DVB configuration and settings
R&S
®
SMW-K52/-K116
28
User Manual 1175.6778.02 ─ 19
BB Header Config
Accesses the baseband header settings, see
Chapter 3.8, "BB header configuration
CRC32
Activates CRC-32 check sum calculation.
The CRC-32 check sum is calculated and appended to the baseband frame
(BBFRAME). The BB header is excluded.
In detail, CRC-32 is calculated over the first (80+DFL-32) bits of the BBFRAME, and
inserted into the final 32 bits of the data field. The technique guarantees, that any
errors in the received BBFRAME can be reliably detected, as BCH error indicator is not
reliable. The CRC polynomial is as follows:
x32 + x26 + x23 + x22 + x12 + x11 + x10 + x8 + x7 + x5 + x4 + x2 + x + 1
Remote command:
[:SOURce<hw>]:BB:DVB:DVBS|DVBX:CRC[:STATe]
BB Scrambler
Activates baseband scrambling.
Remote command:
[:SOURce<hw>]:BB:DVB:DVBS|DVBX:BSCRambler[:STATe]
Outer Coder
Enables the BCH outer coder.
BCH codes are Bose-Chaudhuri-Hocquenghem multiple error correction binary block
codes.
Remote command:
[:SOURce<hw>]:BB:DVB:DVBS|DVBX:OCODer[:STATe]
Inner Coder
Applies LDPC (low-density parity check) encoding to data bits.
Remote command:
[:SOURce<hw>]:BB:DVB:DVBS|DVBX:ICODer[:STATe]
CCM settings
The following settings require mode "CCM/ACM > CCM".
Rate ← CCM settings
Selects the code rate of the inner LDPC coder.
The code rate is calculated as
code rate = m/n
, where:
●
m
is the number of incoming bits
●
n
are the number of bits in the coded output symbol
A wide range of code rates is specified. The available code rates depend on the
selected "Modulation", modulation coder ("MODCOD") and if "VL-SNR Mode" is used
or not.
Remote command:
[:SOURce<hw>]:BB:DVB:DVBS|DVBX:ICODer:RATE
DVB-S2/DVB-S2X System settings