Rohde & Schwarz SMM100A, User Manual

Page: 271 / 1088

Adding noise and predistortions, and impairing the signal
R&S
®
SMM100A
271 User Manual 1179.1341.02 ─ 05
Whether a configuration of C/N or S/N is enabled, depend on the selected output Show
Powers For Output .
●
In "Reference Mode > Carrier": sets the noise power. It does not affect the power of
the useful signal, i.e. the carrier power remains constant.
Thus the power of the c noise signal or the
power of the output signal
changes.
●
In "Reference Mode > Noise", sets the power of the useful signal , i.e. the carrier
power.
The power of the output signal remains constant.
●
The power of the noise signal is derived from the entered C/N or S/N value and
displayed with the parameter "Noise Power" in the units of the useful signal.
●
The power of the useful signal is displayed with the parameter "Carrier Power" and
can also be changed there. This indication corresponds to the "Level" value in the
"Status bar".
●
The power of the output signal is displayed as "C Noise Power".
See also Figure 5-3 .
Remote command:
[:SOURce<hw>]:AWGN:CNRatio
on page 864
E
b
/N
0
In "Additive Noise" mode, sets the ratio of bit energy to noise power density.
●
In "Reference Mode > Carrier": sets the noise power and hence the power of the
output signal, i.e. the c noise signal.
It does not affect the power of the useful signal, i.e. the carrier power is kept con-
stant.
●
In "Reference Mode > Noise": sets the power of the useful signal , i.e. the carrier
power.
The noise power is kept constant.
●
The power of the noise signal is derived from the selected E
b
/N
0
and displayed with
the parameter "Noise Power" in the units of the useful signal.
●
The power of the useful signal is displayed with the parameter "Carrier Power".
This indication corresponds to the "Level" value in the "Status bar".
●
The power of the output signal is displayed as "C Noise Power".
See also Figure 5-3 .
Remote command:
[:SOURce<hw>]:AWGN:ENRatio
on page 864
Carrier Power, Signal Power
("Additive Noise" and "CW Interferer")
The name of this parameter depends on the selected output Show Powers For Output .
●
In "Reference Mode > Carrier": sets the carrier power. This indication corresponds
to the "Level" value in the "Status bar".
The power of the noise signal is derived from the selected C/N or S/N value and
displayed with the parameter "Noise Power" in the units of the useful signal.
●
In "Reference Mode > Noise", indicates the carrier power as derived from the
entered C/N or S/N value. This indication corresponds to the "Level" value in the
"Status bar".
The noise power can be set with the parameter "Noise Power".
Adding noise to the signal