国内卫星网IDR电路2Mbit/s在线测试指标及测试方法分析

在线测试是电路维护的常用手段,根据北京无线通信局制定的<1999年全国卫星维护作业计划>,全国IDR卫星电路在1999年上下半年各要做一次在线测试,由于缺乏仪表和对测试方法和指标的不了解,许多地球站没有进行测试或测试不顺利,笔者与一些同行探讨后做如下分析,供同行参考.     

MPEG-2卫星数据电脑接收与录制系统的使用

MPEG-2卫星数字电视节目接收系统是电视台获取电视节目素材的重要手段.扬州电视台为了接收与录制<体育界>和<娱乐现场>等通过卫星传输的MPEG-2数字电视节目,采用了北京亚太东方通信网络有限公司的MPEG-2卫星数据电脑接收与录制系统.     

新闻卫星车系统指标测试的分析与研究

本文通过对陕西广播电视台新闻卫星车进行系统指标测试,介绍了视音频系统和卫星传输系统测试中所用的测试仪器、测试方法、测试点位、测试结果及测试分析。     

美国空军开始运行EPS卫星系统向北极地区提供安全通信

<正>据C4ISRNet网站2019年10月24日报道,2019年10月22日,美国空军宣布,可向北极地区提供安全通信的军用卫星系统——"增强型极地系统"(EPS)现已开始运行。在成功地完成多用途作战测试和评估之后,EPS系统管理权已移交給科罗拉多州Schriever空军基地的第4太空作战中队。美国空军表示,现在两颗EPS卫星都可供军事领导人使用。     

业内首次从太空实现RF信号定位

<正>据Space Newsfeed网站2019年2月26日消息,HawkEye 360公司已开始通过其3颗新投入使用的"探路者"小卫星从太空识别和定位RF信号。3颗小卫星在地球上空数百英里处以编队形式飞行,独立精确确定了多种RF信号来源的地理位置。初步测试结果表明,系统成功定位了紧急无线电     

卫星覆盖区测试方法及工程应用

卫星覆盖区是卫星系统为用户提供服务能力的重要指标之一,也是卫星系统测试的重要内容。研究通过几个主要评判参数:出站链路卫星发射EIRPs、用户接收误码率,入站链路卫星G/T值的测试评判卫星覆盖区范围。同时介绍并对比了目前卫星覆盖区测试的2种测试方法:移动测试法和卫星姿态偏置测试法,以及测试所需测试设备组成和测试流程,并通过卫星覆盖区测试的工程实践说明了测试的可行性和有效性。     

卫星数字电视系统测试方法的研究（二）——石马流分析和数字音视频指标测试

卫星数字电视编码器和复用器的输出均为传输流。编码器的技术指标对整个卫星数字电视系统的图像传输质量起着决定作用，编码复用部分的指标是这个卫星数字电视系统测试的重点之一。包括四个方面：码流分析、数字接口技术指标、系统模拟音视频指标、功能和兼容性进行测试。测试示意图见图5所示。     

SJ／T11387-2008《直播卫星电视广播接收系统及设备通用规范》概要

本规范依据GD/JN 01-2007<先进卫星广播系统一一帧结构、信道编码与调制>并参考国家广播电影电视总局科技司2008年4月份发布的<中国广播电视直播卫星"村村通"系统技术体制白皮书>(2008)相关要求制定,适用于中国广播电视直播一期工程.     

北斗卫星导航产品认证测试系统功率的校准

北斗卫星导航产品认证测试系统是对北斗RDSS、北斗RNSS各类产品进行认证测试的专用设备,整个系统功率的准确与否,不但直接影响捕获灵敏度、跟踪灵敏度和发射EIRP等直接功率指标的测试精度,还将影响定位精度、测速精度、启动时间和重捕时间等一系列性能和功能指标的测试结果。出于保证北斗产品认证测试准确性的目的,提出了一种分解测量加系统修正的方法,对系统功率值进行校准,并利用标准北斗终端的代表性指标对校准结果进行了验证,测试结果表明该校准方法有效,系统经校准后满足开展北斗卫星导航产品认证测试的要求。     

MPEG-2 TS分析与卫星系统射频测试方法

本文主要介绍了卫星数字电视系统射频指标测试、编解码与复用部分的传输流分析和传输流技术指标的测试。     

有线电视智能前端的网络通信方式

广州有线电视智能前端采用了ROSA监测系统,由此衍生出3种网络通信方式,详细说明它们的工作原理、设备安装以及参数设置.     

Testing HDTV terrestrial broadcasting systems

The Advanced Television Test Center (ATTC) is a private sector, nonprofit organization created to undertake full, fair, and impartial testing of the various advanced television (ATV) systems that have been proposed as the United States terrestrial broadcast standard. Cable Television Laboratories (CableLabs) organized by the cable television industry operates, in cooperation with ATTC, a state-of-the-art laboratory testing facility capable of thoroughly evaluating the proposed ATV systems when transmitted by cable TV, including both coaxial cable and fiber-optic transmission. Presently there are six systems scheduled for test by the ATTC and CableLabs. The systems and their scheduled test dates are shown. One of the systems is an enhanced NTSC compatible system and the other five are high-definition television (HDTV) simulcast systems. Four of the simulcast systems are digital. Both objective and subjective tests of all six systems are discussed     

The HDTV `test kitchens'

The article shows how the Advanced Television Test Center is putting the Grand Alliance's HDTV system through its paces. The testing of prototype hardware is designed to support the proposed US standard for high-definition television (HDTV) terrestrial broadcasting. The standard was developed through the efforts of a group called the Grand Alliance. When the testing on the proposed Grand Alliance system is completed, the prototype will be submitted to the Federal Communications Commission (FCC) for review     

DTMB单频网组网概述

就地面数字电视国标(DTMB)单频网(SFN)组网的概念、系统构成单频网同步原理、激励器原理以及实验室测试方法等作了系统介绍。同时通过对实际组网中可能遇到的问题以及需注意的事项给出分析和解决办法。     

Canadian digital terrestrial television system technical parameters

On November 8, 1997, Canada formally adopted the ATSC Digital Television Standard for terrestrial transmission as defined in document A/53 of the Advanced Television Systems Committee of the USA and as modified by the FCC document MM Docket No. 87-268. This paper discusses the Canadian digital terrestrial television system technical parameters for implementation and frequency planning: interference protection ratios, reference system parameters, and radio frequency emission masks, as well as their design methodology. First, the Canadian terrestrial DTV design guidelines are presented, followed by the introduction of DTV reference receiving system set up and the parameter selection of the interference protection ratios. Last, the design methodology of the emission masks is discussed     

广电呼叫中心客服管理软件系统的建设

介绍了南京广电网络呼叫中心客服管理软件系统的形成、发展和整体扩容建设情况,对广电客服现有业务管理软件系统的各组成部分、功能、测试应用及其主要技术特征进行了简要论述,指出了扩容升级后管理软件系统的先进性、实用性和不足。     

Field testing DigiCipher HDTV in Los Angeles

Test results for DigiCipher, the first all-digital HDTV system developed by the American Television Alliance, showed that the DigiCipher system performed very well in all areas, including the laboratory testing of terrestrial transmissions. Recently, field testing of the DigiCipher HDTV system in the Los Angeles, California, area was undertaken to verify the performance of the system in a real world environment, and to help anticipate how DigiCipher will perform in US FCC field testing. The results indicated that reliable reception can be achieved at distances as far as 42 miles from the transmitter, with only 137 W of average power in the presence of strong adjacent channel and cochannel interference     

Sensing circuit for on-line detection of delay faults

A sensing circuit for on-line testing of delay faults is presented. It can be used to monitor the outputs of circuits that are either general, or designed to be self-checking with respect to steady-state errors. Detailed analyses of the proposed circuit have shown that it is preferable to alternate solutions from the point of view of both the accuracy and the self-testing capability that make it suitable for self-checking applications. Checking architectures for delay faults, making use of the proposed sensing circuit and of standard checkers, are presented     

ATSC标准中8-VSB调制器的算法改进及FPGA设计实现

重点介绍了ATSC标准的8-VSB系统构架以及FPGA系统的具体实现方案.根据具体标准的参数要求,分析了ATSC标准.基于改进的维弗法,提出了频率范围可变的低中频数字信号输出解决方案,给出了系统硬件的设计步骤,并给出实测结果.     

对微波传输机房的电源更新改造

湖北广电总台微波机房原有的电源设备,因元件老化不能保证微波传输设备正常的播出工作。文中详细论述了对原电源设备进行了更新改造过程,包括考察、招标、认证、安装、调试、测试验收,并投入到正式的播出工作中,确保了微波传输机房的交、直流供电,保证了安全播出。