基于SOPC技术的GigE接口X光图像采集系统

设计并实现了一个医学成像设备专用的千兆以太网接口X光图像采集系统。该设计采用SOPC技术,使用Altera公司的三速以太网IP核和自定义以太网打包模块,实现了千兆以太网传输。测试表明,该系统性能稳定,传输速度高,有效地满足了X光机系统的要求。     

X-ray Image Capture System with Gigabit Ethernet Interface Based on SOPC Technique

设计并实现了一个医学成像设备专用的千兆以太网接口X光图像采集系统.该设计采用SOPC技术,使用Altera公司的三速以太网IP核和自定义以太网打包模块,实现了千兆以太网传输.测试表明,该系统性能稳定,传输速度高,有效地满足了X光机系统的要求.     

基于Web方式的学生档案管理系统的设计与实现

重点研究了学生档案管理系统的设计与实现，该系统采用B／S模式设计，使用ASP．net语言编程、Web交互技术并采用Microsoft SQL Server 2000作为数据库服务器来完成的。从系统的需求分析、设计原则、逻辑体系划分、模块划分和设计开发等几个方面详细说明了系统实现的具体方法。     

空管系统中网络数据记录仪的可靠性设计

针对现有空管系统中使用的货架记录仪的特点和不足,自主研制了一套符合空管系统要求的网络数据记录仪。系统采用了硬件冗余设计和软件容错设计等技术,实现了系统的高可靠性,结果证明,该设备在空管系统中运行稳定、可靠。     

基于Windows的考试系统的研究与实现

设计并实现了一种基于Windows操作平台的考试系统.该系统由考试和阅卷2个相对独立的部分构成,实现了考试与阅卷的分离.考试系统的题型为单选题、多选题、填空题和操作题,可以用在含此类题型的各种考试中.该系统采用Visual Basic 6.0实现界面设计和代码编写,后台数据库采用的是Microsoft Access.该系统在本校两年期末考试中使用过,效果良好.     

基于phpexcel的榆林学院工资查询系统的设计与实现

为了提高榆林学院财务处工资管理信息化水平,设计并实现了工资查询系统.该系统基于Codeigniter框架,系统分为前台、后台两部分,前台系统可实现个人资料管理、工资查询等功能,后台系统可实现教职工管理、工资管理、部门管理、短信发送等功能.系统表示层设计采用可Jquery框架,工资信息导入导出功能使用开源组件phpexcel实现,短信发送模块使用模拟登录wap网关的技术实现.系统开发完成后已在榆林学院部署使用,该系统操作简单,既方便了教职工的查询工资信息又减轻了财务人员的压力.     

数字通信系统关键技术设计

介绍了一种数字通信系统的设计思想及其关键技术的实现方法。该系统分为有线通信系统和无线通信系统2个子系统,并将无线通信和有线通信有机地结合在一起,融合为一套有线、无线共存互通的综合通信系统。对系统的各个关键技术做了详细介绍,拼弃了以往设计采用套片的设计思路,关键技术在FPGA内部自主设计。有线部分采用PCM编解码,无线部分采用AMBE话音压缩和RS纠错处理。该系统设计稳定、话音清晰,便于生产和使用。     

呼叫中心在安全监控系统中运用的研究

本文介绍了将呼叫中心技术应用于基于H.263(+)的使用公众电话网(PSTN)传输视频图像的安全监控系统。该呼叫中心采用自动语音应答(IVR)技术实现无人值守时的事故举报,与该安全监控系统进行互动,实现灾情的自动上报和应急方案的调用。文中详细给出了该系统的设计与实现。     

基于查阶跃响应表的高效FIR滤波器设计及其FPGA实现

本文提出了一种采用查阶跃响应表方法实现的FIR数字滤波器设计方案,并以一个649阶FIR滤波器的FPGA设计为例,与传统的采用FPGAIPCORE实现方法进行了对比,分析该设计方法在FPGA的资源利用和系统时钟速率上的优势。通过实验数据验证,该方案可以解决现有技术中FIR滤波器需要大量乘法器和加法器的问题,达到了降低FPGA硬件资源使用、提高系统运行效率的效果。     

基于MSP430单片机的虚拟示波器

虚拟示波器在应用中体现出简易、灵活、便携、易于与PC机通信的特点。该设计中采用超低功耗的MSP430F169单片机作为控制核心,实现模／数转换,它能保证高运算速度和系统的工作稳定。同时使用高速USB接口与PC机进行数据传输,在PC机端对信号进行分析和再现,实现信号的实时显示和信号的特征分析;系统采用USB供电,不仅可降低功耗,而且易于使用和携带。实验结果表明,该设计达到了预期目标。     

GBAS功能需求的地面测试研究

星基导航技术在民航界得到了越来越多的应用和推广,GNSS地基增强系统GBAS作为星基导航提供精密进近必不可少的手段之一受到了广泛关注。和陆基导航设备一样,GBAS在正式使用和对外开放之前都需要进行测试和验证,本文阐述了GBAS的基本组成及工作原理,根据国际民航组织的要求,对GBAS在投入使用前需要进行的功能测试进行了概述,并对测量的参数进行了详细的分析说明。给出了GBAS地面功能测试的方法,详细介绍了GBAS精度的测量,为国内运行GBAS提供了技术参考。     

基于嵌入式平台的公交车辆监控系统

系统基于ARM9嵌入式软硬件平台，整合了CPS（全球定位系统）、GPRS（通用无线分组业务）以及多数据流传感器，实现对公交车辆位置、温度、人数等数据的采集、传输及反馈，提高了公交系统调度效率和增强了安全性。介绍了系统的构成，并给出软硬件的设计方案。     

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。     

无人驾驶车辆终端控制的研究与探索

介绍了一种无人驾驶车辆系统,并着重介绍如何在这种车辆中实现转向的终端控制的方法,以GPRS,GPS和射频识别技术为基础,给出了一种详细的解决方案,并且详细给出了几种关键技术在车辆控制中的应用,最后通过测试证明了方案的有效性:车载在距离标签10 m内能够以915 MHz的频率通过射频模块识别到前方轨道信息,而且能以19200 B/s的波特率与GPRS连接,然后接入GPRS网络与远端网络监控站实时通信,进行数据交换。     

数据驱动的开放动态频谱接入系统构建方法

在认知无线电(CR)背景下,动态频谱接入已成为提高无线网络频谱利用率的重要途径。基于全球移动通信系统-铁路(GSM-R)系统中采集的细粒度频谱监测数据,提出一种数据驱动的深度学习方法,建模频谱模式,并建立一套动态频谱接入访问框架。采用一种深度频谱生成模型指导频谱分配;设计一种综合递归序列表征与场景特征嵌入的深度网络,建模和预测短时频谱占用情况,并由此提出一种动态信道接入策略。进一步,利用软件无线电(SDR)平台实现一套跳频系统,并将其与动态频谱接入策略进行集成。使用真实的历史频谱数据评估该系统的数据吞吐能力,测试结果表明,所提方法及构建的跳频系统能有效提高机会通信能力,高效利用频谱资源。该频谱接入框架及SDR系统实现具有较强的通用性,易于集成到不同场景和频段的系统中。     

Modern analog and digital communication systems development using GNU Radio with USRP

In this modern world many communication devices are highly intelligent and interconnected between each other. Any up-gradation of the hardware in the existing communication devices is not easier one. Compatibility of the new hardware with existing hardware is highly essential. But the new protocols may or may not support the older one. The solution for these problems can be provided by using the reconfigurable hardware design. The hardware can be reprogrammed according to the new change in technology up-gradation. The cost of commercially available hardware and software requirements for setting up such a module is very high. This can be solved by using Open source hardware and software such as Universal Software Radio Peripheral (USRP) and GNU Radio. This work demonstrates how the modern analog communication system like Community Radio Schemes and Radio Data System (RDS) and digital communication systems such as Simple Digital Video Broadcasting (DVB) and OFDM based data communication can be developed using the Open source hardware USRP1. This work will be helpful even for first year level of engineering students to easily implement any communication and control applications with cheaper cost.     

Maximizing Parallel Testing in an FM Receiver

High volume production environments create great challenges for production testing and verification of Radio Frequency (RF) devices. In this environment, much emphasis is put on parallel testing, or the ability to test multiple devices at the same time using a single tester. In order for this parallelism to become a reality, there is a need for production RF tests to be simplified and reduced to requiring only the simplest test stimulus and analysis. In this paper, we present a new method of measuring the performance of a Frequency Modulation (FM) receiver that requires only a continuous wave signal input in order to eliminate the more costly Signal-to-Noise Ratio test. Using this new technique we will then demonstrate how simplifying this test and adding frequency diversity enables testing of up to 8 devices in parallel using a single tester.     

On the use of GPS receivers in railway environments

This paper presents the electromagnetic interference effects on the performance of locomotive onboard Global Positioning System (GPS) receivers due to the railway environment. The evaluation of the maximum tolerated interferences around a train is presented by taking into account European Committee for Electrotechnical Standardization and the International Electrotechnical Commission normative, Mobile Radio for Railway Networks in Europe, and experimental results. These interference levels are used to study the performance of a hardware GPS receiver operating at different modes and considering the possible levels of GPS signal L1 at the earth surface. From the obtained results, it is possible to conclude the reliability of a low-cost GPS receiver for train positioning even if the train equipment has been designed at the threshold of the current normative.     

Differential operation of the Global Positioning System

The principles of differential operation of the Global Positioning System (DGPS) are discussed. DGPS error sources and their influence on spatial and temporal correlation are analyzed. The standards for the differential corrections and the auxiliary messages which have been developed by the Radio Technical Commission for Maritime Services are then described. The dependence of DGPS accuracy on satellite geometry is examined. Two possible DGPS data links are described, and the applications, advantages, and limitations of each are discussed. The first data link would use the extant marine radiobeacon network (a medium-frequency system) and provide coastal coverage. The second data link would use pseudosatellites and provide additional lines of position as well as carry the differential correction     

Optimizing the Use of Random Access Channels in GSM-GPRS

The random access channels and traffic channels are utilized, respectively, for call establishment and information transmission in the uplink direction (from mobile to base station) of the Global System for Mobile communications (GSM) networks. A call is either rejected or blocked depending on its inability to succeed either in the random access channels or in the traffic channels. The optimum number of random access slots is directly proportional to the average call arrival rate, being independent of the average channel holding time and the number of traffic channels. The number of slots occupied by a given call can be changed dynamically in the newly developed General Packet Radio Service (GPRS) systems. A complete analysis is executed for the traffic channel utilization and call blocking probability with the exact number of random access slots that provide almost zero call rejection probability. The overall call success probability is derived considering call rejection and call blocking probabilities.