Comtech EF Data DMD-2050E User Manual
Page 97
DMD2050E Universal Satellite Modem
Theory of Operation
MN-DMD2050E Revision 2
3–55
Table 3-3. Comparison of all Comtech EF Data TPC and LDPC Modes
(DMD2050E with LDPC/TPC Codec)
Mode
Eb/No at
BER = 10
-6
(typical)
Eb/No at
BER = 10
-8
(typical)
Spectral Efficiency
(bps per Hertz)
Symbol Rate
Occupied * Bandwidth
for 1 Mbps Carrier
QPSK Rate 1/2 Viterbi *
5.5 dB
6.8 dB
1.00 bps/Hz
1.0 x bit rate 1190 kHz
BPSK Rate 1/2 LDPC
1.7 dB
1.9 dB
0.50 bps/Hz
2.0 x bit rate 2380 kHz
BPSK Rate 21/44 TPC
2.8 dB
3.0 dB
0.48 bps/Hz
2.1 x bit rate 2493 kHz
BPSK Rate 5/16 TPC
2.4 dB
3.0 dB
0.31 bps/Hz
3.2 x bit rate 3808 kHz
QPSK/OQPSK Rate 1/2 LDPC 1.7 dB
1.9 dB
1.00 bps/Hz
1.0 x bit rate 1190 kHz
QPSK/OQPSK Rate 21/44 TPC 2.8 dB
3.3 dB
0.96 bps/Hz
1.05 x bit rate 1246 kHz
QPSK/OQPSK Rate 2/3 LDPC 2.1 dB
2.4 dB
1.33 bps/Hz
0.75 x bit rate 892 kHz
QPSK/OQPSK Rate 3/4 LDPC 2.7 dB
2.9 dB
1.50 bps/Hz
0.67 x bit rate 793 kHz
QPSK/OQPSK Rate 3/4 TPC
3.4 dB
4.0 dB
1.50 bps/Hz
0.67 x bit rate 793 kHz
QPSK/OQSK Rate 7/8 TPC
4.2 dB
4.3 dB
1.75 bps/Hz
0.57 x bit rate 678 kHz
QPSK/OQPSK Rate 0.95 TPC 6.0 dB
6.5 dB
1.90 bps/Hz
0.53 x bit rate 626 kHz
8-PSK Rate 2/3 TCM **
and RS (IESS-310)
5.6 dB
6.2 dB
1.82 bps/Hz
0.56 x bit rate 666 kHz
8-QAM Rate 2/3 LDPC
4.3 dB
4.6 dB
2.00 bps/Hz
0.50 x bit rate 595 kHz
8-QAM Rate 3/4 LDPC
4.7 dB
5.0 dB
2.25 bps/Hz
0.44 x bit rate 529 kHz
8-PSK/8-QAM Rate 3/4 TPC
6.1 dB
6.7 dB
2.25 bps/Hz
0.44 x bit rate 529 kHz
8-PSK/8-QAM Rate 7/8 TPC
6.7 dB
6.9 dB
2.62 bps/Hz
0.38 x bit rate 453 kHz
8-PSK/8-QAM Rate 0.95 TPC 9.2 dB
10.2 dB
2.85 bps/Hz
0.35 x bit rate 377 kHz
16-QAM Rate 3/4 LDPC
6.7 dB
6.8 dB
3.00 bps/Hz
0.33 x bit rate 396 kHz
16-QAM Rate 3/4 TPC
7.4 dB
8.1 dB
3.00 bps/Hz
0.33 x bit rate 396 kHz
16-QAM Rate 7/8 TPC
7.9 dB
8.1 dB
3.50 bps/Hz
0.28 x bit rate 340 kHz
16-QAM Rate 3/4 **
Viterbi/Reed-Solomon
7.5 dB
8.0 dB
2.73 bps/Hz
0.37 x bit rate 435 kHz
16-QAM Rate 7/8 **
Viterbi/Reed-Solomon
9.0 dB
9.5 dB
3.18 bps/Hz
0.31 x bit rate 374 kHz
* The occupied bandwidth is defined at the width of the transmitted spectrum taken at the –10 dB
points on the plot of power spectral density. This equates to 1.19 x symbol rate for the
DMD2050E transmit filtering.
** Included for comparative purposes