Adding noise and predistortions, and impairing the signal
R&S
®
SMM100A
263
User Manual 1179.1341.02 ─ 05
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Scalable lowpass filters are used to produce a noise level with both a broad
dynamic range and a broad bandwidth range.
AWGN modes
The AWGN generator generates signal in one of the following different modes:
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"Additive Noise":
the generated noise signal superimposes the interference-free
useful signal
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"Noise Only":
a pure noise signal is generated and modulated to the carrier; the
connection to the baseband is interrupted.
Figure 5-1: Representation of an AWGN > Mode > Noise Only in the block diagram
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"CW Interferer":
a sinusoidal signal with an adjustable frequency offset and car-
rier-to-interferer (C/I) power ratio is added to the baseband signal.
Signal and noise parameters
illustrates the relation between the signal and noise parameters.
Figure 5-2: Graphical representation of the relation between system bandwidth and noise bandwidth
(Minimum Noise/System BW = 2)
System BW* = Occupied BW
Adding noise to the signal