5 Error performance requirements
The modem, connected in the IF loop, shall meet the BER versus Eb/No performance requirements given in table 3.
Table 3: IF-Loop performance of the System
Inner code rate
Required Eb/No for
BER = 2 ´ 10-4 after Viterbi
QEF after Reed-Solomon
1/2 4,5
2/3 5,0
3/4 5,5
5/6 6,0
7/8 6,4
NOTE 1: The figures of Eb/No refer to the useful bit-rate before RS coding and include a modem implementation
margin of 0,8 dB and the noise bandwidth increase due to the outer code (10 log 188/204 = 0,36 d
.
NOTE 2: Quasi-Error-Free (QEF) means less than one uncorrected error event per hour, corresponding to
BER = 10-10 to 10-11 at the input of the MPEG-2 demultiplexer.
Indicative figures of the System performance by satellite are given in annex D.