MO-180 DVB-T and DVB-H modulator0 pages

DVB-T/H BROADCASTING 11 >

MO-180 DVB-T/H Modulator for SFN & MFN Broadcasting

DVB-

Built-in Precorrector SNMP compatible

DVB-

10 MHz GPS reference input. 6 dBm output power (option)

The MO-180 is an SFN/MFN DVB-T/H modulator fully compliant with
the DVB-T/H specifications ETSI EN
300 744 v1.5.1 (including annex Freferring to DVB-H), ETSI TS 101191 v1.4.1 (SFN synchronisation)
and ETSI EN 300 468 v1.6.1
(DVB-SI). The unit is contained in anstandard 19 1U chassis.The modulator has two DVB-ASITransport Stream (TS) inputs and
one DVB-SPI TS input. It also has a
1 pps and a 10 MHz input which,
together with the MIP packet embed-ded in the transport stream, are usedfor SFN synchronisation purposes. A
loop-through 10 MHz output is
available as well.In MFNs we can operate the modu-lator in master and slave modes. Inslave mode the modulator is locked
to the incoming TS data rate, which
is defined in document ETSI EN 300744 for each choice of DVB-T/Htransmission parameters. In master
mode the modulator is locked to
either the internal 10 MHz TCXO or
to an external 10 MHz reference.
The input bit rate has to be strictlysmaller than the value given in theDVB-T/H specification. The sync with the external 10 MHz
reference can be used to make the
modulator lock to the input TS rate,
and vice versa. This means thatdisruptions to the output IF/RFCOFDM signals are minimised.
Periodic or aperiodic MIP packets
are constantly monitored so as todynamically adjust the delay of themodulator. In non-hierarchical
transmissions the modulator seam-
lessly switches between ASI inputs
when it detects a sync loss on thecurrently selected TS input. An addi-tional test TS can be generated
internally. This allows to generate
compliant. DVB-T/H signals even in
the absence of a valid TS input. The channel bandwidth can be set to
5, 6, 7 and 8 MHz with no variation in
performance. The DVB-T/H signal is
output in both IF (36 MHz, 0 dBm)and RF (45 MHz to 875 MHz, at-27 dBm with the option of going up
to 6 dBm) with a resolution of 1 Hz.
The polarity of the spectrum may be
set to normal or inverted. The MO-180 supports 2k, 4k and 8kmodes and non-hierarchical and hie-
rarchical transmissions. Several test
modes are available (blanking of
carriers, single tone output, test TSgeneration, CBER and VBER injec-tion). The MER typically measured in
IF is above 41 dB. In RF we measure
MERs greater than 35 dB. MO-180 drops or inserts NULL TS packets as
required to adapt the bit rate to therequired value. PCR re-stamping is implemented tominimise the impact of the bit rate
adaptation process on the timing
jitter of the MPEG-2 TS multiplex.In SFN mode, the modulator can besynchronised with the external 10MHz GPS reference or with the
incoming TS data rate. A loss of >

PID Filtering

Transport streams coming from satellite receivers (QPSK) contain normally a
high number of services and have too high bit rate to be connected to aCOFDM modulator directly. MO-180 dedicatedmenu. The selected services are filtered and will not be modulated. MO-180 has a PID FILTERING function. This allows to enter a high speedtransport stream, coming from a satellite receiver for instance, to the modulator
ASI input at once. It is possible then to select a certain number of services from
the original transport stream by entering their PIDԒs on the >
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