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高通量卫星中多波束天线的同频率波束之间干扰问题,通常以天线载波干扰比(C/I)表征,提高天线C/I性能是获得更高的通信容量途径之一。文中提出了一种多波束天线频率复用优化设计方法,来解决天线C/I性能与频率规划之间的矛盾。在优化过程中将同频波束的频率分配策略作为优化变量,然后利用遗传算法对其进行优化从而实现更高的C/I性能。最后通过一个实例验证该优化算法的有效性和高效性。 相似文献
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在通信信号和雷达信号处理中,通常需要将信号正交分解为两路正交的I,Q信号。然后再做进一步的处理,而I,Q通道间抚养益误差和相位误差会造成镜像干扰。影响系统性能,文中分析了I,Q通道的增益误差和正交误差对镜像干扰抑制比的影响,用实验验证了采用HSP50016后对镜像干扰抑制的改善。 相似文献
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利用计算机模拟对某一给定类型的天线(例如:120°定向天线)计算出天线在不同下倾角度时场强覆盖范围和载波干扰比(C/I)变化的情况;分析了为降低同频道干扰,天线下倾的合适角度。 相似文献
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针对传统相控阵雷达与集中式多输入多输出( MIMO)雷达的干扰抑制性能优劣问题,对集中式MIMO雷达与相控阵雷达的信干噪比和改善因子进行了对比分析,从理论上研究了两种体制雷达的干扰抑制能力并进行了数字仿真。仿真结果表明,与传统相控阵雷达相比,集中式MIMO雷达通过提升信干噪比输出增强了干扰抑制能力。 相似文献
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针对有源欺骗干扰提出了一种新型的基于初相匹配滤波的干扰抑制方法.首先,基于相参雷达接收机匹配滤波器得到脉压信号矩阵.其次结合该矩阵中目标和干扰脉压尖峰矢量,基于最大平均信号干扰能量比(信干比)输出推导出了初相匹配滤波的响应函数解析式,形成了基于有源欺骗干扰抑制的初相匹配滤波算法.该算法在保证目标脉压尖峰矢量不损失的前提下具有较好的抗干扰改善因子.仿真结果表明当雷达发射脉冲串脉冲数为60时,在Swerling I目标起伏下,该算法抗干扰改善因子(干扰抑制深度)为20dB左右.在SwerlingⅡ目标起伏下,该算法干扰抑制深度为19dB左右. 相似文献
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该文分析了基于包错误率(PER)测量及基于我干比(C/I)估计的链路自适应算法的优缺点,在此基础上提出了两种WPAN/WLAN应用环境下的混合算法,即同时考虑PER与C/I的混合算法和选择性考虑PER与C/I的混合算法,并对它们进行了理论分析和数值仿真。结果表明,在理想的单用户接入情况下,同时考虑PER与C/I的混合算法的吞吐量要大于其它算法。在实际的多用户接入情况下,分配给每个用户的资源相对较少,此时,选择性考虑PER与C/I的混合算法能够减小接收包数目较少或C/I估计误差大大以及信道误判等因素造成的吞吐量损失,达到比其它算法更大的网络吞吐量。 相似文献
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Watanabe Y. Kohiyama K. Inoue M. Okubo S. Matsumoto M. Takaki I. 《Selected Areas in Communications, IEEE Journal on》1983,1(1):143-152
The experiment we conducted for integrated digital satellite communications is aimed at realizing integrated services digital networks by satellite communication. The experiment was carried out in 1980 using the Japanese experimental communication satellite "CS." This experiment uses 30/20 GHz small earth stations and demand-assignment time-division multiple-access (TDMA) systems. Communications between customer terminals, which contain video conferencing, high-speed facsimile communication, high-speed computer communication, and packet-switching signal transmission, were carried out through the experimental digital satellite link. This paper describes the configuration of the experimental integrated digital satellite communications system and the experimental results of communications between customer terminals. 相似文献
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卫星地球站监控系统的主要任务是对卫星通信站设备进行监视和控制管理。随着计算机技术、网络技术和远程控制技术的发展,卫星通信地球站向一体化发展,它同时担负着卫星数据传输和卫星站管理监控的双重任务,尤其是对远端站的管理监控。本文总结了以往卫星地面站监控系统优缺点,详细分析了卫星通信地球站集中监控管理系统的工作原理,提出了一套完整的同时针对地球主站和远端站集中监控管理的规划设计和工作流程,并给出了使用效果,旨在为卫星地面站的监控设计和实现提供借鉴思路。 相似文献
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卫星导航系统主要通过人造卫星作为信号转发的中继站,通过上下行链路建立地球站间的无线通信,可实现大容量、远距离、高覆盖面、低延时的信息传输,而且导航系统存在接收电平低、接收机灵敏度高、接收信号比较微弱、导航信号在同一频率发射、调制、信噪比极低、下行链路容易干扰等问题。系统分析了北斗卫星导航接收机抗干扰主要应用技术;介绍了接收机主要干扰类型;提出了时空二维联合处理(STAP)抗窄带干扰技术模型及最小均方误差滤波器(MMSE)算法;通过仿真研究,该方法抑制窄带干扰效果较好。 相似文献
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快速发展的蜂窝网通信和卫星通信 总被引:1,自引:0,他引:1
主要说明无线通信将应用于移动通信、个人通信和全球通信。数字蜂窝网将增设微蜂窝区 ,频率从 90 0MHz升至 1 .8~ 2GHz ,向宽带和多媒体方向发展 ,数据速率从 1 44kb /s升至 2Mb /s。手机将是TDMA /CDMA双模。蜂窝网不仅用于移动通信 ,而且用于固定用户的市内接入网。卫星通信将加快发展低轨道 /中轨道卫星通信网 ,而同步卫星仍需利用。移动卫星网可通电话 ,可进行多媒体通信 ,速率为 2Mb /s,并通过地面信关站 ,与陆地固定通信网结合一起 ,实现全球个人通信。 相似文献
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《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》1984,72(11):1637-1644
Nippon Telegraph and Telephone Public Corporation (NTT) initiated the world's first 30/20-GHz domestic satellite communication system for commercial use, using CS-2s launched from Japan in 1983. This system utilizes TDMA digital communication in the trunk transmission route of the public communication network, which includes interregional-center routes and main-island-to-remoteisland routes. Small transportable earth stations enable easy access to the public communication network from any place in Japan. The adoption of the 30/20-GHz band enables use of a compact on-board antenna that has a shaped beam that effectively covers the main islands of Japan. It also enables the use of high-performance, compact antennas at the earth stations. These antennas can easily be installed on the roof of telephone offices or set on motor vehicles. One apparent disadvantage of using the 30/20-GHz band is rain attenuation. However, NTT has realized a commercial system that is affected very little by rain attenuation. This was accomplished by utilizing high-performance radio equipment and by concentrating on appropriate system design. Adoption of the 30/20-GHz band is quite significant because the wide bandwidth available enables construction of high-capacity economical transmission systems. It also enables use of small antennas, which allow construction of high-speed digital direct-to-user transmission systems using small earth stations. These expand the application of the domestic satellite communication system to even small service areas. Therefore, NTT considers satellite communication to be of primary importance for its proposed digital communication network, and has begun research on a high-capacity, economical, multibeam communication satellite system using the 30/20-GHz band. This paper describes the 30/20-GHz band radio technology, digital communication technology utilizing high-speed TDMA, and operational technology in the public communication network. 相似文献
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梯度法——移动卫星通信天线自动跟踪的新方法 总被引:3,自引:0,他引:3
邓晓琴 《太赫兹科学与电子信息学报》2003,1(3):33-37
某些移动卫星通信天线自动跟踪系统采用激光陀螺进行跟踪,但激光陀螺跟踪有其不足之处。本文提出了移动卫星通信天线自动跟踪的新算法一“梯度法”,可替代激光陀螺进行天线自动跟踪,其技术有所创新。本文将介绍梯度法自动跟踪原理、计算和实现方法。 相似文献
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Brostrup-Jensen P. Moshenberg D. 《Selected Areas in Communications, IEEE Journal on》1992,10(6):1094-1102
The network control systems used by AT&T Business Communications Services and by AT&T International Communications Services are discussed. From the inception of its satellite services, AT&T has supported the concept of centralized monitoring and control (M and C) of its widely dispersed earth stations. Today, the M and C is being handled by the MONARC (monitor and remote controller) in the earth stations, and GSNCS (generic satellite network control system) in the AT&T domestic and international operations centers. The MONARC software allows flexible interface to any equipment; GSNCS provides graphically presented M and C of all earth stations from one central location via voice-grade data lines. By MONARC/GSNCS monitoring the earth stations on a 24-hour basis and being able to initiate event-driven or time-driven operations in response to earth station conditions, AT&T is able to maintain the highest possible network readiness 相似文献