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FEC
Transmit filtering
Scrambling
External Reference
Harmonics/spurious
Transmit on/off ratio
Output phase noise
Introduction
VersaFEC Codec:
Rate 0.488 BPSK (also 0.493 BPSK Ultra-Low-Latency)
Rate 0.533, 0.631, 0.706, 0.803 QPSK (0.493, 0.654, 0.734 Ultra-Low-Latency)
Rate 0.642, 0.711, 0.780 8-QAM (also 0.576 8-QAM Extended CCM)
Rate 0.731, 0.780, 0.829, 0.853 16-QAM (also 0.644 16-QAM Extended CCM)
VersaFEC-2 Long-Block Codec:
Rate 0.489 BPSK
Rate 0.489, 0.537, 0.586, 0.611, 0.635, 0.660, 0.684, 0.733 QPSK
Rate 0.521, 0.537, 0.562, 0.586, 0.611, 0.635, 0.660, 0.684, 0.708, 0.733 8-ARY
Rate 0.586, 0.611, 0.635, 0.660, 0.684, 0.708, 0.733, 0.757, 0.782 16-ARY
Rate 0.660, 0.684, 0.708, 0.733, 0.757, 0.782, 0.801, 0.831, 0.855, 0.879 32-ARY
VersaFEC-2 Short-Block Codec:
Rate 0.489 BPSK
Rate 0.489, 0.537, 0.586, 0.611, 0.635, 0.660, 0.684, 0.733 QPSK
Rate 0.521, 0.537, 0.562, 0.586, 0.611, 0.635, 0.660, 0.684, 0.708, 0.733 8-ARY
Rate 0.586, 0.611, 0.635, 0.660, 0.684, 0.708, 0.733, 0.757, 0.782 16-ARY
Rate 0.660, 0.684, 0.708, 0.733, 0.757, 0.782, 0.801, 0.831 32-ARY
Root-Raised Cosine, alpha = 0.05, 0.10, 0.15, 0.20, 0.25, and 0.35 – front panel/software selectable
See graphs of output spectrum provided at the end of this section
All VersaFEC
, VersaFEC-2
®
®
As an input: 1, 2, 5 or 10MHz -6dBm to +10dBm (nominal 50/75 Ω, BNC female connector)
As an output: 10MHz, 2.7 volts peak-to-peak ±0.4 volts, low impedance output
(The Ext. reference phase locks Tx and Rx synthesizers, and all baseband clock generation)
Better than -60 dBC/4 kHz (typically <-65 dBC/4kHz)
950-2250 MHz band: measured F
50-180 MHz band: measured from 1 to 500 MHz
-60 dBC minimum
< 0.48
rms double sided, 100 Hz to 1MHz (minimum of 16 dB better overall than the INTELSAT
0
IESS-308/309 requirement)
dB/Hz
Frequency Offset
-63.0
100 Hz
-73.0
1 kHz
-83.0
10 kHz
-93.0
100 kHz
Fundamental AC line spurious is -42 dBc or lower
The sum of all other single sideband spurious, from 0 to 0.75 x symbol rate, is -48 dBc or lower
modes use IESS-315/V.35
±500 MHz
0
1–15
CDM-425 Advanced Satellite Modem
MN-CDM-425
Revision 0
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