nr,gnb,rrc: fix sib1 offsetToPointA derivation

srsgnb/src/stack/rrc/cell_asn1_config.cc

@@ -959,14 +959,17 @@ void fill_init_dl_bwp(const rrc_cell_cfg_nr_t& cell_cfg, bwp_dl_common_s& cfg)
 
 void fill_dl_cfg_common_sib(const rrc_cell_cfg_nr_t& cell_cfg, dl_cfg_common_sib_s& cfg)
 {
+  uint32_t scs_hz = SRSRAN_SUBC_SPACING_NR(cell_cfg.phy_cell.carrier.scs);
+  uint32_t prb_bw = scs_hz * SRSRAN_NRE;
+
   srsran::srsran_band_helper band_helper;
   cfg.freq_info_dl.freq_band_list.resize(1);
   cfg.freq_info_dl.freq_band_list[0].freq_band_ind_nr_present = true;
   cfg.freq_info_dl.freq_band_list[0].freq_band_ind_nr         = cell_cfg.band;
-  uint32_t offset_point_a_hz =
-      cell_cfg.phy_cell.dl_freq_hz - band_helper.nr_arfcn_to_freq(cell_cfg.dl_absolute_freq_point_a);
-  uint32_t offset_point_a_rbs = offset_point_a_hz / SRSRAN_SUBC_SPACING_NR(cell_cfg.phy_cell.carrier.scs) / SRSRAN_NRE;
-  cfg.freq_info_dl.offset_to_point_a = offset_point_a_rbs;
+  double   ssb_freq_start            = cell_cfg.ssb_cfg.ssb_freq_hz - SRSRAN_SSB_BW_SUBC * scs_hz / 2;
+  double   offset_point_a_hz         = ssb_freq_start - band_helper.nr_arfcn_to_freq(cell_cfg.dl_absolute_freq_point_a);
+  uint32_t offset_point_a_prbs       = offset_point_a_hz / prb_bw;
+  cfg.freq_info_dl.offset_to_point_a = offset_point_a_prbs;
   cfg.freq_info_dl.scs_specific_carrier_list.resize(1);
   cfg.freq_info_dl.scs_specific_carrier_list[0].offset_to_carrier = 0;
   cfg.freq_info_dl.scs_specific_carrier_list[0].subcarrier_spacing =

srsgnb/src/stack/rrc/test/rrc_nr_test.cc

@@ -56,8 +56,9 @@ void test_sib_generation()
   rrc_nr_cfg_t rrc_cfg_nr = {};
   rrc_cfg_nr.cell_list.emplace_back();
   rrc_cfg_nr.cell_list[0].phy_cell.carrier.pci = 500;
-  rrc_cfg_nr.cell_list[0].dl_arfcn             = 634240;
-  rrc_cfg_nr.cell_list[0].band                 = 78;
+  rrc_cfg_nr.cell_list[0].dl_arfcn             = 368500;
+  rrc_cfg_nr.cell_list[0].band                 = 3;
+  rrc_cfg_nr.cell_list[0].duplex_mode          = SRSRAN_DUPLEX_MODE_FDD;
   rrc_cfg_nr.is_standalone                     = true;
   args.enb.n_prb                               = 50;
   enb_conf_sections::set_derived_args_nr(&args, &rrc_cfg_nr, &phy_cfg);
@@ -179,8 +180,8 @@ int main(int argc, char** argv)
   }
   argparse::parse_args(argc, argv);
 
-  srsenb::test_sib_generation();
   TESTASSERT(srsenb::test_rrc_setup() == SRSRAN_SUCCESS);
+  srsenb::test_sib_generation();
   srsenb::test_rrc_sa_connection();
 
   return SRSRAN_SUCCESS;