基于合作信标的卫星激光通信瞄准捕获仿真系统

针对星间激光通信基于合作激光信标的瞄准与捕获过程,在LabVIEW(虚拟仪器)平台上研制了一套瞄准与捕获仿真系统。该系统模拟卫星轨道姿态动力学,建立双星指向关系,仿真双自由度转台初始对准。根据不确定区域大小,驱动信标激光进行螺旋扫描,根据信标光束散角及探测器视场,确定仿真捕获点以完成捕获。加入含有高斯噪声的最大速度为1°/s,最大加速度为1°/s2的等效正弦扰动进行了动态捕获实验。最终实现了同步轨道卫星和近地轨道卫星间动态双星激光通信瞄准与捕获仿真,形成了基于虚拟仪器的激光通信全过程仿真模式,为跟踪系统仿真及无信标捕获的仿真奠定了基础。     

跳频扩频系统的Matlab模拟仿真实现

跳频扩频技术采用特定的扩频函数及载波跳变来实现频谱展宽,具有很强的抗干扰性,并具有信息隐蔽、多址保密通信的特点;PSK调制方式由基带脉冲控制载波相位。在Matlab／Simulink下建立了采用BPSK方式的跳频扩频（FH—SS）通信系统模拟模型,并编程仿真实现该系统,对跳频扩频通信的实现有重要意义。     

双机通信技术在通信原理CAI课件中的应用

本文以ＰＣＭ系统模拟为例，介绍双机通信技术在《通信原理》课程ＣＡＩ课件中的应用。     

基于HLA OMT的通信对抗建模仿真

传统的通信对抗仿真都采用面向对象(OO)方法建模仿真。这种仿真技术随着IEEE HLA3.1建模和仿真通用性框架协议产生已经不适应当今仿真需求。针对HLA建模和仿真技术,着重介绍基于HLA OMT建模的一种新的思路,实现通信对抗建模仿真。     

基于Creator和Vega的通信对抗模拟训练三维视景仿真设计

随着计算机技术的发展,视景仿真已经成为一种趋势,本文介绍了适用于军事视景仿真的开发环境,主要介绍了Paradigm公司的MultiGen-Creator和MultiGen-Vega,以及高层体系结构（HLA）,并在此软件开发环境的基础上,构建了通信对抗模拟训练三维视景仿真的系统框架、系统运行结构以及通信对抗联邦体系结构,通过仿真结果验证,基于Creator和Vega的通信对抗模拟训练三维视景仿真系统取得了很好的效果。     

现代通信系统设计的模拟方法

模拟技术在通信系统的设计、分析和实现中起着很重要的作用。过去,模拟技术主要用来验证系统的功能,评估系统性能和产生设计细节。现在系统模拟技术应用越来越广泛,地位也越来越重要,从大型通信卫星到个人通信系统(PCS)的设计,都离不开     

高校体育馆人员疏散仿真研究

分析了人员疏散理论的研究现状,在总结现有的各种仿真模型的基础上,提出了基于多智能体的微观离散疏散仿真模型。并且在该模型的基础上开发了相应的人员疏散计算机仿真系统,根据系统模拟人员疏散,对仿真疏散得到的结果进行了分析研究,为实际的疏散工作提供了有价值的参考建议。     

3D运动声源仿真原理

介绍了一种通过离散合成系统模拟３Ｄ运动声源的方法,分析了多普勒效应、双耳效应、耳廓效应和双耳传输函数的数学模型,提出了３Ｄ运动声源仿真的流程。     

一种卫星扩频保密通信系统的Systemview仿真

卫星通信以其通信距离远、覆盖面积大、机动灵活、通信线路稳定可靠等优点在近几年得到迅速的发展,目前已经成为一种强有力的现代化通信手段。而扩频通信技术又有着抗干扰、抗噪声能力强,低截获概率,保密性强,可用于多径干扰等优点。两者的结合是现代军事抗干扰通信的研究热点之一。使用Systemview作为仿真平台,仿真了一个直接扩频...     

同时输出16种信号的发生器

这种测试信号发生器能仿真移动电话基站所用的各种信号,评价多音频放大器的性能。测试元件和器件性能的信号发生器经历了一场无声的革命,简单的连续波(CW)信号源已经过时。现在这类仪器已被更好的能仿真复杂通信系统如蜂窝式通信基站信号的发生器所取代。美国RDL公司(Conshohoken,     

EmStar: development with high system visibility

Recently, increasing research attention has been directed toward wireless sensor networks: collections of small low-power nodes, physically situated in the environment, that can intelligently deliver high-level sensing results to the user. As the community has moved into more complex design efforts large-scale, long-lived systems that truly require self-organization and adaptivity to the environment - a number of important software design issues have arisen. To make software robust, we must carefully observe its behavior and understand its failure modes. However, many of these failures are not manifested until deployment time. Channel and storage limitations make visibility into a deployed system difficult, hindering our understanding of failure modes. Simulation is difficult to apply; the network's physical situatedness makes it sensitive to subtleties of sensors and wireless communication channels that are difficult to model. In this article we describe EmStar, a PC-based software framework that aims to make development easier by improving system visibility. EmStar's novel execution environments encompass pure simulation, true in-situ deployment, and hybrid modes that combine simulation with real wireless communication and sensors situated in the environment.     

A computer simulation model for the evaluation of mobile radio systems in the military tactical environment

A computer simulation model, designed specifically for the analysis and evaluation of military mobile radio communication systems in the tactical environment is discussed. The algorithms and performance models used in the simulation model are briefly described, while statistical characteristics are derived analytically for a simplified scenario. Typical computer-generated histograms and distribution functions are presented for the more complex scenarios. The computer simulation model is shown to be an effective design tool for many different applications.     

CoWare—A design environment for heterogeneous hardware/software systems

This paper addresses CoWare: an environment for design of heterogeneous systems on chip. These systems are heterogeneous both in terms of specification and implementation. CoWare is based on a communicating processes data-model which supports encapsulation and refinement and makes a strict separation between functional and communication behaviour. Encapsulation enables the reuse of existing specification and design environments (languages, simulators, compilers). Refinement provides for a consistent and integrated path from specification to implementation. The design steps that will be addressed include: system specification, simulation at various abstraction levels, data path synthesis, communication refinement and hardware/software co-design. A spread-spectrum based pager system serves to illuminate the design process in the CoWare environment.     

论电磁环境的相对性与接地气的复杂度评估

为了更加客观地评估电磁环境复杂度及其对电子信息系统的影响,该文以通信系统为例剖析了电磁环境复杂度根源表征量 信干噪比,建立了电磁环境等级与2FSK, BPSK, QPSK, MSK, QAM数据通信系统性能的映射,并引入电磁环境余量和信号余量概念,给出了面向典型数据通信系统的电磁环境图谱,为实现有用信号强度、电磁环境干扰和噪声信号强度到电磁环境复杂度等级间转换提供了直接途径。以此为基础,研究了面向电子信息系统的极化量提取、实时频谱分析技术,提出了电磁环境测量评估系统组成,分析了其工作原理,设计了面向电子信息系统的电磁环境测量、评估流程。最后,利用数字仿真方式,对于应用MSK/单极天线、64-QAM/偶极天线、QPSK/喇叭天线、2FSK/缝隙天线的4类通信系统,分析了上述系统在同一电磁环境下的不同效应,其复杂度等级分别为III级,V级,IV级和II级。结果显示,面向对象的电磁环境要素测量可有效地获取与电子信息系统相关的电磁环境分量;相同电磁环境下不同通信设备可产生不同效应,这充分验证了电磁环境的复杂度具有明显的相对性。     

基于多频带陷波的雷达嵌入式通信波形设计

雷达嵌入式通信（radar-embedded communication,REC）系统是一种在雷达回波信号中隐藏通信信息的隐蔽通信方法。但是由于雷达系统所处的电磁波环境极为复杂,以致雷达嵌入式通信系统会受其他通信系统的同频干扰,最终导致接收机无法准确识别回波信号。为了使得雷达系统避免复杂环境的干扰且能保持良好的隐蔽通信性能,本文提出了一种基于多频带陷波的雷达嵌入式通信波形设计。本文首先根据随机雷达波形和理想功率谱密度,并采用功率谱匹配的方法建立目标函数,然后利用拟牛顿优化算法对目标函数进行求解得到多频带陷波,以此来避免其他通信系统带来的同频干扰问题,最后基于多频带陷波,采用一种改进的加权组合方法（improved weighted-combining,IWC）设计通信波形。仿真结果表明,本文所提方法可以保证雷达通信的低误码率（signal error rate,SER）和低拦截率（low probability of intercept,LPI）。      

太赫兹频段星地通信信道建模与仿真

太赫兹频段作为至今尚未被完全开发的超高通信频段,具有超大带宽等优点,将其应用于第五代（the 5th Generation,5G）、后五代（Beyond 5G,B5G）移动通信系统,除实现更高速率传输外,还可实现地面移动网络与卫星网络频谱资源的共享,有利于推动新一代空天地一体化通信网络建设.文章提出了一种适用于星地通信系统的太赫兹信道建模与仿真方法,分析了自由空间损耗、分子吸收损耗、云雾衰减、雨衰减及多普勒频移等太赫兹信道的影响因素,构建了星地太赫兹通信信道建模流程,并给出了分步骤信道参数的生成方法.通过数值仿真,对不同天气状况下传输距离和频率对传输信号的影响进行了分析,并基于所生成的信道响应对误码率进行评估,从而验证了所提出模型和方法的可用性.所提建模方法能够提供不同传输条件下的动态太赫兹信道响应数据,从而为今后太赫兹频段无线通信系统的设计与开发提供评估与测试依据.     

High-level software synthesis for the design of communicationsystems

A synthesis environment that targets software programmable architectures such as digital signal processors (DSPs) is presented. These processors are well suited for implementation of real-time signal processing systems with medium throughput requirements. Techniques that tightly couple the synthesis environment to an existing communication system simulator are also presented. This enables a seamless transition between the simulation and implementation design level of communication systems. Special focus is on optimization techniques for mapping data flow oriented block diagrams onto DSPs. The combination of different mapping and optimization strategies allows comfortable synthesis of real-time code that is highly adapted to application-specific needs imposed by constraints on memory space, sampling rate, or latency. Thus, tradeoff analysis is supported by efficient interactive or automatic exploration of the design space. All presented concepts are illustrated by the design of a phase synchronizer with automatic gain control on a floating-point DSP     

水声扩频通信中多普勒估计与补偿算法研究

通信系统普遍受多普勒效应影响,因而载波同步成为通信中的一项关键技术。在水声通信中,由于声速有限,信道中的多普勒效应的影响更为明显。该文在一个基于软件无线电机制的水声扩频通信系统中,对水声信道的多普勒效应进行分析和建模,并在此基础上提出了一种有效的水声扩频多普勒估计与补偿算法。仿真实验表明,算法能够在-22 dB的情况下有效地对15 m/s以内产生的多普勒频移进行估计与补偿。算法经过海试测试,在6节速度及加速减速过程中,系统均能够成功地完成载波同步。     

基于MATLAB数字基带传输系统的研究

MATLAB软件具有强大的仿真功能,是当今通信系统中一种重要的设计和仿真工具。本文在分析数字基带系统传输特性的基础上,运用MATLAB/Simulink动态仿真环境实现了双极性数字基带信号传输系统的建模和仿真,通过仿真眼图和误码率曲线对系统的抗噪声性能进行分析。实际仿真结果表明,该系统能够模拟双极性数字基带的传输过程,系统性能仿真分析的结果与理论基本一致,该系统达到设计的要求。     

Software synthesis for DSP using ptolemy

Ptolemy is an environment for simulation, prototyping, and software synthesis for heterogeneous systems. It uses modern object-oriented software technology (in C++) to model each subsystem in a natural and efficient manner, and to integrate these subsystems into a whole. The objectives of Ptolemy encompass practically all aspects of designing signal processing and communications systems, ranging from algorithms and communication strategies, through simulation, hardware and software design, parallel computing, and generation of real-time prototypes. In this paper we will introduce the software synthesis aspects of the Ptolemy system. The environment presented here is both modular and extensible. Ptolemy allows the user to choose among various single- or multiple-processor schedulers.