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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.
標簽： frequency-domain interpolation performance Design kbit_s speech coder based and of
上傳時間： 2018-04-08
上傳用戶：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.
標簽： Probability Processes Random and
上傳時間： 2020-05-31
上傳用戶：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.
標簽： Reference Designer Manual Phase DRM 023 AC
上傳時間： 2020-06-10
上傳用戶：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
標簽： Convolutional Networks Neural Guide to
上傳時間： 2020-06-10
上傳用戶：shancjb
基于TMS320F28035芯片為控制核心的空間矢量異步電機變頻器 我們設計的異步電機變頻調速器以TMS320F28035芯片為控制核心，通過輸出三相PWM波控制智能功率模塊IPM驅動三相異步電機。我們使用空間矢量SVPWM算法，并對其進行了優化。采用檢測反電勢的方法省去了昂貴的光電編碼器，大大節省了成本。同時開創性的研發了自動根據運行環境調節的自適應變頻算法，使我們的變頻調速器可以在電網條件惡劣的鄉村山區工作，由此該變頻器已被一家民用水泵生產企業預訂。關鍵字 變頻器 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.
標簽： tms320f28035 芯片
上傳時間： 2022-05-08
上傳用戶：zhanglei193
直接調制將基帶信號直接轉換為射頻信號，不需要二次頻率變換，與上變頻方式相比系統結構簡單，降低了對濾波器的要求，具有體積小，重量輕，成本低等明顯的優點.1/Q正交調制的關鍵指標是誤差矢量（EVM：Error Vector Magnitude）.本文研究的是微波波段的直接調制技術。利用基帶對L波段和s波段幾個不同的載波進行直接調制。首先，在闡述1/Q正交調制基本原理的基礎上，通過對誤差矢量和鄰近信道功率泄漏的詳細分析，定性、定量地討論了各種非理想電路因素（如相位不平衡、幅度不平衡、直流偏差等）對調制器性能的影響；其次，介紹了鎖相環的工作原理和基本組成部分，包括鎖相環的設計和環路濾波器的設計，特別詳述了電荷泵鎖相頻率源；第三，介紹了采用直接調制技術模擬衛星信號的射頻前端的設計；最后，對整個直接射頻調制系統進行測試，結果基本上達到了課題要求。關鍵詞：微波鎖相環，相位噪聲，直接調制
標簽： 射頻調制
上傳時間： 2022-06-20
上傳用戶：
簡介本文檔介紹了如何使用dsPIC30F數字信號控制器（Digital Signal Controller，DSC）控制正弦電流來驅動具有位置傳感器的永磁同步電機（Permanent Mag-net Synchronous Motor，PMSM）.電機控制固件使用dsPIC30F外設，而數學運算則由DSP引擎完成。為充分利用dsPIC30F的特殊DSP運算性能，固件采用C語言編寫，只有某些子程序采用匯編語言編寫。應用特性·使用空間矢量調制（Space Vector Modulation，SVM）方法產生用于驅動PMSM電機各相的正弦電流·正弦電壓與PMSM電機轉子位置同步·四象限運行，可實現正向、反向和制動運行·基于數字比例一積分一微分（Proportional Integral Derivative，PID）控制的閉環轉速控制·相位超前技術可實現更寬的調速范圍·由dsPICODSC的DSP引擎實現小數數學運算
上傳時間： 2022-07-05
上傳用戶：
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.
上傳時間： 2022-07-07
上傳用戶：
VIP專區-嵌入式/單片機編程源碼精選合集系列（105）資源包含以下內容：1. 凌陽公司機sunplus1002在這個芯片下.2. 基于pdiusbd12的c51單片機驅動程序.3. 凌陽公司機sunplus1002在這個芯片做為機頂盒主芯片下的嵌入式字體庫。.4. 常見datasheet中文版--- 很多人不大習慣讀英文的datasheet.5. 倒車雷達系統的研究與設計：系統設計中采用了模塊設計思想.6. TMS320VC5509設備端USB設備驅動程序源文件.7. 利用51單片機控制步進電機并顯示當前轉速.8. 5920是PCI橋芯片,節省了許多用于處理PCI通訊細節的開發時間.這個是相關資料.9. XILINX專用術語,中文,很好的規范教材,可以方便新人能較快的入門.10. 嵌入式的一本好書.11. 該文件中包括89系列 X102開發板的12232液晶屏AD轉換器ADC0809,DA轉換器DAC0832,I2C總線芯片24C02,RAM電路62256,發光二極管電路.12. “霓虹燈”小程序.13. 三星公司S3C2410X中文數據手冊完全版.14. 此程序下位機采集18部0溫度.15. 運行環境:DOS, 通過串口升級的下位程序, 需配合上位升級程序FileUpgrade運行, 可用于嵌入式DOS系統中..16. 在電路中選擇運算放大器(運放)來實現某一特定功能時.17. 嵌入式DOS系統上位升級程序FileUpgrade, 需配合本人上傳的FileUpr程序應用, VC++開發, 非常實用, 內附說明及源碼.18. 步進電機的控制程序.19. moden控制器電路設計.20. dsPICDEM_v1_1開發板的相關例程.21. 程序在visual c＋＋環境下實現了圖像按照輸入參數進行平移旋轉和在水平垂直方向上的鏡像功能。.22. Develop Zigbee network real-time Os.23. AT89C51+CPLD 的EPM7064SLC44-10的學習板電路圖.24. LSVMK Langrangian Support Vector Machine algorithm LSVMK solves a support vector machine problem us.25. 網上尋找的.26. 介紹了關于怎樣用DRAM 芯片用做 攝象機.27. s3c2410的背光源碼.28. s3c2410的觸摸屏源碼.29. 嵌入式系統軟件結構設計 基于uc/os- 2的軟件設計.30. 嵌入式實時操作系統分析 uc/os-2操作系統內核的分析.31. 24C02的讀與寫.32. 學習開源gui庫wxwidgets的入門源碼.33. 2812的ad的詳細說明.34. LED顯示屏設計LED顯 示屏設計 LED顯示屏設計 LED顯示屏設計 LED顯示屏設計.35. mc68hc08 tim 試驗程序實例.36. 附帶圖形界面的2410Flash燒寫程序.37. OrCAD格式的2410開發板 底板原理圖.38. OrCAD格式的S3C2410X核心板原理圖.39. H_323協議詳解（中文） 打開文件的密碼是:21315038.40. stc單片機讀內部eeprom代碼.
標簽： 激光測量
上傳時間： 2013-04-15
上傳用戶：eeworm
