Do not allow empty TBS PUSCH. Account for CQI from inactive cells before activated. (#1667)

lib/src/phy/common/phy_common.c

@@ -303,7 +303,7 @@ uint32_t srslte_N_ta_new(uint32_t N_ta_old, uint32_t ta)
 
 float srslte_coderate(uint32_t tbs, uint32_t nof_re)
 {
-  return (float)tbs / nof_re;
+  return (float)(24 + tbs) / nof_re;
 }
 
 /* Returns the new time advance as indicated by the random access response

srsenb/src/phy/phy_ue_db.cc

@@ -516,8 +516,8 @@ bool phy_ue_db::fill_uci_cfg(uint32_t          tti,
     const cell_info_t&     cell_info = ue.cell_info[cell_idx];
     const srslte_dl_cfg_t& dl_cfg    = cell_info.phy_cfg.dl_cfg;
 
-    // Check report for primary and active cells
-    if (cell_info.state == cell_state_primary or cell_info.state == cell_state_secondary_active) {
+    // Check report for primary and active and inactive cells. CQI reports start after RRC configures the carrier
+    if (cell_info.state != cell_state_none) {
       const srslte_cell_t& cell = cell_cfg_list->at(cell_info.enb_cc_idx).cell;
 
       // Check if CQI report is required

srsenb/src/stack/mac/scheduler_ue.cc

@@ -718,9 +718,8 @@ int sched_ue::generate_format0(sched_interface::ul_sched_data_t* data,
         // Recompute again the MCS and TBS with the new spectral efficiency (based on the available RE for data)
         if (nof_re >= nof_uci_re) {
           tbs = carriers[cc_idx].alloc_tbs_ul(alloc.length(), nof_re - nof_uci_re, req_bytes, &mcs);
-        } else {
-          tbs = 0;
         }
+        // NOTE: if (nof_re < nof_uci_re) we should set TBS=0
       }
     }
     h->new_tx(tti, mcs, tbs, alloc, nof_retx);
@@ -1162,11 +1161,10 @@ int cc_sched_ue::cqi_to_tbs(uint32_t nof_prb, uint32_t nof_re, bool use_tbs_inde
     *mcs = (uint32_t)sel_mcs;
   }
 
-  if (coderate <= SRSLTE_MIN(max_coderate, 0.930 * Qm)) {
-    return tbs;
-  } else {
-    return 0;
-  }
+  // If coderate > SRSLTE_MIN(max_coderate, 0.930 * Qm) we should set TBS=0. We don't because it's not correctly
+  // handled by the scheduler, but we might be scheduling undecodable codewords at very low SNR
+
+  return tbs;
 }
 
 /************************************************************************************************