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TN912005050763短波SFH/GMSK系统差分相位解调方案的性能分析/彭菊红,赵茂泰,甘良才(湖北大学物理学与电子技术学院)//电波科学学报.―2004,19(6).―776～779,784.提出了一种基于Viterbi算法的短波SFH/GMSK系统差分相位检测(DPD)的解调方案,运用Matlab建立了短波SFH/GMSK系统模型,并在该模型上对不同参数下该解调方案的误比特率进行了数值仿真.其仿真结果表明:DPD解调方案的误比特率可以达到10-5～10-6,能满足短波信道性能的需求.图5表0参7TN912005050764一个非否认协议ZG的形式化分析/范红,冯登国(中科院研究生院信息安全国…     

数字化短波调制解调器设计

为了实现高速、可靠、易于实现的数字化短波通信,提出了一种基于通用计算机的调制解调器设计方案。为了实现高可靠性的数字短波信号传输,搭建了用户端到用户端的转换平台设计,其中,模拟短波电台提供系统收发天线,使用计算机声卡实现数字信号与音频之间的数模/模数互转,使用计算机处理器（CPU）调制解调。根据短波通信功率受限的特点,使用恒包络调制——高斯最小频移键控（GMSK）作为调制方式。为了实现快速准确的时间同步,设计了一种多训练序列分段插入的帧结构方案。计算机仿真和实测结果表明,该调制解调器在信噪比15 dB下可达到10-5的误比特率,实现可靠短波通信。     

基于SFH/GMSK调制的军事卫星通信系统及性能仿真

基于高效调制技术的军事卫星跳频通信系统的应用已经越来越广泛。该文将当前军事卫星通信中广泛运用的高效调制方式GMSK与跳频技术相结合,搭建了SFH/GMSK卫星通信系统模型,并在其中加入卷积编码以改善系统性能,最后对系统模型结合一定的干扰条件进行仿真分析。对SFH/GMSK通信系统的研究,对军事卫星通信中的高效传输技术的研究有重要的参考价值。     

RoFSO系统中4FSK仿真及其误比特率性能分析

将射频技术应用到自由空间光通信具有独到的优势。为了研究自由空间光载射频技术,在四进制频移键控调制解调理论基础上,以自由空间光通信为应用背景,采用仿真,从时域角度对四进制频移键控系统进行了编码及解码研究,并推导了经过高斯噪声和瑞利信道后系统误比特率及信道容量。两种解调法的系统误比特率仿真结果表明,当信噪比为12dB时,过零检测法的系统误比特率达到10-15,明显优于相干解调法。     

阴影对GMSK卫星移动通信系统性能的影响

导出了采用L重最大比组合（MRC）和差分相位检测（DPD）方案的高斯最小频移键控（GMSK）卫星移动通信系统在不同信道条件下的误比特率公式，并利用实测数据给出数值计算结果。可用于分析阴影特性对卫星移动信道性能的影响并指导系统设计。     

MFSK和GMSK调制方式在短波跳频通信系统中的应用及性能仿真

本文主要讨论MFSK和GMSK(高斯滤波最小频移键控)调制方式在短波跳频通信系统中的应用,并对其性能进行了数值仿真.对于MFSK调制方式,本文重点讨论了将带反馈链路的选择式频率分集和编码技术应用于短波FH/MFSK系统对性能的改善,并分析当在具有加性高斯噪声的瑞利衰落信道中存在部分频带阻塞时的性能.GMSK具有优良的频谱特性,本文仿真了结合Viterbi算法非相干解调方案时跳频系统的性能.最后对两种调制方式进行了初步比较.     

极小BTb参数GMSK信号的非相干解调

针对高斯滤波器与码元间隔乘积极小（BTb≤1/6）的最小高斯频移键控（GMSK）信号解调,研究了基于1比特相位差分、2比特相位差分和基于维特比（Viterbi）检测算法的相位差分的解调方法,给出了不同了BTb下维特比检测的状态转移计算方法,有效的克服了极小BTb参数引入的码间串扰对解调误比特率的影响。仿真结果表明,在BTb=0.15的情况下,采用基于2比特相位差分的维特比检测（截断长度为4Tb）是较好的解调方案。     

慢符号速率低峰均比调制与信噪比关系的仿真研究

根据无线收发信机的工作原理,设计了慢符号速率调制信号经过各种环境的无线传输后误码率和信噪比变化的仿真原理结构,并应用理论公式和实际例子分析差分算法最适合慢符号速率低阶调制信号的解调.在时域同步和不同步的两种情况下,分别针对慢符号速率信号用GMSK和OQPSK低峰均比调制后经过4种不同的无线通信环境的仿真,详细分析了解调后信号误比特率和信噪比的关系,最后总结并比较了GMSK和OQPSK调制对信噪比的要求和对放大器工作效率的不同.     

一种新的π/4DQPSK解调译码方案

本文提出了一种新的π/4DQPSK解调译码方案.该方案利用非冗余纠错差分解调的硬判决信息对Viterbi软判决译码时的量度加权,从而改变了传统的差分解调结合软判决译码的量度值,使差分解调软输出的信噪比得到改善,提高了Viterbi软判决译码的性能.计算机仿真表明,相对于传统的差分解调结合软判决译码,该算法在误比特率BER为10-5时在AWGN信道中有1.4dB的性能改善,在Rician信道中同样有显著的性能改善.这使得在普遍采用差分解调软判决译码的卫星通信系统中系统容量和通信质量都得到显著改善.     

GMSK信号的后解码相干解调

为提高现有通信系统中高斯最小频移键控(GMSK)信号的接收性能,提出了一种基于后解码的GMSK相干解调方法.对于接收到的GMSK基带信号,首先完成相位和载波的同步,将信号的初始相位补偿到零相位;然后通过交替抽取GMSK基带信号的虚部与实部幅度采样值完成信息提取;最后通过后续解码处理完成信号解调.仿真表明,在误码率为10-3时,基于后解码的GMSK解调性能仅比预编码GMSK相干解调差0.5 dB,与传统基于维特比迭代处理的GMSK相干解调性能基本相当,但算法实现更为简化,有利于在现有非相干解调GMSK通信系统中的性能提升实现.     

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.     

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