SMD 989
– User Manual
Page 49 (105)
With Input Bitrate, the SMD 989 uses the entered bitrate along with the modulation settings to
calculate the needed symbol rate. If it is known that the input transport stream contains a
significant amount of null packets it is possible to enter a bitrate that is lower than the actual input
transport stream bitrate. In this case the SMD 989 will remove existing nulls.
Important Note:
When entering a bitrate lower than the input bitrate or a symbol rate below the
minimum, there must be enough nulls in the input transport stream to be removed to allow the
lower bitrate or symbol rate or errors in the transmission transport stream result.
The SMD 989 contains a symbol rate or input bit rate calculator to assist with these selections. By
clicking the
icon, the recommended symbol rate will be inserted into the Symbol Rate field or
maximum input bitrate inserted in the Bitrate field.
DVB-S2X
Code Rate
QPSK
8PSK
16APSK 32APSK 64APSK
¼
√
√
3/5
√
√
2/3
√
√
¾
√
√
√
√
4/5
√
√
√
√
5/6
√
√
√
√
√
7/8
7/9
√
√
√
8/9
√
√
√
√
9/10
√
√
√
√
11/15
√
√
13/18
√
23/36
√
√
25/36
√
26/45
√
28/45
√
32/45
√
77/90
√
½-L
√
2/3-L
√
√
3/5-L
√
5/9-L
√
√
8/15-L
√
32/45-L
√
26/45-L
√
Figure 42: Modulation/FEC code rates DVB-S2X
