use initial_dl_cqi for first DL tx.

srsenb/hdr/stack/mac/scheduler_ue.h

@@ -50,7 +50,7 @@ struct sched_ue_carrier {
   uint32_t                   get_required_prb_ul(uint32_t req_bytes);
   const sched_cell_params_t* get_cell_cfg() const { return cell_params; }
   bool                       is_active() const { return active; }
-  void                       update_cell_activity();
+  void                       set_dl_cqi(uint32_t tti_tx_dl, uint32_t dl_cqi);
 
   harq_entity harq_ent;
 
@@ -62,6 +62,7 @@ struct sched_ue_carrier {
   uint32_t dl_cqi_tti = 0;
   uint32_t ul_cqi     = 1;
   uint32_t ul_cqi_tti = 0;
+  bool     dl_cqi_rx  = false;
 
   int      max_mcs_dl = 28, max_mcs_ul = 28;
   uint32_t max_aggr_level = 3;
@@ -131,7 +132,7 @@ public:
 
   uint32_t get_required_prb_ul(uint32_t cc_idx, uint32_t req_bytes);
 
-  std::pair<uint32_t, uint32_t> get_requested_dl_rbgs(uint32_t ue_cc_idx, uint32_t nof_ctrl_symbols);
+  std::pair<uint32_t, uint32_t> get_required_dl_rbgs(uint32_t ue_cc_idx, uint32_t nof_ctrl_symbols);
   std::pair<uint32_t, uint32_t> get_requested_dl_bytes(uint32_t ue_cc_idx);
   uint32_t                      get_pending_dl_new_data();
   uint32_t                      get_pending_ul_new_data(uint32_t tti);

srsenb/src/stack/mac/scheduler_metric.cc

@@ -133,7 +133,7 @@ dl_harq_proc* dl_metric_rr::allocate_user(sched_ue* user)
   h = user->get_empty_dl_harq(tti_dl, cell_idx);
   if (h != nullptr) {
     // Allocate resources based on pending data
-    std::pair<uint32_t, uint32_t> req_rbgs = user->get_requested_dl_rbgs(cell_idx, tti_alloc->get_nof_ctrl_symbols());
+    std::pair<uint32_t, uint32_t> req_rbgs = user->get_required_dl_rbgs(cell_idx, tti_alloc->get_nof_ctrl_symbols());
     if (req_rbgs.first > 0) {
       rbgmask_t newtx_mask(tti_alloc->get_dl_mask().size());
       if (find_allocation(req_rbgs.first, req_rbgs.second, &newtx_mask)) {

srsenb/src/stack/mac/scheduler_ue.cc

@@ -44,7 +44,8 @@ namespace srsenb {
 
 namespace sched_utils {
 
-constexpr uint32_t conres_ce_size = 6;
+const uint32_t initial_dl_cqi = 5;
+const uint32_t conres_ce_size = 6;
 
 //! Obtains TB size *in bytes* for a given MCS and N_{PRB}
 uint32_t get_tbs_bytes(uint32_t mcs, uint32_t nof_alloc_prb, bool is_ul)
@@ -329,9 +330,7 @@ void sched_ue::set_dl_cqi(uint32_t tti, uint32_t enb_cc_idx, uint32_t cqi)
 {
   auto p = get_cell_index(enb_cc_idx);
   if (p.second != std::numeric_limits<uint32_t>::max()) {
-    carriers[p.second].dl_cqi     = cqi;
-    carriers[p.second].dl_cqi_tti = tti;
-    carriers[p.second].update_cell_activity();
+    carriers[p.second].set_dl_cqi(tti, cqi);
   } else {
     log_h->warning("Received DL CQI for invalid cell index %d\n", enb_cc_idx);
   }
@@ -534,14 +533,13 @@ std::pair<int, int> sched_ue::compute_mcs_and_tbs(uint32_t               ue_cc_i
   uint32_t nof_re = srslte_ra_dl_grant_nof_re(&carriers[ue_cc_idx].get_cell_cfg()->cfg.cell, &dl_sf, &grant);
 
   // Compute MCS+TBS
-  mcs = carriers[ue_cc_idx].fixed_mcs_dl;
   // Use a higher MCS for the Msg4 to fit in the 6 PRB case
-  if (mcs < 0) {
+  if (carriers[ue_cc_idx].fixed_mcs_dl < 0 or not carriers[ue_cc_idx].dl_cqi_rx) {
     // Dynamic MCS
     tbs_bytes = carriers[ue_cc_idx].alloc_tbs_dl(nof_alloc_prbs, nof_re, req_bytes.second, &mcs);
   } else {
     // Fixed MCS
-    tbs_bytes = sched_utils::get_tbs_bytes((uint32_t)mcs, nof_alloc_prbs, false);
+    tbs_bytes = sched_utils::get_tbs_bytes((uint32_t)carriers[ue_cc_idx].fixed_mcs_dl, nof_alloc_prbs, false);
   }
 
   // If the number of prbs is not sufficient to fit minimum required bytes, increase the mcs
@@ -818,15 +816,24 @@ uint32_t sched_ue::get_pending_dl_new_data_total()
   return req_bytes;
 }
 
-std::pair<uint32_t, uint32_t> sched_ue::get_requested_dl_rbgs(uint32_t ue_cc_idx, uint32_t nof_ctrl_symbols)
+std::pair<uint32_t, uint32_t> sched_ue::get_required_dl_rbgs(uint32_t ue_cc_idx, uint32_t nof_ctrl_symbols)
 {
   std::pair<uint32_t, uint32_t> req_bytes = get_requested_dl_bytes(ue_cc_idx);
   if (req_bytes.first == 0 and req_bytes.second == 0) {
     return {0, 0};
   }
-  uint32_t pending_prbs    = carriers[ue_cc_idx].get_required_prb_dl(req_bytes.first, nof_ctrl_symbols);
+  uint32_t pending_prbs = carriers[ue_cc_idx].get_required_prb_dl(req_bytes.first, nof_ctrl_symbols);
+  if (pending_prbs > carriers[ue_cc_idx].get_cell_cfg()->nof_prb()) {
+    // Cannot fit allocation in given PRBs
+    log_h->error("SCHED: DL CQI=%d does now allow fitting %d non-segmentable DL tx bytes into the cell bandwidth. "
+                 "Consider increasing initial CQI value.\n",
+                 carriers[ue_cc_idx].dl_cqi,
+                 req_bytes.first);
+    return {pending_prbs, pending_prbs};
+  }
   uint32_t min_pending_rbg = (*cell_params_list)[cfg.supported_cc_list[ue_cc_idx].enb_cc_idx].prb_to_rbg(pending_prbs);
   pending_prbs             = carriers[ue_cc_idx].get_required_prb_dl(req_bytes.second, nof_ctrl_symbols);
+  pending_prbs             = std::min(pending_prbs, carriers[ue_cc_idx].get_cell_cfg()->nof_prb());
   uint32_t max_pending_rbg = (*cell_params_list)[cfg.supported_cc_list[ue_cc_idx].enb_cc_idx].prb_to_rbg(pending_prbs);
   return {min_pending_rbg, max_pending_rbg};
 }
@@ -873,7 +880,7 @@ std::pair<uint32_t, uint32_t> sched_ue::get_requested_dl_bytes(uint32_t ue_cc_id
     srb0_data = compute_sdu_total_bytes(0, lch[0].buf_retx);
     srb0_data += compute_sdu_total_bytes(0, lch[0].buf_tx);
     if (conres_ce_pending) {
-      sum_ce_data = sched_utils::conres_ce_size + 1;
+      sum_ce_data = sched_utils::conres_ce_size + ce_subheader_size;
     }
   }
   // Add pending CEs
@@ -1184,8 +1191,9 @@ sched_ue_carrier::sched_ue_carrier(const sched_interface::ue_cfg_t& cfg_,
   harq_ent(SCHED_MAX_HARQ_PROC, SCHED_MAX_HARQ_PROC)
 {
   // only PCell starts active. Remaining ones wait for valid CQI
-  active = ue_cc_idx == 0;
-  dl_cqi = (ue_cc_idx == 0) ? 1 : 0;
+  active    = ue_cc_idx == 0;
+  dl_cqi_rx = false;
+  dl_cqi    = (ue_cc_idx == 0) ? sched_utils::initial_dl_cqi : 0;
 
   // set max mcs
   max_mcs_ul     = cell_params->sched_cfg->pusch_max_mcs >= 0 ? cell_params->sched_cfg->pusch_max_mcs : 28;
@@ -1314,7 +1322,7 @@ uint32_t sched_ue_carrier::get_required_prb_dl(uint32_t req_bytes, uint32_t nof_
   uint32_t n;
   for (n = 0; n < cell_params->nof_prb() and nbytes < req_bytes; ++n) {
     nof_re = srslte_ra_dl_approx_nof_re(&cell_params->cfg.cell, n + 1, nof_ctrl_symbols);
-    if (fixed_mcs_dl < 0) {
+    if (fixed_mcs_dl < 0 or not dl_cqi_rx) {
       tbs = alloc_tbs_dl(n + 1, nof_re, 0, &mcs);
     } else {
       tbs = srslte_ra_tbs_from_idx(srslte_ra_tbs_idx_from_mcs(fixed_mcs_dl, false), n + 1) / 8;
@@ -1326,7 +1334,7 @@ uint32_t sched_ue_carrier::get_required_prb_dl(uint32_t req_bytes, uint32_t nof_
     }
   }
 
-  return n;
+  return (nbytes >= req_bytes) ? n : std::numeric_limits<uint32_t>::max();
 }
 
 uint32_t sched_ue_carrier::get_required_prb_ul(uint32_t req_bytes)
@@ -1360,10 +1368,13 @@ uint32_t sched_ue_carrier::get_required_prb_ul(uint32_t req_bytes)
   return n;
 }
 
-void sched_ue_carrier::update_cell_activity()
+void sched_ue_carrier::set_dl_cqi(uint32_t tti_tx_dl, uint32_t dl_cqi_)
 {
+  dl_cqi     = dl_cqi_;
+  dl_cqi_tti = tti_tx_dl;
+  dl_cqi_rx  = dl_cqi_rx or dl_cqi > 0;
   if (ue_cc_idx > 0 and active != cfg->supported_cc_list[ue_cc_idx].active) {
-    if (dl_cqi > 0) {
+    if (dl_cqi_rx) {
       active = cfg->supported_cc_list[ue_cc_idx].active;
       log_h->info("SCell index=%d is now %s\n", ue_cc_idx, active ? "active" : "inactive");
     }

srsenb/test/mac/scheduler_ca_test.cc

@@ -142,21 +142,21 @@ int test_scell_activation(test_scell_activation_params params)
   tester.test_next_ttis(generator.tti_events);
 
   // Event (20 TTIs): Data back and forth
-  auto generate_data = [&](uint32_t nof_ttis, float prob_dl, float prob_ul) {
+  auto generate_data = [&](uint32_t nof_ttis, float prob_dl, float prob_ul, float rand_exp) {
     for (uint32_t i = 0; i < nof_ttis; ++i) {
       generator.step_tti();
       bool ul_flag = randf() < prob_ul, dl_flag = randf() < prob_dl;
       if (dl_flag) {
-        float exp = dl_data_exps[0] + randf() * (dl_data_exps[1] - dl_data_exps[0]);
+        float exp = dl_data_exps[0] + rand_exp * (dl_data_exps[1] - dl_data_exps[0]);
         generator.add_dl_data(rnti1, pow(10, exp));
       }
       if (ul_flag) {
-        float exp = ul_sr_exps[0] + randf() * (ul_sr_exps[1] - ul_sr_exps[0]);
+        float exp = ul_sr_exps[0] + rand_exp * (ul_sr_exps[1] - ul_sr_exps[0]);
         generator.add_ul_data(rnti1, pow(10, exp));
       }
     }
   };
-  generate_data(20, P_dl, P_ul_sr);
+  generate_data(20, P_dl, P_ul_sr, randf());
   tester.test_next_ttis(generator.tti_events);
 
   // Event: Reconf Complete. Activate SCells. Check if CE correctly transmitted
@@ -196,7 +196,7 @@ int test_scell_activation(test_scell_activation_params params)
 
   // Event: Generate a bit more data, it should *not* go through SCells until we send a CQI
   tester.dl_cqi_info(tester.tti_info.tti_params.tti_rx, rnti1, 1, cqi);
-  generate_data(5, P_dl, P_ul_sr);
+  generate_data(5, P_dl, P_ul_sr, randf());
   tester.test_next_ttis(generator.tti_events);
   TESTASSERT(tester.sched_stats->users[rnti1].tot_dl_sched_data[params.pcell_idx] > 0);
   TESTASSERT(tester.sched_stats->users[rnti1].tot_ul_sched_data[params.pcell_idx] > 0);
@@ -210,7 +210,7 @@ int test_scell_activation(test_scell_activation_params params)
   for (uint32_t i = 1; i < cc_idxs.size(); ++i) {
     tester.dl_cqi_info(tester.tti_info.tti_params.tti_rx, rnti1, cc_idxs[i], cqi);
   }
-  generate_data(10, 1.0, 1.0);
+  generate_data(10, 1.0, 1.0, 1.0);
   tester.test_next_ttis(generator.tti_events);
   for (const auto& c : cc_idxs) {
     TESTASSERT(tester.sched_stats->users[rnti1].tot_dl_sched_data[c] > 0);