improvements in precoding initialization at MAC

common/utils/nr/nr_common.c

@@ -827,18 +827,6 @@ void get_samplerate_and_bw(int mu,
   }
 }
 
-void get_K1_K2(int N1, int N2, int *K1, int *K2)
-{
-  // num of allowed k1 and k2 according to 5.2.2.2.1-3 and -4 in 38.214
-  if(N2 == N1 || N1 == 2)
-    *K1 = 2;
-  else if (N2 == 1)
-    *K1 = 5;
-  else
-    *K1 = 3;
-  *K2 = N2 > 1 ? 2 : 1;
-}
-
 // from start symbol index and nb or symbols to symbol occupation bitmap in a slot
 uint16_t SL_to_bitmap(int startSymbolIndex, int nrOfSymbols) {
  return ((1<<nrOfSymbols)-1)<<startSymbolIndex;

common/utils/nr/nr_common.h

@@ -195,7 +195,6 @@ int get_dmrs_port(int nl, uint16_t dmrs_ports);
 uint16_t SL_to_bitmap(int startSymbolIndex, int nrOfSymbols);
 int get_nb_periods_per_frame(uint8_t tdd_period);
 long rrc_get_max_nr_csrs(const int max_rbs, long b_SRS);
-void get_K1_K2(int N1, int N2, int *K1, int *K2);
 bool compare_relative_ul_channel_bw(int nr_band, int scs, int nb_ul, frame_type_t frame_type);
 int get_supported_bw_mhz(frequency_range_t frequency_range, int bw_index);
 int get_supported_band_index(int scs, frequency_range_t freq_range, int n_rbs);

openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_primitives.c

@@ -223,21 +223,14 @@ uint16_t get_pm_index(const gNB_MAC_INST *nrmac,
     int k1, k2;
     get_k1_k2_indices(layers, N1, N2, i13, &k1, &k2); // get indices k1 and k2 for PHY matrix (not actual k1 and k2 values)
     const int O2 = N2 == 1 ? 1 : 4;
+    int O1 = 4; //Horizontal beam oversampling = 4 for more than 2 antenna ports
     int max_i2 = 0;
     int lay_index = 0;
-    if (layers == 1) {
-      max_i2 = 4;
-      // computing precoding matrix index according to rule set in allocation function init_codebook_gNB
-      lay_index = i2 + (i12 * max_i2) + (i11 * max_i2 * N2 * O2);
-    }
-    else {
-      max_i2 = 2;
-      // num of allowed k1 and k2 according to 5.2.2.2.1-3 and -4 in 38.214
+    max_i2 = layers == 1 ? 4 : 2;
     int K1, K2;
-      get_K1_K2(N1, N2, &K1, &K2);
+    get_K1_K2(N1, N2, &K1, &K2, layers);
     // computing precoding matrix index according to rule set in allocation function init_codebook_gNB
-      lay_index = i2 + (k2 * max_i2) + (k1 * max_i2 * K2) + (i12 * max_i2 * K2 * K1) + (i11 * max_i2 * K2 * K1 * N2 * O2);
-    }
+    lay_index = i2 + (i11 * max_i2) + (i12 * max_i2 * N1 * O1) + (k1 * max_i2 * N1 * O1 * N2 * O2) + (k2 * max_i2 * N1 * O1 * N2 * O2 * K1);
     return 1 + prev_layers_size + lay_index;
   }
 }

openair2/LAYER2/NR_MAC_gNB/mac_proto.h

@@ -36,6 +36,7 @@
 #include "common/ngran_types.h"
 
 void set_cset_offset(uint16_t);
+void get_K1_K2(int N1, int N2, int *K1, int *K2, int layers);
 
 void mac_top_init_gNB(ngran_node_t node_type,
                       NR_ServingCellConfigCommon_t *scc,