DVB configuration and settings
R&S
®
SMW-K52/-K116
29
User Manual 1175.6778.02 ─ 19
SF ← CCM settings
Requires "DVB Standard > DVB-S2X", "VL-SNR Mode > On" and "Code Type >
Short".
Sets the spreading factor. Per default, the VL-SNR mode uses "Modulation > pi/2
BPSK" and "SF = 2". The spreading factor of 2 means that encoded bits are repeated
twice before they are mapped into the constellation.
Remote command:
CCM mode:
[:SOURce<hw>]:BB:DVB:DVBX:SFACtor
[:SOURce<hw>]:BB:DVB:DVBS|DVBX:MTAB:SET<st>:SFACtor?
Code Type ← CCM settings
Selects the FEC code type.
"Code Type > Medium" requires "VL-SNR Mode > On".
In VL-SNR mode, the required Walsh-Hadamard sequence is selected automatically as
function of the parameters "MODCOD" and "Code Type".
Remote command:
CCM mode:
[:SOURce<hw>]:BB:DVB:DVBS|DVBX:CTYPe
[:SOURce<hw>]:BB:DVB:DVBS|DVBX:MTAB:SET<st>:CTYPe
MODCOD ← CCM settings
Selects the "MODCOD" that is the modulation scheme and code rate.
In VL-SNR mode ("VL-SNR > On"), the required Walsh-Hadamard sequence is
selected automatically as function of the parameters "MODCOD" and "Code Type".
Remote command:
CCM mode:
[:SOURce<hw>]:BB:DVB:DVBS|DVBX:MCOD
[:SOURce<hw>]:BB:DVB:DVBS|DVBX:MTAB:SET<st>:MCOD
Modulation ← CCM settings
Selects the modulation scheme.
Suitable modulation schemes are selected automatically to fit the selected "MOD-
COD", see
The DVB-S2/S2X standards specify different modulation schemes, ranging in power
and spectrum efficiency. The available values depend on the used "DVB Standard", the
selected , "Code Type" and if "VL-SNR Mode" is used or not.
●
"DVB Standard > DVB-S2":
QPSK, 8PSK, 16APSK, 32APSK
●
"DVB Standard > DVB-S2X":
QPSK, 8APSK, 8PSK, 16APSK, 32APSK, 64APSK, 128APSK, 256APSK
●
"DVB Standard > DVB-S2X" and "VL-SNR Mode > On":
QPSK, pi/2 BPSK
The constellation diagram illustrates the selected modulation and coding.
DVB-S2/DVB-S2X System settings