Transmitting Digital Television Signals by Satellite - DVB-S/S2 - Digital Video and Audio Broadcasting Technology - page 258

To gain an idea about the C/N to be expected, the levels on the satellite
downlink will now be considered.

from
satellite

MPEG2
transport stream

DVBS
front
end

Viterbi
decoder

RS
decoder

MPEG2
Decoder

BER<110 11
(QEF) =
1 error/hour

BER<310 2 BER<210 4

CR C/N
1/2 >4.1dB
2/3 >5.8dB
3/4 >6.8dB
5/6 >7.8dB
7/8 >8.4dB

Fig. 14.23. Minimum carrier/noise ratios necessary at the receiving end and bit er-
ror ratios

1E+00

1E01

1E02

1E03

1E04

1E05

1E06

1E07

1E08

1E09

1E10

1E11

1E12

1E13

0 5 10 15 20

C/N[dB]

Fig. 14.24. Channel bit error ratio in DVB-S as a function of C/N