5.9 Antenna Test Function measurement procedure

36.5093GPPEvolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Packet Core (EPC)Release 17Special conformance testing functions for User Equipment (UE)TS

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

This clause describes the ATF measurement procedure. An alternative client application procedure is defined in clause 9.1. The procedures described below are defined for a dual antenna single carrier system although it is the intention for this design to be easily extended for quad and octo antenna systems including carrier aggregation (CA) for when these capabilities come online in the future.

The use case for the measurements is that the conditions defined subclause 5.1 in TR 36.978 [40] would be established. Then, for any arbitrary orientation of the UE relative to the probe antenna, the test system can request a set of measurements. After receiving the results the UE can be repositioned and further sets of measurements requested until the required number of points on the sphere has been sampled. Typically a 2D cut of the UE will be measured at both horizontal and vertical polarizations. The complex antenna pattern can then be derived from the reported RSAP and RSARP values. This derivation includes calibration procedures not covered in the scope of this document.

Accuracy requirement for RSAP and RSARP are defined in clause 5.9.2.

5.9.0 Measurements definition

5.9.0.1 Reference Signal Antenna Power (RSAP) definition

The RSAP measurement is based on RSRP as defined in subclause 5.1.1 of [41].

Since it is the intention to measure UE radiated receiver performance using fully allocated downlink channels, the RSAP is a measure of the average power of the CRS resource elements across the entire channel bandwidth.

Table 5.9.0.1-1: Reference Signal Antenna Power (RSAP) definition

Definition

Reference signal antenna power (RSAP) is defined per receive antenna (Rx₀ .. Rx_n) as the linear average over the power contributions (in [W]) of the resource elements that carry cell-specific reference signals across the entire LTE channel bandwidth.

For RSAP determination the cell-specific reference signals R₀ according to TS 36.211 shall be used.

The reference point for the RSAP shall be the antenna connector of the UE.

Measurement period

Since the signal is static there is no minimum measurement period defined but a figure of one 10 ms subframe is suggested.

Applicable for

RRC_CONNECTED intra-frequency

Note 1: The number of resource elements within the measurement period that are used by the UE to determine RSAP is left up to the UE implementation with the limitation that corresponding measurement accuracy requirements have to be fulfilled.

Note 2: The power per resource element is determined from the energy received during the useful part of the symbol, excluding the CP.

5.9.0.2 Reference Signal Antenna Relative Phase (RSARP) definition

The RSARP is similarly defined as RSAP. The relative phase difference of the CRS resource elements is the average across the entire channel bandwidth.

Table 5.9.0.2-1: Reference Signal Antenna Relative Phase (RSARP) definition

Definition

Reference signal antenna relative phase (RSARP), is defined as the difference between the average phase of the resource elements that carry cell-specific reference signals across the entire LTE channel bandwidth received by the reference antenna (chosen here as Rx₀) and the average phase of the resource elements that carry cell-specific reference signals across the entire LTE channel bandwidth received by one other receiver antenna (Rx₁ .. Rx_n).

For RSARP determination, the cell-specific reference signals R₀ according to TS 36.211 [3] shall be used.

The reference point for the RSARP shall be the antenna connector of the UE.

Measurement period

Since the signal is static there is no minimum measurement period defined but a figure of one 10 ms subframe is suggested.

Applicable for

RRC_CONNECTED intra-frequency

Note 1: The number of resource elements within the measurement period that are used by the UE to determine RSARP is left up to the UE implementation with the limitation that corresponding measurement accuracy requirements have to be fulfilled.

Note 2: The phase per resource element is determined from the energy received during the useful part of the symbol, excluding the CP.

5.9.1 Request Antenna Information values

Figure 5.9.1-1: Antenna Test Function measurement procedure

5.9.1.1 General

The SS uses the ATF measurement procedure to request reporting of the current values of RSAP and RSARP according to the requested carrier number. The response depends on the number of receivers NR supported by the UE for the requested carrier number.

5.9.1.2 Initiation

The SS can request antenna information when the UE is in E-UTRA connected state.

NOTE: Refer to TS 36.508 [26] subclause 4.5.1 for more details on UE states.

The SS requests the UE to report its current antenna information values by sending an ANTENNA INFORMATION REQUEST message which specifies the desired carrier number (CN). The mapping from CN to carrier is given in subclause 6.17.

5.9.1.3 Reception of ANTENNA INFORMATION REQUEST by the UE

Upon receiving the ANTENNA INFORMATION REQUEST message the UE shall:

1> perform an RSAP measurement on receiver Rx₀ for the carrier number indicated in the ANTENNA INFORMATION REQUEST message

1> if the number of supported receivers (NR) is >1 perform an RSAP measurement on receiver Rx₁ for the carrier number indicated in the ANTENNA INFORMATION REQUEST message and perform an RSARP measurement using receivers Rx₀ and Rx₁

1> if the number of supported receivers (NR) is >2 perform an RSAP measurement on receiver Rx₂ for the carrier number indicated in the ANTENNA INFORMATION REQUEST message and perform an RSARP measurement using receivers Rx₀ and Rx₂

1> if the number of supported receivers (NR) is >3 perform an RSAP measurement on receiver Rx₃ for the carrier number indicated in the ANTENNA INFORMATION REQUEST message and perform an RSARP measurement using receivers Rx₀ and Rx₃

1> if the number of supported receivers (NR) is >4 perform an RSAP measurement on receiver Rx₄ for the carrier number indicated in the ANTENNA INFORMATION REQUEST message and perform an RSARP measurement using receivers Rx₀ and Rx₄

1> if the number of supported receivers (NR) is >5 perform an RSAP measurement on receiver Rx₅ for the carrier number indicated in the ANTENNA INFORMATION REQUEST message and perform an RSARP measurement using receivers Rx₀ and Rx₅

1> if the number of supported receivers (NR) is >6 perform an RSAP measurement on receiver Rx₆ for the carrier number indicated in the ANTENNA INFORMATION REQUEST message and perform an RSARP measurement using receivers Rx₀ and Rx₆

1> if the number of supported receivers (NR) is >7 perform an RSAP measurement on receiver Rx₇ for the carrier number indicated in the ANTENNA INFORMATION REQUEST message and perform an RSARP measurement using receivers Rx₀ and Rx₇

1> report the used carrier number CN, the number of supported receivers NR, the Rx0 RSAP measurement result and the conditional RSAP and RSARP measurement results to the SS using the ANTENNA INFORMATION RESPONSE message

5.9.2 UE ATF requirements

This subclause defines the accuracy requirements for the RSAP and RSARP measurements.

It should be noted that the two-stage test method includes RSAP and RSARP validation and if necessary linearization of the results prior to calibration of the results against known radiated metrology standards, therefore the requirement for RSAP and RSARP is that they are monotonic over a given range and resolution. As a consequence their absolute accuracies are not relevant. However, due to the similarity with RSRP, in order to guide RSAP implementation, an upper bound limit on accuracy is defined for RSAP. Since RSAP is measured in much easier conditions than RSRP, the RSRP absolute requirement will not increase the demands on existing receiver designs.

5.9.2.1 RSAP

The requirements for RSAP accuracy are given in Table 5.9.2.1-1.

Table 5.9.2.1-1: Reference Signal Antenna Power requirements

Parameter	Value
Absolute accuracy	± 6 dB
Range	RSAP absolute accuracy and monotonicity to be maintained over the range -60 dBm to -80 dBm incident power measured at the orientation of the DUT’s maximum antenna gain.
Monotonicity	Monotonicity over a 1 dB interval. This is necessary to enable linearization of the UE RSAP response as part of the accuracy requirements for the derived complex antenna pattern.

5.9.2.2 RSARP

The requirements for RSARP accuracy are given in Table 5.9.2.1-2.

Table 5.9.2.1-2: Reference Signal Antenna Relative Phase requirements

Parameter	Value
Range	RSARP monotonicity to be maintained over the range -60 dBm to -80 dBm incident power measured at the orientation of the DUT’s maximum antenna gain.
Monotonicity	Monotonicity over a 5 degree interval. This is necessary to enable linearization of the UE RSARP response as part of the accuracy requirements for the derived complex antenna pattern.