Keysight Technologies N5171B EXG, User Manual

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346 Keysight EXG and MXG X-Series Signal Generators User’s Guide
Real–Time Noise—AWGN (Option 403)
Adding Real–Time Noise to a Dual ARB Waveform
Figure 13-5 Real Time I/Q Baseband AWGN - E
b
/N
0
Adjustment Softkeys
Figure 13-6 Carrier to Noise Ratio Components
Example
Use the following steps to modulate a 1 GHz, –10 dBm carrier with the factory–supplied waveform
SINE_TEST_WFM, and then apply noise with a 45 MHz bandwidth signal that has a 30 dB carrier–
to–noise ratio across a 40 MHz carrier bandwidth.
1. Preset the signal generator and set the following:
For details on each key, use key help
as described on
page 40
.
Mode > Dual ARB > Arb Setup > Real-Time AWGN Setup
Selects either the Carrier to
Noise Ratio (
C/N ) or energy per
bit over noise power density at
the receiver (
E
b
/N
o
) as the
variable controlling the ratio of
the carrier power to noise power
in the carrier bandwidth. When
E
b
/N
o
is selected, the second
page of the AWGN Setup menu
shows the
Carrier Bit Rate
softkey to enable the E
b
/N
o
value to be calculated.
Figure 13-6 on page 346
provides additional details on
these settings.
C/N selected
E
b
/N
o
selected
Whether a softkey is available
depends on the
Carrier to
Noise Ratio Format softkey
setting (e.g. C/N or E
b
/N
o
).
The Carrier Bit Rate softkey sets the
carrier bit rate. (The default carrier bit
rate is 1 bps.)
The Carrier Bit Rate softkey is only
available when the Carrier to Noise
Ratio Format Softkey is set to E
b
/N
o
.
To view the carrier bit rate equation,
refer to
page 40
.
E
b
/N
o
is displayed when Carrier to Noise Ratio
Format softkey is set to E
b
/N
o
.
The active
softkey changes
with the Carrier to
Noise Ratio
Format selected
(C/N or E
b
/N
o
).
See below.
Display remains grayed out until
real-time AWGN is enabled.