Packet Spectrum (MB-OFDM)
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The composite trace shows a packet spectrum for all occupied bands. If the trace reports DATA? instead of data, see Trace Problems.
The VSA uses the entire Packet Length to develop this spectrum. Compare this spectrum with the ideal band spectrum defined by the Spectral Mask.
The (RBW Resolution Band Width (RBW or ResBW): specifies the minimum frequency bandwith that two separate frequency spectra can be resolved and viewed seperately. For FFT (digital) based VSA's the process is equivalent to passing a time-domain signal through a bank of bandpass filters, whose center frequencies correspond to the frequencies of the FFT bins. For a traditional swept-tuned (non-digital) spectrum analyzer, the resolution bandwidth is the bandwidth of the IF filter which determines the selectivity.) is the setting of the parameter Packet Avg RBW, with a default value of 5 MHz Megahertz: A unit of frequency equal to one million hertz or cycles per second..
In order to acheive the specified, a number of FFTs and RMS averages are performed on subsets of the Pack Time data for each individual trace update. The RMS annotation at the top of the trace indicates this, even when averaging is turned off.
To view individual High, Low, or Mid Packet spectrums, see Low | Mid | High Band Packet Spectrum.
With Pre-Packet Time = 0 and Post-Packet Time = 0, set the Result Length such that the Packet Time trace goes exactly to the end of the packet. After setting these conditions, the measurement may need to be restarted to acquire the additional data.
See Also
Packet Spectrum (Low | Mid | High Band) (MB-OFDM)
