axing MIE 8-00 Betriebsanleitung Seite 110

Operation instructions | MIE 8-00 | MIE 16-00 | MIE 32-00 | MIE 4-02 | MIE 8-02 | MIE 3-02 | MIE 6-02
 Make the required changes.
 Click SAVE for each modulator.
Only then the changes will be saved, otherwise the changes will be lost.
Parameters:
Common Output level
Norm
Output Channel
DVB-T2 Constallation
FEC Coderate
Bandwidth
Guard Interval
Transmission Modes
FEC length
L1-Post Constellation
Pilot Pattern
Fine Level
Fine Tune
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The Common Output Level option include a general attenuation of all modulator outputs. The
highest output level is reached with a setting of 20 dB, the lowest level with a setting of 0 dB.
In this selection field, you can set the norm for the output channel spacing.
Note: Changing the norm works now according to following rules:
•
CCIR-->Australia : all modulators forced to 7MHz
•
Australia-->CCIR : all modulators forced to 8MHz, however with following exception: low
channels S2-S20 are 7MHz only, so those remain in 7MHz
Each of the modulators can be set to any output channel. No output channel may be selected
more than once!
The modulation can be adjusted to the following methods:
•
QPSK (2 bit) – small data rate – very robust signal.
•
QAM 16 (4 bit) - low data rate.
•
QAM 64 (6 bit) - middle data rate.
•
QAM 256 (8 bit) - high data rate.
Thanks to the error correction, errors resulting from high-disturbed transmission routes can be
balanced by restoring data. The data required to restore the signal are included in the transmitted
FEC bits.
Changing the FEC factor modifies the part of the FEC data in relation to the application data (1/2,
3/5, 2/3, 3/4, 4/5, 5/6). A higher part of FEC data means an higher transmission redundancy. But
this reduces the bandwidth for the useful data too.
•
FEC 1/2 - small data rate - strong protection against errors.
•
FEC 5/6 - high data rate - weak protection against errors.
If CCIR is selected as the Norm, the bandwidth of the channels can be changed. With a larger
bandwidth, more data can be transmitted in one channel.
By adjusting the bandwidth, the channels no longer correspond to the channel grid specified by
the Norm.
A guard interval is transmitted between the transmitted symbols of the useful signal. The guard
interval protects against inter-symbol interferences.
A very long guard interval (e.g. 1/4) leads to a very low data rate. A small guard interval is usually
sufficient for transmission in a coaxial distribution network.
The transmission mode can be set between 1k and 8k (ext). 8k (ext) allows the shortest guard
interval and the highest data transmission.
An FEC frame with 64k FEC length or a (short) one with 16k FEC length can be configured.
The L1 post signaling contains parameters that provide information to the receiver. Constellation
types BPSK, QPSK, QAM16 and QAM64 can be configured for L1 post signaling.
L1 pre-signalling is always BPSK modulated.
Depending on the Guard Interval and the transmission mode, Pilot Pattern PP1 to PP8 can be
selected.
The level fine adjustment attenuates the output level of each individual modulator output
separately from 0 to -3 dB.
In addition, each modulator output can be disabled (Off option).
The fine tuning of the output channel is performed in 0.5 MHz steps.
BA_MIE.pdf | Technical improvements, changes in design, printing- and other errors reserved. | 2022-05-31