TX/RX Spacing
Displays the value by which the TX and RX Frequency is separated, so that when you
specify a transmit frequency, the frequency will be offset by the receiver spacing shown.
RF Band
Displays the RF Band of the ODU.
Serial Number
Displays the serial number of the ODU.
Cable
Equalizer
Select the length of cable you are using:
0–87m
,
87–174m
, or
174–260m
to adjust for cable
loss which typically is 22 dB at 350 MHz. The equalizer is calibrated for LMR-400 and LDF4-
50A cables.
3.4.6 Determining Overall System Capacity Versus Bandwidth
Referring to the figures in
Section 3.4.3
and
Section 3.4.4
, your system throughput (
Sys TP
) is
calculated by the values that you specify in the
Symbol Rate
and
Modulation
fields.
Use the following table to determine the maximum allowed symbol rate to match the allowed
channel bandwidth. For example, if you choose a
Symbol Rate
of
23.0
and a modulation of
16QAM
,
Sys BW
displays
89.0 Mbps
.
Channel
Bandwidth
(MHz)
Maximum
Symbol Rate
(Msps)
Maximum Net Data Rate (Mbps) for
Each Modulation Scheme (
Sys TP
)
QPSK
16QAM
32QAM
64QAM
7
5.7
11.0
22.0
28.0
31.0
10
8.2
14.8
29.9
37.3
44.5
14
11.5
22.0
44.0
56.0
62.4
20
16.4
29.5
59.8
74.6
89.0
28
23.0
44.0
89.0
112.0
132.0
30
24.6
44.3
89.7
111.9
134.0
40
32.8
59.0
119.6
149.2
178.6
For optimal performance, utilization should not exceed 98%; if it does, the number turns red to
indicate an overload that you should correct. You can use the following formula to calculate the
utilization of the DXL8000:
Utilization %
= total of the 4
Data Rates
I
Sys Bw
x 100
Carefully select the
Symbol Rate
,
Modulation
scheme and required transmission
Data Rate
. For
example, if you have a
Sys Bw
40
Mbps and choose a
Data Rate
of
20
Mbps for the type of
input in
Core Channel 1
, the
Utilization %
displays 50%, meaning that you can add another
channel as long as the combined data rates do not cause the
Utilization %
to exceed 95%. A
high speed license is required for symbol rates greater than 20.
3-10 Operating the DXL8000
DXL8000 User and Technical Manual
Summary of Contents for DXL8000
Page 45: ......
