PBCH payload interleaving

openair1/PHY/INIT/nr_parms.c

@@ -146,7 +146,7 @@ int nr_init_frame_parms(nfapi_config_request_t* config,
   frame_parms->samples_per_subframe = (frame_parms->samples_per_subframe_wCP + (frame_parms->nb_prefix_samples0 * frame_parms->slots_per_subframe) +
                                       (frame_parms->nb_prefix_samples * frame_parms->slots_per_subframe * (frame_parms->symbols_per_slot - 1)));
   frame_parms->samples_per_frame = 10 * frame_parms->samples_per_subframe;
-
+  frame_parms->freq_range = (frame_parms->dl_CarrierFreq < 6e9)? nr_FR1 : nr_FR2;
 
   return 0;
 }
@@ -283,7 +283,7 @@ int nr_init_frame_parms_ue(nfapi_config_request_t* config,
   //frame_parms->samples_per_subframe = (frame_parms->samples_per_subframe_wCP + (frame_parms->nb_prefix_samples0 * frame_parms->slots_per_subframe) +
   //                                    (frame_parms->nb_prefix_samples * frame_parms->slots_per_subframe * (frame_parms->symbols_per_slot - 1)));
   frame_parms->samples_per_frame = 10 * frame_parms->samples_per_subframe;
-
+  frame_parms->freq_range = (frame_parms->dl_CarrierFreq < 6e9)? nr_FR1 : nr_FR2;
 
   return 0;
 }

openair1/PHY/NR_TRANSPORT/nr_pbch.c

@@ -45,7 +45,6 @@ int nr_generate_pbch_dmrs(uint32_t *gold_pbch_dmrs,
                           int32_t **txdataF,
                           int16_t amp,
                           uint8_t ssb_start_symbol,
-                          uint8_t nushift,
                           nfapi_config_request_t* config,
                           NR_DL_FRAME_PARMS *frame_parms)
 {
@@ -53,11 +52,12 @@ int nr_generate_pbch_dmrs(uint32_t *gold_pbch_dmrs,
   int16_t a;
   int16_t mod_dmrs[NR_PBCH_DMRS_LENGTH<<1];
   uint8_t idx=0;
+  uint8_t nushift = config->sch_config.physical_cell_id.value &3;
 
   LOG_I(PHY, "PBCH DMRS mapping started at symbol %d shift %d\n", ssb_start_symbol+1, nushift);
 
   /// QPSK modulation
-  for (int m=0; m<NR_PBCH_DMRS_LENGTH>>1; m++) {
+  for (int m=0; m<NR_PBCH_DMRS_LENGTH; m++) {
     idx = ((((gold_pbch_dmrs[(m<<1)>>5])>>((m<<1)&0x1f))&1)<<1) ^ (((gold_pbch_dmrs[((m<<1)+1)>>5])>>(((m<<1)+1)&0x1f))&1);
     mod_dmrs[m<<1] = nr_mod_table[(NR_MOD_TABLE_QPSK_OFFSET + idx)<<1];
     mod_dmrs[(m<<1)+1] = nr_mod_table[((NR_MOD_TABLE_QPSK_OFFSET + idx)<<1) + 1];
@@ -134,22 +134,22 @@ int nr_generate_pbch_dmrs(uint32_t *gold_pbch_dmrs,
 void nr_pbch_scrambling(uint32_t Nid,
                         uint8_t nushift,
                         uint8_t *pbch_a,
-                        uint32_t length)
+                        uint16_t M,
+                        uint16_t length)
 {
   uint8_t reset, offset;
   uint32_t x1, x2, s=0;
-  uint64_t tmp=0;
-  uint8_t M = length - 3; // case Lmax = 4--> 29
 
   reset = 1;
   // x1 is set in lte_gold_generic
   x2 = Nid;
 
   // The Gold sequence is shifted by nushift* M, so we skip (nushift*M /32) double words
-  for (int i=0; i<(uint16_t)ceil((nushift*M)/5); i++) {
+  for (int i=0; i<(uint16_t)ceil((nushift*M)/32); i++) {
     s = lte_gold_generic(&x1, &x2, reset);
     reset = 0;
   }
+  // Scrambling is now done with offset (nushift*M)%32
   offset = (nushift*M)&0x1f;
 
   for (int i=0; i<length; i++) {
@@ -161,57 +161,104 @@ void nr_pbch_scrambling(uint32_t Nid,
   }
 }
 
+uint8_t nr_pbch_payload_interleaving_pattern[32] = {16, 23, 18, 17, 8, 30, 10, 6, 24, 7, 0, 5, 3, 2, 1, 4,
+                                                9, 11, 12, 13, 14, 15, 19, 20, 21, 22, 25, 26, 27, 28, 29, 31};
+
+uint8_t nr_pbch_payload_interleaver(uint8_t i) {
+  uint8_t j_sfn=0, j_hrf=10, j_ssb=11, j_other=14;
+
+  if (24<=i && i<=27) //sfn bits
+    return nr_pbch_payload_interleaving_pattern[j_sfn + i -24];
+  else if (i == 28) // Hrf bit
+    return nr_pbch_payload_interleaving_pattern[j_hrf];
+  else if (29<=i) // SSB bits
+    return nr_pbch_payload_interleaving_pattern[j_ssb + (i-29)];
+  else
+    return nr_pbch_payload_interleaving_pattern[j_other + i];
+}
 
 int nr_generate_pbch(NR_gNB_PBCH *pbch,
                      uint8_t *pbch_pdu,
                      int32_t **txdataF,
                      int16_t amp,
                      uint8_t ssb_start_symbol,
-                     uint8_t nushift,
                      uint8_t n_hf,
+                     uint8_t Lmax,
+                     uint8_t ssb_index,
                      int sfn,
-                     int frame_mod8,
                      nfapi_config_request_t* config,
                      NR_DL_FRAME_PARMS *frame_parms)
 {
 
   int k,l,m;
   int16_t a;
-  int16_t mod_pbch_e[NR_POLAR_PBCH_E<<1];
-  uint8_t sfn_4lsb, idx=0;
+  int16_t mod_pbch_e[NR_POLAR_PBCH_E];
+  uint8_t idx=0;
+  uint16_t M;
+  uint8_t nushift;
 
   LOG_I(PHY, "PBCH generation started\n");
 
   ///Payload generation
     // Fix byte endian
-  if (!frame_mod8)
-    for (int i=0; i<NR_PBCH_PDU_BITS; i++)
-      pbch->pbch_a[NR_PBCH_PDU_BITS-i-1] = pbch_pdu[i];
+  if (!(sfn&7))
+    for (int i=0; i<(NR_PBCH_PDU_BITS>>3); i++)
+      pbch->pbch_a[(NR_POLAR_PBCH_PAYLOAD_BITS>>3)-i-1] = pbch_pdu[i];
+#ifdef DEBUG_PBCH_ENCODING
+  printf("Byte endian fix:\n");
+  for (int i=0; i<4; i++)
+  printf("pbch_a[%d]: 0x%08x\n", i, pbch->pbch_a[i]);
   
-    // Extra bits generation
-  sfn_4lsb = sfn&3;
+#endif
+
+    // Extra byte generation
+  uint8_t *xbyte = pbch->pbch_a;
+  //memset((void*) xbyte, 0, 1);
   for (int i=0; i<4; i++)
-    pbch->pbch_a[NR_PBCH_PDU_BITS+i] = (sfn_4lsb>>i)&1; // 4 lsb of sfn
+    (*xbyte) ^= ((sfn>>i)&1)<<i; // 4 lsb of sfn
 
-  pbch->pbch_a[NR_PBCH_PDU_BITS+4] = n_hf; // half frame index bit
+  (*xbyte) ^= n_hf<<4; // half frame index bit
 
-  pbch->pbch_a[NR_PBCH_PDU_BITS+5] = (config->sch_config.ssb_subcarrier_offset.value>>5)&1; //MSB of k0 -- Note the case Lssb=64 is not supported (FR2)
+  if (Lmax == 64)
+    for (int i=0; i<3; i++)
+      (*xbyte) ^= ((ssb_index>>(3+i))&1)<<(5+i); // resp. 4th, 5th and 6th bits of ssb_index
+  else
+    (*xbyte) ^= ((config->sch_config.ssb_subcarrier_offset.value>>5)&1)<<5; //MSB of k_SSB
 #ifdef DEBUG_PBCH_ENCODING
+  printf("Extra byte:\n");
+  for (int i=0; i<4; i++)
+  printf("pbch_a[%d]: 0x%08x\n", i, pbch->pbch_a[i]);
+#endif
 
+    // Payload interleaving
+  uint32_t* input = (uint32_t*)pbch->pbch_a;
+  uint32_t* output = (uint32_t*)pbch->pbch_a_interleaved;
+  for (int i=0; i<32; i++)
+    (*output) |= (((*input)>>i)&1)<<(nr_pbch_payload_interleaver(i));
+#ifdef DEBUG_PBCH_ENCODING
+  printf("Interleaving:\n");
+  for (int i=0; i<4; i++)
+  printf("pbch_a_interleaved[%d]: 0x%08x\n", i, pbch->pbch_a_interleaved[i]);
 #endif
 
     // Scrambling
-  nr_pbch_scrambling((uint32_t)config->sch_config.physical_cell_id.value, nushift, pbch->pbch_a, NR_POLAR_PBCH_PAYLOAD_BITS);
+  M = NR_POLAR_PBCH_PAYLOAD_BITS - 3; // case Lmax = 4--> 29
+  nr_pbch_scrambling((uint32_t)config->sch_config.physical_cell_id.value, nushift, pbch->pbch_a_interleaved, M, NR_POLAR_PBCH_PAYLOAD_BITS);
 #ifdef DEBUG_PBCH_ENCODING
   
 #endif
 
+
   /// CRC, coding and rate matching
   polar_encoder (pbch->pbch_a, pbch->pbch_e, &frame_parms->pbch_polar_params);
 #ifdef DEBUG_PBCH_ENCODING
   
 #endif
 
+  /// Scrambling
+  M =  NR_POLAR_PBCH_E;
+  nr_pbch_scrambling((uint32_t)config->sch_config.physical_cell_id.value, nushift, pbch->pbch_a, M, NR_POLAR_PBCH_E);
+
   /// QPSK modulation
   for (int i=0; i<NR_POLAR_PBCH_E>>1; i++){
     idx = ((pbch->pbch_e[i<<1]&1)<<1) ^ (pbch->pbch_e[(i<<1)+1]&1);
@@ -224,6 +271,7 @@ int nr_generate_pbch(NR_gNB_PBCH *pbch,
   }
 
   /// Resource mapping
+  nushift = config->sch_config.physical_cell_id.value &3;
   a = (config->rf_config.tx_antenna_ports.value == 1) ? amp : (amp*ONE_OVER_SQRT2_Q15)>>15;
 
   for (int aa = 0; aa < config->rf_config.tx_antenna_ports.value; aa++)

openair1/PHY/NR_TRANSPORT/nr_transport.h

@@ -62,7 +62,6 @@ int nr_generate_pbch_dmrs(uint32_t *gold_pbch_dmrs,
                           int32_t **txdataF,
                           int16_t amp,
                           uint8_t ssb_start_symbol,
-                          uint8_t nushift,
                           nfapi_config_request_t* config,
                           NR_DL_FRAME_PARMS *frame_parms);
 
@@ -74,7 +73,8 @@ int nr_generate_pbch_dmrs(uint32_t *gold_pbch_dmrs,
 void nr_pbch_scrambling(uint32_t Nid,
                         uint8_t nushift,
                         uint8_t *pbch_a,
-                        uint32_t length);
+                        uint16_t M,
+                        uint16_t length);
 
 /*!
 \fn int nr_generate_pbch
@@ -87,11 +87,19 @@ int nr_generate_pbch(NR_gNB_PBCH *pbch,
                      int32_t **txdataF,
                      int16_t amp,
                      uint8_t ssb_start_symbol,
-                     uint8_t nushift,
                      uint8_t n_hf,
+                     uint8_t Lmax,
+                     uint8_t ssb_index,
                      int sfn,
-                     int frame_mod8,
                      nfapi_config_request_t* config,
                      NR_DL_FRAME_PARMS *frame_parms);
 
+/*!
+\fn int nr_generate_pbch
+\brief PBCH interleaving function
+@param bit index i of the input payload
+@returns the bit index of the output
+ */
+uint8_t nr_pbch_payload_interleaver(uint8_t i);
+
 #endif /*__NR_TRANSPORT__H__*/

openair1/PHY/defs_gNB.h

@@ -38,7 +38,8 @@
 
 
 typedef struct {
-  uint8_t pbch_a[NR_POLAR_PBCH_PAYLOAD_BITS];
+  uint8_t pbch_a[NR_POLAR_PBCH_PAYLOAD_BITS>>3];
+  uint8_t pbch_a_interleaved[NR_POLAR_PBCH_PAYLOAD_BITS>>3];
   uint8_t pbch_e[NR_POLAR_PBCH_E];
 } NR_gNB_PBCH;
 

openair1/PHY/defs_nr_common.h

@@ -54,8 +54,8 @@
 #define NR_PSS_LENGTH 127
 #define NR_SSS_LENGTH 127
 
-#define NR_PBCH_DMRS_LENGTH 144
-#define NR_PBCH_DMRS_LENGTH_DWORD 5 // roundup(NR_PBCH_DMRS_LENGTH/32)
+#define NR_PBCH_DMRS_LENGTH 144 // in mod symbols
+#define NR_PBCH_DMRS_LENGTH_DWORD 10 // roundup(2(QPSK)*NR_PBCH_DMRS_LENGTH/32)
 
 #define NR_MAX_NUM_BWP 4
 
@@ -76,6 +76,11 @@ typedef enum{
   nr_ssb_type_E
 } nr_ssb_type_e;
 
+typedef enum {
+  nr_FR1 = 0,
+  nr_FR2
+} nr_frequency_range_e;
+
 typedef struct NR_BWP_PARMS {
   /// Associated numerology index
   uint8_t numerology_index;
@@ -88,6 +93,8 @@ typedef struct NR_BWP_PARMS {
 } NR_BWP_PARMS;
 
 typedef struct NR_DL_FRAME_PARMS {
+  /// frequency range
+  nr_frequency_range_e freq_range;
   /// Number of resource blocks (RB) in DL
   uint8_t N_RB_DL;
   /// Number of resource blocks (RB) in UL

openair1/SCHED_NR/phy_procedures_nr_gNB.c

@@ -123,16 +123,13 @@ void nr_common_signal_procedures (PHY_VARS_gNB *gNB,int frame, int subframe) {
   int **txdataF = gNB->common_vars.txdataF;
   uint8_t *pbch_pdu=&gNB->pbch_pdu[0];
   int ss_subframe = (cfg->sch_config.half_frame_index.value)? 5 : 0;
-  int sfn = 10*frame + subframe;
-  int frame_mod8 = frame&7;
-  uint8_t Lmax, nushift, ssb_index=0, n_hf=0;
+  uint8_t Lmax, ssb_index=0, n_hf=0;
 
   LOG_D(PHY,"common_signal_procedures: frame %d, subframe %d\n",frame,subframe);
 
   int ssb_start_symbol = nr_get_ssb_start_symbol(cfg, fp);
   nr_set_ssb_first_subcarrier(cfg, fp);
   Lmax = (fp->dl_CarrierFreq < 3e9)? 4:8;
-  nushift = (Lmax < 8)? ssb_index&3 : ssb_index&7;
 
 
   if (subframe == ss_subframe)
@@ -147,8 +144,8 @@ void nr_common_signal_procedures (PHY_VARS_gNB *gNB,int frame, int subframe) {
       if (gNB->pbch_configured != 1)return;
       gNB->pbch_configured = 0;
     }*/
-    nr_generate_pbch_dmrs(gNB->nr_gold_pbch_dmrs[n_hf][ssb_index],txdataF, AMP_OVER_2, ssb_start_symbol, nushift, cfg, fp);
-    nr_generate_pbch(&gNB->pbch, pbch_pdu, txdataF, AMP_OVER_2, ssb_start_symbol, nushift, sfn, n_hf, frame_mod8, cfg, fp);
+    nr_generate_pbch_dmrs(gNB->nr_gold_pbch_dmrs[n_hf][ssb_index],txdataF, AMP_OVER_2, ssb_start_symbol, cfg, fp);
+    nr_generate_pbch(&gNB->pbch, pbch_pdu, txdataF, AMP_OVER_2, ssb_start_symbol, n_hf, Lmax, ssb_index, frame, cfg, fp);
   }
 
 }