L64724 LSI Logic Corporation, L64724 Datasheet - Page 172

• Manufacturer Part Number: L64724
• Description: Satellite Receiver
• Manufacturer: LSI Logic Corporation

Figure 7.1
Modem Format
7.1.1 Features
7-2
Code Rate
Symbol 0
Symbol 1
ImQ
Viterbi Decoder Block Diagram
The Viterbi decoder module has the following features:
The FEC Decoder Pipeline
Depuncture
Module
A Viterbi Decoder with a basic rate of 1/2
Compliant with European Digital Video Broadcast (DVB-S)
Depuncturing for code rates of 2/3, 3/4, 5/6, 6/7 and 7/8
Compliant with DVB and DSS channel coding specifications
Programmable Viterbi code rates of 1/2, 2/3, 3/4, 5/6, 6/7, 7/8
Auto code rate, phase inversion, synchronization for Viterbi decoder
with programmable threshold
Auto-rate acquisition over the DVB and DSS code range
Rate detection over the DVB code range
Constraint length of 7
Synchronization monitor
Decoded BER monitor
Maximal Likelihood (ML) decoding algorithm
5.2 dB coding gain for rate 1/2 (no erased input) code at BER of 10
Generating Polynomial 171 (Octal) and 133 (Octal)
(Rate = 1/2)
Decoder
Viterbi
Control
Monitor
Monitor
Sync
BER
Sync
Status
Decoded
Data
Bit Error
Rate
-5