R&S SGT100A User Manual page 538

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R&S SGT100A
PeakOffset_dB
Example:
Usage:
{SAMPLES: Samples}
(recommended for waveforms)
The tag contains the number of I/Q samples in the waveform in ASCII format.
On multi segment waveforms, this tag contains the total I/Q samples of all segments.
Example:
Usage:
{[TRACE] LIST [#]: Pos0:Val0;Pos1:Val1;...Posx:Valx;...PosN-1:ValN-1}
optional for waveforms)
The tag contains the data for the marker and control signals in the control list or the
marker signals of ARB waveforms. To select which of these signals is defined,
[TRACE] and the associated number are used. For ARB waveforms, it is only mean-
ingful to define marker signals (on ARB multi segment waveforms these tags will be
ignored).
User Manual 1176.8674.02 ─ 07
Defines the peak level offset of the signal relative to full scale for
the ARB signal in the WAVEFORM tag. The offset is defined in
ASCII float format.
The value usually equals 0 dB as usually the I/Q samples
(signed 16-bit integer values) are modulated to full scale: Full
scale = 0 dB = max. amplitude of vector of I/Q samples = |S
2 2
max = sqrt(I +Q )max = (2
A positive PeakOffset_dB value indicates that a headroom to
full scale is provided when generating the waveform. A negative
PeakOffset_dB value indicates that overrange is likely for some
samples, i.e. clipping might occur.
The crest factor can be calculated from the two values as fol-
lows:
Crest Factor = |PeakOffset_dB - RMSOffset_dB|
{LEVEL OFFS: 3.45,2}
BB:ARB:WAV:TAG? 'LEVEL OFFS'
Queries the content of the LEVEL OFFS tag of the selected
waveform file.
Response: 3.45,2
The level of the waveform is below full scale, clipping does not
occur.
Setting only
{SAMPLES: 4333}
BB:ARB:WAV:TAG? 'SAMPLES'
Queries the content of the SAMPLES tag of the selected wave-
form file.
Response: '4333'
The waveform contains 4333 I/Q samples.
Setting only
Waveform and List Format
Tag Description
15
)-1 = 32767.
|
IQ
507