C.4 Determination of SSB and CORESET#0 for RRM testing with SSB SCS 120 kHz and 240 kHz

38.508-13GPP5GSPart 1: Common test environmentRelease 17TSUser Equipment (UE) conformance specification

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

C.4.1 General

The requirements to be met and the principles used for determining the SSB and CORESET#0 for a PCell used in RRM test cases are:

1. The complete SSB and CORESET#0 shall be within the carrier’s channel bandwidth.

2. The SSB centre frequency (SSref) shall be on the synchronisation raster.

3. The SSB shall be kept as close as possible to the carrier’s lower edge centre frequency.

4. The CORESET#0 configuration is selected using 24 RBs and Offset_RBs = 0 according to Table 13-8 and Index 0 for SCS_SSB =120 KHz and Table 13-10 and Index 0 for SCS_SSB =240 kHz.

5. The first SSB subcarrier shall be aligned with the defined resource grid given by SCS indicated by subCarrierSpacingCommon in the MIB.

C.4.2 Determination of SSB, CORESET#0 and signalling parameters

The following procedure is used to determine an SSB on the synchronisation raster (GSCN) and a CORESET#0 configuration (k_SSB, Offset_RBs = 0 and OffsetToPointA) as close as possible to the carrier’s lower edge. See figure C1-1 and clause C.1 for definition of parameters referenced in the procedure.

1. The target test frequencies for Low, Mid and High ranges are calculated as described in clause C.2.1.1.

For each of Low, Mid and High ranges do:

2. Determine SSB and CORESET#0:

2a. Calculate the lower of F_SSref, F_{SSref_Min}, correspondent to SSB lowest subcarrier being at the same frequency as the carrier’s lowest subcarrier; and the higher limit of F_SSref, F_{SSref_Max}, correspondent to SSB highest subcarrier being at the same frequency as the carrier’s highest subcarrier F_{SSref_Min}

F_carrierLow = see formula for F_carrierLow in Table C.1-1

F_{SSref_Min} = F_carrierLow + CRB_size * Offset_RBs,min + BW_SSB / 2

F_{SSref_Max} = F_carrierLow + ΔF_{carrierBandwidth}– BW_SSB / 2

2b. Calculate GSCN_MIN correspondent to F_{SSref_Min} in accordance to TS 38.101-2 [7], clause 5.4.3.1 and select the closest valid GSCN value with GSCN >= GSCN_MIN for the carrier in according to the carrier’s synchronisation raster as specified in clause 5.4.3.3 in TS 38.101-2 [8].

2c. Calculate the F_SSref for the selected GSCN value in step 2b in accordance to TS 38.101-2 [7], clause 5.4.3.1 for FR2.

2d. Calculate the frequency F_SSBlow and shift the carrier frequency to achieve F_carrierLow equal or as close as possible F_SSBlow on the carrier’s frequency raster.

F_SSBlow = F_SSref – BW_SSB / 2

F_carrier = calculated using the formula in clause C.2.1.1 with F_{DL_Low}= F_SSBlow

F_carrierLow = see formula for F_carrierLow in Table C.1-1 with new value of F_carrier

2e. Calculate k_SSB

k_SSB = (F_SSBlow – F_carrierLow) / subCarrierSpacingCommon (MIB, FR2) (TS 38.211 [3], clause 7.4.3.1).

N = SCS_SSB / subCarrierSpacingCommon (MIB, FR2).
k_SSB MOD N <> 0 indicates that the SSB subcarriers are not aligned with the resource grid given by the SCS indicated by subCarrierSpacingCommon in the MIB.

If k_SSB is an integer and k_SSB MOD N = 0, then continue from step 3 else modify the carrier frequency to get valid value of k_SSB and k_SSB MOD N = 0.

3. Calculate Point A frequency, ΔF_{offsetToCarrier} and ΔF_{OffsetToPointA}:
The CORESET#0 configuration is selected using 24 RBs and Offset_RBs = 0 according to Table 13-8 and Index 0 for SCS_SSB =120 KHz and Table 13-10 and Index 0 for SCS_SSB =240 kHz (see C.4.1). This means that F_{OffsetToPointA} = F_carrierLow. By selecting Point A equal to F_carrierLow this gives:

FPointA = F_carrierLow

ΔF_{offsetToCarrier}= 0

ΔF_{OffsetToPointA}= 0

4. Calculate signalling parameters:

IE field	Value
ssb-SubcarrierOffset	Set to the 4 least significant bits of k_SSB. The IE field ssb-SubcarrierOffset is signalled in the MIB.
controlResourceSetZero	0 (Index=0 in table 13-8 for SCS_SSB =120 KHz and table 13-10 for SCS_SSB =240 KHz in TS 38.213 [22]. The IE field controlResourceSetZero is signalled in the IE pdcch-ConfigSIB1 in the MIB.
absoluteFrequencySSB	Set to F_SSref expressed in ARFCN as defined in TS 38.101-1 [15] and TS 38.101-2 [39], clause 5.4.2.
absoluteFrequencyPointA	Set to F_PointA expressed in ARFCN as defined in TS 38.101-1 [15] and TS 38.101-2 [39], clause 5.4.2.
offsetToPointA	0 The IE field offsetToPointA is signalled in IE FrequencyInfoDL-SIB.
offsetToCarrier	0 The IE field offsetToCarrier is signalled in IE SCS-SpecificCarrier.