bugfix, sched: fix aggregation level derivation to avoid L > 3

srsenb/src/stack/mac/sched_helpers.cc

@@ -400,10 +400,14 @@ uint32_t get_aggr_level(uint32_t nof_bits,
   l_max = SRSRAN_MIN(max_aggr_lvl, l_max);
 
   uint32_t l = min_aggr_lvl;
-  do {
+  for (; l <= l_max; ++l) {
     coderate = srsran_pdcch_coderate(nof_bits, l);
-    l++;
-  } while (l < l_max && factor * coderate > max_coderate);
+    if (factor * coderate > max_coderate) {
+      break;
+    }
+  }
+  // make aggregation level more conservative
+  l = std::min(l_max, l + 1);
 
   Debug("SCHED: CQI=%d, l=%d, nof_bits=%d, coderate=%.2f, max_coderate=%.2f",
         dl_cqi,

srsenb/test/mac/sched_common_test_suite.cc

@@ -217,7 +217,7 @@ int test_pdcch_collisions(const sf_output_res_t&                   sf_out,
   // Helper Function: checks if there is any collision. If not, fills the PDCCH mask
   auto try_cce_fill = [&](const srsran_dci_location_t& dci_loc, const char* ch) {
     uint32_t cce_start = dci_loc.ncce, cce_stop = dci_loc.ncce + (1u << dci_loc.L);
-    CONDERROR(dci_loc.L == 0, "The aggregation level %d is not valid", dci_loc.L);
+    CONDERROR(dci_loc.L > 3, "The aggregation level %d is not valid", dci_loc.L);
     CONDERROR(
         cce_start >= ncce or cce_stop > ncce, "The CCE positions (%u, %u) do not fit in PDCCH", cce_start, cce_stop);
     CONDERROR(

srsenb/test/mac/sched_test_rand.cc

@@ -294,6 +294,7 @@ sched_sim_events rand_sim_params(uint32_t nof_ttis)
       boolean_dist() ? -1 : std::uniform_int_distribution<>{0, 24}(srsenb::get_rand_gen());
   sim_gen.sim_args.sched_args.pusch_mcs =
       boolean_dist() ? -1 : std::uniform_int_distribution<>{0, 24}(srsenb::get_rand_gen());
+  sim_gen.sim_args.sched_args.min_aggr_level = std::uniform_int_distribution<>{0, 3}(srsenb::get_rand_gen());
 
   generator.tti_events.resize(nof_ttis);