Analysis and design of a 1.8-2.7 GHz tunable 8-band TDD LTE receiver front-end

This paper describes the analysis and design of a 0.13μm CMOS tunable receiver front-end that supports 8 TDD LTE bands,covering the 1.8-2.7 GHz frequency band and supporting the 5/10/15/20 MHz bandwidth and QPSK/16QAM/64QAM modulation schemes.The novel zero-IF receiver core consists of a tunable narrowband variable gain low-noise amplifier(LNA),a current commutating passive down-conversion mixer with a 2nd order low pass trans-impedance amplifier,an LO divider,a rough gain step variable gain pre-amplifier,a tunable 4th order Chebyshev channel select active-RC low pass filter with cutoff frequency calibration circuit and a fine gain step variable gain amplifier.The LNA can be tuned by reconfiguring the output parallel LC tank to the responding frequency band,eliminating the fixed center frequency multiple LNA array for a multi-mode receiver. The large various gain range and bandwidth of the analog baseband can also be tuned by digital configuration to satisfy the specification requirement of various bandwidth and modulation schemes.The test chip is implemented in an SMIC 0.13μm 1P8M CMOS process.The full receiver achieves 4.6 dB NF,-14.5 dBm out of band IIP3, 30-94 dB gain range and consumes 54 mA with a 1.2 V power supply.     

挠性陀螺捷联系统场地快速标定

本文给出了捷联式惯性导航系统一种简单实用的场地标定方法。在系统中，对挠性陀螺仪采用特殊安装，把组合件旋转１８０°，用两位置数据测出陀螺的标度系数、常值漂移、加速度计零位和系统真方位。在标定过程中不需要对惯性组合件做水平调整。     

钝体绕流的分隔板控制技术研究进展

钝体是工程中一种常见结构,流体绕过钝体时产生的旋涡脱落易诱发结构振动,进而导致结构破坏．钝体后安装分隔板是一种典型的被动控制技术,分隔板推迟钝体尾流区剪切层之间的相互作用,进而有效改变钝体后旋涡脱落及尾迹特性,延长结构寿命,并且可以利用钝体一分隔板结构进行能量收集．本文全面回顾了利用分隔板进行流动控制和能量收集的研究及...     

Partitioning series-parallel multigraphs intoν*-excluding edge covers

We prove that, for any given vertexν* in a series-parallel graph G, its edge set can be partitioned into k= min{k′(G) 1,δ(G)} subsets such that each subset covers all the vertices of G possibly except forν*, whereδ(G) is the minimum degree of G and k′(G) is the edge-connectivity of G. In addition, we show that the results in this paper are best possible and a polynomial time algorithm can be obtained for actually finding such a partition by our proof.     

客服系统中排队机与CTI技术的对比

本文着重讲述客服系统两种技术的对比，包括结构和特点，最后介绍了思特奇客服系统的特点。     

A new synchronization control circuit based on FPGA for the laser range-gated imaging system

Synchronization control is a kernel technique of the laser range-gated （LRG） imaging system which controls the synchronization of the pulsed laser and the ICCD camera directly. It can achieve range gating effectively and improve the resolution of image precisely. Conventional control circuits which are composed of discrete components have a poor performance of anti-interference, and the transmitting signal has a-bad delay which affects the conventional circuit＇s precision and stabilization seriously. To solve these problems, a range-gated synchronization control circuit is designed. This circuit, which takes the advantages of FPGA＇s high compact and flexibility, uses the phase-locking-loop （PLL） to multiply the global clock frequency. This design improves the precision and stabilization greatly, makes the precision up to a nanosecond level and provides a real-time selection of the values of pulse width and delays. Experiments results indicate that this circuit has a high precise and stable range-gated pulse.     

数字信号处理器中FFT的实现

本文深入探讨了FFT算法的特点,并对FFT算法在DSP上的实现方法进行了详细的分析.通过分析阐述并总结了利用DSP实现FFT算法的步骤及规律.     

中国海关2000工程广域骨干网

中国海关总署自１９９６年底开始实施海关系统信息化建设的海关２０００工程。海关网由海关总署、各直属海关及直属院校、各分关构成,采用ＢＡＹ的Ｐａｓｓｐｏｒｔ系列多业务ＡＴＭ交换机及接入设备,海关网的一、二级节点都能提供ＩＰ、话音和图像业务的接入,本文较系统地介绍了三级网络的结构及解决方案。     

阿尔卡特呼叫中心解决方案

阿尔卡特呼叫中心解决方案基于局域网,采用ＣＳＴＡ作为主导通信协议,其Ａ４４００ＣＣｘ产品系列包括呼叫中心分配器Ａ４４００ ＣＣＤ、监管系统Ａ４４００ ＣＣＳ１管理器Ａ４４００ＣＣＭ、座席应用组件Ａ４４００ ＣＣＡ、万维网服务器Ａ４４００ ＣＣＷ以及语音应答、语音记录和其它配套设备。其中阿尔卡特４４００综合业务交换平台的基本结构采用阿尔卡特晶体结构技术;而公司的专利技术－－矩阵化分配方式则运用于呼叫     

HIGH ACCURACY FINITE VOLUME ELEMENT METHOD FOR TWO-POINT BOUNDARY VALUE PROBLEM OF SECOND ORDER ORDINARY DIFFERENTIAL EQUATIONS

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