Product Manual

20 | Introduction
Aprisa SR+ Product Description 1.5.0
System Gain vs FEC Coding
This table shows the relationship between modulation, FEC coding, system gain, capacity and coverage.
 Maximum FEC coding results in the highest system gain, the best coverage but the least capacity
 Minimum FEC coding results in lower system gain, lower coverage but higher capacity
 No FEC coding results in the lowest system gain, the lowest coverage but the highest capacity
This table defines the modulation order based on gross capacity:
Modulation
FEC Coding
Capacity
QPSK (High Gain)
Max Coded FEC
Minimum
QPSK (Low Gain)
Min Coded FEC
16QAM (High Gain)
Max Coded FEC
QPSK
No FEC
16QAM (Low Gain)
Min Coded FEC
16QAM
No FEC
64QAM (High Gain)
Max Coded FEC
64QAM (Low Gain)
Min Coded FEC
Maximum
This table defines the modulation order based on receiver sensitivity:
Modulation
FEC Coding
Coverage
QPSK (High Gain)
Max Coded FEC
Maximum
QPSK (Low Gain)
Min Coded FEC
16QAM (High Gain)
Max Coded FEC
QPSK
No FEC
16QAM (Low Gain)
Min Coded FEC
64QAM (High Gain)
Max Coded FEC
16QAM
No FEC
64QAM (Low Gain)
Min Coded FEC
Minimum