Comtech EF Data Vipersat SLM-5650A, Инструкция по установке и эксплуатации

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SLM-5650A Satellite Modem
Revision 10
Specifications 2–9 MN-SLM-5650A
2.2.7 Sequential Decoding with/without Reed-Solomon
Table 2-16. Sequential Decoding
with / without Reed-Solomon BER Performance
E
b
/N
o
(dB) Specifications
Sequential Decoder with / without Reed-Solomon
DESCRIPTION BER
BPSK QPSK/OQPSK
1/2 1/2 3/4 7/8
Sequential – 64 kbps
10
-5
4.8 4.8 5.8 7.0
10
-6
5.2 5.2 6.4 7.5
10
-7
5.6 5.6 6.9 8.0
Sequential – 1544 kbps
10
-5
5.2 5.2 5.9 7.2
10
-6
5.7 5.7 6.5 7.7
10
-7
6.1 6.1 7.0 8.3
SeqRS (225,205)
10
-6
4.4 4.4 5.0 5.6
10
-7
4.6 4.6 5.3 6.0
10
-8
4.8 4.8 5.6 6.4
2.2.8 BER Performance with Symmetrical or Asymmetrical Adjacent
Carriers
Symmetrical Adjacent Carriers
Operating in the presence of two adjacent symmetrical carriers (one lower in frequency and one
higher in frequency with same modulation, data rate, and coding), the modem performance is not
degraded more than as indicated in Table 2-17 Column 3, and a) and b) in this section. This
performance is measured with the adjacent carrier’s center frequencies offset X
R
s
Hz from the
center frequency of the carrier under test, where X is the spacing factor and R
s
is the modulation
symbol rate in Hz of the symmetrical carriers.
The BER of the test carrier is measured at the specified carrier Ratio of Energy per Symbol to
Noise Power Density in a 1 Hz Bandwidth (E
s
/N
0
) Carrier to Noise Ratio (C/N) without the
adjacent carriers. The adjacent carriers are applied at the specified center frequencies and E
s
/N
0
and the BER of the test carrier is measured. The change in BER is equal to the change in E
b
/N
0
based on the characterization curve of the test carrier and the amount of Adjacent Channel
Interference (ACI) degradation. For modulation symbol rates below 38.4 ksps, this paragraph
does not apply.
For X (spacing factor) = 1.2, the symmetric degradation shall be IAW one of the values in Table
2-17 Column 3, and corresponding test carrier E
s
/N
0
in Column 1. Select a test carrier E
s
/N
0
that
will yield timely results based on modulation and coding used in the test configuration. The
adjacent carriers E
s
/N
0
shall be set to corresponding value in Column 2.
For the case of X (spacing factor) = 1.4, the degradation is less than 0.2 dB.