Monitoring signal characteristics
R&S
®
SMM100A
423
User Manual 1179.1341.02 ─ 05
Figure 8-2: Vector diagram (64 QAM)
X-axis, Y-axis = amplitudes of the signal components, scaled to the peak envelope power; where minimum
scaled amplitude = -1, maximum scaled amplitude = +1
Application:
To analyze the transition between the various states of modulation map-
ping, especially with linear modulations like MSK, QPSK or QAM. This mode shows
the signal like an oscilloscope (X/Y-mode).
Signal acquisition points:
See
.
Constellation diagram
Constellation diagrams display the modulation symbols as discrete points in the I/Q
plane. Unlike the vector diagram, the constellation diagram displays only one sample
per symbol. This sample represents the symbol.
Constellation diagrams are helpful when generating signals using the "Custom Digital
Modulation" settings. Compare the displayed constellation diagram with the diagram
displayed in the "Custom Digital Modulation > Modulation" dialog.
Displaying baseband signal characteristics in real-time