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Explain different standards of DVB.
written 6.4 years ago by gravatar for mohdfarhan mohdfarhan • 530 modified 5.4 years ago by gravatar for ankitpandey ankitpandey • 100
tv and video engineering
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written 6.3 years ago by gravatar for mohdfarhan mohdfarhan • 530

Digital Video Broadcast standards are used for communication channels. DVB systems distribute data using a variety of approaches, including:

  • Satellite: DVB-S, DVB-S2 and DVB-SH.
  • Cable: DVB-C, DVB-C2.
  • Terrestrial television: DVB-T, DVB-T2.
  • Digital terrestrial television for handhelds: DVB-H, DVB-SH.
  • Microwave: using DTT (DVB-MT), the MMDS (DVB-MC), and/or MVDS standards (DVB-MS)

These distribution systems differ mainly in the modulation schemes used and error correcting codes used, due to the different technical constraints.

  • DVB-S (SHF) uses QPSK, 8-PSK or 16-QAM.
  • DVB-S2 uses QPSK, 8-PSK, 16-APSK or 32-APSK, at the broadcasters decision. QPSK and 8-PSK are the only versions regularly used.
  • DVB-C (VHF/UHF) uses QAM: 16-QAM, 32-QAM, 64-QAM, 128-QAM or 256-QAM.
  • DVB-T (VHF/UHF) uses 16-QAM or 64-QAM (or QPSK) in combination with (C)OFDM and can support hierarchical modulation.
Sr. No. Parameters DVB-S2 DVB-T2 DVB-C2
1. Inputinterface Multiple transport stream and generic stream encapsulation (GSE) Multiple transport stream and generic stream encapsulation (GSE) Multiple transport stream and generic stream encapsulation (GSE)
2. Modes Variable coding & modulation and adaptive coding & modulation Variable coding & modulation[4] Variable coding & modulation and adaptive coding & modulation
3. FEC LDPC + BCH 1/4, 1/3, 2/5, 1/2, 3/5, 2/3, 3/4, 4/5, 5/6, 8/9, 9/10 LDPC + BCH 1/2, 3/5, 2/3, 3/4, 4/5, 5/6 LDPC + BCH 1/2, 2/3, 3/4, 4/5, 5/6, 8/9, 9/10
4. Modulation Single carrier QPSK with multiple streams OFDM Absolute OFDM
5. Modulation Schemes QPSK, 8-PSK, 16-APSK, 32-APSK QPSK, 16-QAM, 64-QAM, 256-QAM 16- to 4096-QAM
6. Guard Interval Not applicable 1/4, 19/256, 1/8, 19/128, 1/16, 1/32, 1/128 1/64 or 1/128
7. Fourier Transform Size Not applicable 1k, 2k, 4k, 8k, 16k, 32k DFT 4k Inverse FFT
8. Interleaving Bit-Interleaving Bit- time- and frequency-interleaving Bit- time- and frequency-interleaving
9. Pilots Pilot symbols Scattered and continual pilots Scattered and continual pilots
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