Advantech AMT-70, Installation And Operation Manual, Page: 138 / 160

AMT-70/AMT-73/AMT-75 Installation and Operation
A.2.7 Input Level Range Versus Symbol Rate
The composite input power range for the AMT-70L and the AMT-73L is dependant on the Symbol Rate
of the incoming data. (Remember, Symbol Rate is the transmitted data rate, and is dependant on Data
Rate, FEC Code Rate, and Modulation scheme. To calculate the Symbol Rate, the formula is as
follows:)
Symbol Rate
=
Data rate
x
1
/
Code Rate
Modulation
Where Modulation = 1 for BPSK; 2 for QPSK; 3 for 8PSK, and 4 for 16QAM
The charts below provide the range of input power versus data rate for the AMT-70L and the AMT-73L
modems.
AMT-70L Demod IF Carrier versus Symbol Rate
AMT-73L Demod IF Carrier versus Symbol Rate
138
-70.0
-60.0
-50.0
-40.0
-30.0
-20.0
-10.0
0.0
10 100 1000 10000 100000
Desired Carrier Symbol Rate (ksps)
D
esi
red C
a
rri
er
I
n
p
u
t L
evel
(
dB
m
)
Maximum
Nominal
Minimum