Slm-5650B Processing Flow And Symbol Rate Calculation - Comtech EF Data SLM-5650B Installation And Operation Manual

E.2

SLM-5650B Processing Flow and Symbol Rate Calculation

The SLM-5650B supports both serial and Ethernet interfaces, and provides options for framing,
modulation and spreading. Figure E-1 shows the processing flow for these functions when the
SLM-5650B 'J6 EIA530' rear panel connector and the optional Network Processor Module's Port
'1' are used for the Serial and Ethernet interfaces, respectively.
The symbol rate S
with FEC encoding, modulation, and transport overhead factors as shown in the equation
S =B /M C F
"
R R O R
Operands:
•
M
Operand 1 –
O
•
C
Operand 2 –
R
FEC code rate = "3/4")
•
F
Operand 3 –
RS
F = (n/k)
o
RS
F = 1
o
RS
•
F
Operand 4 –
c
F = 15/16
o
C
F = 32605/32768
o
C
F = 1
o
C
Only one of these two features (AUPC Mode or ACPC Mode) may be enabled
at any given time.
Appendix E
Figure E-1. SLM-5650B – Feature Block Diagram
(Carrier 3dB Bandwidth) is a function of the programmed data bit rate B
R
"
F F
(referred to hereafter as "Equation 1"), containing the following
RS T C
= Modulation Order
= Code Rate of the Forward Error Correction (FEC) (e.g., CR = 0.75 if stated
= Reed Solomon Framing Factor, where:
where (201,219) is default RS for MIL-165A
where the RS is disabled.
= CnC AUPC Mode or ACPC Control Framing Factor, where:
if AUPC Mode is enabled;
if ACPC Mode is enabled;
if neither feature is enabled.
'1' if BPSK
'2' if QPSK
'3' if 8PSK
'4' if 16QAM
E–2
SLM-5650B Satellite Modem
Revision 2
R
MN-SLM-5650B