Comtech EF Data DMD1050TS - Basic Setup (Example; Table I-1. ITA Waveforms and Selection

DMD1050TS Satellite Modem Board
Revision 1
Appendix I I–2 MN-DMD1050TS
I.1.2 Basic Setup (Example)
The modems will be initially configured in the lowest modulation and coding rate for the
characteristic of the link. ITA uses a combination or composite data rate (serial + Ethernet) that
will allow selection of any ITA waveforms. This means that all combinations of modulation and
code rate have enough Ethernet bandwidth to achieve proper configuration and that all
modulation and code rates are of the same block size. The setup will cover each of the four
modulations and each of the five code rates by selecting various combinations. Table I-1 is a rank
ordering of modulation and coding rates entered by the operator, by Es/No requirement. The
bits/Symbol provides an indication of the efficiency of the particular combination selected. The
test case ITA waveforms are shown in Table I-1.
Table I-1. ITA Waveforms and Selection
Modulation Code Rate Bits/Symbol
Typical
Eb/No
Required
Es/No
Selected
Test Cases
16APSK 0.95 3.800
10.25 16.05 *
8PSK
0.95 2.850 9.31 13.86
16APSK 0.875
3.500 8.40 13.84 *
8PSK 0.875 2.650 7.50 11.69
16APSK 0.75 3.000 6.59
11.37
16APSK 0.667 2.667 5.64 9.90
8PSK 0.75 2.250 5.64 9.16 *
QPSK 0.95 1.900 6.18 8.96
8PSK 0.667 2.000 4.70 7.71
QPSK 0.875 1.750 4.81
7.24
16APSK 0.5 2.000 4.01 7.02 *
BPSK 0.95 0.950 6.12 5.90
QPSK 0.75 1.500 3.55 5.31
8PSK 0.5 1.500 3.16 4.92
QPSK
0.667 1.330 2.97 4.22 *
BPSK 0.875 0.875 4.78 4.20
BPSK 0.75 0.750 3.52 2.27
QPSK 0.5 1.000 2.07 2.07
BPSK 0.667 0.667 2.95 1.19 *
BPSK 0.5 0.500 2.06 -0.95
Initial configuration is the lowest modulation and coding combination. In this example, the lowest
combination is the BPSK Turbo 2/3 Rate. Selecting a serial rate of 2048k and a symbol rate of
640k allows all possible combinations (except BPSK 1/2, which will be relevant later), to be
achieved within a common block size. The initial configuration was selected from the initial
modem setup parameters, as shown in Table I-2. The ITA configuration is then entered in the
web screens, as shown in Figure I-1 through Figure I-6.