add pdcch_cqi_offset parameter to enb.conf

lib/include/srsran/interfaces/sched_interface.h

@@ -66,6 +66,7 @@ public:
     int         init_ul_snr_value       = 5;
     int         init_dl_cqi             = 5;
     float       max_sib_coderate        = 0.8;
+    int         pdcch_cqi_offset        = 0;
   };
 
   struct cell_cfg_t {

srsenb/enb.conf.example

@@ -180,6 +180,7 @@ enable = false
 # init_ul_snr_value: Initial UL SNR value used for computing MCS in the first UL grant
 # init_dl_cqi:       DL CQI value used before any CQI report is available to the eNB
 # max_sib_coderate:  Upper bound on SIB and RAR grants coderate
+# pdcch_cqi_offset:  CQI offset in derivation of PDCCH aggregation level
 #
 #####################################################################
 [scheduler]
@@ -204,6 +205,7 @@ enable = false
 #init_ul_snr_value=5
 #init_dl_cqi=5
 #max_sib_coderate=0.3
+#pdcch_cqi_offset=0
 
 #####################################################################
 # eMBMS configuration options

srsenb/src/main.cc

@@ -162,6 +162,8 @@ void parse_args(all_args_t* args, int argc, char* argv[])
     ("scheduler.init_ul_snr_value", bpo::value<int>(&args->stack.mac.sched.init_ul_snr_value)->default_value(5), "Initial UL SNR value used for computing MCS in the first UL grant")
     ("scheduler.init_dl_cqi", bpo::value<int>(&args->stack.mac.sched.init_dl_cqi)->default_value(5), "DL CQI value used before any CQI report is available to the eNB")
     ("scheduler.max_sib_coderate", bpo::value<float>(&args->stack.mac.sched.max_sib_coderate)->default_value(0.8), "Upper bound on SIB and RAR grants coderate")
+    ("scheduler.pdcch_cqi_offset", bpo::value<int>(&args->stack.mac.sched.pdcch_cqi_offset)->default_value(0), "CQI offset in derivation of PDCCH aggregation level")
+
 
 
     /* Downlink Channel emulator section */

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

@@ -279,6 +279,7 @@ uint32_t sched_ue_cell::get_aggr_level(uint32_t nof_bits) const
   } else {
     dl_cqi = dl_cqi_ctxt.get_avg_cqi();
   }
+  dl_cqi = std::max(cell_cfg->sched_cfg->pdcch_cqi_offset + (int)dl_cqi, 0);
   return srsenb::get_aggr_level(nof_bits,
                                 dl_cqi,
                                 cell_cfg->sched_cfg->min_aggr_level,