Televes 8674, Руководство пользователя, Страница: 28 / 36

28
User manual Optical Transmitter
Note 8: Minimum input level to the link (V
in
min)
It is the addition of the noise power at the input and the required C/N.
V
in
min = EIN + C/N required
The recommended C/N that must be considered for an analysis of the link; are the following:
Analogue TV signals in TV band (up to 860 MHz): 46 dB
DTT signals in TV band (up to 860 MHz): 35 dB
QPSK digital signals in SAT band: 15 dB
The minimum recommended input levels to the link for analogue TV in TV band and digital TV in SAT band for different optical losses are
shown in the following table.
Optical losses
Minimum input level for analogue TV signals
(C/N = 46 dB)
Minimum input level for digital satellite signals
(C/N = 15 dB)
1 dB 75 dBµV 55 dBµV
2 dB 75 dBµV 55 dBµV
3 dB 76 dBµV 56 dBµV
4 dB 77 dBµV 56,5 dBµV
5 dB 78 dBµV 57 dBµV
6 dB 79 dBµV 57,5 dBµV
7 dB 80 dBµV 58 dBµV
8 dB 81,5 dBµV 59 dBµV
9 dB 83 dBµV 60 dBµV
10 dB 84,5 dBµV 61 dBµV
11 dB 86 dBµV 62,25 dBµV
12 dB 87,5 dBµV 63,5 dBµV
13 dB 89 dBµV 65 dBµV
14 dB 91 dBµV 66,5 dBµV
15 dB 93 dBµV 68 dBµV
16 dB 95 dBµV 69,5 dBµV
17 dB 97 dBµV 71 dBµV