PUSCH DMRS generation

- added get_l_prime function
- added Table 6.4.1.1.3-3
- added added is_dmrs_symbol function

openair1/PHY/NR_REFSIG/dmrs_nr.h

@@ -57,6 +57,19 @@ void generate_dmrs_pbch(uint32_t dmrs_pbch_bitmap[DMRS_PBCH_I_SSB][DMRS_PBCH_N_H
 uint8_t get_l0_ul(uint8_t mapping_type, uint8_t dmrs_typeA_position);
 uint16_t get_dmrs_freq_idx_ul(uint16_t n, uint8_t k_prime, uint8_t delta, uint8_t dmrs_type);
 
+int32_t get_l_prime(uint8_t duration_in_symbols, uint8_t mapping_type, pusch_dmrs_AdditionalPosition_t additional_pos);
+
+uint8_t is_dmrs_symbol(uint8_t l,
+                       uint16_t k,
+                       uint16_t start_sc,
+                       uint8_t k_prime,
+                       uint16_t n,
+                       uint8_t delta,
+                       uint8_t duration_in_symbols,
+                       dmrs_UplinkConfig_t *dmrs_UplinkConfig,
+                       uint8_t mapping_type,
+                       uint16_t ofdm_symbol_size);
+
 #undef EXTERN
 
 #endif /* DMRS_NR_H */

openair1/PHY/NR_TRANSPORT/nr_sch_dmrs.c

@@ -32,7 +32,6 @@
 
 #include "nr_sch_dmrs.h"
 
-
 /*Table 7.4.1.1.2-1 and 7.4.1.1.2-2 38211 Columns: ap - CDM group - Delta - Wf(0) - Wf(1) - Wt(0) - Wt(1)*/
 /*Table 6.4.1.1.3-1 is identical to Table 7.4.1.1.2-1 and Table 6.4.1.1.3-2 is identical to Table 7.4.1.1.2-2. UL DMRS can reuse these tables*/
 int8_t pdsch_dmrs_1[8][7] = {{0,0,0,1,1,1,1},
@@ -57,11 +56,6 @@ int8_t pdsch_dmrs_2[12][7] = {{0,0,0,1,1,1,1},
                               {10,2,4,1,1,1,-1},
                               {11,2,4,1,-1,1,-1}};
 
-void get_l_prime(uint8_t *l_prime, uint8_t n_symbs) {
-  for (int i=0; i<n_symbs; i++)
-    *(l_prime+i) = i;
-}
-
 void get_antenna_ports(uint8_t *ap, uint8_t n_symbs, uint8_t config) {
   if (config == NFAPI_NR_DMRS_TYPE1)
     for (int i=0; i<(4+((n_symbs-1)<<2)); i++)

openair1/PHY/NR_TRANSPORT/nr_sch_dmrs.h

@@ -30,13 +30,14 @@
 * \warning
 */
 
+#ifndef NR_SCH_DMRS_H
+#define NR_SCH_DMRS_H
+
 #include "PHY/defs_nr_common.h"
 
 #define NR_PDSCH_DMRS_ANTENNA_PORT0 1000
 #define NR_PDSCH_DMRS_NB_ANTENNA_PORTS 12
 
-void get_l_prime(uint8_t *l_prime, uint8_t n_symbs);
-
 void get_antenna_ports(uint8_t *ap, uint8_t n_symbs, uint8_t config);
 
 void get_Wt(int8_t *Wt, uint8_t ap, uint8_t config);
@@ -48,3 +49,5 @@ uint8_t get_delta(uint8_t ap, uint8_t config);
 uint16_t get_dmrs_freq_idx(uint16_t n, uint8_t k_prime, uint8_t delta, uint8_t dmrs_type);
 
 uint8_t get_l0(uint8_t mapping_type, uint8_t dmrs_typeA_position);
+
+#endif

openair1/PHY/NR_UE_TRANSPORT/dmrs_nr.c

@@ -33,6 +33,124 @@
 #include "PHY/NR_REFSIG/ss_pbch_nr.h"
 #include "PHY/NR_REFSIG/dmrs_nr.h"
 
+/***********************************************************************/
+
+// TS 38.211 Table 6.4.1.1.3-3: PUSCH DMRS positions l' within a slot for single-symbol DMRS and intra-slot frequency hopping disabled.
+// The first 4 colomns are PUSCH mapping type A and the last 4 colomns are PUSCH mapping type B.
+// When l' = l0, it is represented by 1
+// E.g. when symbol duration is 12 in colomn 7, value 1057 ('10000100001') which means l' =  l0, 5, 10.
+
+int32_t table_6_4_1_1_3_3_pusch_dmrs_positions_l [12][8] = {                             // Duration in symbols
+{-1,          -1,          -1,         -1,          1,          1,         1,         1},       //<4              // (DMRS l' position)
+{1,            1,           1,          1,          1,          1,         1,         1},       //4               // (DMRS l' position)
+{1,            1,           1,          1,          1,          5,         5,         5},       //5               // (DMRS l' position)
+{1,            1,           1,          1,          1,          5,         5,         5},       //6               // (DMRS l' position)
+{1,            1,           1,          1,          1,          5,         5,         5},       //7               // (DMRS l' position)
+{1,          129,         129,        129,          1,         65,        73,        73},       //8               // (DMRS l' position)
+{1,          129,         129,        129,          1,         65,        73,        73},       //9               // (DMRS l' position)
+{1,          513,         577,        577,          1,        257,       273,       585},       //10              // (DMRS l' position)
+{1,          513,         577,        577,          1,        257,       273,       585},       //11              // (DMRS l' position)
+{1,          513,         577,       2337,          1,       1025,      1057,       585},       //12              // (DMRS l' position)
+{1,         2049,        2177,       2337,          1,       1025,      1057,       585},       //13              // (DMRS l' position)
+{1,         2049,        2177,       2337,          1,       1025,      1057,       585},       //14              // (DMRS l' position)
+};
+
+int32_t get_l_prime(uint8_t duration_in_symbols, uint8_t mapping_type, pusch_dmrs_AdditionalPosition_t additional_pos) {
+
+  uint8_t row, colomn;
+  int32_t l_prime;
+
+  colomn = additional_pos;
+
+  if (mapping_type == typeB)
+    colomn += 4;
+
+  if (duration_in_symbols < 4)
+    row = 0;
+  else
+    row = duration_in_symbols - 3;
+
+  l_prime = table_6_4_1_1_3_3_pusch_dmrs_positions_l[row][colomn];
+
+  AssertFatal(l_prime>0,"invalid l_prime < 0\n");
+
+  return l_prime;
+}
+
+/*******************************************************************
+*
+* NAME :         is_dmrs_symbol
+*
+* PARAMETERS : l                      ofdm symbol index within slot
+*              k                      subcarrier index
+*              start_sc               first subcarrier index
+*              k_prime                index alternating 0 and 1
+*              n                      index starting 0,1,...
+*              delta                  see Table 6.4.1.1.3
+*              duration_in_symbols    number of scheduled PUSCH ofdm symbols
+*              dmrs_UplinkConfig      DMRS uplink configuration
+*              mapping_type           PUSCH mapping type (A or B)
+*              ofdm_symbol_size       IFFT size
+*
+* RETURN :       0 if symbol(k,l) is data, or 1 if symbol(k,l) is dmrs
+*
+* DESCRIPTION :  3GPP TS 38.211 6.4.1.1 Demodulation reference signal for PUSCH
+*
+*********************************************************************/
+
+uint8_t is_dmrs_symbol(uint8_t l,
+                       uint16_t k,
+                       uint16_t start_sc,
+                       uint8_t k_prime,
+                       uint16_t n,
+                       uint8_t delta,
+                       uint8_t duration_in_symbols,
+                       dmrs_UplinkConfig_t *dmrs_UplinkConfig,
+                       uint8_t mapping_type,
+                       uint16_t ofdm_symbol_size) {
+
+  uint8_t is_dmrs_freq, is_dmrs_time, dmrs_type, l0;
+  int32_t l_prime_mask;
+  pusch_dmrs_AdditionalPosition_t additional_pos;
+
+  is_dmrs_freq = 0;
+  is_dmrs_time = 0;
+  dmrs_type = dmrs_UplinkConfig->pusch_dmrs_type;
+  additional_pos = dmrs_UplinkConfig->pusch_dmrs_AdditionalPosition;
+
+
+  l0 = get_l0_ul(mapping_type, 2);
+  l_prime_mask = get_l_prime(duration_in_symbols, mapping_type, additional_pos);
+
+  if (k == ((start_sc+get_dmrs_freq_idx_ul(n, k_prime, delta, dmrs_type))%ofdm_symbol_size))
+    is_dmrs_freq = 1;
+
+
+  if (l_prime_mask == 1){
+
+    if (l == l0)
+      is_dmrs_time = 1;
+
+  } else if ( (l==l0) || (((l_prime_mask>>l)&1) == 1 && l!=0) )
+    is_dmrs_time = 1;
+
+  if (dmrs_UplinkConfig->pusch_maxLength == pusch_len2){
+
+    if (((l_prime_mask>>(l-1))&1) == 1 && l!=0 && l!=1)
+      is_dmrs_time = 1;
+
+    if (l-1 == l0)
+      is_dmrs_time = 1;
+
+  }
+
+  if (is_dmrs_time && is_dmrs_freq)
+    return 1;
+  else
+    return 0;
+
+}
+
 /*******************************************************************
 *
 * NAME :         pseudo_random_gold_sequence

openair1/PHY/NR_UE_TRANSPORT/nr_ulsch_ue.c

@@ -287,17 +287,32 @@ void nr_ue_ulsch_procedures(PHY_VARS_NR_UE *UE,
     
 
     uint8_t k_prime=0;
+    uint8_t is_dmrs;
     uint16_t m=0, n=0, dmrs_idx=0, k=0;
 
     for (l=start_symbol; l<start_symbol+harq_process_ul_ue->number_of_symbols; l++) {
 
       k = start_sc;
+      n = 0;
 
       for (i=0; i<harq_process_ul_ue->nb_rb*NR_NB_SC_PER_RB; i++) {
 
         sample_offsetF = l*frame_parms->ofdm_symbol_size + k;
 
-        if ((l == dmrs_symbol) && (k == ((start_sc+get_dmrs_freq_idx_ul(n, k_prime, delta, dmrs_type))%(frame_parms->ofdm_symbol_size)))) {
+        is_dmrs = 0;
+
+        is_dmrs = is_dmrs_symbol(l,
+                                 k,
+                                 start_sc,
+                                 k_prime,
+                                 n,
+                                 delta,
+                                 harq_process_ul_ue->number_of_symbols,
+                                 &UE->dmrs_UplinkConfig,
+                                 mapping_type,
+                                 frame_parms->ofdm_symbol_size);
+
+        if (is_dmrs == 1) {
 
           ((int16_t*)txdataF[ap])[(sample_offsetF)<<1] = (Wt[l_prime[0]]*Wf[k_prime]*AMP*mod_dmrs[dmrs_idx<<1]) >> 15;
           ((int16_t*)txdataF[ap])[((sample_offsetF)<<1) + 1] = (Wt[l_prime[0]]*Wf[k_prime]*AMP*mod_dmrs[(dmrs_idx<<1) + 1]) >> 15;

openair1/PHY/impl_defs_nr.h

@@ -537,6 +537,7 @@ typedef enum {
 typedef enum {
   pusch_dmrs_pos0 = 0,
   pusch_dmrs_pos1 = 1,
+  pusch_dmrs_pos2 = 2,
   pusch_dmrs_pos3 = 3,
 } pusch_dmrs_AdditionalPosition_t;
 typedef enum {