美国地面数字电视广播从ATSC 1.0向ATSC 3.0标准的过渡

ATSC3.0标准制定按原计划顺利进行,已开始其“启动的倒计时”,可望于2016年秋在美国启动下一代地面数字电视广播.届时,地面广播业者不仅可用发送系统增强其传统的广播功能,可在家内实现4K-UHDTV节目源固定接收的崭新免费服务,还将升级为无线互联网网站,以保证手持设备移动接收的崭新免费服务.     

Medium wave DRM field test results in urban and rural environments

This paper presents the results of the first Spanish field trial carried out to analyze a DRM (Digital Radio Mondiale) system in the medium-wave band. A 4-kW average power omni directional ground-wave experimental DRM transmission at a frequency of 1359 kHz was surveyed by means of a measurement vehicle for fixed and mobile reception. Several radial routes starting from the transmitter site provided rural and suburban behavior features of the system. Urban reception trials were performed in several dense and open streets of Madrid, within the expected coverage area. Field strength threshold values were determined for the tested transmission configurations and compared with the AM ground-wave ITU model predictions. Reliability versus distance from the transmitter is stated in this paper for different transmission configurations and the causes of dropouts for different reception conditions are explained. This analysis took into account subjective quality features of each configuration, providing practical planning parameter values.     

ATSC标准的新发展

1引言20世纪90年代中期,美国发展数制订了ATSC标准。1998年在ATSC标准受到广为此,FCC发出征询对标准改进方案的通知。根据资料ATSC改进方案大体是沿着两个:(1)在多径环境下,改善固定;(2)移动接收的解决方案。年NAB会议上,上述两方面的实现综述如下。2在多径环境下固定接收效果的改进LinxElectronics公司经过两年的开发出ATSC兼容的DTV并在2002年NAB展会上首次产生了很大的震动。NAB会后优2003年3月又在东部华盛顿、巴MSTV(TheAssociationfor,第Linx兼容接收机的性能。测试标准:测试标准是依据在一个3分钟的持视频瞬断(hits)…     

XG dynamic spectrum access field test results [Topics in Radio Communications]

The XG Radio system uses dynamic spectrum access technology to determine locally unused spectrum, and then operates on these channels without causing interference to existing non-cooperative users. In August 2006 the XG Radio system was field tested at Fort A.P. Hill, Virginia, in the laboratory, and at field locations in Northern Virginia. There were three major test criteria: to cause no harm (avoid interference), to work (form and maintain connected networks), and to add value (efficiently use spectrum). This article defines the test metrics for fulfillment of these criteria, and describes the test results.     

ATSC制数字电视机顶盒研究

系统全面地阐述了有线数字视频广播系统所涉及的技术以及ATSC系统的构成，并针对ATSC终端接收设备机顶盒，在工作原理，模块构成和关键技术方面作了较为详细的介绍。     

ATSC中NTSC抑制滤波器的设计

讨论了NTSC信号与数字电视ATSC信号在相邻信道中的相互影响以及NTSC抑制滤波器的设计与应用。     

Analysis of ATV transmission subsystem field test data

This paper examines the data from the field test of the Grand Alliance HDTV transmission subsystem conducted in Charlotte, NC in 1994. The field test data provides HDTV system designers and researchers with first-hand information on the performance of digital HDTV terrestrial broadcasting as well as on NTSC performance in the real-world environment. Analyses of the field test data are performed with respect to the system performance of an 8-VSB digital transmission subsystem, the performance of NTSC as reference and the television channel characteristics. Observations and conclusions derived from the analyses are provided     

ATSC的HDTV信道编码的性能分析

本文在对ATSC信道编码标准的总结基础上,在AGWN信道中对纠错编码的性能进行了分析.得到RS编码的编码增益,交织编码和RS编码结合的纠错能力.并分析了TCM-8VSB对4VSB性能的改善.得到ATSC信道编码参数是一组优化的参数的结论.     

加速度计重力场翻滚试验标定方法

分析了高精度加速度计常用的几种静态误差模型系数标定方法,包括重力场正倒置试验、四位置试验和多位置翻滚试验等数据处理方法。对这些方法的特点、适用范围和技术现状进行了详细的讨论,并探讨了高精度加速度计测试的未来发展方向。     

ATSC全数字接收机的符号定时同步方法

描述了以8-ASK作为调制方式的ATSC全数字接收机解调中定时同步问题的解决方法:通过采用基于Farrow结构的sinc()响应FIR,Gardner算法的定时误差检测方法,实现了符号同步.Matlab仿真表明,Gardner算法适用于ATSC接收机的符号同步设计.     

ATSC DTV系统中TCM编译码器的实现和简化

对ATSC DTV 8 VSB系统调制器中数据处理部分进行分析,给出一种硬件实现方案。采用一个2/3码率的TCM编码器代替ATSC标准中12支路并行的编码器,并自然地插入了同步数据,从而降低了系统复杂度。针对系统中TCM译码器,提出一种可变译码深度的译码方法,简化了系统的控制。结合联合均衡和TCM译码技术,提出多重深度译码的方法,降低了错误传播对判决反馈均衡器的影响,从而提高均衡器的性能。     

ATSC3.0物理层技术介绍与讨论

ATSC(美国先进电视系统委员会)在2011年启动了新一代地面数字电视标准ATSC 3.0的编制工作,并从2016年起陆续发表相关标准文本.与现有地面数字电视标准相比,ATSC 3.0具有显著的技术优势,但在新技术应用中仍面临着巨大挑战.本文将对ATSC 3.0系统的核心部分,即物理层技术进行介绍,并试图从技术应用的角度对ATSC 3.0进行初步探讨.     

ATSC与DVB-T数字电视地面广播特性比较

我国的数字电视的发展已经取得了长足的进步，如何制定一个适合我国国情的数字电视地面广播的标准，仍需要广播工作者继续努力。本文介绍了ATSC 8－VSB和DVB－T COFDM两种数字地面发送系统在系统的C／N性能、频谱效率、噪声性能和干扰性能等方面的比较结果，两种系统各有优缺点，供大家参考。     

对变压器局部放电及其现场试验的相关问题的分析及处理

本文研究了电力变压器产生局部放电的现象以及这种现象为什么会发生的原因;一旦这种现象产生以后可能带来的危害。同时本文还研究了在实验中出现的几种关于变压器局部放电的故障类型,此外,还对这种非正常放电产生的原因以及这种非正常放电的可能性。最后,本文通过实验研究指出,在进行变压器的生产中要对装配工艺进行严格的把关,以确保变压器的质量。     

Adaptive Hybrid Beamformer for Mobile Reception of ATSC DTV

An adaptive hybrid beamformer is proposed to improve the reception performance of the advanced television system committee (ATSC) digital television (DTV) in a mobile environment. Dynamic multipaths and Doppler shifts severely degrade the reception performance of the ATSC DTV receiver. Accordingly, a hybrid beamformer, called a Capon and least mean square (CLMS) beamformer, is presented that uses direction of arrival (DOA) information and the least mean square (LMS) beamforming algorithm. The proposed CLMS algorithm efficiently removes dynamic multipaths and compensates for the phase distortion caused by Doppler shifts in mobile receivers. When the CLMS beamformer has an insufficient degree of freedom (DOF), the subsequent use of an equalizer removes any residual multipath effects, thereby significantly improving the performance of DTV receivers. The performances of the proposed CLMS, Capon, and LMS beamformers are compared based on computer simulations. In addition, the overall performance of the CLMS beamformer followed by an equalizer is also considered.     

Electric vehicle field test experience

Thirty-five experimental GMC electric vans accumulated over 300 000 miles in a field test application as telephone service and repair vehicles. Information was obtained on recharging lead-acid traction batteries which led to microprocessor control of the recharge. Energy consumption, ac kilowatt hours per mile, was greatly reduced and recharge efficiency increased by accurate control of the recharge. Battery energy density (range) and wear-out remain concerns which promote the need for a new energy source for commercial electric vehicles.     

美国地面数字电视广播从ATSC 1.0向ATSC3.0标准过渡的进展

ATSC 3.0标准制定按原计划顺利进行;已开始其“启动的倒计时”：可望于2016年秋在美国启动下一代地面数字电视广播。届时,地面广播业者不仅可把发送系统增强其传统的广播功能：可在家内实现4K-UHDTV节目源固定接收的崭新免费服务;还将升级为无线互联网网站,以保证手持设备移动接收的崭新免费服务。     

ATSC和DVB-T固定接收时的回波处理性能对比

地面数字电视广播传输美国标准ATSC(单载波)或欧洲DVB-T(多载波)在接收端都开发了回波处理技术。DVB-T在固定接收应用时,其解调器可利用时间域已知信息(由PN码的片断组成)进行0dB回波处理(类似ATSC),不依赖于保护间隔;因而,可采用1/32可选项;而DVB-T2则进一步把保护间隔扩展到1/128。简要介绍了ATSC和DVB-T固定接收时回波处理性能的对比。     

ATSC标准中专利状况报告(上)

介绍了ATSC标准的基本技术情况,包括ATSC标准文本涉及的技术的分类,并指出含有专利权的相关标准文件;进而分析各专利权人的背景、公司之间的关联,以及有关专利权的法律状态,最后就ATSC中的专利状况相关问题进行分析总结。     

ATSC标准中专利状况报告(下)

主要贡献（主要的技术领域）：高清晰数字电视的传输系统；基于MPEG-2的图像压缩系统和MPEG-2解码集成电路；压缩图像传输的分布式数据网络。