无源定位观测站站址误差自校正算法

无源定位中观测站的站址误差会对定位精度产生不良影响。本文提出了一种基于观测站站址误差自校正的定位算法,推导了高斯噪声模型下定位误差的克拉美罗下界（CRLB）,通过泰勒级数展开建立了关于站址误差的线性方程并得到了误差的线性最小均方误差（LMMSE）估计,改善了观测站的位置,使用Chan算法得到了定位结果,仿真验证了算法的定位精度在高斯噪声模型下能够达到CRLB。      

观测站有位置误差的多维标度时频差定位算法

定位精度对观测站位置误差很敏感。论文针对观测站位置和速度有误差的情况,提出了一种加权多维标度时频差定位算法。该算法利用了多维标度定位通过特征结构和维度信息抑制噪声的优势,它将定位残差表示成测量误差和观测站位置误差的线性形式,然后通过加权最小二乘给出了目标位置和速度估计的闭式解。仿真结果表明,在小的测量误差和观测站位置误差时,该算法对目标位置和速度的估计能够达到克拉美劳下界。与两步加权最小二乘和约束总体最小二乘算法相比,该算法在测量噪声和观测站位置误差较大时有更高的定位精度。      

抑制校正源方位估计偏差的阵元位置误差鲁棒估计算法

针对校正源方位估计偏差会影响阵元位置误差校正精度这一问题,该文在假设校正源方位估计偏差的概率分布先验已知的条件下,根据信号子空间拟合理论和贝叶斯估计理论框架,提出一种能够抑制校正源方位估计偏差的阵元位置误差鲁棒估计算法.该算法以Newton迭代的形式给出,并不需要对校正源方位进行数值优化.理论分析和仿真实验均表明:在一定条件下,文中的新算法对校正源方位估计偏差具有较好的鲁棒性,并且其渐近性能可逼近相应的克拉美罗界.     

差分多普勒无源定位

论述多普勒频率差无源定位技术的实现方法 ,对等多普勒定位曲线误差进行分析 ,利用LMF(Levenberg -Marquardt-Fletcher)算法求解辐射源位置。在三运动平台条件下 ,通过计算机仿真 (按照MonteCarlo方法 )对算法的定位精度和性能作了评估。     

差分多普勒无源定位

论述多普勒频率差无源定位技术的实现方法，对等多普勒定位曲线误差进行分析，利用LMF（Levenberg-Marquardt-Fletcher)算法求解辐射源位置。在三运动平台条件下，通过计算机仿真（按照Monte Carlo方法）对算法的定位精度和性能作了评估。     

考虑载机位置误差的CLS多机无源定位算法

多机无源定位中存在载机位置误差却不予考虑时必然会降低目标的定位跟踪精度。为了解决存在载机位置误差情况下的定位问题,提出了一种考虑载机位置误差的约束最小二乘（CLS）多机无源定位算法。该算法对伪线性观测方程中由于测量误差和载机位置误差而导致的增广系数矩阵的误差协方差阵进行约束,并对伪线性观测方程的误差进行约束最小二乘处理,最终转化为对一组矩阵束的广义特征分解问题。仿真结果表明,相对于最小二乘（LS）算法和扩展卡尔曼滤波（EKF）算法,该算法具有更快的收敛速度和较高的定位精度,并且受载机位置误差影响小,在观测噪声比较大时仍能保持良好的定位性能。      

基于参考站的低轨双星定位误差校正分析

分析了低轨双星时/频差定位体制中的定位误差分布情况,研究了基于参考站的误差校正算法,最后分析了参考信号时/频差测量误差、参考站站址误差以及参考站位置等因素对定位误差的影响,并对不同条件下参考站对定位误差的校正作用开展了计算机仿真试验.该研究从数学上揭示了参考站对系统定位误差的校正原理,可为实际系统中参考站的建设提供理论...     

传感器位置误差下外辐射源雷达三维定位代数解算法

机载外辐射源雷达系统中,部署在飞机上的观测站传感器位置无法精确获知,观测站位置误差将严重影响目标定位精度。对此,该文提出一种观测站位置误差下多基外辐射源雷达3维定位代数解算法。该算法首先利用辅助变量将非线性双基距离和差(BRD)观测方程进行线性化,构造伪线性目标估计模型。然后将观测站位置量测噪声的统计特性融入定位算法,提出一种改进两步加权最小二乘(TS-WLS)算法实现观测站位置误差下外辐射源雷达目标定位。最后推导了克拉美罗下界(CRLB)和算法的理论误差。仿真结果显示,在适中的BRD量测误差和观测站位置误差下,所提算法的目标定位性能能够达到CRLB。     

校正源方位存在偏差时的幅相误差顽健校正算法

针对校正源方位偏差会影响幅相误差校正精度这一问题,在假设校正源方位偏差的概率分布已知的条件下,依据子空间拟合准则和Bayesian估计理论框架,给出了一种抑制校正源方位偏差的幅相误差顽健校正算法。该算法可在无需估计校正源方位的情况下,通过计算某实对称矩阵最小特征值对应的特征向量获得幅相误差的顽健估计。推导了参数估计的CRB(Cramer-Rao bound),分析了顽健算法的渐近性能以及Cheng方法在校正源方位有偏差时的渐近性能。理论分析和仿真实验均表明:在一定条件下,所提出的算法的渐近性能可达到CRB,并且优于Cheng方法的渐近性能(当校正源方位有偏差时)。     

基于RPUKF的固定站无源定位跟踪算法研究

固定单站无源定位跟踪系统面临着可观测性弱、初始误差大等问题,寻找一种快速稳定的定位跟踪算法尤为重要.将距离参数化方法引入固定单站无源定位中,与不敏卡尔曼滤波(UKF)结合给出了基于距离参数化UKF(RPUKF)的固定单站无源定位算法;该算法根据观测站最大探测距离划分距离子区间,每个子区间单独采用UKF算法进行跟踪,将各自跟踪结果进行融合得到最终定位结果.仿真结果表明,在初始误差较大时RPUKF算法仍能实现稳定定位,与RPEKF算法相比在保证实时性的基础上明显改善了定位性能.     

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.     

A rigorous proof of MIMO channel capacity’s increase with antenna number

It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output（MIMO） communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.     

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