ACM technology in DVB-S2 IP Unicast System
TPE package. GTW and transport stream multiplexer (TS-MUX)-one correspondence. MPEG packets can be marked empty and remove the receiver and then be accurately restored to its original position, so that information can reduce the transmission rate and error rate. Traffic demands in the MUX and DEMUX output side of the input data rate is constant in the time domain and the end to end delay is constant, it is necessary to activate the function to delete empty group (useful for packets being transmitted, useless packets are removed) . Merger periodically polling the input buffer, if the cache enough data to fill a base-band frame, put them together with the ACM combiner instructions sent to the ACM modulator. To prevent excessive delay or reduce the cache can be the number of timing mechanism. 33ACMDVB-S2 the originator of the system flow chart in IP unicast system, ACM mode of DVB-S2 system, the originator of the process is shown in Figure 5. IP packet is encapsulated into a single stream or composite stream into the system, and enter the ACM command information input interface to input the current signal is mapped to bits in the form, press the TV data stream router technology ball / Main, No. 4 (i section 286 151] QoS requirements of streaming, each data stream is deposited after the CRC error protection of different levels of cache for MPEG-TS input streams into the cache before the input streams should be synchronized and empty packages removed. combiner out data base with the lead frame to form the baseband, baseband scrambling after treatment and ACM instruction rate and the modulation information carried along into the coding system, which is within the BCH outer codes and LDPC codes cascade, this information through modulation when the output serial bit stream to the constellation mapping, and finally insert the corresponding physical layer signaling and pilot, the frequency modulation sent to the transmitter, the originator to complete the entire DVB-S2 system [41 Figure Figure baseband signal pattern matching l l: clam Pu: △ 'H Bukou and / Tomb Box H Bu HH Star split mode exposed the originator of Figure 5ACM 4 Conclusion ACM system flow chart for the DVB-S2Ku-band multi-station unicast system can greatly improve the bandwidth utilization for Ka-band satellite in heavy rainfall areas of multi-link, its role will become more apparent improvement. ACM Ka satellite technology and multi-point technology and DVB-RCS return channel combination can Satellite high-speed Internet access prices down to 1 / 10, at least in rural areas, causing the ground DVB-S2 standard with Internet access ADSL standard way in the competition. DVB-S2 + ACM will implement the satellite interactive services The key factor, therefore, fully understand and master the key technology DVB-S2 and ACM, for the establishment of China's digital satellite broadcast system is very much needed and meaningful. References [1] DraftETSIEN302307, Secondgenerationframingstructure,
abercrombie france, chart-nelcodingandmodulationsystemsforBroadcastng, InteractiveServices, NewsGatheringandotherbroadbansatelliteapplications [S] .2004. [21ETSITR102376V1.1.1, DigitalVideoBroadcastingUserguide-linesforthesecondgenerationsystemforBroadcasting,
abercrombie france, lnteractivesServices, NewsGatheringandotherbroadbandsatelliteapplication s (DVB-s2) [s] .2005. [31ETSIEN301192, DigitalVideoBroadeasting (DVB), DVBspecifiea-tionfordatabroadcasting [S] .1997. [41 Lin Ying-Zi, Liang Jian, XU Yuan-xin,
franklin marshall soldes, and other second-generation digital television satellite transmission standard DVB-S2 Overview [JJ. TV technology, 2004 (9) :85-86. ◇ ● Author: Guo Moon (1981 a] woman. Master, the main research satellite digital TV reception technology; Huang Yan (1963 -]. Associate Professor,
christian louboutin boutique, Shuodao, the main research satellite digital TV reception technology. Editor: Liu Boyi Received Date :2005 -12-23
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