7.7 OTA Receiver spurious emissions

37.145-23GPPActive Antenna System (AAS) Base Station (BS) conformance testingPart 2: radiated conformance testingRelease 17TS

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

7.7.1 Definition and applicability

The receiver spurious emission requirement is the power of the emissions radiated from the antenna array from a receiver unit. For an OTA AAS BS operating in FDD, OTA RX spurious emissions requirement do not apply as they are superseded by the OTA TX spurious emissions requirement. This is due to the fact that TX and RX spurious emissions cannot be distinguished in OTA domain.

NOTE: The OTA receiver spurious emission requirement applicability for the AAS BS with the RX-only capabilities is FFS.

For an OTA AAS BS operating in TDD, the OTA receiver spurious emissions requirement applies during the transmitter OFF period only.

For RX only multi-band RIB, the RX spurious emissions requirements are subject to exclusion zones in each supported operating band.

7.7.2 Minimum Requirement

For an MSR AAS BS the minimum requirement is in TS 37.105 [6], clause 10.7.2

For AAS BS in single RAT E-UTRA operation the minimum requirement is defined in TS 37.105 [6], clause 10.7.4

For single RAT UTRA AAS BS the minimum requirement is in TS 37.105 [6], clause 10.7.3

7.7.3 Test purpose

The test purpose is to verify the receiver radiated spurious emissions from the AAS BS at the RIB are within the specified requirements.

7.7.4 Method of test

7.7.4.1 Initial conditions

Test environment: normal; see annex G.2.

RF channels to be tested for single carrier: M; see clause 4.12.1.

RF bandwidth positions to be tested in single-band operation: – M_RFBW, see clause 4.12.1,

RF bandwidth positions to be tested in multi-band operation, see clause 4.12.1.

– B_RFBW_T’_RFBW when testing from 30 MHz to F_{DL_Blow_low} – Δf_OBUE

– B’_RFBW_T_RFBW when testing from F_{DL_Bhigh_high} + Δf_OBUE to 12.75 GHz (or to 5^th harmonic)

– B_RFBW_T’_RFBW and B’_RFBW_T_RFBW when testing from F_{DL_Blow_high} + Δf_OBUE to F_{DL_Bhigh_low} – Δf_OBUE

Directions to be tested: Not applicable as Rx only TRP measurement.

7.7.4.2 Procedure

The following procedure for measuring TRP is based on the directional power measurements as described in Annex F. An alternative method to measure TRP is to use a characterized and calibrated reverberation chamber if so follow steps 1, 3, 4, 5, 7 and 10.

1) Place the AAS BS at the positioner.

2) Align the manufacturer declared coordinate system orientation (see table 4.10-1, D9.2) of the AAS BS with the test system.

3) Measurements shall use a measurement bandwidth in accordance to the conditions in TS 37.104 [5] clause 6.6.1.

4) The measurement device characteristics shall be:

– Detection mode: True RMS.

The emission power should be averaged over an appropriate time duration to ensure the measurement is within the measurement uncertainty in Table 4.1.2.3-1.

5) Set the TDD AAS BS to receive only

6) Orient the positioner (and BS) in order that the direction to be tested aligns with the test antenna such that measurements to determine TRP can be performed (see annex F).

7) Measure the emission at the specified frequencies with specified measurement bandwidth

8) Repeat step 6-9 for all directions in the appropriated TRP measurement grid needed for full TRP estimation (see annex F).

NOTE 1: The TRP measurement grid may not be the same for all measurement frequencies.

NOTE 2: The frequency sweep or the TRP measurement grid sweep may be done in any order.

9) Calculate TRP at each specified frequency using the directional measurements.

In addition, for multi-band RIB(s), the following steps shall apply:

10) For multi-band RIBs and single band tests, repeat the steps above per involved band where single band test configurations and test models shall apply with no carrier activated in the other band.

7.7.5 Test Requirement

The TRP of any spurious emission shall not exceed the limits in table 7.7.5-1:

Table 7.7.5-1: Receiver spurious emission test requirement

Frequency range	Maximum level (Note 2, Note 3)	Measurement bandwidth	NOTE
30 MHz ‑ 1 GHz	-36 + X dBm	100 kHz
1 GHz – 12.75 GHz	-30 + X dBm	1 MHz
12.75 GHz – 5^th harmonic of the upper frequency edge of the UL operating band in GHz	-30 + X dBm	1 MHz	Applies only for Bands 22, 42, 43, 48.
NOTE 1: The frequency range between 2.5 * channel bandwidth below the first carrier frequency and 2.5 * channel bandwidth above the last carrier frequency transmitted by the AAS BS may be excluded from the requirement. However, frequencies that are more than Δ_fOBUE below the lowest frequency of any of the AAS BS supported downlink operating band or more than Δ_fOBUE above the highest frequency of any of the AAS BS supported downlink operating band shall not be excluded from the requirement. For a multiband RIB, the exclusion applies for all supported operating bands. NOTE 2: X = 9 dB, unless stated differently in regional regulation. NOTE 3: Additional limits may apply regionally.

In addition to the requirements in table 7.7.5-1, the power of any spurious emission shall not exceed the levels specified for Protection of the E-UTRA FDD BS receiver of own or different BS in clause 6.7.6.3 and for Co-existence with other systems in the same geographical area in clause 6.7.6.4. In addition, the co-existence requirements for co-located base stations specified in clause 6.7.6.5 may also be applied.