R&S WinIQSIM2 Software Manual - Rohde & Schwarz

R&S ® WinIQSIM2
Graphical User Interface
Baseband Block
5.10.2 Digital Modulation - Custom Digital Modulation
The R&S Signal Generator can generate digital modulation signals with user-definable
characteristics. Baseband filtering and the symbol rate can be set within wide limits.
5.10.2.1 Modulation Types - Custom Digital Mod
The available predefined modulation types are ASK (amplitude shift keying), FSK (frequency
shift keying), PSK (phase shift keying) and QAM (quadrature amplitude modulation).
Additionally, a user defined modulation mapping can be applied (see ​"User Mapping"
on page 54).
The actual modulation procedure is described by mapping, which assigns I and Q values
(PSK and QAM) or frequency shifts (FSK) to every modulation symbol that occurs. This
is represented graphically in the constellation diagrams.
The mapping for the selected modulation type is displayed in the "More..." submenu in
the "Modulation" menu section (see ​"More - Modulation Type - Digital Modulation"
on page 70).
The QAM procedures 16QAM, 32QAM, 64QAM have been produced in accordance with
ETSI standard ETS 300429 for digital video broadcasting (DVB). The QAM procedures
256QAM and 1024QAM are not specified in this standard, but have been produced
according to the same basic principles.
In the case of all FSK procedures, the user can set the symbol rate fSYMB up to a maximum
value (see data sheet). If MSK is selected, the frequency deviation (FSK deviation)
cannot be set since it is permanently set to ¼ of the symbol rate.
Table 5-4: Modulation type and associated mapping
ASK
1 bit per symbol
SOUR:BB:DM:FORM ASK
PSK
BPSK
1 bit per symbol
​SOUR:BB:DM:FORM BPSK
QPSK
2 bits per symbol
SOUR:BB:DM:FORM QPSK
QPSK 45° Offset
2 bits per symbol, 45° rotation
SOUR:BB:DM:FORM QPSK45
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