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为完成俄制大气机与国产航管应答机的交连,设计了由单片机、A/D转换器、电平转换电路、驱动电路、隔离电路和电源等电路组成的俄制大气机高度输出接口板电路。采取数据校准和抗干扰技术,简化硬件电路,提高高度数据转换精度和系统的抗干扰能力。实验表明,该接口电路实现了高度数据的数字化,能够将俄制大气机输出的模拟高度电平信号转换成满足国产航空应答机要求的数字编码信号。 相似文献
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分析当航管应答机接收到航管雷达询问信号时,由于多径效应造成应答概率下降的机理.利用航管询问信号I/Q解调后的幅度、相位信息,提出了一种快速高效的瞬时测频算法;通过比较每个询问脉冲信号的频率差值和相位差值,使航管应答机能区分出直射询问信号和反射询问信号,并滤除反射信号干扰.最后通过仿真分析,验证了该方法可有效提高航管应答机的应答概率. 相似文献
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航管二次雷达测试应答机机房往往为无人值守机房。为了满足对航管二次雷达测试应答机机房环境的监测需要,文章以NodeMCU开发板和OneNET物联网平台为核心,设计一种设备机房环境监测系统,实现了对航管二次雷达测试应答机机房市电状态和温湿度数据的实时监测和远程显示,达到提前发现测试应答机机房环境异常的目的,提高了对航管二次雷达的综合保障能力。 相似文献
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吴键 《中国电子科学研究院学报》2021,16(4):386-390,407
介绍了S模式航管应答机的特点,分析其应答延时指标,然后在给出综合化S模式应答机方案的同时对比了与传统独立端机的设计区别,指出A/C应答延时是综合化S模式应答机实现的关键技术.文中提出了压缩接收链路延时、改进波形算法与优化发射链路时序相结合的方法,解决了综合化通信导航识别设备中航管应答功能从传统A/C模式升级至S模式的关... 相似文献
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航管应答机的中频数字化设计 总被引:1,自引:1,他引:0
提出了一种航管应答机的中频数字化设计方案,并详细论述了如何应用带通采样定理、正交相干检波理论实现接收信号的中频直接数字化,同时对高速模拟/数字变换器(ADC)、低通滤波器、基带信号处理等各主要功能模块进行了介绍,并给出了相关的计算和仿真. 相似文献
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一种小型化高可靠USB测控应答机的设计与实现 总被引:1,自引:0,他引:1
《信息通信》2016,(3)
文章介绍了一种基于USB体系的星载测控应答机,通过在收发通道中使用射频集成器件、用有源滤波器来提取测距信号和遥控BPSK信号等技术方案,使其体积和重量相比传统的USB测控应答机减小了一半以上。同时,优化了锁相环环路参数,使该应答机能实现较高的锁定灵敏度和较宽的频率跟踪范围。实测结果表明,该应答机的锁定灵敏度、频率跟踪范围、遥控信道的信噪比、遥控BPSK信号保真度、主次侧音相位偏差等指标均能满足系统要求,测距性能优良。该应答机完全用模拟器件实现,抗辐照能力强,具有较高的实用价值,可广泛用于各类军用和民用卫星。 相似文献
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基于DSP设计了一种可编程实时信号模拟器。该模拟器包括USB、模拟、数字、用户自定义接口。其中USB接口可以方便地和PC机进行通信,模拟、数字和用户接口输出模拟器产生的模拟和数字信号。DSP是模拟器的核心器件,对数据进行处理,和各部分的管理。FPGA完成DAC等器件的时序及接口控制等。本模拟器提供在线升级功能,用户经USB接口可对板上的FPGA和DSP程序进行升级。另外,FPGA编程可产生用户需要的各种接口信号。这样便于和其他模块进行连接,扩大了适用范围。DSP编程可以产生用户需要的波形。该模拟器在数据通信系统等领域,具有一定的实用意义。 相似文献
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Ozgur Ercetin Michael O. Ball Leandros Tassiulas 《International Journal of Satellite Communications and Networking》2004,22(2):157-179
U.S. airspace is reaching its capacity with the current air traffic control (ATC) system. The number of flights is constantly rising and it is estimated to be over 58 million per year by 2005. The FAA has undertaken several projects to modernize the National Airspace System (NAS) to ensure the safety of the increasing number of flights. Of special importance is the modernization of the air–ground communications infrastructure, which is the heart of the ATC. The current plan in the modernization of the air–ground communications is to migrate from analog voice only system to integrated digital voice and data system. The next generation satellite systems can be an alternative to the terrestrial air–ground systems by their low propagation and transmission delays, global coverage, high capacity and free flight suitable characteristics. In this paper, we give an overview of the current and the future ATC architectures, describe the systems and the communications issues in these systems and develop a framework in which next generation satellite systems can be integrated to the future ATC systems. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
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Giovanni Giambene Enrico Zoli 《International Journal of Satellite Communications and Networking》2003,21(2):199-225
In this paper, we investigate a packet access scheme that is able to support mixed traffics in the presence of high propagation delays. Referring to a Time‐Code Division Multiple Access air interface, we propose a Medium Access Control (MAC) protocol based on a random access scheme. A successful attempt grants the use of a slot‐code resource. This protocol is named Adaptive Time Code‐Packet Reservation Multiple Access (ATC‐PRMA), since the access parameters are changed, depending on the traffic load conditions, so as to fulfil Quality of Service requirements. Numerical examples are carried out for the Low Earth Orbit (LEO)‐Mobile Satellite System (MSS) scenario, but all these considerations could be applied to High‐Altitude Platform Stations (HAPSs) as well. In both cases, high propagation delays prevent an immediate feedback to users. An analytical approach is proposed to study the stability of our MAC scheme. Accordingly, we define a criterion for optimizing system performance. The predicted ATC‐PRMA behaviour is supported by simulation results. Finally, we show the performance improvement of ATC‐PRMA with respect to a MAC protocol not employing adaptive parameters. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
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A new technique for designing three-dimensional cellular systems for VHF air/ground communications is proposed to solve the problem of frequency congestion for air traffic control (ATC) and flight services. In VHF air/ground communication systems, a radio line of sight (RLOS) between the aircraft and ground station must exist. The frequency reuse distance is reduced by using the radio horizon to block cochannel interferences. In the proposed system, cells of different sizes to cover different altitude ranges are separated by different reuse distances. With nine groups of channels, the altitude range from 740 ft to 45000 ft can be covered without interference. The proposed system utilizes the spectrum efficiently by covering a certain airspace according to a well-organized plan with the minimum number of frequency channels and cell sites. Thus, it has more frequency reuse than the current systems 相似文献
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为了实现大光斑直径高均匀度太阳辐照模拟,设计了大光斑发散式太阳模拟器。根据太阳光谱分布特性选取短弧氙灯作为光源,建立光源功率计算模型;基于成像倍率和氙弧峰值点离焦量之间的关系,优化设计聚光系统和光学积分器,提高太阳模拟器的辐照均匀度;同时,结合短弧氙灯的光谱特性,建立光谱匹配模型,设计光学滤光片在不同波长的透过率。实验结果表明:设计的发散式太阳模拟器辐照面积为2 m,当工作距离为6、8、10 m时,辐照不均匀度分别优于3.33%、3.51%和4.3%,且光谱与AM1.5太阳光谱A级标准相匹配。 相似文献