Agilent Technologies PSA Series User And Programming Manual page 303

allow the variables to be entered in terms of time.
For early firmware revisions you need to know the sample interval. In
the waveform measurement it is equal to the aperture value. Query
:WAVeform:APERture? to find the sample interval. (Note: the
WAV:APER? command always takes decimation into account.) The
sample interval (aperture value) is dependent on the settings for
resolution bandwidth, filter type, and decimation. See the following
table to see how these value relate.
The parameters for this GSM example are:
MEAN,9,197,1730 (or with later firmware:
MEAN,25us,526us,579.6us,8)
• MEAN calculates the mean of the measurement points indicated
• 9 is how many points you want to discard before you look at the data.
This allows you to skip over any "unsettled" values at the beginning
of the burst. You can calculate this start offset by
(25 µ s/sampleInterval)l
• 197 is the length of the data you want to use. This would be the
portion of the burst that you want to find the mean power over. You
can calculate this length by (526 µ s/sampleInterval)
• 1730 is how much data you have before you repeat the process. For
this example it's the time between the start offset point on the burst
in the first slot (first frame) to the same spot on the burst in the first
slot (second frame). You can calculate this by
(576.9 µ s*N/sampleInterval) where N is the number of data items
that you want. In this case it is the number of slots in the frame,
N=8.)
Table 5-1 GSM Parameters for 1 Slot/Frame Measurement Requirements
Resolution Filter
Bandwidth Type
500 or 300 Flat or
kHz Gaussian
500 kHz Gaussian
500 kHz Gaussian
500 kHz Flat
500 kHz Flat
300 kHz Gaussian
300 kHz Gaussian
300 kHz Flat
300 kHz Flat
a. The use of time values is only allowed in firmware versions of A.02.00 and later.
Chapter 5
Decimation Aperture
4 or 1 dependent
on settings
0.2 µ sec
1
0.8 µ sec
4
0.4 µ sec
1
1.6 µ sec
4
0.2667 µ sec
1
1.07 µ sec
4
0.6667 µ sec
1
2.667 µ sec
4
Programming Fundamentals
Improving Measurement Speed
Start Length Repeat
24 µ sec a 526 µ sec a 576.9 µ sec
124 2630 2884.6
31 657 721.15
61 1315 1442.3
15 329 360.575
90 1972 2163.1
22 492 539.16
36 789 865.31
9 197 216.33
a
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