4RF Aprisa SR+ User Manual - page 110
108 | Managing the Radio
Aprisa SR+ User Manual 1.5.3
ADAPTIVE CODING MODULATION
These settings are only used if the ACM Control is set to Enabled and only apply to the base to remote
direction of transmission (downstream).
Modulation Range
This parameter sets the upper limit of the range that the base station will recommend to the remote
radios.
The lower limit is fixed to QPSK (High Gain).
MODEM - Remote Station
Modulation Type
The remote to base / base-repeater / repeater direction of transmission can be adaptive modulation or
fixed modulation.
This parameter sets the TX Modulation Type for the remote station radio.
Option
Function
Adaptive
Sets the modulation type to Adaptive Code Modulation.
The remote radio receives the modulation type recommendation
from the base / base-repeater / repeater station and adjusts the
modulation and FEC code rate in the remote to base / base-
repeater / repeater direction of transmission (upstream) if the
modulation type recommendation is within the defined Modulation
Range (see Modulation Range setting below).
If the recommendation is outside the defined Modulation Range,
the upper limit is used for the remote radio.
QPSK (High Gain)
Sets the modulation to QPSK with Max Coded FEC.
QPSK (Low Gain)
Sets the modulation to QPSK with Min Coded FEC.
QPSK
Sets the modulation to QPSK with no FEC.
16QAM (High Gain)
Sets the modulation to 16 QAM with Max Coded FEC.
16QAM (Low Gain)
Sets the modulation to 16 QAM with Min Coded FEC.
16QAM
Sets the modulation to 16 QAM with no FEC.
64QAM (High Gain)
Sets the modulation to 64 QAM with Max Coded FEC.
64QAM (Low Gain)
Sets the modulation to 64 QAM with Min Coded FEC.