L64780 LSI Logic Corporation, L64780 Datasheet - Page 18

• Manufacturer Part Number: L64780
• Description: Dvb-t Cofdm Demodulator Technical Manual 2/00
• Manufacturer: LSI Logic Corporation

1-8
Figure 1.5
point indicated by “carriers coincident about here” shows the point where
the vision carrier of the PAL-I signal lines up directly with one of the
carriers on the ODFM frequency raster.
Figure 1.5
Figure 1.6
demodulator. The graph shows that in the selected mode, the
demodulator works without failure inside the guard interval and without
failure significantly outside it.
Figure 1.6
Introduction
10
12
10
2
0
2
4
6
8
0
2
4
6
8
2500
64 QAM Rate 2/3
16 QAM Rate 3/4
QPSK Rate 1/2
0 10 20 30 40 50 60 70 80 90 100
No failure for echo here.
illustrates the target protection ratio of PAL-I into DVB-T. The
illustrates the maximum level of echo acceptable to the
DVB-T Carrier to Co-channel PAL-I Interference Ratio
for Failure
Maximum Level of a Single Echo for Failure of QPSK,
Rate 1/2, Guard Interval 7
1500
Normal Frequency Offset (Hz)
Carriers coincident
about here
Delay ( s)
500
500
1500
2500
Less Robust
More Robust