共查询到17条相似文献,搜索用时 468 毫秒
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针对低轨(LEO)大规模卫星星座系统存在电磁空间复杂且难于观测的问题,对低轨卫星星座链路特征进行研究。以Starlink和OneWeb星座为研究对象,根据低轨卫星的星座参数,获取等效全向辐射功(EIRP)值并进行可视化处理;对获取到的低轨电磁卫星数据进行分析,获取数据的衰减特性和时间、频率等的数据关系,计算星间的链路干扰以及时间上的分布特征;获取相对干扰时间的特征值以及星间数据的衰减与时频的多维特性,并分析不同场景下的干扰时间特征,从多个维度分析低轨大规模卫星星座系统间星间链路的干扰情况并进行仿真验证。实验证明了低轨大规模卫星星座系统之间的星间链路存在干扰情况,且频率越高,干扰现象越明显。 相似文献
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低轨互联网星座是当前全球研究和发展的热点,互联网星座支持随遇接入遥感卫星和信息在轨直接处理的应用前景备受期待,但由于轨道高度不同会产生双向高动态异构星座的接入互联问题。首先,通过设定低轨卫星互联网星座在不同轨道特性、不同卫星数量情况下的随遇接入仿真场景,重点探讨了时空非连续可视性和多普勒频移问题对遥感卫星接入性能的影响;其次,基于遥感卫星随遇接入互联网星座场景的特点,分析了不同时延性在轨处理任务的流程及其星地功能分配;最后,对当前在轨智能处理算法存在的问题和未来研究重点进行阐述,为未来低轨互联网星座及遥感卫星的发展和联合组网应用提供可靠的理论支撑。 相似文献
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在低轨电子侦察、遥感卫星领域,针对非连续覆盖条件下的星座优化设计问题,提出了一种间隔重访的低轨星座设计方法。通过改进极轨覆盖带设计方法,将对地覆盖区域等效为矩形;以对地目标的平均重访间隔时间为输入,从同轨卫星间和相邻轨道面间两方面分析,得到近似最优的星座参数。通过STK仿真验证,设计的星座可满足重访间隔时间要求。 相似文献
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随着物联网(IoT)规模的不断发展,其业务需求呈现出多样化、全球化的趋势。针对地面物联网无法覆盖全球的缺点,卫星物联网尤其是低轨卫星星座(LEOSC)物联网可以有效地为地面物联网提供覆盖性能上的补充和延伸。由于低轨卫星星座物联网系统广覆盖、高动态的特点,其业务量统计特性需要考虑到环境因素造成的影响,这导致其业务量分布与地面物联网存在显著差异。从合理高效利用星上有限资源角度出发,该文研究基于低轨卫星星座的全球物联网业务模型。结合多样化的业务特点以及卫星通信系统特性,采用统计建模理论,得出了全球物联网业务模型框架。并且初步提出了一种基于最高优先级的接入策略,以供设备节点实时选择接入的卫星。仿真结果表明:泊松过程可以用于近似模拟低轨卫星物联网中大量存在的异步流量的叠加过程;由于低轨卫星具有高动态性,其业务源高速变化,导致了卫星业务忙闲不均,峰均比(PAR)较高。 相似文献
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随着物联网(IoT)规模的不断发展,其业务需求呈现出多样化、全球化的趋势.针对地面物联网无法覆盖全球的缺点,卫星物联网尤其是低轨卫星星座(LEOSC)物联网可以有效地为地面物联网提供覆盖性能上的补充和延伸.由于低轨卫星星座物联网系统广覆盖、高动态的特点,其业务量统计特性需要考虑到环境因素造成的影响,这导致其业务量分布与地面物联网存在显著差异.从合理高效利用星上有限资源角度出发,该文研究基于低轨卫星星座的全球物联网业务模型.结合多样化的业务特点以及卫星通信系统特性,采用统计建模理论,得出了全球物联网业务模型框架.并且初步提出了一种基于最高优先级的接入策略,以供设备节点实时选择接入的卫星.仿真结果表明:泊松过程可以用于近似模拟低轨卫星物联网中大量存在的异步流量的叠加过程;由于低轨卫星具有高动态性,其业务源高速变化,导致了卫星业务忙闲不均,峰均比(PAR)较高. 相似文献
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地球静止轨道(geostationary earth orbit,GEO)卫星轨道位置资源稀缺已久,巨型低轨卫星星座的发展浪潮使得低轨轨道资源也变得空前紧张,中地球轨道(medium earth orbit,MEO)星座作为GEO和低地球轨道(low earth orbit,LEO)星座的折中,必将成为各国博弈的角逐场,参考世界各MEO星座和我国国情,提出了一种(6+4)MEO星座方案,并使用STK(Satellite Tool Kit)软件对星座覆盖性能、星际链路特性和信关站选址及覆盖性能进行了仿真分析,该方案通过地面站中继实现轨道间通信,有效规避了利用星际链路实现轨际通信时存在的各种问题,使系统得到简化、可靠性得到提高,在全球低轨卫星轨道资源紧张的形势下具有很强的战略价值。 相似文献
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《IEE Review》1999,45(3):107-111
Anyone who has surfed the Internet knows how slow it can be. Some have even suggested that it could become entirely gridlocked early in the next millennium. The author explains how satellites could help avert such a catastrophe. The primary advantage of a satellite system for Internet delivery is the same as it is for other types of communication: coverage area. A single satellite in geostationary orbit can serve approximately one third of the planet's surface, so three can cover most of the world's population. For regions where terrestrial infrastructure is limited or nonexistent, satellite coverage may be the only option. The author discusses the proposed Teledesic broadband low Earth satellite system operating in the Ku band, which is backed by Microsoft, and its only direct competitor SkyBridge which is backed by Alcatel and Loral. The author also discusses the geosynchronous Earth orbit broadband satellite systems. The commercial viability of these systems is discussed 相似文献
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Ravandran Muttiah 《International Journal of Satellite Communications and Networking》2023,41(5):441-459
Satellite constellation design plays an important role in satellite networks. Network constellation system design can affect the effectiveness of current improvements of the communications link and the management of the entire network. The power requirement of the mobile stations and ground stations is very high in a geostationary Earth orbit communication system, which means the terrestrial terminal is hard to be made handheld for fifth generation mobile communications. The emergence of nongeostationary orbit satellites such as low Earth orbit satellites greatly compensates for the disadvantage of geostationary Earth orbit satellites. Based on the classical constellation design method, the orthogonal circular orbit constellation is proposed. The design objectives considered here are the following: global Earth coverage by low Earth orbit satellites, the duration of continuously covering one mobile station by one satellite is more than 9.57 min, the access satellite link duration time of the mobile station is more than 4.79 min, and the number of satellites and orbits is to be minimum. 相似文献
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中国低轨移动卫星通信系统星座设计 总被引:15,自引:2,他引:13
本文研究低轨移动卫星通信系统设计中的一个基本问题--星座设计问题,并给邮了我国低圆轨道移动卫星通信系统的星座设计方案,该星座是以三个轨道平面组成的24颗星系统,它的高度为1326km,轨道参数由本文提出的优化算法进行设计,本文用统计的方法对我国低轨系统方案和Globalstar系统(24颗星方案)的覆盖性能进行分析比较,结果表明本文提出的系统对我国的覆盖特性优于Globalstar系统,本文还对圆 相似文献
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Pedram Hajipour Ali Shahzadi Saeed Ghazi‐Maghrebi 《International Journal of Satellite Communications and Networking》2020,38(3):229-253
With the advent of the fifth generation of mobile radio communication by 2020, there will be many challenges such as increasing service demand with low delay in providing billions of end users called the satellite mobile users. It is expected that terrestrial communication systems will be faced with a dense network having many small cells anywhere and anytime. Therefore, there are some remote regions in the world where terrestrial systems cannot provide any services to end users. Furthermore, because of lack of spectral resources, it is very important that the spectrum is shared between satellite systems and terrestrial equipment by a suitable solution to interference management. In this paper, a heterogeneous satellite network that includes low earth orbit (LEO) satellite constellation and terrestrial equipment is proposed to provide low delay services. In this type of structure, interference management based on transmission power control between LEO satellite systems and mobile users is very important for obtaining high throughput. Moreover, in order to mitigate interference, transmission power control is shown based on noncooperative Stackelberg game under many subgames through pricing‐based algorithm and convex optimization method. Finally, the simulation results show that the performance of this study's system model will be improved through the proposed algorithm. 相似文献
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针对我国Ka频段使用卫星固定业务的非对地静止卫星轨道(Non-Geostationary Satellite Orbit,NGSO)星座系统对对地静止卫星轨道(Geostationary Satellite Orbit,GSO)系统的干扰问题开展研究.在梳理国际电联技术建议书和《无线电规则》的基础上,通过理论分析和仿真计算等手段,对不同链路场景下NGSO星座系统对GSO系统在Ka频段的干扰问题进行分析计算.研究结果表明,在NGSO星座系统与GSO系统上下行通信有重叠部分的频段,其对GSO系统都会产生严重干扰.最后给出降低干扰的措施与建议.为我国未来拟使用Ka频段的NGSO星座系统对GSO系统的干扰分析提供参考. 相似文献
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新兴的非静止轨道(non geo-stationary orbit,NGSO)卫星星座系统可支持分布在地球任何位置的海量地面终端,NGSO星座系统大多使用与GSO卫星星座系统同频的频段,再加上NGSO星座系统在空、时、频、码等域的高动态特性,必然会对GSO星座系统带来时变的频率干扰问题.为解决NGSO星座系统上行链路对... 相似文献