Code Rate

QPSK

16-QAM

64-QAM

2K mode 8K mode 2K mode 8K mode 2K mode 8K mode
1/2 252 1008 504 2016 756 3024
2/3 336 1344 672 2688 1008 4032
3/4 378 1512 756 3024 1134 4536
5/6 420 1680 840 3360 1260 5040
7/8 441 1764 882 3528 1323 5292

Number of Reed-Solomon Packets per OFDM Super-frame for all combinations of code rates
and modulation forms.

Modulation

Code Rate

Guard interval

1/4 1/8 1/16 1/32

QPSK

1/2 498 553 585 603
2/3 664 737 781 804
3/4 746 829 878 905
5/6 829 922 976 1005
7/8 871 968 1025 1056

16-QAM

1/2 995 1106 1171 1206
2/3 1327 1475 1561 1609
3/4 1493 1659 1756 1810
5/6 1659 1843 1952 2011
7/8 1742 1935 2049 2111

64-QAM

1/2 1493 1659 1756 1810
2/3 1991 2212 2342 2413
3/4 2239 2488 2635 2714
5/6 2488 2765 2927 3016
7/8 2613 2903 3074 3167

Useful bitrate ( Mbit/s ) for all combinations of guard interval, constellation and code rate
for non-hierarchical systems for 8MHz channels irrespective of the transmission modes.

 

Useful bitrate
MPEG-2 layer
Mbit/s

Total bitrate
incl. RS(204,188)
Mbit/s

Cable
Symbol rate
MBaud

Occupied
Bandwidth
MHz

Modulation
Scheme

38.10 41.34 6.89 7.92 64-QAM
31.90 34.61 6.92 7.96 32-QAM
25.20 27.34 6.84 7.86 16-QAM
31.672 PDH 34.367 6.87 7.90 32-QAM
18.90 20.52 3.42 3.93 64-QAM
16.00 17.40 3.48 4.00 32-QAM
12.80 13.92 3.48 4.00 16-QAM
9.60 10.44 1.74 2.00 64-QAM
8.00 8.70 1.74 2.00 32-QAM
6.40 6.96 1.74 2.00 16-QAM

Examples of useful bitrates and total bitrates for transparent re-transmission and spectrum
efficient use on cable networks.