maki/openairinterface5g
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Fix FR2 SSB start subcarrier and SSB frequency at gNB

Browse Source 
for FR2 offsetToPointA is expressed in terms of 60 kHz SCS and k_SSB expressed in terms of the subcarrier spacing provided by the higher-layer parameter subCarrierSpacingCommon
This commit is contained in:
luis_pereira87
2024-02-14 13:13:42 +00:00
parent c78399ee36
commit 3d8b38f7e6
2 changed files with 25 additions and 13 deletions
Download Patch File Download Diff File Expand all files Collapse all files
openair2/RRC/NR/rrc_gNB.c
+8 -8
View File
@@ -197,21 +197,21 @@ static int get_ssb_arfcn(const f1ap_served_cell_info_t *cell_info, const NR_MIB_
uint32_t dl_arfcn = get_dl_arfcn(cell_info);
int scs = get_ssb_scs(cell_info);
int band = get_dl_band(cell_info);
uint64_t freqpointa = from_nrarfcn(band, scs, dl_arfcn);
uint64_t freqssb = 0;
// 3GPP TS 38.211 sections 7.4.3.1 and 4.4.4.2
// for FR1 offsetToPointA and k_SSB are expressed in terms of 15 kHz SCS
// for FR2 offsetToPointA is expressed in terms of 60 kHz SCS and k_SSB expressed in terms of the subcarrier spacing provided
// by the higher-layer parameter subCarrierSpacingCommon
// FR1 includes frequency bands from 410 MHz (ARFCN 82000) to 7125 MHz (ARFCN 875000)
// FR2 includes frequency bands from 24.25 GHz (ARFCN 2016667) to 71.0 GHz (ARFCN 2795832)
uint64_t scaling = 0;
if (dl_arfcn >= 82000 && dl_arfcn < 875000)
scaling = 1;
freqssb = freqpointa + 15000 * (offsetToPointA * 12 + kssb) + 10ll * 12 * (1 << scs) * 15000;
else if (dl_arfcn >= 2016667 && dl_arfcn < 2795832)
scaling = 4;
freqssb = freqpointa + 60000 * offsetToPointA * 12 + (1 << scs) * 15000 * (kssb + 10ll * 12);
else
AssertFatal(false, "Invalid absoluteFrequencyPointA: %d\n", dl_arfcn);
uint64_t freqpointa = from_nrarfcn(band, scs, dl_arfcn);
// offsetToPointA and kSSB are both on 15kHz SCS for FR1 and 60kHz SCS for FR2 (see 38.211 sections 7.4.3.1 and 4.4.4.2)
// SSB uses the SCS of the cell and is 20 RBs wide, so use 10
uint64_t freqssb = freqpointa + scaling * 15000 * (offsetToPointA * 12 + kssb) + 10ll * 12 * (1 << scs) * 15000;
int bw_index = get_supported_band_index(scs, band, get_dl_bw(cell_info));
int band_size_hz = get_supported_bw_mhz(band > 256 ? FR2 : FR1, bw_index) * 1000 * 1000;
uint32_t ssb_arfcn = to_nrarfcn(band, freqssb, scs, band_size_hz);