一种低误码率的ADS-B接收机的设计

针对广播式自动相关监控（ADS-B）接收机存在高误码率的问题,设计一种基于FPGA的ADS-B接收机,通过ADC电路转换解调后的模拟信号为数字信号,并利用FPGA的并行处理的特点,采用流水线方式处理ADS-B信号;利用有关数字滤波和数字信号提取算法,计算得到ADS-B信息,并经过PL2303HX发送电脑上位机中。实验结果证明,可以较好地完成1090MHz ES ADS-B信号的接收,实现了内部数字信号滤波算法和CRC校验,有效地降低设备的误码率。本文网络版地址：http：//www.eepw. com.cn/article/274749.htm     

基于FPGA和ARM的GPS信号处理平台

介绍了GPS信号处理平台的具体实现.该平台采用GP2015芯片作为GPS接收机的射频前端,在FPGA上采用Verlog硬件描述语言实现GPS信号12通道相关器,采用基于ARM7核的微处理器实现GPS信号的基带处理,在上位机显示处理结果.最终测试结果表明该GPS信号处理平台成功实现了对GPS信号的捕获与跟踪,能够实时显示卫星方位与用户坐标,扩展性强,应用前景广阔.     

基于虚拟仪器的自动测试系统设计

为满足接收机的自动化检测需求,提出了一种基于虚拟仪器技术的接收机测试系统方案。介绍了测试系统原理,其硬件部分主要用来模拟接收机的各种输入信号,对输出信号进行测量,软件部分采用ATLAS语言进行编程,实现了对接收机的自动测试功能。实际应用表明,该系统操作简便、测试准确,满足接收机测试要求。     

基于BDS的ADS-B报文生成系统

目前国际民航组织（ICAO）和美国航空无线电技术委员会（RTCA）有关广播式自动相关监视（ADS-B）标准中的报文数据源均规定来自全球定位系统（GPS）,而中国自主建设的“北斗”卫星导航系统（BDS）作为ADS-B数据源是必然趋势。设计了基于BDS的ADS-B报文生成系统的总体架构,利用BDS接收机接收的真实数据仿真生成了ADS-B的6种报文,并以空中位置报文的生成为例,详细阐述了报文产生涉及的关键技术以及报文的生成过程。通过运行集成后的ADS-B报文生成系统以及对所产生的6种报文的仿真验证,证明该系统总体设计思路合理,运行结果正确,可为基于BDS的ADS-B相关技术研究提供稳定可靠的ADS-B报文源。     

广播式自动相关监视机载接收组件设计与实现

本文主要围绕 ADS-B 机载接收组件实际工程开发,研究了 ADS-B 接收系统总体技术,提出了 ADS-B 机载接收组件的总体设计方案;给出了 ADS-B 射频接收前端和信号处理后端软硬件实现方法,基于 RTCA DO-260B 标准,阐述了增强型扩展报文算法的实现方法,给出了接收设备的实验室测试和实际环境测试方法和测试结果。     

基于GP4020的GPS接收平台的设计及实现

介绍了一种基于GP4020的GPS信号处理平台的具体实现.该平台采用GP2015芯片作为GPS接收机的射频前端,使用ZARLINK公司推出的GP4020芯片进行GPS信号的基带处理,该芯片内嵌ARM7核作为微处理器,在上位机显示处理结果.具体包括了接收机外围扩展电路的设计以及软件开发环境的建立和软件开发过程.该平台可用以测试不同的GPS算法,扩展性强,应用前景广泛.     

基于数字射频调制的ADS-B目标模拟器设计与实现

广播式自动相关监视器(ADS-B)是一种用于空中交通管制的监视设备，因为其优越的各项性能，在雷达监视领域被广泛推广。为了方便快捷地测试ADS-B设备的准确性、可靠性和及时性等技术指标，需要使用目标模拟器来生成各种场景的ADS-B射频测试信号，包括不同的衰减、时延、多普勒频移和交织情况等。文中给出了一种基于数字射频调制技术的目标模拟器设计与实现，阐明了其工作原理与具体实现方法。对该模拟器的测试和使用表明：该模拟器可按照设定产生多个ADS-B目标叠加信号，操作简单且运行稳定，能够实现对ADS-B接收系统性能和功能测试，具有很好的应用价值。     

基于超宽带采样保持器的数字接收机设计

直接射频采样技术是数字接收机的发展新趋势。由于 ADC 器件的水平限制,直接射频采样技术在接收机中的应用受到很大的限制。采用 SHA（采样保持器）＋ADC 的系统结构,设计了一种支持超宽带信号输入的数字接收机,实现了射频信号的直接采样。简述了采样保持器的工作原理,介绍了直接射频采样数字接收机的系统组成,详细介绍了数据采集子板的设计。综合 FPGA 分析工具 CHIPSCOPE 与MATLAB 软件,对数字接收机进行了测试和指标分析。结果表明,该数字接收机在采样保持器带宽范围内,可以满足常规指标要求,简化了系统设计,降低了成本,具有一定的应用价值。     

广播式自动相关监视信号接收系统设计

针对低成本、高性能的广播式自动相关监视(ADS-B)系统的设计需求,研究了ADS-B信号接收技术.基于软件无线电技术,设计了基于1090ES模式的ADS-B信号软件接收机;利用廉价的软件无线电平台(RTL-SDR)及Matlab,对设计进行了验证,实现对民航航班ADS-B信号的实际接收.相对于传统的ADS-B接收机,结...     

基于Visual Basic的射频信号自动测试系统

本文针对射频信号手动测试的局限性,提出了一套基于Visual Basic语言的自动测试系统。该自动测试系统通过调用SCPI（可编程仪器标准命令集）对带有GPIB接口的无线通信综测仪及射频信号发生器进行程控,并根据测试流程自动完成相关测试项目。实际生产测试检验证明,较之传统的人工测试,可以大幅提高测试效率与精确度;此外,系统结构灵活,扩展性强,具有很好的市场应用前景。     

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