sched: helper for checking for PUCCH F0 and F2 case in cell_configuration

Author: jonathan-srs

lib/scheduler/config/cell_configuration.h

@@ -79,9 +79,10 @@ class cell_configuration
   /// UL HARQ Mode B.
   bool ul_harq_mode_b;
 
+  /// Checks if the cell is configured in TDD mode.
   bool is_tdd() const { return tdd_cfg_common.has_value(); }
 
-  /// Checks if DL/UL is active for current slot
+  /// Checks if DL is active for all symbols in the given slot.
   bool is_fully_dl_enabled(slot_point sl) const
   {
     if (dl_symbols_per_slot_lst.empty()) {
@@ -95,6 +96,8 @@ class cell_configuration
     return dl_symbols_per_slot_lst[sl.to_uint() % dl_symbols_per_slot_lst.size()] ==
            get_nsymb_per_slot(dl_cfg_common.init_dl_bwp.generic_params.cp);
   }
+
+  /// Checks if UL is active for all symbols in the given slot.
   bool is_fully_ul_enabled(slot_point sl) const
   {
     if (ul_symbols_per_slot_lst.empty()) {
@@ -109,6 +112,7 @@ class cell_configuration
            get_nsymb_per_slot(ul_cfg_common.init_ul_bwp.generic_params.cp);
   }
 
+  /// Checks if DL is active for at least one symbol in the given slot.
   bool is_dl_enabled(slot_point sl) const
   {
     if (dl_symbols_per_slot_lst.empty()) {
@@ -121,6 +125,8 @@ class cell_configuration
     }
     return dl_symbols_per_slot_lst[sl.to_uint() % dl_symbols_per_slot_lst.size()] > 0;
   }
+
+  /// Checks if UL is active for at least one symbol in the given slot.
   bool is_ul_enabled(slot_point sl) const
   {
     if (ul_symbols_per_slot_lst.empty()) {
@@ -133,6 +139,8 @@ class cell_configuration
     }
     return ul_symbols_per_slot_lst[sl.to_uint() % ul_symbols_per_slot_lst.size()] > 0;
   }
+
+  /// Returns the number of active DL symbols in the given slot.
   unsigned get_nof_dl_symbol_per_slot(slot_point sl) const
   {
     if (dl_symbols_per_slot_lst.empty()) {
@@ -145,6 +153,8 @@ class cell_configuration
     }
     return dl_symbols_per_slot_lst[sl.to_uint() % dl_symbols_per_slot_lst.size()];
   }
+
+  /// Returns the number of active UL symbols in the given slot.
   unsigned get_nof_ul_symbol_per_slot(slot_point sl) const
   {
     if (ul_symbols_per_slot_lst.empty()) {
@@ -157,6 +167,8 @@ class cell_configuration
     }
     return ul_symbols_per_slot_lst[sl.to_uint() % ul_symbols_per_slot_lst.size()];
   }
+
+  /// Returns the coreset configuration for the given coreset ID.
   const coreset_configuration& get_common_coreset(coreset_id cs_id) const
   {
     // The existence of the Coreset (either CommonCoreset or Coreset0) has been verified by the validator.
@@ -166,6 +178,15 @@ class cell_configuration
                : dl_cfg_common.init_dl_bwp.pdcch_common.coreset0.value();
   }
 
+  /// Checks if the cell is configured with PUCCH Format 0 and Format 2 resources.
+  bool is_pucch_f0_and_f2() const
+  {
+    // [Implementation-defined] Format 0/1 resources are at the beginning of the list, while Format 2/3/4 are at the
+    // end.
+    return not ded_pucch_resources.empty() and ded_pucch_resources.front().format == pucch_format::FORMAT_0 and
+           ded_pucch_resources.back().format == pucch_format::FORMAT_2;
+  }
+
   /// \brief Determines the use of transform precoding according to the parameter \e msg3-transformPrecoder.
   ///
   /// The UE determines the use of the transform precoder in TS 38.214 Section 6.1.3. It uses this parameter when a

lib/scheduler/pucch_scheduling/pucch_allocator_impl.cpp

@@ -857,9 +857,7 @@ pucch_allocator_impl::find_common_and_ded_harq_res_available(cell_slot_resource_
     // In the case of Formats 0 and 2, the PUCCH (dedicated) resources that can be used when there are SR/CSI
     // pre-allocated are constrained in the PUCCH resource indicator. Therefore, the \ref multiplex_and_allocate_pucch
     // function might not preserve the requested PUCCH resource indicator \ref d_pri.
-    const bool is_f0_and_f2 = pucch_cfg.pucch_res_list.front().format == pucch_format::FORMAT_0 and
-                              pucch_cfg.pucch_res_list.back().format == pucch_format::FORMAT_2;
-    if (not d_pri_ded.has_value() or (is_f0_and_f2 and d_pri_ded.value() != d_pri)) {
+    if (not d_pri_ded.has_value() or (cell_cfg.is_pucch_f0_and_f2() and d_pri_ded.value() != d_pri)) {
       resource_manager.cancel_last_ue_res_reservations(pucch_alloc.slot, rnti, ue_cell_cfg);
       continue;
     }
@@ -1441,20 +1439,15 @@ pucch_allocator_impl::get_pucch_res_pre_multiplexing(slot_point
     // set 1.
     const pucch_res_set_idx pucch_set_idx =
         new_bits.harq_ack_nof_bits <= 2U ? pucch_res_set_idx::set_0 : pucch_res_set_idx::set_1;
-    // NOTE: Not all UEs are capable of transmitting more than 1 PUCCH; this would be the case in which the UE has
-    // Format 0 resources, and it needs to transmit HARQ-ACK bits + SR or CSI in the same slot, and the resource symbols
-    // for HARQ and SR/CSI do not overlap. In these slots, we force, the UE to use a PUCCH resource for HARQ-ACK that is
-    // guaranteed to overlap (in symbols) with the SR or CSI resource.
-    const bool has_format_0 =
-        std::find_if(pucch_cfg.pucch_res_list.begin(), pucch_cfg.pucch_res_list.end(), [](const auto& pucch_res) {
-          return pucch_res.format == pucch_format::FORMAT_0;
-        }) != pucch_cfg.pucch_res_list.end();
-    const bool has_format_2 =
-        std::find_if(pucch_cfg.pucch_res_list.begin(), pucch_cfg.pucch_res_list.end(), [](const auto& pucch_res) {
-          return pucch_res.format == pucch_format::FORMAT_2;
-        }) != pucch_cfg.pucch_res_list.end();
-    const bool ue_with_f0_sr_csi_allocation =
-        has_format_0 and has_format_2 and (new_bits.sr_bits != sr_nof_bits::no_sr or new_bits.csi_part1_nof_bits != 0U);
+
+    // Not all UEs support transmission of more than 1 PUCCHs per slot. This would be the case if:
+    //  - UE configured with F0 and F2 resources
+    //  - UE needs to transmit HARQ-ACK + SR or CSI in the same slot
+    //  - The resource for HARQ-ACK and the resource for SR/CSI do not overlap in symbols
+    //  [Implementation-defined] In this case, we force the UE to use a PUCCH resource for HARQ-ACK that is guaranteed
+    //  to overlap (in symbols) with the SR or CSI resource.
+    const bool ue_with_f0_sr_and_f2_csi_alloc =
+        cell_cfg.is_pucch_f0_and_f2() and (new_bits.sr_bits != sr_nof_bits::no_sr or new_bits.csi_part1_nof_bits != 0U);
 
     candidate_resources.harq_resource.emplace(pucch_grant{.type = pucch_grant_type::harq_ack});
     pucch_grant& harq_candidate_grant = candidate_resources.harq_resource.value();
@@ -1464,11 +1457,11 @@ pucch_allocator_impl::get_pucch_res_pre_multiplexing(slot_point
     // or CSI in the same slot.
     if ((ue_current_grants.pucch_grants.harq_resource.has_value() and
          ue_current_grants.pucch_grants.harq_resource.value().harq_id.pucch_set_idx == pucch_set_idx) or
-        ue_with_f0_sr_csi_allocation) {
+        ue_with_f0_sr_and_f2_csi_alloc) {
       // NOTE: If the UE has Format 0 resources, and it needs to transmit HARQ-ACK bits + SR or CSI in the same slot,
       // use the HARQ-ACK resource that has highest PUCCH resource indicator; the UE's dedicated PUCCH config has been
       // constructed in such a way that this resource overlaps with the SR or CSI resource.
-      const unsigned pucch_res_ind = ue_with_f0_sr_csi_allocation
+      const unsigned pucch_res_ind = ue_with_f0_sr_and_f2_csi_alloc
                                          ? get_pucch_resource_ind_f0_sr_csi(new_bits, pucch_cfg)
                                          : ue_current_grants.pucch_grants.harq_resource.value().harq_id.pucch_res_ind;
 
@@ -1478,7 +1471,7 @@ pucch_allocator_impl::get_pucch_res_pre_multiplexing(slot_point
                                             : resource_manager.reserve_harq_set_1_resource_by_res_indicator(
                                                   sl_tx, ue_current_grants.rnti, pucch_res_ind, pucch_cfg);
       if (pucch_res == nullptr) {
-        if (ue_with_f0_sr_csi_allocation) {
+        if (ue_with_f0_sr_and_f2_csi_alloc) {
           srsran_assertion_failure("rnti={}: PUCCH HARQ-ACK that should be reserved for this UE is not available",
                                    ue_current_grants.rnti);
         } else {

lib/scheduler/pucch_scheduling/pucch_resource_manager.cpp

@@ -42,6 +42,7 @@ static int get_csi_cell_res_id(const ue_cell_configuration& ue_cell_cfg)
 /////////////   Public methods   /////////////
 
 pucch_resource_manager::pucch_resource_manager(const cell_configuration& cell_cfg_) :
+  cell_cfg(cell_cfg_),
   collision_manager(cell_cfg_),
   slots_ctx({static_vector<rnti_t, pucch_constants::MAX_NOF_CELL_PUCCH_RESOURCES>(cell_cfg_.ded_pucch_resources.size(),
                                                                                   rnti_t::INVALID_RNTI)})
@@ -381,13 +382,10 @@ pucch_harq_resource_alloc_record pucch_resource_manager::reserve_next_harq_res_a
   // Get the array of resources for the specific UE.
   const auto& ue_res_set_id_list = pucch_cfg.pucch_res_set[pucch_res_set_idx_to_uint(res_set_idx)].pucch_res_id_list;
 
-  // [Implementation-defined] Format 0/1 resources are at the beginning of the list, while Format 2/3/4 are at the end.
-  const bool is_f0_and_f2 = pucch_cfg.pucch_res_list.front().format == pucch_format::FORMAT_0 and
-                            pucch_cfg.pucch_res_list.back().format == pucch_format::FORMAT_2;
-
   // For PUCCH F0 and F2, we don't use the last 2 resources of the PUCCH resource set; these are reserved for CSI and SR
   // slots and should only be picked for through the specific PUCCH resource indicator.
-  const unsigned nof_eligible_resource = is_f0_and_f2 ? ue_res_set_id_list.size() - 2U : ue_res_set_id_list.size();
+  const unsigned nof_eligible_resource =
+      cell_cfg.is_pucch_f0_and_f2() ? ue_res_set_id_list.size() - 2U : ue_res_set_id_list.size();
   srsran_assert(nof_eligible_resource >= 1U,
                 "rnti={}: Not enough eligible resources from PUCCH resource set={}",
                 crnti,
@@ -465,14 +463,10 @@ const pucch_resource* pucch_resource_manager::reserve_harq_resource_by_res_indic
   // [Implementation-defined] We assume at most 8 resources per resource set. If this is the case, r_pucch = d_pri.
   const auto pucch_res_id = ue_res_id_set_for_harq[d_pri];
 
-  // [Implementation-defined] Format 0/1 resources are at the beginning of the list, while Format 2/3/4 are at the end.
-  const bool is_f0_and_f2 = pucch_cfg.pucch_res_list.front().format == pucch_format::FORMAT_0 and
-                            pucch_cfg.pucch_res_list.back().format == pucch_format::FORMAT_2;
-
   // For Format 0 and Format 2, the resources indexed by PUCCH res. indicators >= ue_res_id_set_for_harq.size() - 2 are
   // reserved for CSI and SR slots. In the case, we don't need to reserve these in the PUCCH resource manager, we only
   // need to return the resources.
-  if (is_f0_and_f2 and d_pri >= ue_res_id_set_for_harq.size() - 2U) {
+  if (cell_cfg.is_pucch_f0_and_f2() and d_pri >= ue_res_id_set_for_harq.size() - 2U) {
     const auto* res_cfg = std::find_if(
         pucch_cfg.pucch_res_list.begin(), pucch_cfg.pucch_res_list.end(), [pucch_res_id](const pucch_resource& res) {
           return res.res_id.ue_res_id == pucch_res_id.ue_res_id;
@@ -533,13 +527,10 @@ bool pucch_resource_manager::release_harq_resource(slot_point          slot_harq
   // Get the array of resources for the specific UE.
   const auto& ue_res_set_id_list = pucch_cfg.pucch_res_set[pucch_res_set_idx_to_uint(res_set_idx)].pucch_res_id_list;
 
-  // [Implementation-defined] Format 0/1 resources are at the beginning of the list, while Format 2/3/4 are at the end.
-  const bool is_f0_and_f2 = pucch_cfg.pucch_res_list.front().format == pucch_format::FORMAT_0 and
-                            pucch_cfg.pucch_res_list.back().format == pucch_format::FORMAT_2;
-
   // For PUCCH F0 and F2, we don't use the last 2 resources of the PUCCH resource set; these are reserved for CSI and SR
   // slots and should only be picked for through the specific PUCCH resource indicator.
-  const unsigned nof_eligible_resource = is_f0_and_f2 ? ue_res_set_id_list.size() - 2U : ue_res_set_id_list.size();
+  const unsigned nof_eligible_resource =
+      cell_cfg.is_pucch_f0_and_f2() ? ue_res_set_id_list.size() - 2U : ue_res_set_id_list.size();
   srsran_assert(nof_eligible_resource >= 1U,
                 "rnti={}: Not enough eligible resources from PUCCH resource set={}",
                 crnti,

lib/scheduler/pucch_scheduling/pucch_resource_manager.h

@@ -178,7 +178,8 @@ class pucch_resource_manager
                              const pucch_config& pucch_cfg,
                              pucch_res_set_idx   res_set_idx);
 
-  pucch_collision_manager collision_manager;
+  const cell_configuration& cell_cfg;
+  pucch_collision_manager   collision_manager;
 
   // Ring buffer of slot contexts to keep track of PUCCH resource usage in recent slots.
   circular_array<slot_context, cell_resource_allocator::RING_ALLOCATOR_SIZE> slots_ctx;