Measurements and results
R&S
®
FSVA3000/ R&S
®
FSV3000
155
User Manual 1178.8520.02 ─ 08
5.2.6.2
Measuring the signal-to-noise ratio of burst signals
When TDMA transmission methods are used, the signal-to-noise ratio or the dynamic
range for deactivation can be measured by comparing the power values during the
activation phase and the deactivation phase of the transmission burst. Therefore, the
R&S
FSV/A provides a measurement for absolute and relative power in zero span. In
the following example, the measurement is performed using a GSM burst.
Signal-to-Noise Ratio of a GSM Signal
Figure 5-18: Test setup
Table 5-7: Signal generator settings (e.g. R&S SMW)
Frequency
890 MHz
Level
0 dBm
Modulation
GSM, one time slot is switched on
1. Select [PRESET] to reset the instrument.
2. Set the center frequency to
890
MHz
.
3. Set the frequency span to
0
Hz
.
4. Set the resolution bandwidth to
1
MHz
.
5. Set the reference level to
0
dBm
(= level of the signal generator).
6. Set the sweep time to
2
ms
([SWEEP] > "Sweep Time Manual" ).
The R&S
FSV/A shows the GSM burst continuously across the display.
7. Use the trigger source "Video" and the trigger slope "Rising" to trigger on the rising
edge of the burst and shift the start of the burst to the center of the display (see
"Measuring the edges of a GSM burst with high time resolution"
8. Activate power measurement within the activation phase of the burst in zero span.
a) Press the [MEAS] key.
b) Select "Time Domain Power".
c) Select "Time Dom Power Config".
d) Set the "Limits" state to "On".
e) Select the "Left Limit" input field.
f) By turning the rotary knob clockwise, move the vertical line "S1" to the start of
the burst.
g) Select the "Right Limit" input field.
Basic measurements
