Awgn Settings; General Settings - R&S SGT100A User Manual

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R&S SGT100A
The noise signal is not generated arbitrarily for a particular bandwidth, but instead it is
generated in steps. Noise therefore also occurs outside the set system bandwidth. This
means that the total measurable noise power usually exceeds the displayed value
"Noise Power".
For a correct measurement of the noise power within the system bandwidth, it is rec-
ommended that you perform channel power measurement with a signal analyzer.
In the "Additive Noise" mode, the output signal is the signal with the noise distribution.
Hence, the power level at the RF output corresponds to the carrier+noise power.
The noise power of digitally modulated signal is characterized by the parameter E
indicating the ratio of bit energy to noise power density. The correlation to the SNR is
as follows:
C/N or S/N = (E
where B
Bit Rate f
Application fields
Typically, the noise generator is required for the following tests:
●
In receiver sensitivity tests with predefined SNR of the receiver
●
In bit-error or block-error measurements, depending on the set signal-to-noise ratio
(SNR)
●
Whenever a pure noise signal is required

7.2.2 AWGN Settings

7.2.2.1

General Settings

► To access the dialog box, select "SGMA-GUI > Instrument Name > AWGN > Gen-
eral"
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Additive White Gaussian Noise (AWGN) - Noise Generator
/N )*(f /B ),
b 0 bit sys
is the system bandwidth and
sys
= "Symbol Rate" * Modulation Value
bit
Signal Generator Settings
/N
b 0
125