DFT-S-OFDM Err Vector Traces
specifies whether DFT discrete Fourier transform-spread subcarrier points are despread before computing Error Vector traces.
This parameter only affects DFT-spread data, and only in Error Vector traces that are "vs. Sym" or "vs. Carrier." It is only available when Multiple Access Scheme is set to DFT or Pilot In Time Domain is selected.
See Error Vect vs. Sym (Carrier overlay) for an explanation of how this parameter affects the contents of the Error Vector traces.
The purpose of this parameter is to allow you to see the frequency domain performance of DFT-spread subcarriers.
In previous releases, all data was despread before computing the error vectors. This meant that the effect of any frequency-dependent impairment (such as a spur on a particular subcarrier) was spread over multiple Error Vector trace points (since performing an IDFT inverse discrete Fourier transform to despread some points also spreads the impairment over those points).
In this release, you can choose to preserve frequency-domain impairments.
This parameter does not affect IQ Meas or IQ Ref traces, which always show data after IDFT despread.
See Also
Error Vect vs. Carrier (Sym overlay)
