PBCH DMRS TX

cmake_targets/CMakeLists.txt

@@ -1262,6 +1262,9 @@ set(PHY_SRC_UE
   ${OPENAIR1_DIR}/PHY/INIT/nr_parms.c
   ${OPENAIR1_DIR}/PHY/NR_TRANSPORT/nr_pss.c
   ${OPENAIR1_DIR}/PHY/NR_TRANSPORT/nr_sss.c
+  ${OPENAIR1_DIR}/PHY/NR_TRANSPORT/nr_pbch.c
+  ${OPENAIR1_DIR}/PHY/LTE_REFSIG/lte_gold.c
+  ${OPENAIR1_DIR}/PHY/NR_REFSIG/nr_gold.c
   ${OPENAIR1_DIR}/PHY/TOOLS/file_output.c
   ${OPENAIR1_DIR}/PHY/TOOLS/cadd_vv.c
   ${OPENAIR1_DIR}/PHY/TOOLS/lte_dfts.c

openair1/PHY/INIT/nr_init.c

@@ -112,6 +112,7 @@ int phy_init_nr_gNB(PHY_VARS_gNB *gNB,
         );*/
   LOG_D(PHY,"[MSC_NEW][FRAME 00000][PHY_gNB][MOD %02"PRIu8"][]\n", gNB->Mod_id);
 
+  nr_init_pbch_dmrs(gNB);
 /*
   lte_gold(fp,gNB->lte_gold_table,fp->Nid_cell);
   generate_pcfich_reg_mapping(fp);

openair1/PHY/NR_REFSIG/defs.h

+/*
+ * Licensed to the OpenAirInterface (OAI) Software Alliance under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The OpenAirInterface Software Alliance licenses this file to You under
+ * the OAI Public License, Version 1.1  (the "License"); you may not use this file
+ * except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.openairinterface.org/?page_id=698
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *-------------------------------------------------------------------------------
+ * For more information about the OpenAirInterface (OAI) Software Alliance:
+ *      contact@openairinterface.org
+ */
+
+/* Definitions for LTE Reference signals */
+/* Author R. Knopp / EURECOM / OpenAirInterface.org */
+#ifndef __NR_REFSIG_DEFS__H__
+#define __NR_REFSIG_DEFS__H__
+#include "PHY/defs.h"
+
+
+/*!\brief This function generates the NR Gold sequence (38-211, Sec 5.2.1) for the PBCH DMRS.
+@param PHY_VARS_gNB* gNB structure provides configuration, frame parameters and the pointers to the 32 bits sequence storage tables
+ */
+void nr_init_pbch_dmrs(PHY_VARS_gNB* gNB);
+
+
+#endif

openair1/PHY/NR_REFSIG/nr_gen_mod_table.m

@@ -3,9 +3,6 @@
 % 0        .. "0"
 % 1,2      .. BPSK(0),BPSK(1)
 
-% 2^15 /sqrt(2) K = 768;
-K = 768*sqrt(2)/2^15;
-
 % Amplitude for BPSK (\f$ 2^15 \times 1/\sqrt{2}\f$)
 BPSK = 23170;
 
@@ -14,7 +11,7 @@ for b = 0:1
 bpsk_table(b+1) = (1 - 2*b)*BPSK + 1j*(1-2*b)*BPSK;
 end
 
-table = round(K * [ 0; bpsk_table(:) ]);
+table = [ 0; bpsk_table(:) ];
 
 save mod_table.mat table
 

openair1/PHY/NR_REFSIG/nr_gold.c

+/*
+ * Licensed to the OpenAirInterface (OAI) Software Alliance under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The OpenAirInterface Software Alliance licenses this file to You under
+ * the OAI Public License, Version 1.1  (the "License"); you may not use this file
+ * except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.openairinterface.org/?page_id=698
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *-------------------------------------------------------------------------------
+ * For more information about the OpenAirInterface (OAI) Software Alliance:
+ *      contact@openairinterface.org
+ */
+
+#include "defs.h"
+
+void nr_init_pbch_dmrs(PHY_VARS_gNB* gNB)
+{
+
+  unsigned int n, x1, x2;
+  unsigned char Nid, i_ssb, i_ssb2;
+  unsigned char Lmax, l, n_hf, N_hf;
+  nfapi_config_request_t *cfg = &gNB->gNB_config;
+  NR_DL_FRAME_PARMS *fp = &gNB->frame_parms;
+
+  Nid = cfg->sch_config.physical_cell_id.value;
+
+  Lmax = (fp->dl_CarrierFreq < 3e9)? 4:8;
+  N_hf = (Lmax == 4)? 2:1;
+
+  for (n_hf = 0; n_hf < N_hf; n_hf++) {
+
+    for (l = 0; l < Lmax ; l++) {
+      i_ssb = l & Lmax;
+      i_ssb2 = (i_ssb<<2) + n_hf;
+
+      x1 = 1 + (1<<31);
+      x2 = (1<<11) * (i_ssb2 + 1) * ((Nid>>2) + 1) + (1<<6) * (i_ssb2 + 1) + (Nid&3);
+      x2 = x2 ^ ((x2 ^ (x2>>1) ^ (x2>>2) ^ (x2>>3))<<31);
+
+      // skip first 50 double words (1600 bits)
+      for (n = 1; n < 50; n++) {
+        x1 = (x1>>1) ^ (x1>>4);
+        x1 = x1 ^ (x1<<31) ^ (x1<<28);
+        x2 = (x2>>1) ^ (x2>>2) ^ (x2>>3) ^ (x2>>4);
+        x2 = x2 ^ (x2<<31) ^ (x2<<30) ^ (x2<<29) ^ (x2<<28);
+      }
+
+      for (n=0; n<NR_PBCH_DMRS_LENGTH_DWORD; n++) {
+        x1 = (x1>>1) ^ (x1>>4);
+        x1 = x1 ^ (x1<<31) ^ (x1<<28);
+        x2 = (x2>>1) ^ (x2>>2) ^ (x2>>3) ^ (x2>>4);
+        x2 = x2 ^ (x2<<31) ^ (x2<<30) ^ (x2<<29) ^ (x2<<28);
+        gNB->nr_gold_pbch_dmrs[n_hf][l][n] = x1 ^ x2;
+      }
+
+    }
+  }
+
+}

openair1/PHY/NR_REFSIG/nr_mod_table.h

-/*
- * Licensed to the OpenAirInterface (OAI) Software Alliance under one or more
- * contributor license agreements.  See the NOTICE file distributed with
- * this work for additional information regarding copyright ownership.
- * The OpenAirInterface Software Alliance licenses this file to You under
- * the OAI Public License, Version 1.1  (the "License"); you may not use this file
- * except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.openairinterface.org/?page_id=698
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- *-------------------------------------------------------------------------------
- * For more information about the OpenAirInterface (OAI) Software Alliance:
- *      contact@openairinterface.org
- */
-
 #define MOD_TABLE_SIZE_SHORT 6
 #define MOD_TABLE_BPSK_OFFSET 1
-short nr_mod_table[MOD_TABLE_SIZE_SHORT] = {0,0,768,768,-768,-768};
+short nr_mod_table[MOD_TABLE_SIZE_SHORT] = {0,0,23170,23170,-23170,-23170};

openair1/PHY/NR_TRANSPORT/nr_pbch.c

@@ -37,4 +37,53 @@
 #include "PHY/extern.h"
 #include "PHY/sse_intrin.h"
 
-//#define DEBUG_PBCH 1
+#define DEBUG_PBCH
+
+short nr_mod_table[MOD_TABLE_SIZE_SHORT] = {0,0,23170,23170,-23170,-23170};
+
+int nr_generate_pbch_dmrs(uint32_t *gold_pbch_dmrs,
+                          int32_t **txdataF,
+                          int16_t amp,
+                          uint8_t ssb_start_symbol,
+                          nfapi_config_request_t* config,
+                          NR_DL_FRAME_PARMS *frame_parms)
+{
+  int m,k,l;
+  int a, aa;
+  uint16_t mod_dmrs[2 * NR_PBCH_DMRS_LENGTH];
+
+
+  /// BPSK modulation
+  for (m=0; m<NR_PBCH_DMRS_LENGTH; m++) {
+    mod_dmrs[2*m] = nr_mod_table[2*(1 + (*(gold_pbch_dmrs + m/32))&(1<<(m&0xf)) )];
+    mod_dmrs[2*m + 1] = nr_mod_table[2*(1 + (*(gold_pbch_dmrs + m/32))&(1<<(m&0xf)) ) + 1];
+#ifdef DEBUG_PBCH
+  printf("m %d  mod_dmrs %d %d", m, mod_dmrs[2*m], mod_dmrs[2*m + 1]);
+#endif
+  }
+
+  /// Resource mapping
+  a = (config->rf_config.tx_antenna_ports.value == 1) ? amp : (amp*ONE_OVER_SQRT2_Q15)>>15;
+
+  for (aa = 0; aa < config->rf_config.tx_antenna_ports.value; aa++)
+  {
+
+    // PBCH DMRS are mapped
+    k = frame_parms->first_carrier_offset + frame_parms->ssb_start_subcarrier + 56; //and
+    l = ssb_start_symbol + 1;
+
+    for (m = 0; m < NR_PBCH_DMRS_LENGTH; m++) {
+      ((int16_t*)txdataF[aa])[2*(l*frame_parms->ofdm_symbol_size + k)] = (a * mod_dmrs[2*m]) >> 15;
+      ((int16_t*)txdataF[aa])[2*(l*frame_parms->ofdm_symbol_size + k) + 1] = (a * mod_dmrs[2*m + 1]) >> 15;
+#ifdef DEBUG_PBCH
+  int idx = 2*(l*frame_parms->ofdm_symbol_size + k);
+  printf("aa %d m %d  txdataF  %d %d %d", aa, m, txdataF[aa][idx], txdataF[aa][idx+1]);
+#endif
+      k++;
+
+      if (k >= frame_parms->ofdm_symbol_size)
+        k-=frame_parms->ofdm_symbol_size;
+    }
+  }
+  return (0);
+}

openair1/PHY/defs.h

@@ -134,6 +134,7 @@ static inline void* malloc16_clear( size_t size )
 #include "PHY/CODING/defs.h"
 #include "PHY/TOOLS/defs.h"
 #include "platform_types.h"
+
 #define MAX_NUM_RU_PER_eNB 64 
 
 #include "PHY/LTE_TRANSPORT/defs.h"
@@ -169,6 +170,9 @@ static inline void* malloc16_clear( size_t size )
 
 #define nr_subframe_t lte_subframe_t
 
+#define NR_PBCH_DMRS_LENGTH 144
+#define NR_PBCH_DMRS_LENGTH_DWORD 5 // roundup(NR_PBCH_DMRS_LENGTH/32)
+
 typedef enum{
   nr_ssb_type_A = 0,
   nr_ssb_type_B,
@@ -1989,6 +1993,9 @@ typedef struct PHY_VARS_gNB_s {
   int16_t d_pss[NR_PSS_LENGTH];
   int16_t d_sss[NR_SSS_LENGTH];
 
+  /// PBCH DMRS sequence
+  uint32_t nr_gold_pbch_dmrs[2][64][NR_PBCH_DMRS_LENGTH_DWORD];
+
   /// Indicator set to 0 after first SR
   uint8_t first_sr[NUMBER_OF_UE_MAX];
 

openair1/SCHED_NR/defs.h

@@ -45,6 +45,11 @@ int nr_generate_sss(  int16_t *d_sss,
                       uint8_t ssb_start_symbol,
                       nfapi_config_request_t* config,
                       NR_DL_FRAME_PARMS *frame_parms);
+int nr_generate_pbch_dmrs(uint32_t gold_sequence,
+                          int32_t **txdataF,
+                          int16_t amp,
+                          nfapi_config_request_t* config,
+                          NR_DL_FRAME_PARMS *frame_parms);
 void nr_set_ssb_first_subcarrier(nfapi_config_request_t *cfg, NR_DL_FRAME_PARMS *fp);
 
 #endif

openair1/SCHED_NR/phy_procedures_nr_gNB.c

@@ -126,11 +126,14 @@ void nr_common_signal_procedures (PHY_VARS_gNB *gNB,int frame, int subframe) {
   int ssb_start_symbol = nr_get_ssb_start_symbol(cfg, fp);
   nr_set_ssb_first_subcarrier(cfg, fp);
 
+
   if (subframe == ss_subframe)
   {
+    // Current implementation is based on SSB in first half frame, first candidate
     LOG_I(PHY,"SS TX: frame %d, subframe %d, start_symbol %d\n",frame,subframe, ssb_start_symbol);
     nr_generate_pss(gNB->d_pss, txdataF, AMP, ssb_start_symbol, cfg, fp);
     nr_generate_sss(gNB->d_sss, txdataF, AMP_OVER_2, ssb_start_symbol, cfg, fp);
+    nr_generate_pbch_dmrs(gNB->nr_gold_pbch_dmrs[0][0],txdataF, AMP_OVER_2, ssb_start_symbol, cfg, fp);
   }
 
 }