sched small fixes - use 0.930 instead of 0.932 for max coderate. Allow computing mcs/tbs based on max coderate directly. Other small fixes

lib/include/srsran/adt/accumulators.h

@@ -38,8 +38,10 @@ private:
 
 template <typename T>
 struct exp_average_fast_start {
-  exp_average_fast_start(T alpha_, uint32_t start_size = 100) : alpha(alpha_), start_count_size(start_size)
+  exp_average_fast_start(T alpha_val) : exp_average_fast_start(alpha_val, 1.0 / alpha_val) {}
+  exp_average_fast_start(T alpha_val, uint32_t start_size) : alpha_(alpha_val), start_count_size(start_size)
   {
+    assert(alpha_ < 1);
     assert(start_size > 0);
   }
   void push(T sample)
@@ -48,16 +50,18 @@ struct exp_average_fast_start {
       avg_ += (sample - avg_) / (count + 1);
       count++;
     } else {
-      avg_ = (1 - alpha) * avg_ + alpha * sample;
+      avg_ = (1 - alpha_) * avg_ + alpha_ * sample;
     }
   }
   T    value() const { return count == 0 ? 0 : avg_; }
+  T    alpha() const { return alpha_; }
+  bool is_exp_average_mode() const { return count >= start_count_size; }
 
 private:
   T        avg_  = 0;
   uint32_t count = 0;
   uint32_t start_count_size;
-  T        alpha;
+  T        alpha_;
 };
 
 namespace detail {
@@ -112,7 +116,6 @@ private:
 
 template <typename T>
 struct null_sliding_average {
-
   null_sliding_average(uint32_t N) : window(N, null_value()) {}
   void push(T sample) { window.push(sample); }
   void push_hole() { window.push(null_value()); }

srsenb/hdr/stack/mac/sched_phy_ch/sched_dci.h

@@ -47,6 +47,19 @@ tbs_info compute_mcs_and_tbs(uint32_t nof_prb,
                              bool     ulqam64_enabled,
                              bool     use_tbs_index_alt);
 
+/**
+ * Compute MCS, TBS based on maximum coderate, N_prb
+ * \remark See TS 36.213 - Table 7.1.7.1-1/1A
+ * @return resulting TBS (in bytes) and mcs. TBS=-1 if no valid solution was found.
+ */
+tbs_info compute_mcs_and_tbs(uint32_t nof_prb,
+                             uint32_t nof_re,
+                             float    max_coderate,
+                             uint32_t max_mcs,
+                             bool     is_ul,
+                             bool     ulqam64_enabled,
+                             bool     use_tbs_index_alt);
+
 /**
  * Compute lowest MCS, TBS based on CQI, N_prb that satisfies TBS >= req_bytes (best effort)
  * \remark See TS 36.213 - Table 7.1.7.1-1/1A

srsenb/src/stack/mac/sched_phy_ch/sched_dci.cc

@@ -77,16 +77,26 @@ tbs_info compute_mcs_and_tbs(uint32_t nof_prb,
                              bool     is_ul,
                              bool     ulqam64_enabled,
                              bool     use_tbs_index_alt)
+{
+  float max_coderate = srsran_cqi_to_coderate(std::min(cqi + 1U, 15U), use_tbs_index_alt);
+  return compute_mcs_and_tbs(nof_prb, nof_re, max_coderate, max_mcs, is_ul, ulqam64_enabled, use_tbs_index_alt);
+}
+
+tbs_info compute_mcs_and_tbs(uint32_t nof_prb,
+                             uint32_t nof_re,
+                             float    max_coderate,
+                             uint32_t max_mcs,
+                             bool     is_ul,
+                             bool     ulqam64_enabled,
+                             bool     use_tbs_index_alt)
 {
   assert((not is_ul or not use_tbs_index_alt) && "UL cannot use Alt CQI Table");
   assert((is_ul or not ulqam64_enabled) && "DL cannot use UL-QAM64 enable flag");
 
-  float    max_coderate = srsran_cqi_to_coderate(std::min(cqi + 1U, 15U), use_tbs_index_alt);
   uint32_t max_Qm = (is_ul) ? (ulqam64_enabled ? 6 : 4) : (use_tbs_index_alt ? 8 : 6);
-  max_coderate          = std::min(max_coderate, 0.932F * max_Qm);
+  max_coderate    = std::min(max_coderate, 0.930F * max_Qm);
 
   int mcs = 0;
-  float prev_max_coderate = 0;
   do {
     // update max TBS based on max coderate
     int max_tbs = coderate_to_tbs(max_coderate, nof_re);
@@ -113,7 +123,7 @@ tbs_info compute_mcs_and_tbs(uint32_t nof_prb,
     // update max coderate based on mcs
     srsran_mod_t mod = (is_ul) ? srsran_ra_ul_mod_from_mcs(mcs) : srsran_ra_dl_mod_from_mcs(mcs, use_tbs_index_alt);
     uint32_t     Qm  = srsran_mod_bits_x_symbol(mod);
-    max_coderate     = std::min(0.932F * Qm, max_coderate);
+    max_coderate     = std::min(0.930F * Qm, max_coderate);
 
     if (coderate <= max_coderate) {
       // solution was found
@@ -125,7 +135,7 @@ tbs_info compute_mcs_and_tbs(uint32_t nof_prb,
 
     // start with smaller max mcs in next iteration
     max_mcs = mcs - 1;
-  } while (mcs > 0 and max_coderate != prev_max_coderate);
+  } while (mcs > 0);
 
   return tbs_info{};
 }

srsenb/src/stack/mac/sched_ue.cc

@@ -93,17 +93,11 @@ void sched_ue::new_subframe(tti_point tti_rx, uint32_t enb_cc_idx)
     current_tti = tti_rx;
     lch_handler.new_tti();
     for (auto& cc : cells) {
-      if (cc.configured()) {
-        cc.harq_ent.new_tti(tti_rx);
+      cc.new_tti(tti_rx);
     }
   }
 }
 
-  if (cells[enb_cc_idx].configured()) {
-    cells[enb_cc_idx].tpc_fsm.new_tti();
-  }
-}
-
 /*******************************************************
  *
  * FAPI-like main scheduler interface.

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

@@ -114,8 +114,14 @@ void sched_ue_cell::set_ue_cfg(const sched_interface::ue_cfg_t& ue_cfg_)
 
 void sched_ue_cell::new_tti(tti_point tti_rx)
 {
+  if (not configured()) {
+    return;
+  }
   current_tti = tti_rx;
 
+  harq_ent.new_tti(tti_rx);
+  tpc_fsm.new_tti();
+
   // Check if cell state needs to be updated
   if (ue_cc_idx > 0 and cc_state_ == cc_st::deactivating) {
     // wait for all ACKs to be received before completely deactivating SCell

srsenb/test/mac/sched_benchmark.cc

@@ -246,7 +246,7 @@ run_data expected_run_result(run_params params)
       break;
     default:
       ret.avg_dl_throughput *= 0.96;
-      ret.avg_ul_throughput *= 0.85;
+      ret.avg_ul_throughput *= 0.84;
       break;
   }
   return ret;