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
Many good textbooks exist on probability and random processes written at the under- graduate level to the research level. However, there is no one handy and ready book that explains most of the essential topics, such as random variables and most of their frequently used discrete and continuous probability distribution functions; moments, transformation, and convergences of random variables; characteristic and generating functions; estimation theory and the associated orthogonality principle; vector random variables; random processes and their autocovariance and cross-covariance functions; sta- tionarity concepts; and random processes through linear systems and the associated Wiener and Kalman filters.
标签： Probability Processes Random and
上传时间： 2020-05-31
上传用户：shancjb
This reference design describes the design of a 3-phase AC induction vector control drive with position encoder coupled to the motor shaft. It is based on Motorola’s DSP56F805 dedicated motor control device. AC induction motors, which contain a cage, are very popular in variable speed drives. They are simple, rugged, inexpensive and available at all power ratings. Progress in the field of power electronics and microelectronics enables the application of induction motors for high-performance drives, where traditionally only DC motors were applied. Thanks to sophisticated control methods, AC induction drives offer the same control capabilities as high performance four-quadrant DC drives.
标签： Reference Designer Manual Phase DRM 023 AC
上传时间： 2020-06-10
上传用户：shancjb
General paradigm in solving a computer vision problem is to represent a raw image using a more informative vector called feature vector and train a classifier on top of feature vectors collected from training set. From classification perspective, there are several off-the-shelf methods such as gradient boosting, random forest and support vector machines that are able to accurately model nonlinear decision boundaries. Hence, solving a computer vision problem mainly depends on the feature extraction algorithm
标签： Convolutional Networks Neural Guide to
上传时间： 2020-06-10
上传用户：shancjb
基于TMS320F28035芯片为控制核心的空间矢量异步电机变频器 我们设计的异步电机变频调速器以TMS320F28035芯片为控制核心，通过输出三相PWM波控制智能功率模块IPM驱动三相异步电机。我们使用空间矢量SVPWM算法，并对其进行了优化。采用检测反电势的方法省去了昂贵的光电编码器，大大节省了成本。同时开创性的研发了自动根据运行环境调节的自适应变频算法，使我们的变频调速器可以在电网条件恶劣的乡村山区工作，由此该变频器已被一家民用水泵生产企业预订。关键字 变频器 TMS320f28035 IPM SVPWM In our design, the asynchronous machine inverter based on the chip of TMS320F28035 drives the three-Phase asynchronous machine by sending three-phase PWM waves to the IPM, which is short for the Intelligent-Power-Module. The SVPWM (space vector pulse width modulation) strategy is applied to our control algorithm and we optimize it mainly in two aspects. Firstly the inverter detects the speed by measuring the Back EMF instead of installing an expensive photoelectric encoder for costs reduction.
标签： tms320f28035 芯片
上传时间： 2022-05-08
上传用户：zhanglei193
直接调制将基带信号直接转换为射频信号，不需要二次频率变换，与上变频方式相比系统结构简单，降低了对滤波器的要求，具有体积小，重量轻，成本低等明显的优点.1/Q正交调制的关键指标是误差矢量（EVM：Error Vector Magnitude）.本文研究的是微波波段的直接调制技术。利用基带对L波段和s波段几个不同的载波进行直接调制。首先，在阐述1/Q正交调制基本原理的基础上，通过对误差矢量和邻近信道功率泄漏的详细分析，定性、定量地讨论了各种非理想电路因素（如相位不平衡、幅度不平衡、直流偏差等）对调制器性能的影响；其次，介绍了锁相环的工作原理和基本组成部分，包括锁相环的设计和环路滤波器的设计，特别详述了电荷泵锁相频率源；第三，介绍了采用直接调制技术模拟卫星信号的射频前端的设计；最后，对整个直接射频调制系统进行测试，结果基本上达到了课题要求。关键词：微波锁相环，相位噪声，直接调制
标签： 射频调制
上传时间： 2022-06-20
上传用户：
简介本文档介绍了如何使用dsPIC30F数字信号控制器（Digital Signal Controller，DSC）控制正弦电流来驱动具有位置传感器的永磁同步电机（Permanent Mag-net Synchronous Motor，PMSM）.电机控制固件使用dsPIC30F外设，而数学运算则由DSP引擎完成。为充分利用dsPIC30F的特殊DSP运算性能，固件采用C语言编写，只有某些子程序采用汇编语言编写。应用特性·使用空间矢量调制（Space Vector Modulation，SVM）方法产生用于驱动PMSM电机各相的正弦电流·正弦电压与PMSM电机转子位置同步·四象限运行，可实现正向、反向和制动运行·基于数字比例一积分一微分（Proportional Integral Derivative，PID）控制的闭环转速控制·相位超前技术可实现更宽的调速范围·由dsPICODSC的DSP引擎实现小数数学运算
上传时间： 2022-07-05
上传用户：
Agenda■Motor Types Overview■BLDC Motor Applications■Comparison of DC to Brushless DC Motors■Hall Sensors■Six-Step Commutation■Sensorless Commutation with Back-EMFVector Motor Control basicsClosed-Loop Speed Control■Introduction to BLDC Motor Control Evaluation Kit■SummaryAll the popular motor types have their specific applications, and all can be controlled with microcontrollers.We wll talk about Brushless DC motors as it is the fast growing motor type today.Motors used in modern Air conditioners, home appliances, tools, even electric bikes are all going to Brushless DC.
上传时间： 2022-07-07
上传用户：
VIP专区-嵌入式/单片机编程源码精选合集系列（105）资源包含以下内容：1. 凌阳公司机sunplus1002在这个芯片下.2. 基于pdiusbd12的c51单片机驱动程序.3. 凌阳公司机sunplus1002在这个芯片做为机顶盒主芯片下的嵌入式字体库。.4. 常见datasheet中文版--- 很多人不大习惯读英文的datasheet.5. 倒车雷达系统的研究与设计：系统设计中采用了模块设计思想.6. TMS320VC5509设备端USB设备驱动程序源文件.7. 利用51单片机控制步进电机并显示当前转速.8. 5920是PCI桥芯片,节省了许多用于处理PCI通讯细节的开发时间.这个是相关资料.9. XILINX专用术语,中文,很好的规范教材,可以方便新人能较快的入门.10. 嵌入式的一本好书.11. 该文件中包括89系列 X102开发板的12232液晶屏AD转换器ADC0809,DA转换器DAC0832,I2C总线芯片24C02,RAM电路62256,发光二极管电路.12. “霓虹灯”小程序.13. 三星公司S3C2410X中文数据手册完全版.14. 此程序下位机采集18部0温度.15. 运行环境:DOS, 通过串口升级的下位程序, 需配合上位升级程序FileUpgrade运行, 可用于嵌入式DOS系统中..16. 在电路中选择运算放大器(运放)来实现某一特定功能时.17. 嵌入式DOS系统上位升级程序FileUpgrade, 需配合本人上传的FileUpr程序应用, VC++开发, 非常实用, 内附说明及源码.18. 步进电机的控制程序.19. moden控制器电路设计.20. dsPICDEM_v1_1开发板的相关例程.21. 程序在visual c＋＋环境下实现了图像按照输入参数进行平移旋转和在水平垂直方向上的镜像功能。.22. Develop Zigbee network real-time Os.23. AT89C51+CPLD 的EPM7064SLC44-10的学习板电路图.24. LSVMK Langrangian Support Vector Machine algorithm LSVMK solves a support vector machine problem us.25. 网上寻找的.26. 介绍了关于怎样用DRAM 芯片用做 摄象机.27. s3c2410的背光源码.28. s3c2410的触摸屏源码.29. 嵌入式系统软件结构设计 基于uc/os- 2的软件设计.30. 嵌入式实时操作系统分析 uc/os-2操作系统内核的分析.31. 24C02的读与写.32. 学习开源gui库wxwidgets的入门源码.33. 2812的ad的详细说明.34. LED显示屏设计LED显 示屏设计 LED显示屏设计 LED显示屏设计 LED显示屏设计.35. mc68hc08 tim 试验程序实例.36. 附带图形界面的2410Flash烧写程序.37. OrCAD格式的2410开发板 底板原理图.38. OrCAD格式的S3C2410X核心板原理图.39. H_323协议详解（中文） 打开文件的密码是:21315038.40. stc单片机读内部eeprom代码.
标签： 激光测量
上传时间： 2013-04-15
上传用户：eeworm
