Product specifications

CDD-880 Multi Receiver Router Revision 0
Forward Error Correction MN-CDD880
6–2
Figure 6-1. The VersaFEC Codes versus Shannon Capacity
There are 12 ModCods in the VersaFEC set (Table 6-1). T
he modulation types (BPSK,
QPSK, 8-QAM and 16-QAM) and the code rates have been chosen to give a continuous
progression of performance in terms of both Eb/No and spectral efficiency – an essential
aspect of a well-engineered ACM system.
Table 6-1. The VersaFEC ModCod Set
Modulation Code Rate
Spectral
Efficiency,
bps/Hz
Block
size, bits
Typical
Eb/No, for
BER = 5 x 10
-8
Latency at
64 kbps, in
milliseconds
Min. Data
Rate,
CCM mode
Max. Data
Rate,
CCM mode
BPSK 0.488 0.49 2k 2.4 dB 26 16 kbps 2.19 Mbps
QPSK 0.533 1.07 4.1k 2.2 dB 53 18 kbps 4.80 Mbps
QPSK 0.631 1.26 4.1k 2.7 dB 59 21 kbps 5.67 Mbps
QPSK 0.706 1.41 4.1k 3.4 dB 62 23 kbps 6.34 Mbps
QPSK 0.803 1.61 4.1k 3.8 dB 66 26 kbps 7.22 Mbps
8-QAM 0.642 1.93 6.1k 4.6 dB 89 31 kbps 8.67 Mbps
8-QAM 0.711 2.13 6.1k 5.2 dB 93 35 kbps 9.60 Mbps
8-QAM 0.780 2.34 6.1k 5.6 dB 97 38 kbps 10.53 Mbps
16-QAM 0.731 2.93 8.2k 6.3 dB 125 47 kbps 13.16 Mbps
16-QAM 0.780 3.12 8.2k 7.0 dB 129 50 kbps 14.04 Mbps
16-QAM 0.829 3.32 8.2k 7.5 dB 131 54 kbps 14.91 Mbps
16-QAM 0.853 3.41 8.2k 8.0 dB 132 55 kbps 15.35 Mbps