sched,feature: Enable setting the target PHR below which the maximum UL grant size starts decreasing

lib/include/srsran/interfaces/enb_rrc_interface_types.h

@@ -61,6 +61,7 @@ struct cell_cfg_t {
   int                                 target_pusch_sinr_db;
   uint32_t                            initial_dl_cqi;
   bool                                enable_phr_handling;
+  int                                 min_phr_thres;
   asn1::rrc::mob_ctrl_info_s::t304_e_ t304;
   std::vector<scell_cfg_t>            scell_list;
   rrc_meas_cfg_t                      meas_cfg;

lib/include/srsran/interfaces/sched_interface.h

@@ -80,6 +80,7 @@ public:
     /* pusch configuration */
     srsran_pusch_hopping_cfg_t pusch_hopping_cfg;
     float                      target_pusch_ul_sinr;
+    int                        min_phr_thres;
     bool                       enable_phr_handling;
     bool                       enable_64qam;
 

srsenb/hdr/stack/mac/sched_ue_ctrl/tpc.h

@@ -40,6 +40,7 @@ public:
                float    target_pucch_snr_dB_  = -1.0,
                float    target_pusch_sn_dB_   = -1.0,
                bool     phr_handling_flag_    = false,
+               int      min_phr_thres_        = 0,
                uint32_t min_tpc_tti_interval_ = 1,
                float    ul_snr_avg_alpha      = 0.05,
                int      init_ul_snr_value     = 5) :
@@ -47,6 +48,7 @@ public:
     nof_prb(cell_nof_prb),
     target_pucch_snr_dB(target_pucch_snr_dB_),
     target_pusch_snr_dB(target_pusch_sn_dB_),
+    min_phr_thres(min_phr_thres_),
     snr_estim_list(
         {ul_ch_snr_estim{ul_snr_avg_alpha, init_ul_snr_value}, ul_ch_snr_estim{ul_snr_avg_alpha, init_ul_snr_value}}),
     phr_handling_flag(phr_handling_flag_),
@@ -83,7 +85,7 @@ public:
       max_prbs_cached = PHR_NEG_NOF_PRB;
       int phr_x_prb   = std::roundf(last_phr + 10.0F * log10f(grant_nof_prbs)); // get what the PHR would be if Nprb=1
       for (int n = nof_prb; n > PHR_NEG_NOF_PRB; --n) {
-        if (phr_x_prb >= 10 * log10f(n)) {
+        if (phr_x_prb >= 10 * log10f(n) + min_phr_thres) {
           max_prbs_cached = n;
           break;
         }
@@ -193,6 +195,7 @@ private:
   uint32_t              nof_prb;
   uint32_t              min_tpc_tti_interval = 1;
   float                 target_pucch_snr_dB, target_pusch_snr_dB;
+  int                   min_phr_thres;
   bool                  phr_handling_flag;
   srslog::basic_logger& logger;
 

srsenb/rr.conf.example

@@ -65,6 +65,8 @@ cell_list =
     //meas_gap_offset_subframe = [6, 12, 18, 24, 30];
     // target_pusch_sinr = -1;
     // target_pucch_sinr = -1;
+    // enable_phr_handling = false;
+    // min_phr_thres = 0;
     // allowed_meas_bw = 6;
     // t304 = 2000; // in msec. possible values: 50, 100, 150, 200, 500, 1000, 2000
 

srsenb/src/enb_cfg_parser.cc

@@ -771,6 +771,7 @@ static int parse_cell_list(all_args_t* args, rrc_cfg_t* rrc_cfg, Setting& root)
     HANDLEPARSERCODE(parse_default_field(cell_cfg.target_pusch_sinr_db, cellroot, "target_pusch_sinr", -1));
     HANDLEPARSERCODE(parse_default_field(cell_cfg.target_pucch_sinr_db, cellroot, "target_pucch_sinr", -1));
     HANDLEPARSERCODE(parse_default_field(cell_cfg.enable_phr_handling, cellroot, "enable_phr_handling", false));
+    HANDLEPARSERCODE(parse_default_field(cell_cfg.min_phr_thres, cellroot, "min_phr_thres", 0));
     parse_default_field(cell_cfg.meas_cfg.allowed_meas_bw, cellroot, "allowed_meas_bw", 6u);
     srsran_assert(srsran::is_lte_cell_nof_prb(cell_cfg.meas_cfg.allowed_meas_bw), "Invalid measurement Bandwidth");
     HANDLEPARSERCODE(asn1_parsers::default_number_to_enum(

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

@@ -40,6 +40,7 @@ sched_ue_cell::sched_ue_cell(uint16_t rnti_, const sched_cell_params_t& cell_cfg
           cell_cfg->cfg.target_pucch_ul_sinr,
           cell_cfg->cfg.target_pusch_ul_sinr,
           cell_cfg->cfg.enable_phr_handling,
+          cell_cfg->cfg.min_phr_thres,
           cell_cfg->sched_cfg->min_tpc_tti_interval,
           cell_cfg->sched_cfg->ul_snr_avg_alpha,
           cell_cfg->sched_cfg->init_ul_snr_value),

srsenb/src/stack/rrc/rrc.cc

@@ -635,6 +635,7 @@ void rrc::config_mac()
     item.target_pucch_ul_sinr = cfg.cell_list[ccidx].target_pucch_sinr_db;
     item.target_pusch_ul_sinr = cfg.cell_list[ccidx].target_pusch_sinr_db;
     item.enable_phr_handling  = cfg.cell_list[ccidx].enable_phr_handling;
+    item.min_phr_thres        = cfg.cell_list[ccidx].min_phr_thres;
     item.delta_pucch_shift    = cfg.sibs[1].sib2().rr_cfg_common.pucch_cfg_common.delta_pucch_shift.to_number();
     item.ncs_an               = cfg.sibs[1].sib2().rr_cfg_common.pucch_cfg_common.ncs_an;
     item.n1pucch_an           = cfg.sibs[1].sib2().rr_cfg_common.pucch_cfg_common.n1_pucch_an;

srsenb/test/mac/sched_test_rand.cc

@@ -274,6 +274,7 @@ sched_sim_events rand_sim_params(uint32_t nof_ttis)
   sim_gen.sim_args.cell_cfg[0].target_pucch_ul_sinr     = pick_random_uniform({10, 15, 20, -1});
   sim_gen.sim_args.cell_cfg[0].target_pusch_ul_sinr     = pick_random_uniform({10, 15, 20, -1});
   sim_gen.sim_args.cell_cfg[0].enable_phr_handling      = false;
+  sim_gen.sim_args.cell_cfg[0].min_phr_thres            = 0;
   sim_gen.sim_args.default_ue_sim_cfg.ue_cfg            = generate_default_ue_cfg();
   sim_gen.sim_args.default_ue_sim_cfg.periodic_cqi      = true;
   sim_gen.sim_args.default_ue_sim_cfg.ue_cfg.maxharq_tx = std::uniform_int_distribution<>{1, 5}(srsenb::get_rand_gen());

srsenb/test/mac/sched_test_utils.h

@@ -52,6 +52,8 @@ inline srsenb::sched_interface::cell_cfg_t generate_default_cell_cfg(uint32_t no
   cell_cfg.initial_dl_cqi       = 6;
   cell_cfg.target_pusch_ul_sinr = -1;
   cell_cfg.target_pucch_ul_sinr = -1;
+  cell_cfg.enable_phr_handling  = false;
+  cell_cfg.min_phr_thres        = 0;
   cell_cfg.nrb_cqi              = 1;
   cell_cfg.n1pucch_an           = 12;
   cell_cfg.delta_pucch_shift    = 1;

srsenb/test/mac/sched_ue_cell_test.cc

@@ -28,6 +28,7 @@ void test_neg_phr_scenario()
   sched_interface::cell_cfg_t cell_cfg    = generate_default_cell_cfg(50);
   cell_cfg.target_pucch_ul_sinr           = 20;
   cell_cfg.target_pusch_ul_sinr           = 20;
+  cell_cfg.min_phr_thres                  = 0;
   cell_cfg.enable_phr_handling            = true;
   sched_interface::sched_args_t sched_cfg = {};
   sched_cell_params_t           cell_params;
@@ -37,11 +38,14 @@ void test_neg_phr_scenario()
   sched_ue_cell ue_cc(0x46, cell_params, tti_point(0));
   ue_cc.set_ue_cfg(ue_cfg);
 
-  float snr = 0;
+  float     snr = 20;
-  ue_cc.set_ul_snr(tti_point(0), snr, 0);
+  tti_point tti{0};
-  ue_cc.set_ul_snr(tti_point(0), snr, 1);
+  for (; ue_cc.tpc_fsm.get_ul_snr_estim(0) < snr - 2; ++tti) {
+    ue_cc.set_ul_snr(tti, snr, 0);
+    ue_cc.set_ul_snr(tti, snr, 1);
     ue_cc.tpc_fsm.set_phr(-5, 1);
-  ue_cc.new_tti(tti_point(0));
+    ue_cc.new_tti(tti);
+  }
 
   uint32_t req_bytes    = 10000;
   uint32_t pending_prbs = get_required_prb_ul(ue_cc, req_bytes);