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Press F1 key to get detailed channel parameter information. The channel parameter
table shows in Figure 4.3.12.
On the screen you will see the following parameters:
a) DVB bandwidth – channel bandwidth;
b) Spectrum – spectrum type: inverted or normal;
c) Guard interval – guard interval relative duration;
d) Hierarch mode – hierarchical modulation mode;
e) Code rate (HP) – high priority stream relative code rate;
f) Code rate (LP) – low priority stream relative code rate (for hierarchical modulation
only);
g) TPS cell ID – transmitter ID in hexadecimal format.
Press
key to return to MER/BER measurement mode.
AMP power supply, is controlled by pressing the
4.3.7 CONSTELLATION measurement mode
This measurement mode is selected from MER/BER mode by pressing the F2 key.
This mode displays the DVB-T channel constellation diagram. See Figure 4.3.13:
On the screen you will see the following data:
1 – Channel number
2 – Quadrant marker
3 – Channel name (when working with selected channel plan)
4 – Demodulator status
5 – Status of AMP power supply (Section 4.3.8)
6 – MER value in dB
7 – preBER value
8 – postBER value
9 – Diagram zoom scale choosing key
When there is no synchronization with the channel, constellation diagram is empty.
After synchronization is achieved, quadrature modulation points is displayed on the
diagram. For example: for QAM64 subcarrier modulation 64 points of data subcarriers and
16
Figure 4.3.12
key briefly (section 4.3.8).
Figure 4.3.13
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