sched: use SS used for RA, Paging and SIB1 in case of retransmission of HARQ scheduled using fallback DCI format scrambled with C-RNTI

Author: herlesupreeth

lib/scheduler/ue_scheduling/ue_cell.cpp

@@ -189,12 +189,28 @@ void ue_cell::handle_csi_report(const csi_report_data& csi_report)
   }
 }
 
-template <typename FilterSearchSpace>
+template <typename FilterSearchSpace, typename DciRntiType>
 static static_vector<const search_space_info*, MAX_NOF_SEARCH_SPACE_PER_BWP>
-get_prioritized_search_spaces(const ue_cell& ue_cc, FilterSearchSpace filter, bool is_dl)
+get_prioritized_search_spaces(const ue_cell&        ue_cc,
+                              FilterSearchSpace     filter,
+                              bool                  is_dl,
+                              optional<DciRntiType> dci_type)
 {
   static_vector<const search_space_info*, MAX_NOF_SEARCH_SPACE_PER_BWP> active_search_spaces;
 
+  // Case of retransmission of HARQ scheduled using fallback DCI format.
+  // As per TS 38.213, the UE monitors PDCCH candidates for DCI format 0_0 and DCI format 1_0 with CRC scrambled by the
+  // C-RNTI, the MCS-C-RNTI, or the CS-RNTI in the one or more search space sets in a slot where the UE monitors PDCCH
+  // candidates for at least a DCI format 0_0 or a DCI format 1_0 with CRC scrambled by SI-RNTI, RA-RNTI or P-RNTI.
+  if (dci_type.has_value() and
+      ((is_dl and static_cast<dci_dl_rnti_config_type>(dci_type.value()) == dci_dl_rnti_config_type::c_rnti_f1_0) or
+       (not is_dl and
+        static_cast<dci_ul_rnti_config_type>(dci_type.value()) == dci_ul_rnti_config_type::c_rnti_f0_0))) {
+    for (const auto ss_id : ue_cc.cfg().get_sib1_other_si_ra_pg_ss_ids()) {
+      active_search_spaces.push_back(&ue_cc.cfg().search_space(ss_id));
+    }
+  }
+
   // Get all Search Spaces configured in PDCCH-Config for active BWP.
   // See TS 38.213, A UE monitors PDCCH candidates in one or more of the following search spaces sets:
   // - a Type3-PDCCH CSS set configured by SearchSpace in PDCCH-Config with searchSpaceType = common for DCI formats
@@ -259,7 +275,7 @@ ue_cell::get_active_dl_search_spaces(slot_point                        pdcch_slo
     }
     return true;
   };
-  return get_prioritized_search_spaces(*this, filter_ss, true);
+  return get_prioritized_search_spaces(*this, filter_ss, true, required_dci_rnti_type);
 }
 
 static_vector<const search_space_info*, MAX_NOF_SEARCH_SPACE_PER_BWP>
@@ -290,7 +306,7 @@ ue_cell::get_active_ul_search_spaces(slot_point                        pdcch_slo
                                             ? dci_ul_rnti_config_type::c_rnti_f0_0
                                             : dci_ul_rnti_config_type::c_rnti_f0_1));
   };
-  return get_prioritized_search_spaces(*this, filter_ss, false);
+  return get_prioritized_search_spaces(*this, filter_ss, false, required_dci_rnti_type);
 }
 
 /// \brief Get recommended aggregation level for PDCCH given reported CQI.

lib/scheduler/ue_scheduling/ue_configuration.cpp

@@ -573,6 +573,14 @@ ue_cell_configuration::ue_cell_configuration(rnti_t                     crnti_,
 {
   // Apply UE-dedicated Config.
   reconfigure(serv_cell_cfg_);
+
+  std::set<search_space_id> ss_id_set;
+  ss_id_set.emplace(cell_cfg_common.dl_cfg_common.init_dl_bwp.pdcch_common.sib1_search_space_id);
+  ss_id_set.emplace(cell_cfg_common.dl_cfg_common.init_dl_bwp.pdcch_common.ra_search_space_id);
+  if (cell_cfg_common.dl_cfg_common.init_dl_bwp.pdcch_common.paging_search_space_id.has_value()) {
+    ss_id_set.emplace(cell_cfg_common.dl_cfg_common.init_dl_bwp.pdcch_common.paging_search_space_id.value());
+  }
+  sib1_other_si_ra_pg_ss_ids.assign(ss_id_set.begin(), ss_id_set.end());
 }
 
 void ue_cell_configuration::reconfigure(const serving_cell_config& cell_cfg_ded_req)

lib/scheduler/ue_scheduling/ue_configuration.h

@@ -17,6 +17,7 @@
 #include "srsran/ran/pdcch/cce_to_prb_mapping.h"
 #include "srsran/ran/pdcch/pdcch_candidates.h"
 #include "srsran/scheduler/config/bwp_configuration.h"
+#include <set>
 
 namespace srsran {
 
@@ -138,6 +139,10 @@ class ue_cell_configuration
   /// Get the number of active DL ports for this UE.
   unsigned get_nof_dl_ports() const { return nof_dl_ports; }
 
+  /// Get the ids of search space sets where the UE monitors PDCCH candidates for DCI with CRC scrambled by SI-RNTI,
+  /// RA-RNTI and P-RNTI.
+  span<const search_space_id> get_sib1_other_si_ra_pg_ss_ids() const { return sib1_other_si_ra_pg_ss_ids; }
+
 private:
   void configure_bwp_common_cfg(bwp_id_t bwpid, const bwp_downlink_common& bwp_dl_common);
   void configure_bwp_common_cfg(bwp_id_t bwpid, const bwp_uplink_common& bwp_ul_common);
@@ -163,6 +168,10 @@ class ue_cell_configuration
 
   /// Number of DL ports for this UE.
   unsigned nof_dl_ports = 1;
+
+  /// Ids of search space sets where the UE monitors PDCCH candidates for DCI with CRC scrambled by SI-RNTI, RA-RNTI and
+  /// P-RNTI.
+  std::vector<search_space_id> sib1_other_si_ra_pg_ss_ids;
 };
 
 } // namespace srsran