N.1 Reference coordinate system

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

This annex defines the measurement coordinate system for the NR UE. The reference coordinate system as defined in IEEE Std 149 [27] is provided in Figure N.1-1 below while Figure N.1.-2 shows an example DUT in the default alignment, i.e., the DUT and the reference coordinate systems are aligned with α = 0^o and β = 0^o and γ = 0^o where α, β, and γ describe the relative angles between the two coordinate systems.

Figure N.1-1: Reference coordinate system

Figure N.1-2: Example of DUT default alignment to coordinate system

The following aspects are necessary:

– A basic understanding of the top and bottom of the device is needed in order to define unambiguous DUT positioning requirements for the test, e.g., in the drawings used in this annex, the three buttons are on the bottom of the device (front) and the camera is on the top of the device (back).

– An understanding of the origin and alignment the coordinate system inside the test system i.e. the directions in which the x, y, z -axes points inside the test chamber is needed in order to define unambiguous DUT orientation, DUT beam, signal, interference, and measurement angles