User`s guide

Agilent PXT Wireless Communications Test Set
User’s Guide
213
Modulation Quality Summary
Figure 6-13: Modulation Quality Summary
Key Path: Mode > SA > LTE > Meas > UL Demodulation
The modulation quality summary provides you with the information you need to comply with 3GPP Test
Specification (TS) 36.521.1 requirements. Frequency error, IQ Offset, and EVM are calculated for each slot
and the overall summary is displayed in the lower section of the window, as shown in the figure above. All
calculations in this summary are defined by the 3GPP TS 36.521.1. Each measurement is listed below with
the specific section of this specification where the calculation is defined.
Slot Frequency Error and IQ Offset are calculated according to 3GPP TS 36.521-1, section E.3.1.
The overall frequency error is the largest absolute value of frequency error determined over all slots in the
measurement interval. (Refer to 3GPP TS 36.521-1, section 6.5.1.5.)
The overall IQ Offset value is the least negative value of IQ offset determined over all slots in the
measurement interval. (Refer to 3GPP TS 36.521-1, section 6.5.2.2.5.)
To display the measurements for a particular slot press Meas Setup -> Modulation Quality Summary Slot
Index. You can set this to any slot in the settable measurement period range (from Start to Stop subframe).
For each slot in the measurement interval, you also find calculations for early window, center window and
late window DMRS EVM and Data EVM in the case of PUSCH and PUCCH. The Fast-Fourier Transform
(FFT) calculations for these values are made as defined in 3GPP TS 36.521-1, section E.3.2. Post FFT
equalization is performed as defined in 3GPP TS 36.521-1, section E.3.3.