一种结合HT算法和LSCMA的联合自适应算法

最小二乘恒模算法(LSCMA)是阵列信号处理中广泛使用的一种能全局收敛且稳定性强的算法,但是在低信噪比的情况下会发生干扰捕获问题.正交化(Hung-Turner)算法在低信噪比情况下有较好的收敛性能,且计算简单.本文提出了一种正交化算法和最小二乘恒模算法的联合算法.仿真结果表明这种算法能较好的解决干扰捕获问题,其收敛性能比LSCMA要好,尤其在低信噪比的情况下.     

线性受限最小二乘恒模波束形成算法

将线性受限条件运用于最小二乘，提出了一种线性受限最小二乘恒模波束形成算法，称为LC-LSCMA，并将它与传统的最小二乘恒模波束形成算法(LSCMA)及预解扩最小二乘恒模波束形成算法(P-LSCMA)进行了仿真比较。仿真结果表明，提出的LC-LSCMA算法比LSCMA及P-LSCMA的信干比性能和误码率性能要好，特别在低信噪比情况下性能仍优于LSCMA。     

线性受限最小二乘恒模盲多用户检测算法

本文将线性受限条件运用于最小二乘恒模算法,提出了一种线性受限最小二乘恒模盲多用户检测算法,称为LCLSCMA,并将它与传统的最小二乘恒模算法(LSCMA)进行了仿真比较。仿真结果表明,本文提出的LCLSCMA算法比传统的最小二乘恒模算法的信干比性能和误码率性能要好,特别在低信噪比强多址干扰情况下性能仍优于LSCMA。     

一种基于天线阵列的预处理盲多用户检测算法

该文提出了一种基于天线阵列的预处理判决反馈最小二乘恒模盲多用户检测算法,称为P-DFB-LSCMA算法。它是对天线阵列接收信号经预处理,采用判决反馈最小二乘恒模算法进行多用户检测。仿真结果表明,P-DFB-LSCMA算法比仅采用判决反馈最小二乘恒模算法(DFB-LSCMA)和传统的LSCMA算法性能要好,特别在低信噪比下性能仍优于后二者。     

块衰落信道下训练序列辅助的恒模多用户检测器研究

恒模算法(CMA)是一种广泛应用于阵列处理、均衡、多用户检测中的盲算法.最小二乘恒模算法(LSCMA)由于其全局收敛性及稳定性受到关注.本文研究块衰落信道下基于训练序列辅助的LSCM算法的性能.本文的研究基于同步CDMA系统,系统中每个用户经历独立的平坦瑞利衰落信道.在发送端,为了在接收端获得数据的信号子空间,目标用户的第一帧中插入少量的训练序列.通过信号子空间信息的辅助,本文提出的训练序列非周期辅助最小二乘恒模(TSA-LSCM-NP,Training Soquence Aided Least Squares Constant Modulus non-periodically)算法在提高少许复杂度的基础上能够获得优于LSCM算法的检测性能.     

子空间约束的最小二乘常模算法

常模算法(CMA)是一种性能优良的盲多用户检测算法.最小二乘常模算法(LSCMA)因其全局收敛性和稳定性而备受关注,但是在信噪比低时性能不理想.本文将最小二乘常模算法,紧缩近似投影子空间(PASTd)算法和奇异值分解(SVD)相结合,提出了一种子空间约束的最小二乘常模算法,称为SUB_LSCMA,其复杂度比已有的基于直接对接收信号自相关矩阵做特征值分解(ED)的LSCMA_SUB[6]复杂度低.仿真结果表明这种算法的收敛速度、跟踪性能和误码性能和LSC-MA_SUB基本相同.     

基于天线阵列的一种预处理LCLSCM多用户检测算法

给出了一种天线阵列信号的预处理方法,并将线性受限条件和判决反馈用于最小二乘,提出了一种基于天线阵列的预处理线性受限判决反馈最小二乘恒模多用户检测算法,称为PLC-DFB-LSCMA算法,并与判决反馈最小二乘恒模算法(DFB-LSCMA)及传统的最小二乘恒模算法(LSCMA)进行了仿真比较,仿真结果表明,PLC-DFB-LSCMA算法的信干比性能及误码性能仍优于后二者。     

SMI-LSCMA盲自适应多波束形成算法研究

提出一种基于协方差矩阵求逆(SMI)和最小二乘恒模(LSCMA)的恒模阵列盲多波束形成算法。该算法由SMI算法决定LSCMA算法的初始权向量,充分利用SMI结合LSCMA算法的所有优点,在干扰信号较强时,确保权向量收敛至弱期望信号。并且有稳定的SINR输出,具有良好的信号分离提取性能。仿真结果证明了SMI-LSCMA算法具有较强的稳健型和较快的收敛速度。     

一种改进的波束形成算法

论文分析研究了最陡下降恒模算法（SDCMA）在波束形成应用中收敛稳定性好和最小二乘恒模算法（LSCMA）收敛速度快的特点,将两种算法以新的方式相结合,吸收二者的优点,提出了一种基于预解扩判决反馈盲波束形成组合算法（SD—LSCMA）。通过和传统算法在相同环境下进行MATLAB仿真比较,结果表明,文中提出的算法具有更好的抗强多址干扰性能。     

一种基于DFP方法的拟牛顿恒模算法跟踪信道变化能力的研究

本文根据信道变化快慢程度,把信道模型分成剧变信道和渐变信道.分析研究了恒模盲均衡算法(CMA)在不同的信道模型下跟踪信道变化的能力.针对于原有典型恒模盲均衡算法的性能上的劣势,结合最优化理论,提出了一种线性受限拟牛顿恒模算法,称之为LC-DFPCMA,并将它与传统的线性受限恒模算法(LC-CMA)及最小二乘恒模算法(LSCMA)进行了仿真比较.仿真结果表明,提出的LC-DFPCMA算法比LC-CMA算法能更快地跟踪信道变化且收敛效果较好;与LSCMA算法相比,算法复杂度有明显降低.     

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.     

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 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.