基于GEESE算法对GTD模型参数估计的影响因素研究

将利用信号子空间特征向量的广义特征值（GEESE）算法应用到能够精确描述雷达目标电磁散射的几何绕射（GTD）模型中,仿真结果表明GEESE算法能精确估计目标散射中心的距离参数、类型参数和幅度参数,最后分析了影响GEESE算法估计精度的几个重要因素。     

一种GTD模型参数估计的新方法

本文将能够精确描述高频电磁散射的几何绕射(GTD)模型取代传统的多重信号分类(MUSIC)算法所采用的指数和模型,并对MUSIC算法做了相应改进.提出利用特征分析方法的信号与噪声子空间正交特性,使改进后的MUSIC算法既能够精确估计目标散射中心位置,又能估计散射中心类型,取得了较好的效果.本文针对各种空间平滑预处理方法对噪声子空间与信号正交特性的影响进行了仿真,指出空间平滑预处理方法会影响噪声子空间及信号子空间结构,进而影响散射中心类型的估计,所以应对散射中心类型的最终结果进行修正.     

色噪声环境下GTD模型的参数估计

本文将能够精确描述高频电磁散射的GTD信号模型引入MUSIC算法,并对MUSIC算法做了相应改进。提出利用特征分析方法中信号与噪声子空间正交特性,使改进后的MUSIC算法既能够精确估计目标散射中心位置,又能估计散射中心类型。本文采用基于四阶累量的MUSIC算法,在一定程度上克服了高斯色噪声对MUSIC算法的影响,拓宽了GTD 模型参数求解的条件。     

基于Stokes子矢量估计的弱信号检测

研究了窄带极化雷达的弱信号检测问题。首先给出目标散射波和随机极化波瞬态Stokes子矢量序列（ISVS）的表征方法和匹配距离的概念，而后提出了一种雷达目标散射信号Stokes子矢量的估计方法。最后，利用目标散射信号和接收机噪声的ISVS之间的差异，基于径向积累的思想提出了一种弱信号检测算法，可以显著改善雷达系统的检测性能，对于反隐身、预警和空间探测等具有一定的指导意义。     

一种新颖的DOA估计算法

子空间类波达方向(Direction Of Arrival, DOA)估计算法的关键在于得到高质量的信号子空间估计。该文利用矩阵伪逆的双正交性,针对源信号不相关而其本身是色信号的情况,给出了一种新颖的DOA估计算法,它不需要知道噪声统计特性。该算法利用一组空时相关矩阵的结构化信息,能稳健而精确地估计出信号子空间,从而得到DOA的精确估计。仿真实验证实了所给算法的有效性。     

基于SP-LCCMA的STBC MC-CDMA系统盲信道估计

研究了空时编码多载波码分多址系统（STBC MC—CDMA）盲信道估计技术。根据信道位于信号子空间的特点,提出基于信号子空间投影线性约束恒模算法（SP—LCCMA）的盲信道估计,避免了噪声子空间信道估计的缺点,将估计信道应用于STBC MC—CDMA系统多用户检测。仿真结果表明,提出算法的收敛速度和信干噪比（SINR）性能优于一般恒模算法。     

基于G-S正交的信号子空间宽带聚焦DOA估计算法

提出基于G-S（Gram-Schmidt）正交算法的信号子空间宽带聚焦DOA估计算法。该算法基于G-S正交方法,求得矩阵的信号子空间,并利用局域子空间投影算法（LSP）,构造宽带信号子空间最佳聚焦矩阵。分析表明,该算法不需矩阵特征分解,运算量小于双边变换（TCT）方法,性能优于TCT方法。仿真结果证明了算法的有效性。     

K分布杂波下基于M-CPSO的散射中心参数估计

研究了非高斯K分布杂波条件下雷达目标散射中心参数估计问题,提出一种基于协同粒子群优化(CPSO Coop- erative-Particle Swarm Optimization)算法的M估计方法。针对K分布杂波的非高斯尖峰特性,首先利用M估计中的损失函数构造出散射中心参数估计的目标优化函数,然后利用协同粒子群算法,通过迭代优化得到目标的散射中心参数。该方法能够同时得到散射中心幅度和位置的稳健估计,通过与基于子空间的估计方法进行仿真实验对比,结果表明,在K分布杂波条件下该方法能够的得到更好的估计结果。     

宽带信号源数目和DOA快速估计

宽带信号源数目估计与其波达方向（DOA）估计是紧密相连的。文章综合考虑信号源数目和DOA估计,从减少算法的运算量出发,提出了一种新的宽带信号源数目和DOA快速估计方法。该方法首先利用多级维纳滤波器（MSWF）算法来估计信号子空间,避免了特征分解方法估计信号子空间所需要的大运算量;然后基于信号子空间的旋转不变性,提出了一种新的宽带信号源数目估计快速算法;最后利用信号子空间的旋转不变性来估计DOA,避免了谱峰搜索所需要的大运算量。计算机仿真试验验证了此方法的有效性。     

CDMA系统中载频频偏估计的新方法

本文针对存在载频频偏的CDMA系统，提出了一种新的估计该固有频偏的方法，先从理论上分析了CDMA信号经过广义平稳非相干散射信道（WSSUS）时载频频偏估计的最大似算法；根据CDMA系统设有连续导频的特点，对该算法进行改进，大大降低了计算的复杂度，并易于工程实现。仿真结果表明，该算法能够精确地载频频偏。     

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.     

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     

JOURNAL OF ELECTRONICS(CHINA)

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NEXT GENERATION WIRELESS NETWORKS–ESPECIALLY THE USE OF MILLI-MICROWAVE BANDS

The global bandwidth shortage of wireless communications has motivated the exploration of the naillimeter wave （ram-wave） frequency spectrum for the next generation wireless communications. Recent advances in RF CMOS technology and high speed baseband signal processing technologies have enabled tile extensive research and development of turn-wave wireless communications. The multi gigabit per second data rate of ram-wave system will lead to applications in many important scenarios, such as WPAN, WLAN,back-haul for cellular system. And the frequency bands include 28 GHz, 38 GHz, 45GHz, 60GHz, E-BAND and even beyond 100 GHz. The propagation and the imitation of the RF circuits design in these frequency bands make the directional antennas be inevitable for mm-wave communications.