Configuring the Internal Baseband Source
R&S
®
SMW200A
245User Manual 1175.6632.02 ─ 30
Figure 5-12: Simultaneous triggering of two basebands in coupled trigger settings mode
** = this example assumes identical basebands and shows only the first two of them
The signal generation starts simultaneous in all basebands but you can still delay the
basebands compared to each other.
Some test setups require the signal of two or more baseband sources but do not have
a coupled trigger setting. In this case, trigger the baseband sources from a common
trigger source. Use, for example, an external trigger source or to distribute the internal
trigger signal of one of the basebands to the other.
For a step-by-step description, see Chapter 5.5.3.1, "Trigger the Baseband Sources
with a Common Signal", on page 259.
5.5.1.4 Supported Modulation Signals
The R&S SMW supports a range of predefined digital and analog modulation signals.
This section focuses on the possibility to digitally modulate the baseband signal.
The analog modulation methods provided for shifting the frequency bandwidth of the
RF signal are described in Chapter 8.8, "Analog Modulations", on page 529.
In communication techniques, commonly used digital modulation schemes are based
on keying. From the several existing keying techniques, this instrument supports ASK
(amplitude shift keying), FSK (frequency shift keying), PSK (phase shift keying), and
QAM (quadrature amplitude modulation).
The digital modulation procedure is described by mapping. That is, by the assignment
of I and Q values (PSK and QAM) or frequency shifts (FSK) to every modulation sym-
Common Functions and Settings in the Baseband Domain
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