高速8PSK调制信号的频率捕获及跟踪算法研究

载波频率同步是载波恢复的重要环节之一。本文基于高速8PSK调制信号完成载波频率估计的前提下,提出了一种采用二叉树(Binary Search Tree)频率搜索方法实现捕获及采用平均"滑动窗"递推最小二乘(RLS)一步预测方法实现频率跟踪的算法;并针对此方法进行了理论推导和蒙特卡洛(Monte Carlo)仿真。结果表明,该方法适用于全数字高速数传8PSK调制信号接收系统,同时也可移植、推广至全数字雷达接收机中。     

SC-FDE宽带航空数传接收机的设计与实现

为满足航空信道条件下的远距离宽带数据传输需求,基于单载波频域均衡传输(SC-FDE)体制,采用8 PSK调制体制进行了宽带数字接收机的设计,包括传输帧同步、载波同步、定时同步、信道估计和频域均衡.同时,为保证灵活应用的需求,采用数字内插的方式进行了可变传输速率设计.基于Xilinx现场可编程门阵列(FPGA)平台对硬件实现进行优化,最终实现了传输速率能够从112.5 Mbit/s覆盖到900 Mbit/s的数传接收机.仿真分析和硬件测试结果表明,该接收解调设备能够实现很好的性能指标,同时SC-FDE架构具备有效补偿多径传播影响的能力,适合应用于高动态无线宽带航空数据传输系统中.     

基于FPGA的8PSK解调器设计

8PSK是一种高带宽效率的多相位键控调制解调技术,在高速数据传输领域具有广阔的应用前景。对Gardner算法和PFD频相联合检测算法进行了仿真研究,给出了实现8PSK全数字解调器符号同步和载波同步的完整结构。在XILINX公司的ISE环境下,用Verilog语言设计实现了8PSK全数字解调器。对该8PSK解调器的解调性能进行了测试,在误码率为10^-6时,解调损失小于1 dB。     

用并行内插算法恢复宽带信号的定时信息

提出了一种卫星高速数传的定时恢复方法,以解决实现复杂、硬件依赖性强的问题.以固定采样钟为基础,利用误差信号对多路数据排序筛选,并行内插实现定时信息的恢复,支持GHz宽带变速率信号的同步.硬件仿真结果表明,该方法的解调损失不超过1 dB.采用该方法的高速接收机可工作在统一平台上,使卫星测控通信地面资源配置更加灵活.     

宽带数字接收机IQ不平衡估计与自适应补偿算法

针对宽带调制解调技术中广泛存在的IQ不平衡问题,在IQ不平衡模型及补偿原理的分析基础上提出了一种宽带数字接收机IQ不平衡估计与自适应补偿算法。首先利用解调数据对IQ不平衡参数进行实时估计,然后利用估计参数对接收信号进行自适应补偿。实验结果表明,所提算法可以有效解决宽带调制解调系统中普遍存在的IQ不平衡问题,提升系统误码性能。     

采用压缩感知的直扩测控信号处理

鉴于扩频测控系统宽带化带来的高速采样压力和高数据率问题,研究了基于压缩感知的直扩测控信号处理方法。通过深入分析直扩测控信号稀疏性,构造了延时-多普勒基字典,提出了基于压缩感知直扩测控信号处理框架,并针对直扩测控信号特点给出了改进正交匹配追踪重构算法,最后针对该信号处理方法的可行性和性能分别进行了仿真实验。仿真结果不仅验证了方法的可行性,同时表明可以在不影响解调性能条件下大幅度降低采样率或数据率,并具有一定的降噪效果,这将为直扩测控通信系统提供一种高效的模数转换和同步解调处理方式。     

采用CPCI总线的通用高速数传接收机

针对高速数传技术的快速发展和广泛应用,提出了一种DSP实现CPCI总线的高速数传通用接收机实现方案.该设计兼容模数混合和全数字硬件输入接口,采用ADC采样率在线设置和程序动态加载技术,可实时完成对不同码速率和不同调制编码方式数据源的解调译码.对450 Mbit/s和600 Mbit/s两种高速数传性能进行了测试,结果表明其接收机解调损失分别小于1 dB和1.5 dB,满足工程应用需求.     

800 Mb/s高速解调器的定时恢复算法及实现研究

针对800 Mb/s高速率数传系统,设计并实现了一种8PSK信号的数字定时同步算法。首先推导出高速数据的Martin Oerder包络平方定时相位误差估计算法的并行实现结构,然后采用FPGA芯片设计实现了定时偏差估计。计算机仿真和硬件实现研究的结果验证了该算法结构在高速数据传输系统下具有良好的估计性能。     

数字调制信号接收技术

为了实现对多种数字信号的解调,设计了一种全数字接收机体制。对通用环载波同步方法及内插滤波码元同步方法进行了深入分析和设计。仿真结果表明,在误比特率为10-4时,所需Eb/N0比理论值高2 dB。基于通用环和内插定时技术的全数字接收机适用于对PSK,QAM数字调制信号的接收解调,满足数字VSLI硬件实现高集成度、小型化接收机的要求。     

基于DTTL算法的8PSK符号定时恢复技术

本文阐述了DTTL全数字符号定时恢复算法在8PSK解调系统中的实现。文中结合8PSK解调系统,对DTTL算法中插值器、定时误差检测器、环路滤波器以及数控振荡器等进行了详细的分析。系统仿真显示了该算法稳定的跟踪性能。     

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