高质量0.6 Kb/s声码器的TMS320VC55x实现

给出了一种编码速率为600b／s的高质量声码器算法及基于DSP芯片的硬件实现。介绍了语音编解码算法原理、声码器系统的硬件结构、工作流程以及软件实现与代码优化。针对C55xDSP芯片的结构特点,采用C与汇编混合编程,汇编指令优化等方法,大大降低了算法的存储复杂度和运算复杂度,达到了实时性要求。     

多速率声码器系统

文中介绍了一种全双工多速率声码器系统的设计方法，该系统采用高速数字信号处理器ＴＭＳ３２０Ｃ２５作为中心处理器，实时实现了多种速率的语音压缩编码算法。系统中的信道接口是由设计的专用集成电路芯片构成，该芯片还包括一些定时和控制逻辑电路。     

一种适用于多种公钥密码算法的模运算处理器

文章设计了一种能够实现多种公钥密码算法（如RSA、ECC、DSA等）的协处理器。通过分析几种常用的公钥密码算法，归纳了一组最常用的基本模运算指令。基于基本指令，设计优化了处理器硬件结构。用微代码循环调用执行这些基本指令，实现其他各种模运算指令。基于这些模运算指令，处理器可实现多种公钥密码算法的运算。该处理器支持从106位到2048位多种长度的模运算。采用流水线结构设计，处理速度较快。处理器占用芯片面积小，核心电路等效门数约为26000门，适用于智能卡等对芯片面积有严格限制的应用。     

基于ARM SoC的G.729A编码实现

G.729A是国际电信联盟(ITU)于1996年提出的一种语音压缩标准,在G.729基础上进行了必要的简化,该算法是一种共轭结构代数码激励线性预测(CS-ACELP)的8 kbits语音编码算法.文中主要介绍一种基于ARM处理器的系统架构和G.729A编码的过程,以及将该编码算法应用于此系统需要注意的一些原则和方法.针对算法本身采用了一些快速算法,并且针对ARM处理器的特性进行了一些优化,以便能降低编码复杂度,做到实时编码.     

基于TMS320C54x DSKplus的实时TCM语音编解码算法的实现

描述了基于TMS320C54x数字信号处理器的TCM语音压缩编码系统。该系统是在TMS320C54xDSP入门套件（DSK,DSP Starter Kit）板上实现,充分发挥了芯片的专用硬件逻辑、专业化的指令以及板上TLC320AC01模拟接口语音处理系统。有效而快速地完成了TCM语音压缩系统的模拟,并给出相应的实验结果。     

GRCC:一种通用可重构协处理器

描述了一种改进型可重构处理器--GRCC(General Reconfigurable Coprocessor).该处理器能够使用一般通用RISC处理器的协处理器接口,通过与通用处理器的协处理器指令通信,达到辅助主处理器进行大规模密集计算的目的.着重介绍了DCT算法在GRCC中的映射与实现,仿真结果显示,GRCC能达到6倍以上于通用处理器的性能,并在实现复杂度、运行效率与通用性中达到了一个权衡.     

基于DSP的音频信号压缩通信系统的设计与实现

针对数据采集系统中语音传输受传输距离、成本等方面限制的问题,设计了一种低成本的语音信号压缩实时通信系统。采用模块化的方法进行硬件设计,通过将精简的TCP/IP协议移植到以太网控制芯片中来实现局域网通信,在DSP上优化实现了G.723.1语音编码算法,编码后的语音数据通过socket传送到PC端,PC端接收解码并实时播放。实验结果表明在语音质量略有退化的情况下,算法复杂度降低了,系统实现了语音信号远距离的实时传输。     

多速率语音芯片AMBE-2020的开发和应用

AMBE-2020是由DVSI公司推出的高性能多速率语音编码、解码芯片，它的语音算法采用专利的AMBE语音压缩技术。该芯片能在较低的速率下实现全双工、高质量的语音通信，并且操作简单、编码速率可变、功耗小等优点。介绍了AMBE-2020芯片，并建立了一个简单的语音压缩系统的应用实例。     

AMR语音编码算法研究及复杂度剖析

作为 3GPPWCDMA的语音编码 (SpeechCoding)候选方案 ,自适应多速率 (AMR)语音编码是一种多模式集成的ACELP类语音编码方案。本文根据该编码方案的标准 ,分析了其方案实现中的关键算法 :高性能码本设计、高效码本搜索算法、多级矢量量化技术、预处理算法的简化等。最后 ,设计了定点ANSI -C程序对AMR语音编码算法各部分的复杂度进行了测算     

一种适应移动设备的CELP宽带语音编码算法

本文介绍了一种新的CELP宽带语音编码算法,由于使用了分带技术,使得该算法同时支持窄带和宽带等不同采样率的语音编码.该算法还有其它算法所不具有的可变码率、平均码率控制、语音激活和非连续发送等功能,所以在保证语音质量的同时码率也比较低.因为在编码时尽量避免了利用其它帧的信息,所以对丢包有一定的鲁棒性,再加上计算复杂度不高,延时小,所以该算法适合于应用在嵌入式的移动设备上.     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers

A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.     

Diode-end-pumped Nd:YVO4/LBO lasers with 4.2W continuous-wave output at 457 nm

A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.     

Call for Papers

正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks     

Call for Papers—Feature Topic,Vol.12,No.7,2015

正Information Centric Networking Information-Centric Networking(ICN) is an emerging direction in Future Internet architecture research,gaining significant tractions among academia and industry.Aiming to replace the conventional host-to-host communication model by a data-centric model,ICN treats data content as the first