一种基于脉冲样本图和模糊理论的雷达辐射源识别

在现代信号密集环境中,传统的雷达信号特征描述方式很难对复杂体制雷达辐射源进行描述和识别.因此提出了一种基于脉冲样本图和模糊理论的雷达辐射源识别算法,运用格贴近度的模糊识别算法进行雷达辐射源识别.该方法省略了特征提取过程,简化了处理环节,仿真结果表明,这种方法具有很高的识别准确率.     

基于参数样本图的雷达辐射源识别

在现代信号环境中,基于传统的雷达信号特征描述方式很难对复杂体制雷达辐射源进行准确描述和识别。提出一种新的雷达参数样本图的描述方式,并研究了基于参数样本图的雷达辐射源识别算法,利用脉冲序列与雷达参数样本图进行匹配识别,给出了参数类型匹配及参数样本图匹配的方案。仿真结果表明,这种方法是有效的。     

探讨一种新的雷达信号描述方式和识别技术

现代雷达信号体制越来越复杂,这使得现有的雷达信号特征描述方式很难有效地对其进行描述和分析。文章提出了一种雷达信号脉冲样本图的描述方法,利用这种描述方法可以很好地对复杂体制雷达信号特征进行描述和分析。文章还讨论了基于脉冲样本图的雷达信号处理识别方法,跟传统识别方法相比,该方法具有更快速、更可靠的特点。     

基于脉冲样本图的雷达辐射源识别方法

雷达辐射源识别是雷达对抗侦察信号处理的关键环节。由于现代雷达体制日益复杂,传统的辐射源识别方法面临着越来越严峻的问题。因此针对这种情况,提出了一种基于脉冲样本图雷达辐射源识别算法。这种算法无需对相互叠加的雷达辐射源信号进行完全分选,并且不需要进行传统识别方法中的特征提取过程,简化了处理环节。在脉冲流密度适中的情况下,该算法具有很好的判别准确率。仿真结果验证了该方法的可行性和实用性。     

基于脉间特征深度学习的雷达辐射源识别

多功能雷达在复杂程序调度下,发射信号参数呈现取值范围宽、捷变速度快、变化随机性强等特点,非合作接收方难以对其建立有效的信号模型,给电子侦察系统的雷达辐射源识别带来严峻挑战。本文提出一种基于深度学习的复杂体制雷达辐射源识别方法,利用大样本全脉冲数据形成脉间参数变化的图像特征表示,从宏观上揭示雷达辐射源隐含的波形设计机理,并设计了基于AlexNet网络的图像特征深度学习网络开展辐射源识别,实测数据实验表明了本文的方法对一定时间跨度内的有限部同型多功能雷达具有良好的识别性能,为多功能雷达辐射源智能个体识别提供了新的解决思路。      

基于脉冲神经网络的雷达辐射源调制类型识别

面对日益复杂的电磁环境和层出不穷的新体制雷达,基于人工方式提取雷达辐射源特征难以满足现代认知电子战的需求.为提升雷达辐射源识别的智能化水平,提出一种新的基于脉冲神经网络(Spiking Neuron Network,SNN)进行雷达辐射源调制类型识别的算法.首先利用时频分析的方法,将5种常见雷达时域信号转换为二维灰度图...     

雷达信号成形规律的样本体系描述方法

针对多功能雷达工作在搜索方式时,其工作模式的转换以及同一模式下的脉冲信号均有规律可循的工作特点,提出一种基于雷达信号成形规律的样本体系描述技术。该方法利用多功能雷达工作模式的转换规律和脉冲本身的时频域参数变化规律,建立搜索模式转换样本、脉冲样本图和样本脉冲的层级数学模型,对多功能雷达脉冲信号成形规律进行提取和准确描述。仿真实验表明,样本体系描述技术不仅能够提取其对应的复杂体制雷达工作模式和脉冲信号,而且对噪声环境具有较好的适应能力。     

基于改进EfficientNet的雷达信号调制方式识别

针对在复杂电磁环境下的雷达辐射源信号识别中传统方法失效,深度学习算法存在低信噪比下识别效果差、网络复杂参数多的问题,提出一种改进EfficientNet模型对雷达辐射源信号进行识别。首先引入卷积注意力模块(Convolutional Block Attention Module, CBAM)改进网络,提高网络对通道和空间特征的提取能力;结合h-Swish和ReLU两种激活函数进一步改进网络在保持网络精度的情况下加快网络训练;对样本进行标签平滑,对9种不同调制信号的时频图像做CutMix数据增强后输入网络,增强模型的泛化能力。通过实验分析,改进后的模型在信噪比为-10 dB的情况下对9种调制信号的综合识别率达到了94.24%,验证了该方法能够在低信噪比条件下有效识别雷达辐射源信号。     

基于时差多参分选的多层感知器网络脉间识别

现代战争中,雷达系统发展迅速。为识别复杂的雷达信号调制模式以及混合体制雷达,该文提出一种基于多站获取脉冲时差参数联合其他脉冲描述字分选的办法,利用多层感知器神经网络得到脉间调制识别结果。该文通过时差参数与其他脉冲描述字去交错解决传统脉冲重复周期估计算法无法对复杂的脉间调制方式进行估计。利用训练好的多层感知器,获取完成去交错后的脉冲序列其特征向量,获得其脉间调制类型识别。通过实验仿真,在脉冲丢失率不高于20%情况下,对复杂脉间调制方式的正确识别概率在90%以上。     

基于句法模式识别的雷达识别方法研究

针对参数相近的复杂体制雷达难以识别的问题,提出了一种基于句法模式识的雷达信号识别方法。该方法首先对已知雷达脉冲数据进行结构分析,用雷达脉冲序列参数作为句法识别中的基元进行描述,然后通过训练已知样本得出正则文法扩展生成式并构造一种多位有限态自动机作为识别器,最后选取雷达样本数据进行识别实验。理论分析和实验结果论证了该句法方法的可靠性和有效性。     

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.     

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.     

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.     

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.     

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.     

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