Comtech EF Data SDM-300A - Manual (Page 374)

SDM-300A Satellite Modem Revision 6
Specifications MN/SDM300A.IOM
19–18
19.6.1 Performance with Noise, Viterbi Decoder, and Open Network Mode
Table 19-10 lists the Viterbi specifications for the E
b
/N
0
required to achieve 10 -3 to 10 -8
BER
for different coding configurations. All values are for operating in QPSK mode. Without
coding, the modem provides QPSK operation within 0.8 dB of theoretical for BER in the
range 10
-1 to 10 -6 . Performance measurements were recorded with transmit and receive IF
connected back-to-back through an additive white Gaussian noise channel.
Table 19-10. Viterbi Decoder with Open Network BER Data
Eb/N0 (dB) Specification
BER 1/2 Rate 3/4 Rate 7/8 Rate
10-3 4.2 5.2 6.4
10-4 4.8 6.0 7.2
10-5 5.5 6.7 7.9
10-6 6.1 7.5 8.6
10-7 6.7 8.2 9.2
10-8 7.2 8.8 9.9
19.6.2 Performance with Noise, Viterbi Decoder, and Closed Network
Table 19-11 lists the Viterbi with Closed Network specifications for the E
b
/N
0
required to
achieve 10 -5 to 10 -10 BER for different configurations.
Table 19-11. Viterbi Decoder with Closed Network BER Data
Eb/N0 (dB) Specification
BER 1/2 Rate 3/4 Rate 7/8 Rate
10-3 3.8 4.9 6.1
10-4 4.6 5.7 6.9
10-5 5.3 6.4 7.6
10-6 6.0 7.2 8.3
10-7 6.6 7.9 8.9
10-8 7.2 8.5 9.6