地面数字电视广播标准的原理分析与思考

简要介绍当前三套地面数字电视广播标准的原理、性能和对比。     

数字电视广播的条件接收技术

本介绍了数字电视广播条件接收系统的基本原理以及系统构成，比较了条件接收系统的同密技术和多密技术的区别，并详细论述了条件接收系统的三级加密体制。     

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.     

数字电视的地面广播

本文系统介绍了数字电视地面广播的标准、系统．播出试验和设备以及我国在数字电视地面广播领域所做出的成绩，对数字电视地面广播做了较详细的描述和探讨．     

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。     

数字电视地面广播技术与传输标准

1引言数字电视广播主要通过卫星、有线电视及地面无线等三种传输方式实现。一般认为,卫星广播着重于解决大面积覆盖。有线电视广播着重于解决“信息到户”,特别是在城镇等人口居住稠密地区。而地面无线广播作为电视广播的传统手段,由于其所独具的简单接收和移动接收的能力,能够满足现代信息化社会所要求的“信息到人”的基本需求。所以,数字电视地面广播在未来数十年中将具备极大的商业价值。另一方面,数字电视广播近十年来的技术发展告诉人们,卫星和有线电视广播的基本传输体制已确定,世界技术先进国家在系统设计和芯片开发上已有相当技术…     

数字电视广播中的条件接收技术

简要探讨了条件接收系统的主要技术特点,对EUROCRYPT,特别是DVB系统中的条件接收系统进行了介绍,并就条件接收技术在中国的应用前景发表了看法。     

关于地面数字电视广播传输标准的学习笔记

在学习美国和欧洲(还有日本)的地面数字电视广播(DTTB)传输标准的基础上,针对地面数字电视广播快速移动接收的需求,提出:1)与制订地面数字电视广播新传输标准有关,在系统层设计中合理地缩小数据结构,并合理地设计同步码/训练序列(PN码);2)在接收端的解调器中,采用某种"过取样的相位跟踪技术",以充分利用主信号(有或无)和强回波信号的能量,保证在复杂多径效应环境下容易实现可靠的移动接收.对于制订具有更多自主知识产权的中国地面数字电视广播的传输标准而言,上述两方面的重要措施只有在采用VSB,QAM或OQAM调制的单载波系统的时间域高速数字处理中才能够实现.而且,这种新的单载波系统在组成单频网(SFN)时,与任何多载波系统相比,其技术简单而不需要卫星GPS系统,因而造价低、容易实现和维护.     

地面数字电视广播ATSC标准与DVB-T标准浅析

本文简单介绍了数字电视地面广播的系统组成,重点介绍了ATSC和DVB-T两种数字地面发送技术的原理、性能等,并对两种技术各自的优缺点进行了分析和论述。     

Transmission techniques for digital terrestrial TV broadcasting

The authors discuss the potential of OFDM signaling, with its limitations and inherent problems, as well as another potential technique that has so far been overlooked: single-carrier transmission with frequency-domain equalization. The carrier synchronisation issue is dealt with before the authors introduce coded-OFDM (COFDM), which makes use of channel coding and frequency-domain interleaving     

一种应用于数字电视地面广播的OFDM多载波调制方法

介绍了数字多媒体电视广播协议（DMB-T）中的信号帧结构,该结构引入PN码帧头用于时域同步。从理论上分析了时域同步正交频分复用多载波调制（TDS-OFDM）的参数选取策略。重点说明了子载波数量确定为3780的选择步骤。在这种信号结构下,TDS-OFDM信号的通带带宽为7.56MHz,既满足了电视带宽的要求,又满足了奈奎斯特采样定律。最后简要介绍了实现3780点快速傅立叶变换（FFT）的算法。其计算复杂度和容量复杂度都与标准的4096点FFT算法相当。     

地面数字电视广播覆盖网建设的分析与思考

在加紧建设地方广播电视节目地面数字电视广播覆盖网的背景下,结合保山市地方广播电视节目地面数字电视广播覆盖网建设实例,从5个方面对整个系统进行了详细阐述.重点围绕技术方案展开探讨,总结了部分实用的技术数据、符合地方实际的成功做法.提出了下一步建设完善地方广播电视节目地面数字电视广播覆盖网的一些思路.     

分级传输技术在数字电视地面广播中的应用研究

阐述分级调制的基本原理,描述均匀星座和非均匀星座ＭＱＡＭ格雷映射的实现方法,分级传输可实现数字电视的多分辨率地面广播,介绍分级信道编码的原理,提出分级信道编码的一种多步译码方法。     

基于电视广播的IP传输及其实现方案

介绍了ＤＶＢ数据广播的各种规范,着重讲述了传输ＩＰ数据报的多协议封装,有在此基础上提出了基于电视广播的ＩＰ传输方案。     

地面数字电视广播覆盖的研究

在诸多应用领域当中,地面数字电视广播独具优势,但因受经济及相关设备的影响,地面数字电视广播的发展也存在一定局限性。文章围绕地面数字电视广播覆盖展开了一系列讨论。     

Single carrier digital terrestrial television broadcasting

A transmission system for digital terrestrial television broadcasting has been designed. This system is based on the European cable system but uses stronger error correction and better equalization. The stronger error correction is a concatenation of Reed Solomon coding RS [204,188,17] and convolutional coding with R_conv=1/2, 2/3, 3/4, 5/6 and 7/8. The algorithm which is used for convolutional decoding is the Viterbi algorithm. To provide the Viterbi decoder with soft decision information, every symbol bit will be expanded with two soft decision (reliability) bits. The modulation scheme of the terrestrial transmission system is 64-QAM square root raised cosine filtered with a roll off factor α=0.15. The mapping of the symbols into the 64-QAM constellation is a Gray-mapping over the complete I,Q-plane. In this paper the performances of the terrestrial transmission system are simulated and analyzed     

地面数字多媒体电视广播传输系统研究

描述地面数字多媒体电视广播传输（DMB-T）系统结构,对该系统的分层传输特性、同步性能、抗干扰性和抗多径性能进行了讨论,同时介绍了设计实现的流程。     

A concept of digital terrestrial television broadcasting

The future terrestrial television broadcasting system should support the transmission of a digital HDTV signal with a high spectral efficiency. In addition, this system should maintain graceful degradation as the actual analog systems, and should be compatible with the SDTV. The system compatibility can be achieved by using a hierarchical HDTV source-coding scheme that can provide at least two (HDTV, SDTV) or three (HDTV, EDTV, SDTV) hierarchy levels: SDTV image quality will be expected for portable receivers, and HDTV/EDTV image quality will destinate to stationary receivers with roof-top antennas. Taking into account the receivers' antenna gains and the different channel conditions, there will be a difference of 25–30 dB between the received powers of the stationary and the portable receivers. Therefore, the design of a powerful and a suitable transmission scheme for the future broadcasting of the digital HDTV signal will be a technological challenge. In this article we describe a concept of a flexible reconfigurable hierarchical digital terrestrial TV broadcasting system for clear and taboo channels. The flexibility of the proposed scheme easily permits the receivers to support different reconfigurable modes: One HDTV program or multi-programming EDTV or SDTV (for fixed receivers up to 5 × SDTV in clear and up to 2 × SDTV in taboo channels; for portable receivers up to 2 × SDTV.) The system achieves a high interoperability with the Satellite Baseline system. It maintains a graceful degradation and provides a hierarchical complexity. It is based on a concatenated coding scheme. The inner code of the concatenated coding scheme is combined with multi-resolution modulation. The basic constellation is a 64-QAM, which will be operated in clear channels. It can be reconfigured to a 16-QAM in the case of taboo channels. The principle of OFDM with very rugged frequency/time synchronization mechanisms is used to combat the frequency selectivity and the co-channel interference (CCI) in the channel. Known pilot symbols are sent regularly in order to perform coherent detection.The authors are within the RACE-dTTb and the German HDTV-T project.