MIMO传输技术在卫星通信中的应用

本文讨论了在卫星移动通信环境中应用多输入多输出（MIMU）传输的技术,该技术能够在传输过程中提供复用感和分集增益,可以大大提高卫星移动通信系统的传输有效性和可靠性。     

一种多路卫星节目转播服务器的设计

在MPEG-2TS流播出服务器和多路数字卫星节目收录服务器的基础上,设计了一种基于实时收录系统的多路卫星节目转播服务器,通过卫星节目收录系统,将收到的多路实时卫星节目在服务器内部进行选择、切换和复用,然后通过ASI接口转发到HFC网络.测试表明转播服务器能够稳定地进行节日转播,节目之间切换流畅.     

宽频带低轴比双圆极化频率复用天馈系统设计

分析了影响卫星数据地面接收系统交叉极化鉴别率的主要因素,提出了天馈系统的 体系结构和设计方案。该方案已用于频率复用高码速率遥感卫星数据接收系统工程中,并成 功实现了国内首颗双圆极化频率复用遥感卫星（“资源三号”卫星,数据速率450 Mbit/s× 2）的 数据接收。     

基于带宽协调的多波束卫星同频组网技术

多波束卫星广泛采用三色/四色等传统频率复用方案，建立了多波束卫星系统模型，并将地面移动通信中的同频组网技术引入多波束卫星通信系统中，提出了一种基于带宽协调的频率复用技术。该技术将系统资源分配分为波束间资源分配和波束内资源分配，波束间资源基于部分频率复用方法进行分配，波束内资源采用均匀方式和基于注水算法2种方式进行分配。仿真结果表明，相比于传统复用技术，所提出的基于带宽协调的频率复用技术在系统总吞吐量性能方面有较大提升。     

频率复用高码速率遥感卫星数据接收系统设计

针对双圆极化频率复用、高码速数据接收等关键技术,分析了影响系统交叉极化鉴别率、高码速数据接收链路误码性能的主要环节,提出了天馈、高码速数据接收链路的体系结构和设计方案.据此设计并建成的频率复用高码速率遥感卫星数据接收系统已成功接收了国内首颗双圆极化频率复用遥感卫星(“资源三号”卫星,数据速率450 Mbit/s×2)的...     

基于部分信道信息的卫星多波束联合预编码优化方法

在现有的卫星多波束联合预编码技术研究中,普遍假设卫星发射机有理想的用户信道信息;遗憾的是,由于长距离信号传播延迟,这种假设并不适合于卫星移动通信系统,特别是地球同步卫星系统.为了解决这个问题,提出了基于部分信道信息的多波束协作传输方法;利用阴影-莱斯信道模型,本文导出了闭合形式的中断容量表示,给出了基于部分信道信息的多波束联合预编码优化算法,克服了现有方法的局限性.仿真结果表明,与传统的单波束频率复用方法比较,提出的方法大大降低了系统的发射功率.     

双圆极化遥感卫星数据接收系统极化鉴别率需求分析

针对双圆极化频率复用中的交叉极化干扰问题,分析了雨衰及雨致去极化对LEO卫星X频段双圆极化频率复用的影响,然后将交叉极化干扰按高斯白噪声处理,并依据数据接收链路误码率门限要求,提出了X频段双圆极化频率复用遥感卫星数据接收系统极化鉴别率的技术需求。研究结果已用于双圆极化遥感卫星数据接收系统的设计,并已成功接收了国内首颗双圆极化频率复用遥感卫星(资源三号卫星,数据速率为450 Mb/s×2)的数据。     

卫星寻呼广域联网系统组网方案

卫星寻呼广域联网系统是专门为跨省、跨地区经营的大寻呼台实现区域覆盖及广域联网而设计的ＶＳＡＴ应用系统，该系统采用单向广播主站实现寻呼的同播覆盖，采用以向小站实现区域间联网信息的交流，圆满解决了广域寻呼系统的漫游联网，同播覆盖、多频复用、同频干扰等问题，为卫星数据广播在寻呼领域内的应用开辟了广阔的前景。     

分布式码流实时监控与录制系统的设计与实现

介绍一种分布式码流实时监控与录制系统.该系统实现江苏省地面数字电视省前端卫星接收、编码、复用、单频网适配、输出、空收各环节信号码流的实时监控与录制,为地面数字电视省前端的安全播出工作提供了可靠的技术保障.     

空间编队卫星平台激光通信链路组网技术

研究了三维变轨卫星群组成的机动平台中基于激光链路的主星与子星相互间波束点对点多信号持续跟踪、瞄准、捕获技术,提出了基于波分复用(WDM)的星间激光链路通信组网思路,分析了编队卫星激光通信系统的拓扑结构和光码分多址(OCDMA)接入,这样就形成了基于WDM/OCDMA的编队卫星网络.初步探讨了未来天基宽带卫星激光通信网的基本框架.     

Throughput analysis of tandem-type go-back-N ARQ scheme forsatellite communications

The tandem-type go-back-N (GBN) scheme has been proposed for satellite communications to reduce the long roundtrip delay using the onboard processing of satellites. The author considers the exact analysis of the throughput performance of this scheme and its application to a broadcast communications system such as a point-to-multipoint file transfer system. First, the throughput expression for the point-to-point tandem-type GBN scheme is derived. Second, applying the results of this point-to-point tandem-type GBN scheme to a broadcast (point-to-multipoint) communications system, the relationship of the number of receiving stations to the link bit error rate and the roundtrip propagation delay is shown     

数据广播接收卡驱动程序设计

介绍一种数据广播接收卡的驱动程序的实现方法，它在MPEG－2和DVB－C标准的基础上，接收IP数据或MPEG－2传输流数据，用它可以进行有线电视系统的新闻、证券、文件、视频等广播数据的接收，也可以接收数字电视节目。     

一种基于Photoshop批处理的播出标识文件快速生产方法

为更好地服务收视群体,从中央电视台上星频道、各省级卫视到诸多城市地面频道,在播出电视剧节目时几乎都于荧幕左下角或右下角位置叠加了剧名。为落实这一举措,需要在节目的制作或播出环节制作相当数量的剧名标识文件以供调用。笔者针对此现状,结合自身的工作经验,开发出一种快速批量生产TGA格式剧名标识文件的程序化方法。该方法采用流程化思想进行设计,基于Photoshop的批处理实现,使电视剧名TGA文件的制作效率比传统方法有了大幅的提高。     

基于拓扑和位置感知的卫星导航增强信息播发网络构建研究

It is an effective method to broadcast the augmentation information of satellite navigation system using GEO technology. However, it becomes difficult to receive GEO signal in some special situation, for example in cities or canyons, in which the signal will be sheltered by big buildings or mountains. In order to solve this problem, an Internet based broadcast network has been proposed to utilize the infrastructure of the Internet to broadcast the augmentation information of satellite navigation system, which is based on application layer multicast protocols. In this paper, a topology and position aware overlay network construction protocol is proposed to build the network for augmentation information of satellite navigation system. Simulation results show that the new algorithm is able to achieve better performance in terms of delay, depth and degree utilization.     

应用NICAM－728系统实现广播电视节目同时上星

山东电视台利用ＮＩＣＡＭ－７２８系统，同时将广播和电视节目送上了卫星。本文简要介绍了该系统的工作性能特点及其在卫星广播中的应用，认为使用该系统实现广播电视同时上星具有诸多优点，是一个值得推广的方案。     

Satellite radio interface and radio resource management strategy for the delivery of multicast/broadcast services via an integrated satellite-terrestrial system

A variety of hybrid systems combining third-generation mobile communication networks with broadcast systems have been proposed for the delivery of multimedia broadcast multicast services (MBMS) to mobile users. The article discusses one of these alternatives, which involves the use of a geostationary satellite component for MBMS delivery. In particular, it proposes a radio access scheme for the satellite component of the system that features maximum commonalities with the standardized T-UMTS WCDMA-based interface. The ultimate advantages of this approach are more efficient delivery of MBMS as far as the mobile network operator is concerned. The required adaptations at the interface layers are described, and the radio resource management strategy that fulfills the particular requirements of the satellite system is presented.     

Satellite onboard processing for multimedia applications

For future multimedia applications, satellites might play an important role. For broadcast applications satellites are ideally suited to illuminate a large geographical area. However, multimedia applications are interactive, and are therefore a combination of a broadcast mission and a multipoint-to-point mission. The natural question is, can a satellite system compete with the capacity provided by terrestrial cable networks? If the answer is positive, and it shown in this article that it is, a second question arises: what new developments are required to migrate from the state-of-the art satellite technology to such advanced concepts? Taking the example of the European Space Agency's activities in this field, an overview of the required building blocks which make up a complete multimedia communication satellite system are described. Based on this technological overview a discussion of the systems developed by European space industries with support from the European Space Agency is given     

电视直播技术与应用

目前常用的电视直播技术手段有微波、光纤、卫星和3G网络等,结合实际的电视直播工作,探讨针对不同直播任务和要求,如何合理使用直播传送技术。     

卫星数字电视信号干扰检测与预警实现

随着数字通信技术的发展，广播电视由模拟向数字化全面过渡。卫星数字广播具有诸多优点，受到世界各国的广泛重视，同时也成为不法分子的攻击对象。新型专业卫星数字电视解码器（IRD）通过运行防止非法信号干扰的软件，实时分析卫星数字电视信号的特征，从而提前发现外来非法干扰信号并实施预警。分析卫星数字电视信号在受干扰过程中的信号特征，然后根据此特征提出对恶意干扰进行预警的一种实现算法。     

Hybrid satellite and terrestrial networks

The role of satellite communications in networks that provide new services, such as frame relay and multimedia, is investigated. Both passive and active (on-board switching/processing) satellite systems are considered. Novel techniques are developed for each system to demonstrate, via detailed analysis and simulation, how the communications bandwidth agility of multipoint/broadcast satellite channels, and the on-board switching/processing, makes it feasible to provide these new services via hybrid satellite and terrestrial networks in a resource-efficient manner.