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。     

Choosing an American digital HDTV terrestrial broadcasting system

A public process has been in place in the United States for six years to establish an HDTV terrestrial broadcasting standard. The process, having moved through a planning phase, a competition phase, and an examination phase, has now entered a cooperation phase. Remarkable progress has been made-a testament to the process. During 1994 the American digital HDTV terrestrial broadcasting system will be tested, fully documented, and recommended to the FCC for adoption     

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。     

Modulation for terrestrial broadcasting of digital HDTV

The digital modulation methods used by the DigiCipher, DSC-HDTV, ADTV, and ATVA-P digital high-definition television (HDTV) systems are discussed. Three of the systems use a quadrature amplitude modulation method and the fourth uses a vestigial sideband modulation method. The channel equalization and spectrum sharing of the digital HDTV systems is discussed     

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     

数字电视地面广播系统的三种标准制式

1引言数字电视以其卓越的画质和音响、多功能、多用途及与信息高速公路互联互通的特点,成为广播电视发展的必然趋势。与之相应,数字电视传输系统的研究与开发也取得了长足的进展。根据国际电信联盟（ITU）无线电通信部的规定,数字电视系统可由三个子系统组成,见图1。目前,全球数字电视广播有三个相对成熟的标准制式：欧洲的DVB、美国的AThC和日本的ISDB,其中美国的AThC与欧洲的DVB占主导地位,而DVB制式应用最广泛、最灵活。DVB制式主要包括数字卫星电视（DVB－S）、数字有线电视（DVB－C）和数字地面广播电视（DVB－T…     

Source coding for digital HDTV terrestrial broadcasting

It is claimed that an all-digital system will provide true high-definition television quality and coverage area equivalent to NTSC without noise and interference. Less transmission power may be required, and the signal will be easy to encrypt. The proposed source coding algorithms are reviewed, and the methods by which they are used in the proposed digital HDTV terrestrial broadcasting systems are discussed     

Multicarrier modem for digital HDTV terrestrial broadcasting

A digital modulation system using orthogonal frequency division and multiplexing (OFDM) is addressed in this paper. Such a system presents the advantage of coping with echoes more easily than classical single-carrier modems, thanks to the insertion of a guard interval between two symbols. The signal equalization is then achieved in the frequency domain. This OFDM modem is improved by using dual polarizations. In this configuration, it can convey a 70 Mbits/s (HDTV) bit stream in an 8 MHz UHF channel. Some experimental results relate field trials carried out in several countries with such equipment.     

Channel coding for digital HDTV terrestrial broadcasting

In order to transmit the HDTV signal in 6 MHz, the four United States digital HDTV proponents, the DigiCipher, DSC-HDTV, ADTV and ATVA-P systems, are reducing the video data rate of HDTV to 15-17 Mb/s, a compression ratio of approximately 60-70 times. The high compression dictates that channel coding be used to avoid block errors and multiframe error propagation. High efficiency in channel utilization required by the 6-MHz limitation means that the channel must be properly equalized and that the multipath and interfering signals must be severely limited. The channel coding techniques used for error reduction include data interleaving, error detection and replacement, and error correction at different levels of protection for bits and blocks of unequal importance     

加强数字电视性能的EIA/CEA-861A新标准

美国消费电子协会（CEA）DTV接　口分会最近已经通过了一项新的标准　EIA/CEA-861A,它是由CEA的R-4.8　工程组（第7工作组）制订出来的,确立　了通过数字视频接口（DVI）和OpenLDI　视频接口规范发送数字视频信号的方法。　新标准与2000年11月批准的EIA/CEA-861标准完全后向兼容。 原来的标准861把高清晰度电视（HDTV）和加强清晰度电视（EDTV）视　频格式和要求加进DVI1.0中。新标准861A将加强用户友好的界面,改善和优　化数字电视的质量。它将让DTV源设备     

一种新的地面数字多媒体/电视广播传输系统

针对传输信道线性时变的宽带传输信道特性，设计了一种时域同步正交频分复用（简称TDS－OFDM）的多载波调制方式。这种调制方式既适用于具有多径干扰和多普勒频移的地面数字电视广播传输信道，也适用于其它宽带数字传输系统。为了进一步提高传输效率，提出的地面数字多媒体／电视广播DMB－T传输系统还采用了最新的纠错编码和交织编码技术，在额定的8MHz带宽中，净载数据传输率可达32．511Mbps。     

ATSC数字地面电视标准综述

详细介绍了应用于ＨＤＴＶ的ＡＴＳＣ数字电视标准,包括所描述系统的组成（编码与压缩、服务复用和传送、ＲＦ／传输）和数据结构等。     

符合中国数字电视地面广播标准的前向纠错码编码器设计

文章提供了一种符合中国数字电视地面广播标准中的前向纠错码BCH-LDPC级联编码器的硬件实现方案.设计充分利用了此LDPC码的G矩阵的准循环特性,在结构、存储空间和时序上得以较大的优化.此结构也具有一定的灵活性,能通过对G矩阵列划分改变其并行度,从而改变速度和面积上的折中.并且通过在控制电路中设定不同的状态跳转条件实现不同码率的编码要求,使编码器大部分模块得到了重用.     

Coded OFDM with transmitter diversity for digital television terrestrial broadcasting

Space-frequency coded (SFC) and channel coded orthogonal frequency-division multiplexing (COFDM) is considered under narrow-band interference (NBI). Analytical expressions for the bit error probability (BEP) are derived for OFDM with SFC in a frequency-selective fading environment. It is shown that SFC increases the resistance of COFDM against the NBI and reduces the BEP considerably. Specific attention is paid to Digital Terrestrial Television Broadcasting (DTTB), and the associated coding gains are discussed.     

60 GHz band 64 QAM/OFDM terrestrial digital broadcasting signaltransmission by using millimeter-wave self-heterodyne system

This paper describes the first time experimental studies on 60-GHz band transmissions of terrestrial digital broadcasting signals (ISDB-T) with 64-QAM modulations on coded orthogonal frequency division multiplexing (COFDM) format. It has been a very difficult experiment to accomplish because it requires very stable and low phase-noise oscillators in the millimeter-wave band. The use of our proposed millimeter-wave self-heterodyne system, overcame this problem without using a stable oscillator, and provided a bit error rate (BER) of less than 10^-6 without any forward error correction. We also discuss the relationship between the carrier-to-noise power ratio and the BER obtained, and demonstrate that the penalty of the required CNR for our experimental system is less than 1 dB compared to the results of a back-to-back BER test     

日本的综合业务数字广播地面传输协议

1.引言高清晰度电视按传输媒质[1]分为地面、卫星和同轴电缆3种.对卫星和同轴电缆传输方式,各国基本已完全决定自己所采用的标准,中国分别采用欧洲的DVB-S和DVB-C标准.对于地面传输方式,美国发展比较快,1995年末形成标准,1998年末开始有线电视台播送此类节目.欧洲在1997年形成标准,日本在1998年形成标准.其它国家也在积极推进高清晰度电视地面传输协议的选择和制定,西班牙、澳大利亚、加拿大[2]和新加坡等国家分别对高清晰度电视广播进行了协议比较和场测.对于中国的地面高清晰度电视标准,有关部门正在讨论制定中,并积极进行场测试验.下面将介绍高清晰度电视地面传输协议的发展概况,同时重点介绍日本的高清晰度电视地面传输协议--综合业务数字广播地面(ISDB-T)传输协议.     

OFDM system channel estimation using time-domain training sequencefor mobile reception of digital terrestrial broadcasting

A channel estimation technique using time-domain training sequence is investigated. It is demonstrated that this technique can estimate the channel status more accurately, under low C/N situations, than the conventional frequency domain technique using in-band pilots. A novel channel estimation and compensation scheme for a fast fading channel is developed for an OFDM system using time-domain training sequence. It is compared with the frequency domain pilot channel estimation scheme     

应用于数字广播系统的高线性下变频器

An integrated downconverter with high linearity for digital broadcasting system receivers is implemented in a 0.13 m CMOS process with an active area of 0.1 mm2. The current-mode scheme is adopted to improve linearity performance by avoiding voltage fluctuation. A passive CMOS switching pair is utilized to improve the even-order linearity of the downconverter. A current amplifier is used to provide low input impedance which will easily lead to a wide operating bandwidth and high linearity. Moreover, a current-mode Sallen-Key low-pass filter is adopted for effective rejection of out-of-band interferers and also low input impedance. The digital-assisted DC offset calibration improves the second-order distortion of the downconverter. This design achieves a maximum gain of 40 d B and a dynamic range of 10 d B. Measured noise figure is 8.2 d B, an IIP2 of 63 d Bm, an IIP3 of 17 d Bm at the minimum gain of 30 d B. The downconverter consumes about 7.7 m A under a supply of 1.2 V.     

WCDMA系统中智能天线PSALS-SDRMTA自适应算法

本文结合3GPP协议针对第三代移动通信WCDMA系统推导出了基于最小二乘准则的导频符号辅助解扰解扩重扩多目标阵列自适应算法,然后对此算法作了仿真,结果证明PSALS-SDRMTA算法是有效的。     

用于智能天线系统的多小区空时联合处理算法

TD-SCDMA系统同频组网时,邻区用户同样会产生多址接入干扰,而传统的联合检测无法消除.为了抑制邻区干扰,对上行链路接收端提出了一种将联合检测扩展到多个小区并与智能天线相结合的多小区空时联合处理算法.该算法根据对邻区用户信道估计的结果选择其中的强干扰用户,并将邻区强干扰用户和本小区用户的复合信道冲激响应同时纳入空时联合处理的系统矩阵.仿真结果表明,在室内-室外和高速车载信道模型下,采用多小区空时联合处理算法的接收机解调性能有3～4.8 dB的提升.此外,讨论了邻区相关信息的获取、邻区强干扰用户的选择和运算复杂度等具体实现时需考虑的问题.多小区空时联合处理算法可有效消除邻区强干扰用户的干扰,从而大幅提高了同频组网时系统的性能.