subband CQI feature - add K parameter in sched_interface::ue_cfg_t and update it from RRC

lib/include/srsran/phy/phch/cqi.h

@@ -50,6 +50,7 @@ typedef struct {
   uint32_t                 ri_idx;
   bool                     ri_idx_present;
   bool                     format_is_subband;
+  uint8_t                  subband_wideband_ratio; ///< K value in TS 36.331. 0 for wideband reporting, (1..4) otherwise
   uint32_t                 subband_size;
   srsran_cqi_report_mode_t periodic_mode;
   srsran_cqi_report_mode_t aperiodic_mode;

srsenb/hdr/stack/mac/sched_ue_ctrl/sched_dl_cqi.h

@@ -30,7 +30,7 @@ namespace srsenb {
 class sched_dl_cqi
 {
 public:
-  sched_dl_cqi(uint32_t cell_nof_prb_, uint32_t K_, uint32_t init_dl_cqi = 1) :
+  sched_dl_cqi(uint32_t cell_nof_prb_, uint32_t K_, uint32_t init_dl_cqi) :
     cell_nof_prb(cell_nof_prb_),
     cell_nof_rbg(cell_nof_prb_to_rbg(cell_nof_prb_)),
     K(K_),
@@ -41,6 +41,12 @@ public:
     srsran_assert(K <= 4, "K=%d outside of {0, 4}", K);
   }
 
+  void set_K(uint32_t K_)
+  {
+    srsran_assert(K <= 4, "K=%d outside of {0, 4}", K);
+    K = K_;
+  }
+
   void cqi_wb_info(tti_point tti, uint32_t cqi_value)
   {
     if (cqi_value > 0) {
@@ -75,9 +81,8 @@ public:
     last_pos_cqi_tti = {};
     last_wb_tti      = {};
     wb_cqi_avg       = dl_cqi;
-    for (auto& bp : bp_list) {
-      bp.cqi_val           = dl_cqi;
-      bp.last_feedback_tti = {};
+    for (bandwidth_part_context& bp : bp_list) {
+      bp = bandwidth_part_context(dl_cqi);
     }
   }
 
@@ -92,7 +97,7 @@ public:
     float    cqi     = 0;
     uint32_t sbstart = rbg_to_sb_index(interv.start()), sbend = rbg_to_sb_index(interv.stop() - 1) + 1;
     for (uint32_t sb = sbstart; sb < sbend; ++sb) {
-      cqi += subband_cqi[sb];
+      cqi += bp_list[get_bp_index(sb)].last_feedback_tti.is_valid() ? subband_cqi[sb] : wb_cqi_avg;
     }
     return static_cast<int>(cqi / (sbend - sbstart));
   }
@@ -110,10 +115,14 @@ public:
       return static_cast<int>(wb_cqi_avg);
     }
     float    cqi   = 0;
-    for (int rbg = mask.find_lowest(0, mask.size()); rbg != -1; rbg = mask.find_lowest(rbg + 1, mask.size())) {
-      cqi += subband_cqi[rbg_to_sb_index(rbg)];
+    uint32_t count = 0;
+    for (int rbg = mask.find_lowest(0, mask.size()); rbg != -1; rbg = mask.find_lowest(rbg, mask.size())) {
+      uint32_t sb = rbg_to_sb_index(rbg);
+      cqi += bp_list[get_bp_index(sb)].last_feedback_tti.is_valid() ? subband_cqi[sb] : wb_cqi_avg;
+      count++;
+      rbg = static_cast<int>(((sb + 1U) * cell_nof_rbg + N() - 1U) / N()); // skip to next subband index
     }
-    return static_cast<int>(cqi / mask.count());
+    return static_cast<int>(cqi / count);
   }
 
   /// Get CQI-optimal RBG mask
@@ -177,11 +186,12 @@ private:
 
   /// context of bandwidth part
   struct bandwidth_part_context {
-    tti_point last_feedback_tti;
+    tti_point last_feedback_tti{};
     uint32_t  last_cqi_subband_idx;
     float     cqi_val;
 
-    explicit bandwidth_part_context(float alpha) : cqi_val(alpha), last_cqi_subband_idx(max_nof_subbands) {}
+    explicit bandwidth_part_context(uint32_t init_dl_cqi) : cqi_val(init_dl_cqi), last_cqi_subband_idx(max_nof_subbands)
+    {}
   };
 
   tti_point last_pos_cqi_tti;

srsenb/hdr/stack/mac/sched_ue_ctrl/sched_ue_cell.h

@@ -88,11 +88,14 @@ private:
  *                    TBS/MCS derivation
  ************************************************************/
 
+/// Compute DL grant optimal TBS and MCS given UE cell context and DL grant parameters
 tbs_info cqi_to_tbs_dl(const sched_ue_cell& cell,
                        uint32_t             nof_prb,
                        uint32_t             nof_re,
                        srsran_dci_format_t  dci_format,
                        int                  req_bytes = -1);
+
+/// Compute UL grant optimal TBS and MCS given UE cell context and UL grant parameters
 tbs_info
 cqi_to_tbs_ul(const sched_ue_cell& cell, uint32_t nof_prb, uint32_t nof_re, int req_bytes = -1, int explicit_mcs = -1);
 

srsenb/src/stack/mac/sched_ue_ctrl/sched_ue_cell.cc

@@ -54,6 +54,7 @@ void sched_ue_cell::set_ue_cfg(const sched_interface::ue_cfg_t& ue_cfg_)
     }
   }
   if (ue_cc_idx < 0 and prev_ue_cc_idx < 0) {
+    // CC was inactive and remain inactive
     return;
   }
 
@@ -67,6 +68,13 @@ void sched_ue_cell::set_ue_cfg(const sched_interface::ue_cfg_t& ue_cfg_)
     max_mcs_dl = std::min(max_mcs_dl, 27U);
   }
 
+  if (ue_cc_idx >= 0) {
+    const auto& cc = ue_cfg_.supported_cc_list[ue_cc_idx];
+    if (cc.dl_cfg.cqi_report.periodic_configured) {
+      dl_cqi_ctxt.set_K(cc.dl_cfg.cqi_report.subband_wideband_ratio);
+    }
+  }
+
   // If new cell configuration, clear Cell HARQs
   if (ue_cc_idx != prev_ue_cc_idx) {
     clear_feedback();

srsenb/src/stack/rrc/mac_controller.cc

@@ -343,9 +343,14 @@ void ue_cfg_apply_phy_cfg_ded(ue_cfg_t& ue_cfg, const asn1::rrc::phys_cfg_ded_s&
   auto& pcell_cfg = ue_cfg.supported_cc_list[0];
   if (phy_cfg.cqi_report_cfg_present) {
     if (phy_cfg.cqi_report_cfg.cqi_report_periodic_present) {
-      auto& cqi_cfg                                   = phy_cfg.cqi_report_cfg.cqi_report_periodic.setup();
+      const auto& cqi_cfg                                = phy_cfg.cqi_report_cfg.cqi_report_periodic.setup();
       ue_cfg.pucch_cfg.n_pucch                           = cqi_cfg.cqi_pucch_res_idx;
       pcell_cfg.dl_cfg.cqi_report.pmi_idx                = cqi_cfg.cqi_pmi_cfg_idx;
+      pcell_cfg.dl_cfg.cqi_report.subband_wideband_ratio = 0;
+      if (cqi_cfg.cqi_format_ind_periodic.type().value ==
+          cqi_report_periodic_c::setup_s_::cqi_format_ind_periodic_c_::types_opts::subband_cqi) {
+        pcell_cfg.dl_cfg.cqi_report.subband_wideband_ratio = cqi_cfg.cqi_format_ind_periodic.subband_cqi().k;
+      }
       pcell_cfg.dl_cfg.cqi_report.periodic_configured = true;
     } else if (phy_cfg.cqi_report_cfg.cqi_report_mode_aperiodic_present) {
       pcell_cfg.aperiodic_cqi_period                   = rrc_cfg.cqi_cfg.period;
@@ -447,9 +452,10 @@ void ue_cfg_apply_reconf_complete_updates(ue_cfg_t&                      ue_cfg,
           if (ul_cfg.cqi_report_cfg_scell_r10.cqi_report_periodic_scell_r10_present and
               ul_cfg.cqi_report_cfg_scell_r10.cqi_report_periodic_scell_r10.type().value == setup_opts::setup) {
             // periodic CQI
-            auto& periodic = ul_cfg.cqi_report_cfg_scell_r10.cqi_report_periodic_scell_r10.setup();
+            const auto& periodic = ul_cfg.cqi_report_cfg_scell_r10.cqi_report_periodic_scell_r10.setup();
             mac_scell.dl_cfg.cqi_report.periodic_configured    = true;
             mac_scell.dl_cfg.cqi_report.pmi_idx                = periodic.cqi_pmi_cfg_idx;
+            mac_scell.dl_cfg.cqi_report.subband_wideband_ratio = 0;
           } else if (ul_cfg.cqi_report_cfg_scell_r10.cqi_report_mode_aperiodic_r10_present) {
             // aperiodic CQI
             mac_scell.dl_cfg.cqi_report.aperiodic_configured =

srsenb/test/mac/sched_cqi_test.cc

@@ -18,7 +18,7 @@ namespace srsenb {
 void test_sched_cqi_one_subband_cqi()
 {
   // 50 PRBs, K=4
-  sched_dl_cqi ue_cqi(50, 4);
+  sched_dl_cqi ue_cqi(50, 4, 0);
 
   // J == 3, N == 9
   TESTASSERT(ue_cqi.nof_bandwidth_parts() == 3);
@@ -57,7 +57,7 @@ void test_sched_cqi_wideband_cqi()
   uint32_t nof_prb  = 50;
   uint32_t nof_rbgs = cell_nof_prb_to_rbg(nof_prb);
 
-  sched_dl_cqi ue_cqi(nof_prb, 0);
+  sched_dl_cqi ue_cqi(nof_prb, 0, 0);
 
   ue_cqi.cqi_wb_info(tti_point(0), 5);