The Spectrum Application (RF Measurements)
R&S
®
FPL1000
112
User Manual 1178.3370.02 ─ 11
b) Select "Marker Demodulation".
The R&S
FPL1000 automatically switches on the AM audio demodulator. A
1
kHz tone can be heard over headset (via the headphones connector). If nec-
essary, use the volume control to turn up the volume.
6.2.1.6
Measurement Examples in Zero Span
For radio transmission systems that use the TDMA method (for example, GSM), trans-
mission quality is determined not only by spectral characteristics but also by character-
istics in zero span. A timeslot is assigned to each user since several users share the
same frequency. Smooth operation is ensured only if all users adhere exactly to their
assigned timeslots.
Both the power during the send phase as well as the timing and duration of the TDMA
burst, and rise and fall times of the burst, are important.
Measuring the Power Characteristic of Burst Signals
........................................... 112
Measuring the Signal-to-Noise Ratio of Burst Signals
.......................................... 116
Measuring the Power Characteristic of Burst Signals
To measure power in zero span, the R&S
FPL1000 offers easy-to-use functions that
measure the power over a predefined time.
Measuring the Power of a GSM Burst During the Activation Phase
Figure 6-13: Test setup
Table 6-6: Signal generator settings (e.g. R&S SMW)
Frequency
890 MHz
Level
0 dBm
Modulation
GSM, one timeslot activated
1. Select [PRESET] to reset the instrument.
2. Set the center frequency to
890
MHz
([FREQ]).
3. Set the frequency span to
0
Hz
([SPAN] > "Zero Span").
4. Set the reference level to
10
dBm
(= level of the signal gen10
dB) (AMPT).
5. Set the attenuation to
20
dB
([AMPT] > "RF Atten Manual").
6. Set the resolution bandwidth to
1
MHz
([BW] > "Res BW").
7. Set the sweep time to
1
ms
([SWEEP] > "Sweep Time Manual" ).
Measurements and Results
