Digital Video Broadcasting - Second Generation Terrestrial is the second generation standards for terrestrial transmission. to know more go though the slides

1. By Susmita Pandey
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2. 
Dvb.

Dvb –t2 history.

Dvb-t2 modulator.

Architecture model.

Key technologies.

Comparison.

Conclusion.
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3. 
Include DVB-S, DVB-S2, DVB-C, DVB-T and DVBT 2.

DVB-T stands for Digital Video Broadcasting –
Terrestrial.

These standards define the physical layer and data link
layer of the distribution system.

Transmits a compressed digital audio/video
stream, using OFDM modulation with concatenated
channel coding .
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4.  The
first country that deployed DVB-T2 is the
UK, launched in March 2010.
 Launched
in Italy, Sweden, and Finland in 2010
and 2011.

Outside of Europe DVB-T2 pay-TV services were
launched in Zambia, Nigeria, Kenya.
 Trials
are currently taking place across the globe, it
is thought to be installed in India by 2014.
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5. Multiple
TS or
GS
streams
Up to 255 input streams
Input
processing
Bit interleaved
coding &
modulation
COFDM
generation
Input
preprocessor(
s)
Frame
builder
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7.  Enable
the transport of data independent of its
structure.
 Both
the allocated capacity and the robustness can
be adjusted.
 Two
general modes are defined.
Fig. Different PLP's occupying different time slices
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8.  Most
simple mode can be viewed as a
straightforward extension of DVB-T.
 Not
sub-divided into multiple PLPs.
 Only
a single PLP is used, transporting a single
transport stream.
 The
same robustness is applicable to all content.
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9.  This
more advanced mode of operation applies the
concept of multiple physical-layer pipes.
 Service -specific robustness.
 Offers potentially longer time-interleaving depth
as well as the option of power saving in the
receiver.
Fig. T2- frame for single RF
channel, multiple PLP mode (here: 5
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PLPs)

10.  The
initial symbols of a DVB-T2 physical-layer
frame are preamble symbols.
 The frame starts with the highly robust
differentially BPSK-modulated P1 symbol, with
guard intervals at both ends.
 P2 symbols provide all static, configurable and
dynamic layer-1 signalling.
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11. 
Bit interleaver after FEC based on a LDPC word.
 Cell
interleaver after mapping based on a FEC frame.
 Time
interleaver after cell interleaver based on a TI frame.
 Frequency
interleaver before IFFT based on a symbol
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13.  Bit
interleaver interleaves code bits in a LDPC
word.
 Cell interleaver interleaves mapped I Q values in a
FEC frame.
 Time interleaver is a protection against long
impulsive interferers.
 Frequency interleaver is a protection against
frequency selective interferers (e.g. notches).
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17.  Largest
entity of a DVB-T2 system.
 Carries
T2-frames and may also carry FutureExtension Frame (FEF).
 The
maximum number of T2-frames in a super
frame is 255.
 The
maximum length of a T2-frame is 250 ms and
the maximum length of a FEF part is 250 ms.
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18.  T2-frame
consists of a P1 symbol and a
configurable number of data symbols.
Fig. Structure of the T2-frame
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19. DVB-T
Transport
Input interface
stream
Modulation
64-QAM
FFT size
8K
Guard Interval 1/4
FEC
CC + RS
Carrier mode Standard
Capacity
19 Mbit/s
DVB-T2
Transport and
generic stream
256-QAM
32 K
1/16
LDPC + BCH
Extended
33 Mbit/s
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20.  The
availability of the DVB-T2 standard brings
new opportunities for the terrestrial television
delivery platform.
 Broadcasters
consider offering new services on the
DTT platform which would have been difficult
given the limited frequency capacity available in
the VHF and UHF frequency bands.
 It
can be expected that the DVB-T2 standard will
be relevant for many years into the future.
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