Solved PDSCH Power Allocation p_b on eNB side

lib/include/srslte/phy/enb/enb_dl.h

@@ -88,6 +88,7 @@ typedef struct SRSLTE_API {
   float sss_signal5[SRSLTE_SSS_LEN]; 
     
   float tx_amp;
+  float rho_b;
 
   uint8_t tmp[1024*128];
   
@@ -122,6 +123,14 @@ SRSLTE_API int srslte_enb_dl_set_cell(srslte_enb_dl_t *q,
 SRSLTE_API void srslte_enb_dl_set_cfi(srslte_enb_dl_t *q,
                                       uint32_t cfi);
 
+SRSLTE_API void srslte_enb_dl_set_power_allocation(srslte_enb_dl_t *q,
+                                                   float rho_a,
+                                                   float rho_b);
+
+SRSLTE_API void srslte_enb_dl_apply_power_allocation(srslte_enb_dl_t *q);
+
+SRSLTE_API void srslte_enb_dl_prepare_power_allocation(srslte_enb_dl_t *q);
+
 SRSLTE_API void srslte_enb_dl_set_amp(srslte_enb_dl_t *q, 
                                       float amp); 
 

lib/src/phy/enb/enb_dl.c

@@ -213,6 +213,70 @@ void srslte_enb_dl_set_cfi(srslte_enb_dl_t *q, uint32_t cfi)
   srslte_regs_set_cfi(&q->regs, cfi);
 }
 
+void srslte_enb_dl_set_power_allocation(srslte_enb_dl_t *q, float rho_a, float rho_b)
+{
+  if (q) {
+    q->rho_b = rho_b;
+    srslte_pdsch_set_power_allocation(&q->pdsch, rho_a);
+  }
+}
+
+void srslte_enb_dl_apply_power_allocation(srslte_enb_dl_t *q)
+{
+  uint32_t nof_symbols_slot = SRSLTE_CP_NSYMB(q->cell.cp);
+  uint32_t nof_re_symbol = SRSLTE_NRE * q->cell.nof_prb;
+
+  if (q->rho_b != 0.0f && q->rho_b != 1.0f) {
+    float scaling = q->rho_b;
+    for (uint32_t i = 0; i < q->cell.nof_ports; i++) {
+      for (uint32_t j = 0; j < 2; j++) {
+        cf_t *ptr;
+        ptr = q->sf_symbols[i] + nof_re_symbol * (j * nof_symbols_slot + 0);
+        srslte_vec_sc_prod_cfc(ptr, scaling, ptr, nof_re_symbol);
+        if (q->cell.cp == SRSLTE_CP_NORM) {
+          ptr = q->sf_symbols[i] + nof_re_symbol * (j * nof_symbols_slot + 4);
+          srslte_vec_sc_prod_cfc(ptr, scaling, ptr, nof_re_symbol);
+        } else {
+          ptr = q->sf_symbols[i] + nof_re_symbol * (j * nof_symbols_slot + 3);
+          srslte_vec_sc_prod_cfc(ptr, scaling, ptr, nof_re_symbol);
+        }
+        if (q->cell.nof_ports == 4) {
+          ptr = q->sf_symbols[i] + nof_re_symbol * (j * nof_symbols_slot + 1);
+          srslte_vec_sc_prod_cfc(ptr, scaling, ptr, nof_re_symbol);
+        }
+      }
+    }
+  }
+}
+
+void srslte_enb_dl_prepare_power_allocation(srslte_enb_dl_t *q)
+{
+  uint32_t nof_symbols_slot = SRSLTE_CP_NSYMB(q->cell.cp);
+  uint32_t nof_re_symbol = SRSLTE_NRE * q->cell.nof_prb;
+
+  if (q->rho_b != 0.0f && q->rho_b != 1.0f) {
+    float scaling = 1.0f / q->rho_b;
+    for (uint32_t i = 0; i < q->cell.nof_ports; i++) {
+      for (uint32_t j = 0; j < 2; j++) {
+        cf_t *ptr;
+        ptr = q->sf_symbols[i] + nof_re_symbol * (j * nof_symbols_slot + 0);
+        srslte_vec_sc_prod_cfc(ptr, scaling, ptr, nof_re_symbol);
+        if (q->cell.cp == SRSLTE_CP_NORM) {
+          ptr = q->sf_symbols[i] + nof_re_symbol * (j * nof_symbols_slot + 4);
+          srslte_vec_sc_prod_cfc(ptr, scaling, ptr, nof_re_symbol);
+        } else {
+          ptr = q->sf_symbols[i] + nof_re_symbol * (j * nof_symbols_slot + 3);
+          srslte_vec_sc_prod_cfc(ptr, scaling, ptr, nof_re_symbol);
+        }
+        if (q->cell.nof_ports == 4) {
+          ptr = q->sf_symbols[i] + nof_re_symbol * (j * nof_symbols_slot + 1);
+          srslte_vec_sc_prod_cfc(ptr, scaling, ptr, nof_re_symbol);
+        }
+      }
+    }
+  }
+}
+
 void srslte_enb_dl_clear_sf(srslte_enb_dl_t *q)
 {
   for (int i=0;i<q->cell.nof_ports;i++) {

lib/src/phy/phch/pdsch.c

@@ -818,6 +818,12 @@ int srslte_pdsch_encode(srslte_pdsch_t *q,
       }
     }
 
+    /* Set scaling configured by Power Allocation */
+    float scaling = 1.0f;
+    if (q->rho_a != 0.0f) {
+      scaling = q->rho_a;
+    }
+
     // Layer mapping & precode if necessary
     if (q->cell.nof_ports > 1) {
       int nof_symbols;
@@ -841,9 +847,13 @@ int srslte_pdsch_encode(srslte_pdsch_t *q,
 
       /* Precode */
       srslte_precoding_type(x, q->symbols, cfg->nof_layers, q->cell.nof_ports, cfg->codebook_idx,
-                            nof_symbols, 1.0f, cfg->mimo_type);
+                            nof_symbols, scaling, cfg->mimo_type);
     } else {
-      memcpy(q->symbols[0], q->d[0], cfg->nbits[0].nof_re * sizeof(cf_t));
+      if (scaling == 1.0f) {
+        memcpy(q->symbols[0], q->d[0], cfg->nbits[0].nof_re * sizeof(cf_t));
+      } else {
+        srslte_vec_sc_prod_cfc(q->d[0], scaling, q->symbols[0], cfg->nbits[0].nof_re);
+      }
     }
 
     /* mapping to resource elements */

srsenb/hdr/enb.h

@@ -68,6 +68,7 @@ typedef struct {
   uint32_t    pci; 
   uint32_t    nof_ports;
   uint32_t    transmission_mode;
+  float       p_a;
 }enb_args_t;
 
 typedef struct {

srsenb/hdr/phy/phch_common.h

@@ -72,6 +72,7 @@ public:
   srslte_refsignal_dmrs_pusch_cfg_t pusch_cfg; 
   srslte_pusch_hopping_cfg_t        hopping_cfg;
   srslte_pucch_cfg_t                pucch_cfg; 
+  uint8_t                           pdsch_p_b;
   phy_args_t                        params; 
 
   srslte::radio     *radio;

srsenb/hdr/upper/rrc.h

@@ -80,6 +80,7 @@ typedef struct {
   LIBLTE_RRC_MAC_MAIN_CONFIG_STRUCT        mac_cnfg; 
   LIBLTE_RRC_PUSCH_CONFIG_DEDICATED_STRUCT pusch_cfg;   
   LIBLTE_RRC_ANTENNA_INFO_DEDICATED_STRUCT antenna_info;
+  LIBLTE_RRC_PDSCH_CONFIG_P_A_ENUM         pdsch_cfg;
   rrc_cfg_sr_t                             sr_cfg; 
   rrc_cfg_cqi_t                            cqi_cfg; 
   rrc_cfg_qci_t                            qci_cfg[MAX_NOF_QCI]; 

srsenb/src/enb_cfg_parser.cc

@@ -866,6 +866,18 @@ int enb::parse_rr(all_args_t* args, rrc_cfg_t* rrc_cfg)
     rrc_cfg->antenna_info.codebook_subset_restriction_present = true;
   }
 
+  /* Parse power allocation */
+  rrc_cfg->pdsch_cfg = LIBLTE_RRC_PDSCH_CONFIG_P_A_N_ITEMS;
+  for (int i = 0; i < LIBLTE_RRC_PDSCH_CONFIG_P_A_N_ITEMS; i++) {
+    if (args->enb.p_a == liblte_rrc_pdsch_config_p_a_num[i]) {
+      rrc_cfg->pdsch_cfg = (LIBLTE_RRC_PDSCH_CONFIG_P_A_ENUM) i;
+    }
+  }
+  if (rrc_cfg->pdsch_cfg == LIBLTE_RRC_PDSCH_CONFIG_P_A_N_ITEMS) {
+    ERROR("Invalid p_a value (%f) only -6, -4.77, -3, -1.77, 0, 1, 2, 3 values allowed.", args->enb.p_a);
+    return SRSLTE_ERROR;
+  }
+
   /* MAC config section */
   parser::section mac_cnfg("mac_cnfg");
 

srsenb/src/main.cc

@@ -79,6 +79,7 @@ void parse_args(all_args_t *args, int argc, char* argv[]) {
     ("enb.n_prb",         bpo::value<uint32_t>(&args->enb.n_prb)->default_value(25),               "Number of PRB")
     ("enb.nof_ports",     bpo::value<uint32_t>(&args->enb.nof_ports)->default_value(1),            "Number of ports")
     ("enb.tm",            bpo::value<uint32_t>(&args->enb.transmission_mode)->default_value(1),    "Transmission mode (1-8)")
+    ("enb.p_a",           bpo::value<float>(&args->enb.p_a)->default_value(0.0f),                  "Power allocation rho_a (-6, -4.77, -3, -1.77, 0, 1, 2, 3)")
 
     ("enb_files.sib_config", bpo::value<string>(&args->enb_files.sib_config)->default_value("sib.conf"),      "SIB configuration files")
     ("enb_files.rr_config",  bpo::value<string>(&args->enb_files.rr_config)->default_value("rr.conf"),      "RR configuration files")

srsenb/src/phy/phch_worker.cc

@@ -776,6 +776,10 @@ int phch_worker::encode_pdcch_dl(srslte_enb_dl_pdsch_t *grants, uint32_t nof_gra
 }
 
 int phch_worker::encode_pdsch(srslte_enb_dl_pdsch_t *grants, uint32_t nof_grants) {
+
+  /* Scales the Resources Elements affected by the power allocation (p_b) */
+  srslte_enb_dl_prepare_power_allocation(&enb_dl);
+
   for (uint32_t i = 0; i < nof_grants; i++) {
     uint16_t rnti = grants[i].rnti;
     if (rnti) {
@@ -871,6 +875,18 @@ int phch_worker::encode_pdsch(srslte_enb_dl_pdsch_t *grants, uint32_t nof_grants
 
       int rv[SRSLTE_MAX_CODEWORDS] = {grants[i].grant.rv_idx, grants[i].grant.rv_idx_1};
 
+      /* Set power allocation */
+      float rho_a = 1.0f, rho_b = 1.0f;
+      if (ue_db[rnti].dedicated.pdsch_cnfg_ded < LIBLTE_RRC_PDSCH_CONFIG_P_A_N_ITEMS) {
+        float rho_a_db = liblte_rrc_pdsch_config_p_a_num[ue_db[rnti].dedicated.pdsch_cnfg_ded];
+        rho_a = powf(10.0f, rho_a_db / 20.0f) * ((enb_dl.cell.nof_ports == 1) ? 1.0f : sqrtf(2.0f));
+      }
+      if (phy->pdsch_p_b < 4) {
+        uint32_t idx0 = (phy->cell.nof_ports == 1) ? 0 : 1;
+        float cell_specific_ratio = pdsch_cfg_cell_specific_ratio_table[idx0][phy->pdsch_p_b];
+        rho_b = sqrtf(cell_specific_ratio);
+      }
+      srslte_enb_dl_set_power_allocation(&enb_dl, rho_a, rho_b);
       if (srslte_enb_dl_put_pdsch(&enb_dl, &phy_grant, grants[i].softbuffers, rnti, rv, sf_tx, grants[i].data, mimo_type)) {
         fprintf(stderr, "Error putting PDSCH %d\n", i);
         return SRSLTE_ERROR;
@@ -880,6 +896,9 @@ int phch_worker::encode_pdsch(srslte_enb_dl_pdsch_t *grants, uint32_t nof_grants
       ue_db[rnti].metrics_dl(phy_grant.mcs[0].idx);
     }
   }
+
+  srslte_enb_dl_apply_power_allocation(&enb_dl);
+
   return SRSLTE_SUCCESS;
 }
 

srsenb/src/phy/phy.cc

@@ -80,7 +80,10 @@ void phy::parse_config(phy_cfg_t* cfg)
   workers_common.pucch_cfg.N_cs               = cfg->pucch_cnfg.n_cs_an;
   workers_common.pucch_cfg.n_rb_2             = cfg->pucch_cnfg.n_rb_cqi;
   workers_common.pucch_cfg.srs_configured     = false;
-  workers_common.pucch_cfg.n1_pucch_an        = cfg->pucch_cnfg.n1_pucch_an;; 
+  workers_common.pucch_cfg.n1_pucch_an        = cfg->pucch_cnfg.n1_pucch_an;
+
+  // PDSCH configuration
+  workers_common.pdsch_p_b                    = cfg->pdsch_cnfg.p_b;
 }
 
 bool phy::init(phy_args_t *args, 

srsenb/src/upper/rrc.cc

@@ -1148,7 +1148,7 @@ void rrc::ue::send_connection_setup(bool is_setup)
   phy_cfg->ul_pwr_ctrl_ded.p_srs_offset = 3; 
   
   phy_cfg->pdsch_cnfg_ded_present = true; 
-  phy_cfg->pdsch_cnfg_ded = LIBLTE_RRC_PDSCH_CONFIG_P_A_DB_0; 
+  phy_cfg->pdsch_cnfg_ded = parent->cfg.pdsch_cfg;
   
   phy_cfg->cqi_report_cnfg_present = true; 
   if(parent->cfg.cqi_cfg.mode == RRC_CFG_CQI_MODE_APERIODIC) {