DVB T DTMB NORDIG数字电视测试标准详解
3星 · 超过75%的资源 需积分: 25 79 浏览量
更新于2024-08-01
收藏 919KB PDF 举报 "该资源涉及的是DVB (Digital Video Broadcasting)、DTMB (Digital Terrestrial Television Broadcasting) 和 NORDIG 相关的测试标准及资料。主要引用了 ETSI EN 300744 V1.4.1 (2001-01) 规范，这是关于数字地面电视的帧结构、信道编码和调制的标准。文档可能包含了与DVB技术、MPEG视频编码、音频和数据传输等相关的关键信息。"
详细说明:
DVB T (Digital Video Broadcasting - Terrestrial) 是一种数字电视广播标准，用于通过地面无线方式传输数字电视信号。这一标准由欧洲电信标准协会(ETSI)制定，旨在替代传统的模拟电视广播，提供更高质量的视频和音频服务。ETSI EN 300744是DVB-T的核心规范，它详细定义了数字地面电视的帧结构、信道编码和调制方法，确保了信号的有效传输和接收。
- **帧结构**: 在DVB-T中，电视信号被分割成多个时间帧，每个帧包含多个传输块，这些传输块可以独立编码和调制，以适应不同的信道条件。这种结构允许系统动态调整编码率和调制模式，以应对多路径传播和干扰。
- **信道编码**: DVB-T通常采用卷积码和Turbo码进行前向错误校正(FEC)，提高在有噪声或衰落信道中的数据传输可靠性。编码后的数据被分割成更小的数据单元，便于在不同的频率上并行传输。
- **调制**: DVB-T支持多种调制方式，如QPSK（四相相移键控）、16QAM（16阶正交幅度调制）和64QAM（64阶正交幅度调制），调制方式的选择取决于信道质量和需要传输的数据速率。高阶调制方式可以提供更高的数据速率，但对信道质量要求也更高。
DTMB (Digital Terrestrial Multimedia Broadcasting) 是中国推出的一种数字地面广播标准，它在一定程度上借鉴了DVB-T，但也有一些独特之处，如采用时分复用(TDM)和正交频分复用(OFDM)相结合的方式，以及自适应编码和调制策略。
NORDIG是北欧和波罗的海国家的一个合作组织，致力于制定统一的数字电视接收设备标准。NORDIG测试标准确保不同制造商的产品在这些地区的兼容性和互操作性。
该资源提供的文档可能包括了详细的测试程序、参数设置和性能评估方法，对开发和测试DVB-T和DTMB接收设备的工程师非常有价值。同时，对于理解数字电视广播系统的原理和技术也有重要参考价值。用户可以从 ETSI 官方网站下载此文档的PDF版本，以获取最权威的信息。
ETSI
ETSI EN 300 744 V1.4.1 (2001-
0
1)
9
4 Baseline system
4.1 General considerations
The system is defined as the functional block of equipment performing the adaptation of the baseband TV signals from
the output of the MPEG-2 transport multiplexer, to the terrestrial channel characteristics. The following processes shall
be applied to the data stream (see figure 1):
- transport multiplex adaptation and randomization for energy dispersal;
- outer coding (i.e. Reed-Solomon code);
- outer interleaving (i.e. convolutional interleaving);
- inner coding (i.e. punctured convolutional code);
- inner interleaving;
- mapping and modulation;
- Orthogonal Frequency Division Multiplexing (OFDM) transmission.
The system is directly compatible with MPEG-2 coded TV signals ISO/IEC 13818 [1].
Since the system is being designed for digital terrestrial television services to operate within the existing VHF and UHF
(see note) spectrum allocation for analogue transmissions, it is required that the System provides sufficient protection
against high levels of Co-Channel Interference (CCI) and Adjacent-Channel Interference (ACI) emanating from
existing PAL/SECAM/NTSC services. It is also a requirement that the System allows the maximum spectrum
efficiency when used within the VHF and UHF bands; this requirement can be achieved by utilizing Single Frequency
Network (SFN) operation.
NOTE: The OFDM system in the present document is specified for 8 MHz, 7 MHz and 6 MHz channel spacing.
The basic specification is the same for the three bandwidths except for the parameter elementary period T,
which is unique for the respective bandwidths. From an implementation point of view the elementary
period T can normally be seen as the inverse of the nominal system clock rate. By adjusting the system
clock rate the bandwidth and bit rate are modified accordingly.
To achieve these requirements an OFDM system with concatenated error correcting coding is being specified.
To maximize commonality with the Satellite baseline specification (see EN 300 421 [2]) and Cable baseline
specifications (see EN 300 429 [3]) the outer coding and outer interleaving are common, and the inner coding is
common with the Satellite baseline specification. To allow optimal trade off between network topology and frequency
efficiency, a flexible guard interval is specified. This will enable the system to support different network configurations,
such as large area SFN and single transmitter, while keeping maximum frequency efficiency.
Two modes of operation are defined: a "2K mode" and an "8K mode". The "2K mode" is suitable for single transmitter
operation and for small SFN networks with limited transmitter distances. The "8K mode" can be used both for single
transmitter operation and for small and large SFN networks.
The system allows different levels of QAM modulation and different inner code rates to be used to trade bit rate versus
ruggedness. The system also allows two level hierarchical channel coding and modulation, including uniform and multi-
resolution constellation. In this case the functional block diagram of the system shall be expanded to include the
modules shown dashed in figure 1. The splitter separates the incoming transport stream into two independent MPEG
transport streams, referred to as the high-priority and the low-priority stream. These two bitstreams are mapped onto the
signal constellation by the Mapper and Modulator which therefore has a corresponding number of inputs.
To guarantee that the signals emitted by such hierarchical systems may be received by a simple receiver the hierarchical
nature is restricted to hierarchical channel coding and modulation without the use of hierarchical source coding.
剩余48页未读，继续阅读
424 浏览量
412 浏览量
123 浏览量
188 浏览量
2021-10-12 上传
132 浏览量
108 浏览量
xsx2008xsx
- 粉丝: 0
- 资源: 9
我的内容管理
展开
最新资源
- J2EE开发全程实录.doc
- J2EE WEB端知识及案例使用顺序.pdf
- Microsoft编写优质无错C程序秘诀
- risk and utility in portfolio optimization
- End-to-End Web Content in WebSphere Portal using Web Content Management 6.0(中文版)
- Java+Struts教程(chinese).pdf
- CCIE BGP命令配置手册
- GFS（google文件系统）
- ARM MMU详解（中文版本）
- ASP_NET的网站信息发布管理系统设计与实现
- Experiences with MapReduce
- Bigtable(google的技术论文)
- MAX471数据手册
- 2008年程序员下半年
- MAX485芯片详细资料
- 学位论文撰写及排版格式手册（插图版）.pdf
