数字电视基础培训

1、1数字电视基础培训 part 1有线所2005-09confidential2内容 数字与模拟 图像压缩 数字调制基础 数字电视标准 数字电视传输体系 数字电视服务体系 小结 参考文献confidential3数字与模拟analogdigital confidential4图像压缩 为什么要进行压缩编码为什么要进行压缩编码 数字复合ntsc : 143mbps 数字复合pal : 177mbps 数字分量itu-r 601 : 270mbpsconfidential5图像压缩confidential6图像压缩压缩标准：压缩标准：jpeg： joint picture experts group

2、 motion-jpegmpeg：moving picture experts group mpeg-1 mpeg-2 mpeg-3 mpeg-4confidential9图像压缩video incoded framesquantizevariable lengthcoderdctmuxbufferrate controllosslessaddpass /subtractanchor frame storemotion estimationpredicetdframe storegop controlmotion vectors422 to420inversedctconfidential10

3、图像压缩12345678910111213i1p4b2b3p7b5b6p10 b8b9i13b11b1212345678910111213confidential11图像压缩pes packet payloadpes packet headeraudio or video elementary stream ts packetts packet headerconfidential12图像压缩elementary streamsvideoaudiompeg audioencodermpeg videoencoderinternalmultiplexerbasic encoder functio

4、nspts -single program mpegtransport streamspsimpts -multiple program transport streamremuxpsi/simanageroutput adapterbasic multiplexer functionspts -spts -spts -spts -data -confidential13图像压缩0channel complexityrelative activity 电影新闻节目体育节目20%40%60%80%100%电影新闻节目体育节目confidential14数字调制基础 信源编码的目的是提高信源的效率

5、 信道编码的目的是增加传输的可靠性透明，对所传信息的内容没有任何限定具有与信道相适应的频谱特征效率高包含同步信息有纠错能力差错扩散度低confidential15数字调制基础0000000100100011010001010110011110001001101010111100110111101111confidential16数字调制基础confidential17数字调制基础0000-0011-1001-1111-1100-0111-0101-1000-0110-0010-01000000001110011111110001110101100001100010010000000011100

6、111111100011101011000011000100100需要需要vlc等对数据的优化等对数据的优化confidential18数字电视标准av信源av编码压缩码流复用信道编码调制信道解调解码av解码av显示confidential19数字电视标准标准体系 atsc dvb 视频编码 mpeg-2 mpeg-2 音频编码 dolby ac-3 mpeg-2 /dolby ac-3 地面广播标准/调制方式 8-vsb dvb-t cofdm 有线广播标准/调制方式 无 * dvb-c n-qam 卫星广播标准/调制方式 qpsk 可选 8psk、16qam dvb-s qpsk 欧洲：d

7、vb美国：atsc日本：isdb-tconfidential20数字电视传输体系 有线信道数字有线电视 无线信道数字卫星电视数字地面电视数字手持电视confidential21数字电视传输体系数字有线电视16qam, 32qam,64qam,128qam,256qamconfidential22数字电视传输体系数字卫星电视confidential23数字电视传输体系数字地面电视调制方式： cofdm coded orthogonal frequency division multiplex2k：17058k：6817confidential24数字电视传输体系数字地面电视confidentia

8、l25数字电视传输体系数字手持电视based on dvb-t, backwards fully compatiblegives additional features to support handheld portable and mobile receptionbattery saving mobility with high data rates, single antenna reception, sfn networksimpulse noise toleranceincreased general robustnesssupport for seamless handoverth

9、e above have been achieved by adding optionstime-slicing for power savingmpe-fec for additional robustness and mobility4k mode for mobility and network design flexibilityplus additional minor changes, e.g., in signallingdvb-h is meant for ip-based services via mpe insertiondvb-h can share dvb-t mult

10、iplex with mpeg2 servicesportable/indoor coverage should be built to the network for fully exploit the dvb-h possibilities businesswiseconfidential26数字电视传输体系数字手持电视dvb-tumtsdvb-ttransmitterbroadcastcontentprovidermuxdtvbroadcast network operatorispcorenetworkumtsbase stationmobile operatormobiletermi

11、naldvb-umtsimtiboibiiimoco-operation platformdvb-hpowerconsumptionis key !hconfidential27数字电视传输体系数字手持电视based on dvb-t, can share multiplex with dvb-t servicesip-based solution, mpe used over dvb-tnew 1: time slicing for power savingnew 2: mpe-fec for mobile performance and tolerance to impulse noise

12、, (reuses memory of time slicing, has effectively a virtual time interleaver)new 3: features to dvb-t phyoptional 4k mode and 4k symbol interleaver for mobility in large and medium sized sfnsoptional in-depth interleaver for 2k and 4kadditional signalling in tpsmandatory use of cell-id5 mhz channels

13、 for non-broadcasting bandsconfidential28数字电视传输体系数字手持电视muxmpeg-2 tv servicempeg-2 tv servicempeg-2 tv servicempeg-2 tv servicempempe-fectimeslicingdvb-hip- encapsulatorip8k 4k 2kdvb-h tpsdvb-t modulatortsrfrftransmitter8k 4k 2k dvb-h tpsdvb-t demodulatortsmpempe-fectimeslicingdvb-hip- decapsulatorip

14、receivernew to dvb-hexistingchannelconfidential29数字电视传输体系数字手持电视time sliced and non-time sliced services in common multiplex only receiver switched off, transmitter on all the time support for time slicing not mandatory to receive time sliced serviceeven 90% power saving for the front-end can easily

15、be achieved.uninterrupted service reception with single receiver hand-over.service 1 (not time sliced)service 2 (time sliced)service 3 (time sliced)service 4 (time sliced)timecapacity sharets bitrateconfidential30数字电视传输体系数字手持电视eeef1f2f3dvb-h ipe-time slicing-mpe-fecdvb-t tx-4k capable, if neededrepe

16、ater-repeaters may be used.ip-backbonedense sfn-fft-size selected according the planning requirements-some operators use 4k some 8kconfidential31数字电视服务体系confidential32数字电视服务体系confidential33数字电视服务体系confidential34数字电视服务体系confidential35数字电视服务体系cw ecm emm cw 视频/音频/ 数据 视频/音频/数据 （已加扰） 视频/音频/数据 （已解扰） 加扰 控制

17、字生成 ecm 生成（加密） 用户管理系统（sms） 用户授权系统（sas） 传 输 系 统 解扰 智能卡 confidential36数字电视服务体系os, drivers, firmware, .java virtual machineinteroperable applicationtrans-portproto-col(s)dvb specificapissun javaapisdavicapisdatahaviapisapplicationmanager(navigator)interoperableapplication(and libraries)system softwareconfidential37数字电视服务体系content deliverycontent creationcontent receptionconfidential38数字电视服务体系数据广播数据广播音视频内容音视频内容数据内容数据内容音视频处理单元音视频处理单元数据广播子系统数据广播子系统复复 用用 器器ca/sms系统系统网络接口网络接口传输网络传输网络用户接收端用户接收端数字电视系统数字电视系统confidential39数字电视服务体系应应 用用mpeg-2