R&S SMJ100A, Руководство по эксплуатации, Страница: 192 / 874

Instrument Function
R&S
®
SMJ100A
176 Operating Manual 1403.7458.32 ─ 14
5.3.3.3 Constellation Diagram
In the constellation diagram, the Q component is also displayed over the I component.
However, only the values at the constellation points (signal value at the ideal scanning
instant of the symbol) are displayed, i.e. for each symbol only 1 value in the form of a
circle is shown for the I and Q component.
The amplitudes of the signal components scaled to the peak envelope power (PEP)
are plotted on the X and Y axis (minimum scaled amplitude = -1; maximum scaled
amplitude = +1). The recording depth is 2kSamples.
This signal is picked off at the output of the baseband main module ("Impairment" func-
tion block), i.e. contained in the displayed signal is:
●
impairment of the signal as defined by the user and the addition of noise.
This display shows the various states of modulation mapping which occur in the signal.
The example shows the constellation diagram of a QPSK modulation signal.
Graphical Display - Graphics