Add NR-PUSCH-DMRS amplitude option and procedure

lib/include/srslte/phy/phch/phch_cfg_nr.h

@@ -59,7 +59,7 @@ typedef enum {
 } srslte_dmrs_sch_add_pos_t;
 
 /**
- * @brief Provides PDSCH DMRS configuration from higher layers
+ * @brief Provides PDSCH DMRS configuration
  * @remark Parameters described in TS 38.331 V15.10.0
  */
 typedef struct {
@@ -122,6 +122,10 @@ typedef struct SRSLTE_API {
   /// Described in TS 38.214 Section 5.1.6.2
   uint32_t nof_dmrs_cdm_groups_without_data;
 
+  /// Linear DMRS power offset. Zero means unset and it is equivalent to one.
+  /// For PUSCH, see TS 38.214 Table 6.2.2-1 for more information
+  float beta_dmrs;
+
   /// Spatial resources
   uint32_t nof_layers;
 

lib/include/srslte/phy/phch/ra_ul_nr.h

@@ -66,6 +66,16 @@ srslte_ra_ul_nr_pdsch_time_resource_default_A(uint32_t scs_cfg, uint32_t m, srsl
 SRSLTE_API int srslte_ra_ul_nr_nof_dmrs_cdm_groups_without_data_format_0_0(const srslte_sch_cfg_nr_t* cfg,
                                                                            srslte_sch_grant_nr_t*     grant);
 
+/**
+ * @brief Calculates the ratio of PUSCH EPRE to DM-RS EPRE
+ *
+ * @remark Defined by TS 38.214 V15.10.0 Table 6.2.2-1: The ratio of PUSCH EPRE to DM-RS EPRE
+ *
+ * @param[out] grant Provides grant pointer to fill
+ * @return Returns SRSLTE_SUCCESS if the provided data is valid, otherwise it returns SRSLTE_ERROR code
+ */
+SRSLTE_API int srslte_ra_ul_nr_dmrs_power_offset(srslte_sch_grant_nr_t* grant);
+
 /**
  * @brief Calculates the minimum number of PRB required for transmitting NR-PUCCH Format 2, 3 or 4
  * @remark Based in TS 38.213 9.2.5.1 UE procedure for multiplexing HARQ-ACK or CSI and SR in a PUCCH

lib/src/phy/ch_estimation/dmrs_sch.c

@@ -71,6 +71,7 @@ static uint32_t srslte_dmrs_get_lse(srslte_dmrs_sch_t*       q,
                                     uint32_t                 start_prb,
                                     uint32_t                 nof_prb,
                                     uint32_t                 delta,
+                                    float                    amplitude,
                                     const cf_t*              symbols,
                                     cf_t*                    least_square_estimates)
 {
@@ -88,7 +89,7 @@ static uint32_t srslte_dmrs_get_lse(srslte_dmrs_sch_t*       q,
   }
 
   // Generate sequence for the given pilots
-  srslte_sequence_state_gen_f(sequence_state, M_SQRT1_2, (float*)q->temp, count * 2);
+  srslte_sequence_state_gen_f(sequence_state, amplitude, (float*)q->temp, count * 2);
 
   // Calculate least square estimates
   srslte_vec_prod_conj_ccc(least_square_estimates, q->temp, least_square_estimates, count);
@@ -134,12 +135,13 @@ static uint32_t srslte_dmrs_put_pilots(srslte_dmrs_sch_t*       q,
                                        uint32_t                 start_prb,
                                        uint32_t                 nof_prb,
                                        uint32_t                 delta,
+                                       float                    amplitude,
                                        cf_t*                    symbols)
 {
   uint32_t count = (dmrs_type == srslte_dmrs_sch_type_1) ? nof_prb * 6 : nof_prb * 4;
 
   // Generate sequence for the given pilots
-  srslte_sequence_state_gen_f(sequence_state, M_SQRT1_2, (float*)q->temp, count * 2);
+  srslte_sequence_state_gen_f(sequence_state, amplitude, (float*)q->temp, count * 2);
 
   switch (dmrs_type) {
     case srslte_dmrs_sch_type_1:
@@ -162,6 +164,12 @@ static int srslte_dmrs_sch_put_symbol(srslte_dmrs_sch_t*           q,
                                       uint32_t                     delta,
                                       cf_t*                        symbols)
 {
+  // Get signal amplitude
+  float amplitude = M_SQRT1_2;
+  if (isnormal(grant->beta_dmrs)) {
+    amplitude *= grant->beta_dmrs;
+  }
+
   const srslte_dmrs_sch_cfg_t* dmrs_cfg         = &pdsch_cfg->dmrs;
   uint32_t                     prb_count        = 0; // Counts consecutive used PRB
   uint32_t                     prb_start        = 0; // Start consecutive used PRB
@@ -200,14 +208,16 @@ static int srslte_dmrs_sch_put_symbol(srslte_dmrs_sch_t*           q,
     }
 
     // Get contiguous pilots
-    pilot_count += srslte_dmrs_put_pilots(q, &sequence_state, dmrs_cfg->type, prb_start, prb_count, delta, symbols);
+    pilot_count +=
+        srslte_dmrs_put_pilots(q, &sequence_state, dmrs_cfg->type, prb_start, prb_count, delta, amplitude, symbols);
 
     // Reset counter
     prb_count = 0;
   }
 
   if (prb_count > 0) {
-    pilot_count += srslte_dmrs_put_pilots(q, &sequence_state, dmrs_cfg->type, prb_start, prb_count, delta, symbols);
+    pilot_count +=
+        srslte_dmrs_put_pilots(q, &sequence_state, dmrs_cfg->type, prb_start, prb_count, delta, amplitude, symbols);
   }
 
   return pilot_count;
@@ -455,9 +465,8 @@ static uint32_t srslte_dmrs_sch_seed(const srslte_carrier_nr_t*   carrier,
     n_id = dmrs_cfg->scrambling_id1;
   }
 
-  return (uint32_t)(((((SRSLTE_NSYMB_PER_SLOT_NR * slot_idx + symbol_idx + 1UL) * (2UL * n_id + 1UL)) << 17UL) +
+  return SRSLTE_SEQUENCE_MOD((((SRSLTE_NSYMB_PER_SLOT_NR * slot_idx + symbol_idx + 1UL) * (2UL * n_id + 1UL)) << 17UL) +
-                     (2UL * carrier->id + n_scid)) &
+                             (2UL * carrier->id + n_scid));
-                    (uint64_t)INT32_MAX);
 }
 
 int srslte_dmrs_sch_init(srslte_dmrs_sch_t* q, bool is_rx)
@@ -585,6 +594,12 @@ static int srslte_dmrs_sch_get_symbol(srslte_dmrs_sch_t*           q,
                                       const cf_t*                  symbols,
                                       cf_t*                        least_square_estimates)
 {
+  // Get signal amplitude
+  float amplitude = M_SQRT1_2;
+  if (isnormal(grant->beta_dmrs)) {
+    amplitude /= grant->beta_dmrs;
+  }
+
   const srslte_dmrs_sch_cfg_t* dmrs_cfg = &pdsch_cfg->dmrs;
 
   uint32_t prb_count        = 0; // Counts consecutive used PRB
@@ -624,16 +639,30 @@ static int srslte_dmrs_sch_get_symbol(srslte_dmrs_sch_t*           q,
     }
 
     // Get contiguous pilots
-    pilot_count += srslte_dmrs_get_lse(
+    pilot_count += srslte_dmrs_get_lse(q,
-        q, &sequence_state, dmrs_cfg->type, prb_start, prb_count, delta, symbols, &least_square_estimates[pilot_count]);
+                                       &sequence_state,
+                                       dmrs_cfg->type,
+                                       prb_start,
+                                       prb_count,
+                                       delta,
+                                       amplitude,
+                                       symbols,
+                                       &least_square_estimates[pilot_count]);
 
     // Reset counter
     prb_count = 0;
   }
 
   if (prb_count > 0) {
-    pilot_count += srslte_dmrs_get_lse(
+    pilot_count += srslte_dmrs_get_lse(q,
-        q, &sequence_state, dmrs_cfg->type, prb_start, prb_count, delta, symbols, &least_square_estimates[pilot_count]);
+                                       &sequence_state,
+                                       dmrs_cfg->type,
+                                       prb_start,
+                                       prb_count,
+                                       delta,
+                                       amplitude,
+                                       symbols,
+                                       &least_square_estimates[pilot_count]);
   }
 
   return pilot_count;

lib/src/phy/phch/ra_nr.c

@@ -553,24 +553,11 @@ ra_ul_dmrs(const srslte_sch_hl_cfg_nr_t* pusch_hl_cfg, srslte_sch_grant_nr_t* pu
       cfg->dmrs.length                 = srslte_dmrs_sch_len_1;
       cfg->dmrs.scrambling_id0_present = false;
       cfg->dmrs.scrambling_id1_present = false;
-
-      if (pusch_grant->dci_format == srslte_dci_format_nr_0_0) {
-        if (srslte_ra_ul_nr_nof_dmrs_cdm_groups_without_data_format_0_0(cfg, pusch_grant) < SRSLTE_SUCCESS) {
-          ERROR("Error loading number of DMRS CDM groups\n");
-          return SRSLTE_ERROR;
-        }
     } else {
-        ERROR("Invalid case\n");
-        return SRSLTE_ERROR;
-      }
-
-      return SRSLTE_SUCCESS;
-    }
-
       ERROR("Unsupported configuration");
       return SRSLTE_ERROR;
     }
-
+  } else {
     if (pusch_grant->mapping == srslte_sch_mapping_type_A) {
       cfg->dmrs.additional_pos         = pusch_hl_cfg->dmrs_typeA.additional_pos;
       cfg->dmrs.type                   = pusch_hl_cfg->dmrs_typeA.type;
@@ -584,6 +571,24 @@ ra_ul_dmrs(const srslte_sch_hl_cfg_nr_t* pusch_hl_cfg, srslte_sch_grant_nr_t* pu
       cfg->dmrs.scrambling_id0_present = false;
       cfg->dmrs.scrambling_id1_present = false;
     }
+  }
+
+  // Set number of DMRS CDM groups without data
+  if (pusch_grant->dci_format == srslte_dci_format_nr_0_0) {
+    if (srslte_ra_ul_nr_nof_dmrs_cdm_groups_without_data_format_0_0(cfg, pusch_grant) < SRSLTE_SUCCESS) {
+      ERROR("Error loading number of DMRS CDM groups\n");
+      return SRSLTE_ERROR;
+    }
+  } else {
+    ERROR("Invalid case\n");
+    return SRSLTE_ERROR;
+  }
+
+  // Set DMRS power offset Table 6.2.2-1: The ratio of PUSCH EPRE to DM-RS EPRE
+  if (srslte_ra_ul_nr_dmrs_power_offset(pusch_grant) < SRSLTE_SUCCESS) {
+    ERROR("Error setting DMRS power offset");
+    return SRSLTE_ERROR;
+  }
 
   return SRSLTE_SUCCESS;
 }

lib/src/phy/phch/ra_ul_nr.c

@@ -15,6 +15,7 @@
 #include "srslte/phy/ch_estimation/dmrs_pucch.h"
 #include "srslte/phy/common/phy_common.h"
 #include "srslte/phy/utils/debug.h"
+#include "srslte/phy/utils/vector.h"
 
 typedef struct {
   srslte_sch_mapping_type_t mapping;
@@ -216,6 +217,24 @@ int srslte_ra_ul_nr_nof_dmrs_cdm_groups_without_data_format_0_0(const srslte_sch
   return SRSLTE_SUCCESS;
 }
 
+int srslte_ra_ul_nr_dmrs_power_offset(srslte_sch_grant_nr_t* grant)
+{
+  if (grant == NULL) {
+    return SRSLTE_ERROR_INVALID_INPUTS;
+  }
+
+  float ratio_dB[3] = {0, -3, -4.77};
+
+  if (grant->nof_dmrs_cdm_groups_without_data < 1 || grant->nof_dmrs_cdm_groups_without_data > 3) {
+    ERROR("Invalid number of DMRS CDM groups without data (%d)", grant->nof_dmrs_cdm_groups_without_data);
+    return SRSLTE_ERROR;
+  }
+
+  grant->beta_dmrs = srslte_convert_dB_to_amplitude(-ratio_dB[grant->nof_dmrs_cdm_groups_without_data - 1]);
+
+  return SRSLTE_SUCCESS;
+}
+
 #define RA_UL_PUCCH_CODE_RATE_N 8
 #define RA_UL_PUCCH_CODE_RATE_RESERVED NAN