交流伺服驱动器操作手册，PLC自动化控制者适用
标签： 电机驱动器
上传时间： 2022-01-09
上传用户：XuVshu
