EVM Settings (6GR)
The section of the Advanced tab controls how EVM Error vector magnitude (EVM): A quality metric in digital communication systems. See the EVM metric in the Error Summary Table topic in each demodulator for more information on how EVM is calculated for that modulation format. is computed and reported. All parameters are auto-coupled — see Auto and Manual Parameter Coupling.
3GPP EVM (Conformance) - Computes EVM per the 3GPP conformance test definition. While selected, the Tracking settings are forced to the values the conformance specification requires.
Default: Selected
Symbol Time Adjustment Mode / Symbol Time Adjustment - Adjust where within the cyclic prefix the symbol timing is placed. The mode selects the reference point; the adjustment value applies only when 3GPP EVM (Conformance) is off and the mode is Percent of FFT Fast Fourier Transform: A mathematical operation performed on a time-domain signal to yield the individual spectral components that constitute the signal. See Spectrum. Size.
- Max of EVM Window Start/End - Reports the maximum EVM from the 3GPP-defined CP 1) Contention period, or 2) Cyclic prefix EVM window start and end points.
- Min of EVM Window Start/End - Reports the minimum EVM from the window start and end points.
- EVM Window Start - Reports EVM from the 3GPP-defined CP EVM window start point.
- EVM Window End - Reports EVM from the window end point.
- EVM Window Center - Reports EVM from the window center point.
- Percent of FFT Size - Reports EVM from a user-specified CP point, set as a percentage of the FFT size.
Default: Max of EVM Window Start/End (while 3GPP EVM (Conformance) is selected); adjustment value -3.125%
Range (percent value): -25% to 0%
Report EVM in dB - Reports EVM results in dB instead of percent.
Default: Cleared
Error Vector Time Basis / Error Vector Freq Basis - Set the unit the error vector is averaged over for the Error Vector Spectrum, Error Vector Time, Error Vector 3D, and RMS Error Vector traces: Error Vector Time Basis sets the time unit and Error Vector Freq Basis the frequency unit. They affect those traces only — the EVM reported in the Summary table is not changed by either setting.
Default: Per Symbol (time), Per Subcarrier (frequency)
Choices (time): Per Symbol, Per Slot, Per Subframe. Choices (frequency): Per Subcarrier, Per RB, All REs
EVM Window Length Mode / EVM Window Length - Selects the EVM window length used for EVM computation. 3GPP applies the standard-defined EVM window lengths appropriate for each bandwidth; Custom applies a user-defined window length in FFT-size samples (the length value is ignored in 3GPP mode).
Default: 3GPP, length 172 samples
Range (length): 1 sample to a maximum that depends on the analysis bandwidth and synchronization type
Condition Number Config - Configures the channel condition-number computation. Affects the Eq Condition Number trace.
- Off - The MIMO Multiple Input, Multiple Output: A physical layer (PHY) configuration in which both transmitter and receiver use multiple antennas. condition number calculation is off.
- Per Subcarrier - On, with per-subcarrier frequency granularity.
- User Defined RBs - On, with the RB granularity set by Condition Number RB Granularity.
- Wideband - On, with granularity over all RBs allocated for the PDSCH Physical Downlink Shared Channel or PUSCH.
Default: Off
Choices: Off, Per Subcarrier, User Defined RBs, Wideband
Condition Number RB Granularity - The resource-block granularity of the condition-number result when Condition Number Configuration is User Defined RBs.
Default: 1
Range: 1 to 275
See Also
