互质阵列信号处理研究进展:波达方向估计与自适应波束成形

阵列信号处理是雷达领域各类应用的核心技术之一。近年来,互质阵列的提出打破了传统方法受限于奈奎斯特采样速率这一瓶颈,其稀疏布设的阵列结构和互质欠采样的信号处理方式大幅降低了系统所需的软硬件开销,为当前不断提升的实际应用需求提供了理论基础和技术前提。鉴于其在自由度、分辨率及计算复杂度等方面的性能优势,互质阵列信号处理的理论和技术研究受到了国内外学者的广泛关注。该文分别从波达方向估计和自适应波束成形这两个阵列信号处理领域的基本问题出发,介绍了互质阵列信号处理方向的研究进展。在互质阵列波达方向估计方面,该文总结了互质子阵分解方法和虚拟阵列信号处理方法等两类典型技术路线,并以此为基础介绍了压缩感知和无网格化技术在低复杂度和超分辨估计等方面的最新研究工作。在互质阵列波束成形方面,该文剖析了其与互质阵列波达方向估计问题的区别与联系,并介绍了面向互质阵列的高效鲁棒自适应波束成形设计方法。该文旨在通过对互质阵列信号处理研究前沿的分类归纳和总结,探讨各类方法的优势和未来的研究方向,为其在雷达等领域的产业需求和实际应用提供理论和技术参考。      

信号处理技术的若干进展(国内)

本文着重介绍我国在信号处理领域中有关的若干专题的研究进展。这些专题包括离散变换,谱估计理论,空间谱估计,自适应滤波算法和数字滤波器。文中对数字信号处理硬件设计方面的进展亦做了介绍;同时就信号处理在语声处理、文字识别、图像处理和计算机视觉方面的应用成果也做了概要的说明。     

智能天线在无线通信中的应用分析

为了在复杂的电磁传播环境中保证信号传输的可靠性，智能天线技术逐渐得到人们的广泛关注。智能天线的概念使得天线从传统的单一场路转换器件发展成具有一定信号处理功能，并和接收机后端处理紧密结合的天线系统。本文介绍并分析了传统自适应天线及空时二维信号处理技术在蜂窝系统中的应用，对用于时分多址系统的自适应波束形成器及用于码分多址系统的2D RAKE进行了仿真，并通过仿真说明了基于空时二维处理的智能天线系统在性能上的优越性。     

数字多波束技术信号处理算法研究

介绍了数字多波束技术的应用。重点分析了目前较为常用的3种数字多波束技术信号处理的自适应算法并对各种算法进行了比较。自适应算法的选择决定了在环境变化时，波束自适应控制能力和反应速度，以及实现算法所需硬件的复杂性。     

一种自适应雷达侦察信号处理方法

自适应侦察信号处理是电子侦察信号处理技术由固定模式向认知模式发展的重要阶段,也是认知模式的重要组成部分.从自适应技术特点出发,提出自适应技术在雷达侦察信号处理中的应用原理,并给出了开环和闭环两种自适应侦察信号处理方式,以及相应的过程评估方法.最后,通过计算机仿真提供了一种可参考的过程评估示例.     

快速自适应算法在扩频通信系统中的应用

本文首先介绍了自适应信号处理和快速自适应算法,然后针对扩频通信过程中的多径效应问题分别使用LMS、RLS两种快速自适应算法进行信号处理,完成计算机仿真。通过仿真结果对两种算法进行分析,为其进一步在通信系统中的实际应用打下了基础。     

雷达侦收自适应信号处理架构研究

针对复杂电磁环境中雷达侦察信号自适应处理的需求,对雷达信号侦察问题进行了建模与分析,讨论了若干可能的自适应侦察信号处理架构。在雷达侦察信号处理模块算法方面,研究了特征自适应检测与分析、信号自适应分选等处理架构,以提升低可识别信号的自适应处理能力;在侦察系统处理流程方面,研究了具有跟踪与预测能力的自适应处理架构,以增强对电磁环境态势的动态感知能力;在侦察系统与其他分系统协作层面,研究了基于雷达系统抗干扰需求和干扰机智能化干扰需求的自适应侦察协作架构,以提升电子战系统效能。该研究可为自适应雷达对抗处理研究提供有益思路。     

自适应滤波器的算法研究及DSP仿真实现

随着DSP技术的高速发展,人们对信号处理的实时性、准确性和灵活性的要求越来越高,DSP技术在信号处理中的地位也越来越重要.自适应滤波器是一种复杂的算法,设计它是为了在均衡信道,抵消回波,增强谱线,抑制噪声等方面有所应用.而自适应滤波器的实现主要采用最小均方误差算法完成.自适应算法通过调整滤波器系数来实现可以更好地跟踪信号的变化,最终实现自适应滤波.     

高速数字微波传输中频率选择性衰落的自适应对抗技术

实现高速多电平数字微波传输需要解决的一个主要问题,是多径传播效应引起的频率选择性衰落。它可能导致通信的中断。本文以QAM多电平调制方式为例,论述对抗这种衰落的几种自适应信号处理技术。文中在引入多径传播模型的基础上,以频率域自适应均衡技术为重点,较详细地介绍了自适应信号处理技术的基本原理和构成方法;还介绍了衡量各类自适应对抗性能优劣的特征曲线(Signature),以及测试这种曲线的设备——衰落模拟器。     

匹配场处理——水声物理学与信号处理的结合

本文扼要介绍信号处理与物理学相交叉的一个新兴研究领域－－水下声源的匹配场处理。论述水声信号处理与水声物理学相结合的重要性，介绍水下声场建模的基本理论以及匹配场处理的基本方法，阐明匹配场处理与广义波束形成，高分辨谱估计等信号处理技术的密切关系。最后对现存的问题、发展及应用前景等进行讨论。     

Technology innovation and process integrations for sub-100nm gate patterning

This paper presents a brief overview of the Applied Centura(R)DPS(R)system,configured with silicon etch DPS Ⅱ chamber, with emphasis on discussing tuning capability for CD uniformity control. It also presents the studies of etch process chemistry and film integration impact for an overall successful gate patterning development. Discussions will focus on resolutions to key issues, such as CD uniformity, line-edge roughness, and multilayer film etching integration.     

White organic light-emitting devices based on fac tris（2- phenylpyridine） iridium sensitized 5,6,11,12-tetraphenylnap -hthacene

We have fabricated the white organic light-emitting devices （WOLEDs） based on 4,4＇ -bis（2,2 -diphenyl vinyl）-1,1＇ - biphenyl （DPVBi） and phosphorescence sensitized 5,6,11,12,-tetraphenylnaphthacene （rubrene）. The device structure is ITO/2T-NATA （20 nm）/NPBX （20 nm）/CBP： x%Ir（ppy）3：0.5% rubrene （8 nm）/NPBX （5 nm）/DPVBi （30 nm）/Alq（30 nm）/LiF（0.5 nm）/A1. In the devices, DPVBi acts as a blue light-emitting layer, the rubrene is sensitized by a phosphorescent material, fac tris （2-phenylpyridine） iridium [Ir（ppy）3], acts as a yellow light-emitting layer, and N,N＇ -bis- （1-naphthyl）- N,N＇ -diphenyl -1, 1＇ -biphenyl-4,4＇ -diamine （NPBX） acts as a hole transporting and exciton blocker layer, respectively. When the concentration of Ir （PPY）3 is 6wt%, the maximum luminance is 24960 cd/m^2 at an applied voltage of 15 V, and the maximum luminous efficiency is 5.17 cd/A at an applied voltage of 8 V.     

Complete approach to automatic identification and subpixel center location for ellipse feature

To meet the need of automatic image features extraction with high precision in visual inspection, a complete approach to automatic identification and sub-pixel center location for similar-ellipse feature is proposed. In the method, the feature area is identified automatically based on the edge attribute, and the sub-pixel center location is accomplished with the leastsquare algorithm. It shows that the method is valid, practical, and has high precision by experiment. Meanwhile this method can meet the need of instrumentation of visual inspection because of easy realization and without man-machine interaction.     

小角度扩展相关性近似算法分析

本论文提出一种在多天线MIMO信道相关性建模中小角度扩展近似理论算法,并应用于分析MIMO系统性能。分析中分别对三种不同角能量分布情况下的空间相关性研发快速近似计算法,并同时提出双模(Bi-Modal)角能量分布情况下的近似运算。通过分析这些新方法的近似效率,可以得到计算简单、复杂度低、而且符合实际的MIMO相关信道矩阵,对系统级的快速高效计算法的研究和系统级的评估以及误差分析具有重要的意义。     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.     

A Versatile Mixed-Signal Pin Approach for Cost-Effective Test of Automotive ICs

Integrated circuits (ICs) intended for increasingly sophisticated automotive applications bring unique test demands. Advanced ICs for applications such as highly integrated automatic braking system (ABS) and airbag controllers combine high voltage digital channels, significant VI demands and precise timing capability. Along with continued missioncritical reliability concerns, the trend toward higher voltage operation and increased device integration requires specialized test capabilities able to extend across the wide operating ranges found in automotive applications. Among these capabilities, automotive test requirements increasingly dictate a need for a cost-effective versatile mixed-signal pin electronics with very high data rates reaching up to 50MHz with a voltage swing of-2 V to +28 V.     

Critical Stage Rule-Based Real Time Dispatch（RTD）System in Highly-Mixed-Products （HMP） FAB

An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB.     

Optical vibration and deviation measurement of rotating machine parts

It is of interest to get appropriate information about the dynamic behaviour of rotating machinery parts in service. This paper presents an approach of optical vibration and deviation measurement of such parts. Essential of this method is an image derotator combined with a high speed camera or a laser doppler vibrometer （LDV）.