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2074
User Manual
(n)PSK
3-46
programmed for the carrier waveform:
CW Frequency – defines the frequency of the carrier waveform.
Using this standard AM function, the shape of the carrier waveform
is always sine. The CW parameter, as programmed in this menu is
shared by all other modulation options.
Amplitude – defines the carrier amplitude level. The same level is
used throughout the instrument when you move from waveform
shape to another. The Amplitude parameter, as programmed in this
menu is shared by all other waveform options.
Offset – defines the offset level for the carrier waveforms. The
same level is used throughout the instrument when you move from
waveform shape to another. The Offset parameter, as programmed
in this menu is shared by all other waveform options.
Figure 3-22, Modulation OFF Parameters
There are 6 different types of phase shift keying that the 2074 can
generate: BPSK, QPSK, OQPSK, pi/4DQPSK, 8PSK and 16PSK. If
another constellation scheme is required, one can use the User
PSK to design his/her own symbol list and constellation. An
example of a QPSK display is shown in Figure 3-23.
There are other parameters that control the (n)PSK function, these
are:
PSK Type – selects from one of BPSK, QPSK, OQPSK,
pi/4DQPSK, 8PSK and 16PSK. Once a type is selected the
associated parameters are automatically available on the display for
adjustments.
PSK Data – provides access to the PSK data symbols. By default
the table is empty so the symbols must be loaded into the table
before the (n)PSK function can be used. For testing and/or
demonstration purpose, a default table is available to download
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