L64780 LSI Logic Corporation, L64780 Datasheet - Page 15

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

Figure 1.3
UHF/VHF
L-band
Receiver Architecture for Satellite and Terrestrial Reception
Terrestrial Tuner
Satellite Tuner
Figure 1.3
combined in one unit. For satellite reception, the IF signal (for example,
from 1 to 2 GHz) from the dish unit is fed into a satellite tuner. This tuner:
1. Selects one RF signal from the 1 to 2 GHz range
2. Converts the signal to one or more intermediate frequencies
3. Down-converts the signal to base band
4. Feeds its I and Q components into the L64724 single-chip DVB-S
The L64724:
1. Samples the I and Q baseband signals
2. Demodulates the QPSK
3. Processes the error correction functions
The L64724 also implements a bypass of the ADC and demodulation
functions. Thus, it can accept the soft decisions delivered by L64780 and
feed them directly to the Viterbi decoder. This architecture implements a
cost-effective solution for mixed satellite and terrestrial front-ends.
RF Tuner Block Functions
satellite receiver
illustrates how terrestrial and satellite reception can be
L64780
L64724
MPEG Transport Stream
1-5