ITU和FCC对NGSO卫星的功率通量密度限值研究

文章梳理了《无线电规则》和美国联邦法规之卫星通信中关于功率通量密度的使用条件和范围,对比国际电信联盟和美国联邦通信委员会对不同频段的具体规定,掌握功率通量密度相关规则的适用条件和适用对象。结合典型的非静止轨道星座系统,分析相关操作者对规则的遵守情况,以促进我国空间业务系统与美国相关系统的协调。     

Satellite visibility in Northern Europe based on digital maps

This paper presents the calculation of satellite visibility and system availability based on digital elevation maps. New models for satellite visibility are derived for both non‐geostationary orbiting satellite constellations and geostationary satellites. Regression models for satellite visibility and average number of visible satellites based on easily available surface roughness variables are developed and tested. Cumulative distributions for the percentage of time that Iridium satellites are visible, taking terrain obstacles into account, are calculated and the relation between satellite visibility and system availability is discussed. Copyright © 2000 John Wiley & Sons, Ltd.     

非静止轨道卫星网络中同频干扰问题的分析与仿真

随着非静止轨道(NGSO)卫星系统的增加,使用相同频率、轨道邻近的卫星网络越来越多,这使得NGSO网络之间以及NGSO网络与传统的静止轨道(GSO)网络之间的同频干扰问题变得日益严重。深入研究了NGSO网络的同频干扰问题,针对NGSO网络具有时变性的特点,给出了计算NGSO网络同频干扰的思路和方法,在此基础上实现了仿真并对仿真结果进行了分析,得出了一些规律性的结论,为今后此类问题的研究提供了参考。     

FCC卫星通信业务及台站概述

文章从美国联邦通信委员会对美国非联邦使用的卫星通信业务和台站的定义出发,分析其业务定义和使用台站分类的方法,总结出美国非联邦卫星通信业务及其使用台站的管理特点,为我国空间业务的全球布局提供参考数据。     

基于里程碑方法的NGSO卫星系统频率投入使用研究

目前,世界主要发达国家正加快构建类型多样、规模庞大的NGSO卫星互联网系统,纷纷申报空间频率轨道资源,争取空间信息领域战略入口,频率资源占用冲突也愈发严重,实际解决各NGSO系统的频率轨道资源冲突已成为ITU及各国NGSO卫星建设部门的重要工作,里程碑决议应运而生。本文对ITU里程碑决议进行解析,并基于ITU里程碑方法及FCC里程碑要求对FCC已授权的三大重点NGSO星座系统频率投入使用及部署情况进行研究,同时分析了国外NGSO星座系统部署能力及动态,为我国空间频率资源协调和卫星系统发展提供参考。     

车载非静止轨道卫星监测系统链路计算

非静止轨道(NGSO)卫星通信发展迅猛,但由于相关设备的缺乏,对其下行信号频率轨道资源占用情况监测较少,因此,设计NGSO监测系统为当前急需解决的问题。设计车载监测系统要求具有低的余量,而当前卫星监测系统通信链路计算过程考虑不够精确,文章通过研究ITU相关建议书,考虑NGSO通信链路中存在的大气、雨水、云层和电离层闪烁等相关因素,计算在特定接收余量下的车载监测系统地空链路损耗,为该系统设计提供更精确的依据,同时对GSO链路设计也具有参考意义。     

Q/V频段5G基站对NGSO星座系统地球站的干扰分析

针对Q/V频段5G基站对非静止轨道(Non-geostationary Orbit,NGSO)星座系统地球站的同频干扰问题,提出了一种5G毫米波系统与NGSO星座系统下行链路间的干扰分析方法.结合NG-SO星座系统地球站天线指向的时变性,建立了基于时间离散的"拉远式"和"挖洞式"的动态干扰分析模型,并从强度和集总效应两...     

非同步轨道卫星移动业务馈送链路的干扰研究

本文讨论了卫星移动通信中由于ＮＧＳＯ／ＭＳＳ馈送链路与ＧＳＯ／ＦＳＳ共享频率而引起的干扰问题，作为解决手段引入了反向频率工作模式。通过对具体数据的分析表明，这一模式可以有效地减轻两个系统之间的干扰，是协调ＮＧＳＯ与ＧＳＯ间干扰的一种最具吸引力的方案。     

ATM‐based multimedia communication via NGSO‐satellites

Future broadband satellite networks for multimedia will be seamlessly integrated into terrestrial broadband networks which often use asynchronous transfer mode (ATM) and recently also the less complex multi protocol label switching (MPLS) technique as transmission and switching protocol. In light of this, future broadband satellite networks may adopt the ATM transmission scheme and implement ATM or ATM‐like switches on board the satellites. However, as compared to communication in fixed networks, satellite communication is characterized by special constraints (e.g. signal delay, channel quality, dynamic network topology) that require novel ATM‐based communication technology for satellite systems. This paper presents results from the ATM‐Sat project that aims to complete this technically challenging and important R&D task in the cooperation between DLR, Fraunhofer Gesellschaft and Tesat‐Spacecom. In brief the following aspects have been addressed in the ATM‐Sat project:

• development of the concept and communication technology for a multimedia satellite system with,
  • non‐geostationary orbit (NGSO) satellites;
  • inter satellite links (ISLs);
  • on‐board ATM switching;
  • fixed and mobile terminals;
• verification of the developed communication technology with a demonstrator.

In particular the ATM‐Sat R&D tasks cover the system and protocol architecture, on‐board processing, ISL routing, up/downlink and on board ATM resource management (including medium access control), error control, IP over satellite‐ATM, and active intelligent antennas. Copyright © 2005 John Wiley & Sons, Ltd.     

非静止卫星星座地球站的等效全向辐射功率包络计算方法

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...