O.2.6.2 Combined-axes system

38.521-23GPPNRPart 2: Range 2 StandaloneRadio transmission and receptionRelease 17TSUser Equipment (UE) conformance specification

Tools: ARFCN - Frequency Conversion for 5G NR/LTE/UMTS/GSM

In order to keep the quality of the quiet zone characterization manageable in terms of test times, it is suggested to perform the reference measurements for the reference AUT placed at the 7 antenna positions with the antenna rotated around the x axis with 5 different angles , i.e.,  = -90^o, -45^o, 0^o, 45^o, and 90^o and rotated around the y axis with 8 different angles  = 0^o, 45^o, 90^o, 135^o, 180^o, 225^o, 270^o, and 315^o. A graphical illustration of some sample reference AUT orientations is shown in Figure O.2.6.2-1 with a reference AUT placed at position 4, P4, for reference antenna polarization _pol = 0^o; Figure O.2.6.2-2 illustrates the reference AUT orientations for the reference polarization _pol = 90^o.

The matrix operation for the rotations and translation is defined as

for the combined-axes system.

Figure O.2.6.2-1: Sample reference AUT orientations for position 4, P4, for reference antenna polarization _pol= 0^o

Figure O.2.6.2-2: Sample reference AUT orientations for position 4, P4, for reference antenna polarization _pol= 90^o

When facing the y axis,  = 90^o and  = -90^o, the antenna does not need to be evaluated for the 8 different rotations around the y axis. A single rotation is sufficient since those orientations are unique. Due to the pedestal of the 2-axis positioner, combined-axes systems are not able to measure towards the  = 180^o direction; for those systems, the reference measurements at this reference AUT orientation can be skipped.

If the device re-positioning approach outlined in Annex N is adopted for all EIRP/EIS/TRP based conformance test cases, the quality of quiet zone analysis is sufficient only for  = 0^o, 45^o, 90^o, 270^o, and 315^o_.

The positioner relative coordinates/orientations with respect to the measurement antenna/reflector shall remain the same for each reference antenna orientation, e.g., in the sample combined-axes system shown in O.2.5.2-2 the reference antenna shall be pointed towards the positioner for b = 135^o and 225^o for the initial position of (q,f) of (0,0).