Comtech EF Data SDM-100A - Manual (Page 201)

SDM-100A Satellite Modem Options
Rev. 0 B–19
B.3 Reed-Solomon Codec
The Reed-Solomon Codec firmware works in conjunction with the interface card to
provide concatenated, convolutional encoding and decoding.
Refer to Figure B-4 for a block diagram of the Reed-Solomon Codec.
The two main sections of the Codec that will be included in the theory of operation are
the Reed-Solomon encoder (Section B.3.2.1) and the Reed-Solomon decoder
(Section B.3.2.2).
CHASSIS
INTERFACE
CDR DATA LOOPBACK
TX DATA
TX CLK
MUXDATA
MUX CLK
INTERFACE
PCB
MUX
CDR CLK
DECDATA
OVERHEAD
PROCESSOR
RX
DATA
LOOPBACK
MUX
DMXDATA
DMX CLK
RX CLK
DEC CLK
REED-SOLOMON
Figure B-4. Reed-Solomon Codec Block Diagram
B.3.1 Reed-Solomon Encoder
A block diagram of the Reed-Solomon encoder section is shown in Figure B-5.
The Reed-Solomon encoder section includes the following circuits:
• Synchronous Scrambler • Serial/Parallel Converter
• Reed-Solomon Codec • Parallel/Serial Converter
• Synchronous First In/First Out • Interleaver