fembms: FeMBMS top-level routines for generating and decoding the PBCH/BCH...

	fembms: FeMBMS top-level routines for generating and decoding  the PBCH/BCH physical/transport channel
Signed-off-by: Javier Morgade <javier.morgade@ieee.org>

openair1/PHY/LTE_TRANSPORT/pbch.c

@@ -20,12 +20,12 @@
  */
 
 /*! \file PHY/LTE_TRANSPORT/pbch.c
-* \brief Top-level routines for generating and decoding  the PBCH/BCH physical/transport channel V8.6 2009-03
+* \brief Top-level routines for generating and decoding  the PBCH/BCH physical/transport channel V8.6 2009-03, V14.1 (FeMBMS)
 * \author R. Knopp, F. Kaltenberger
 * \date 2011
 * \version 0.1
 * \company Eurecom
-* \email: knopp@eurecom.fr,florian.kaltenberger.fr
+* \email: knopp@eurecom.fr,florian.kaltenberger.fr, javier.morgade@ieee.org
 * \note
 * \warning
 */
@@ -139,6 +139,285 @@ int allocate_pbch_REs_in_RB(LTE_DL_FRAME_PARMS *frame_parms,
   return(0);
 }
 
+void pbch_scrambling_fembms(LTE_DL_FRAME_PARMS *frame_parms,
+                     uint8_t *pbch_e,
+                     uint32_t length)
+{
+  int i;
+  uint8_t reset;
+  uint32_t x1, x2, s=0;
+
+  reset = 1;
+  // x1 is set in lte_gold_generic
+  x2 = frame_parms->Nid_cell + (1<<9); //this is c_init for FeMBMS in 36.211 Sec 6.6.1
+  //  msg("pbch_scrambling: Nid_cell = %d\n",x2);
+
+  for (i=0; i<length; i++) {
+    if ((i&0x1f)==0) {
+      s = lte_gold_generic(&x1, &x2, reset);
+      //      printf("lte_gold[%d]=%x\n",i,s);
+      reset = 0;
+    }
+
+    pbch_e[i] = (pbch_e[i]&1) ^ ((s>>(i&0x1f))&1);
+
+  }
+}
+
+int generate_pbch_fembms(LTE_eNB_PBCH *eNB_pbch,
+                  int32_t **txdataF,
+                  int amp,
+                  LTE_DL_FRAME_PARMS *frame_parms,
+                  uint8_t *pbch_pdu,
+                  uint8_t frame_mod4)
+{
+
+  int i, l;
+
+  uint32_t  pbch_D,pbch_E;//,pbch_coded_bytes;
+  uint8_t pbch_a[PBCH_A>>3];
+  uint8_t RCC;
+
+  uint32_t nsymb = (frame_parms->Ncp==NORMAL) ? 14:12;
+  uint32_t pilots;
+#ifdef INTERFERENCE_MITIGATION
+  uint32_t pilots_2;
+#endif
+  uint32_t second_pilot = (frame_parms->Ncp==NORMAL) ? 4 : 3;
+  uint32_t jj=0;
+  uint32_t re_allocated=0;
+  uint32_t rb, re_offset, symbol_offset;
+  uint16_t amask=0;
+
+  pbch_D    = 16+PBCH_A;
+
+  pbch_E  = (frame_parms->Ncp==NORMAL) ? 1920 : 1728; //RE/RB * #RB * bits/RB (QPSK)
+  //  pbch_E_bytes = pbch_coded_bits>>3;
+
+  LOG_D(PHY,"%s(eNB_pbch:%p txdataF:%p amp:%d frame_parms:%p pbch_pdu:%p frame_mod4:%d)\n", __FUNCTION__, eNB_pbch, txdataF, amp, frame_parms, pbch_pdu, frame_mod4==0);
+
+  if (frame_mod4==0) {
+    bzero(pbch_a,PBCH_A>>3);
+    bzero(eNB_pbch->pbch_e,pbch_E);
+    memset(eNB_pbch->pbch_d,LTE_NULL,96);
+    // Encode data
+
+    // CRC attachment
+    //  crc = (uint16_t) (crc16(pbch_pdu, pbch_crc_bits-16) >> 16);
+
+    /*
+    // scramble crc with PBCH CRC mask (Table 5.3.1.1-1 of 3GPP 36.212-860)
+    switch (frame_parms->nb_antenna_ports_eNB) {
+    case 1:
+    crc = crc ^ (uint16_t) 0;
+    break;
+    case 2:
+    crc = crc ^ (uint16_t) 0xFFFF;
+    break;
+    case 4:
+    crc = crc ^ (uint16_t) 0xAAAA;
+    break;
+    default:
+    msg("[PBCH] Unknown number of TX antennas!\n");
+    break;
+    }
+    */
+
+    // Fix byte endian of PBCH (bit 23 goes in first)
+    for (i=0; i<(PBCH_A>>3); i++)
+      pbch_a[(PBCH_A>>3)-i-1] = pbch_pdu[i];
+
+    //  pbch_data[i] = ((char*) &crc)[0];
+    //  pbch_data[i+1] = ((char*) &crc)[1];
+    //#ifdef DEBUG_PBCH
+
+    for (i=0; i<(PBCH_A>>3); i++)
+      LOG_D(PHY,"[PBCH] pbch_data[%d] = %x\n",i,pbch_a[i]);
+
+    //#endif
+
+    if (frame_parms->nb_antenna_ports_eNB == 1)
+      amask = 0x0000;
+    else {
+      switch (frame_parms->nb_antenna_ports_eNB) {
+      case 1:
+        amask = 0x0000;
+        break;
+
+      case 2:
+        amask = 0xffff;
+        break;
+
+      case 4:
+        amask = 0x5555;
+      }
+    }
+
+    ccodelte_encode(PBCH_A,2,pbch_a,eNB_pbch->pbch_d+96,amask);
+
+
+#ifdef DEBUG_PBCH_ENCODING
+
+    for (i=0; i<16+PBCH_A; i++)
+      LOG_D(PHY,"%d : (%d,%d,%d)\n",i,*(eNB_pbch->pbch_d+96+(3*i)),*(eNB_pbch->pbch_d+97+(3*i)),*(eNB_pbch->pbch_d+98+(3*i)));
+
+#endif //DEBUG_PBCH_ENCODING
+
+    // Bit collection
+    /*
+      j2=0;
+      for (j=0;j<pbch_crc_bits*3+12;j++) {
+      if ((pbch_coded_data[j]&0x80) > 0) { // bit is to be transmitted
+      pbch_coded_data2[j2++] = pbch_coded_data[j]&1;
+      //Bit is repeated
+      if ((pbch_coded_data[j]&0x40)>0)
+      pbch_coded_data2[j2++] = pbch_coded_data[j]&1;
+      }
+      }
+
+      #ifdef DEBUG_PBCH
+      msg("[PBCH] rate matched bits=%d, pbch_coded_bits=%d, pbch_crc_bits=%d\n",j2,pbch_coded_bits,pbch_crc_bits);
+      #endif
+
+      #ifdef DEBUG_PBCH
+      LOG_M"pbch_encoded_output2.m","pbch_encoded_out2",
+      pbch_coded_data2,
+      pbch_coded_bits,
+      1,
+      4);
+      #endif //DEBUG_PBCH
+    */
+#ifdef DEBUG_PBCH_ENCODING
+    LOG_D(PHY,"Doing PBCH interleaving for %d coded bits, e %p\n",pbch_D,eNB_pbch->pbch_e);
+#endif
+    RCC = sub_block_interleaving_cc(pbch_D,eNB_pbch->pbch_d+96,eNB_pbch->pbch_w);
+
+    lte_rate_matching_cc(RCC,pbch_E,eNB_pbch->pbch_w,eNB_pbch->pbch_e);
+
+#ifdef DEBUG_PBCH_ENCODING
+    LOG_D(PHY,"PBCH_e:\n");
+
+    for (i=0; i<pbch_E; i++)
+      LOG_D(PHY,"%d %d\n",i,*(eNB_pbch->pbch_e+i));
+
+    LOG_D(PHY,"\n");
+#endif
+
+
+
+#ifdef DEBUG_PBCH
+    if (frame_mod4==0) {
+      LOG_M("pbch_e.m","pbch_e",
+                   eNB_pbch->pbch_e,
+                   pbch_E,
+                   1,
+                   4);
+
+      for (i=0; i<16; i++)
+        printf("e[%d] %d\n",i,eNB_pbch->pbch_e[i]);
+    }
+#endif //DEBUG_PBCH
+    // scrambling
+
+    pbch_scrambling_fembms(frame_parms,
+                    eNB_pbch->pbch_e,
+                    pbch_E);
+#ifdef DEBUG_PBCH
+    if (frame_mod4==0) {
+      LOG_M("pbch_e_s.m","pbch_e_s",
+                   eNB_pbch->pbch_e,
+                   pbch_E,
+                   1,
+                   4);
+
+      for (i=0; i<16; i++)
+        printf("e_s[%d] %d\n",i,eNB_pbch->pbch_e[i]);
+    }
+#endif //DEBUG_PBCH 
+  } // frame_mod4==0
+
+  // modulation and mapping (slot 1, symbols 0..3)
+  for (l=(nsymb>>1); l<(nsymb>>1)+4; l++) {
+
+    pilots=0;
+#ifdef INTERFERENCE_MITIGATION
+    pilots_2 = 0;
+#endif
+
+    if ((l==0) || (l==(nsymb>>1))) {
+      pilots=1;
+#ifdef INTERFERENCE_MITIGATION
+      pilots_2=1;
+#endif
+    }
+
+    if ((l==1) || (l==(nsymb>>1)+1)) {
+      pilots=1;
+    }
+
+    if ((l==second_pilot)||(l==(second_pilot+(nsymb>>1)))) {
+      pilots=1;
+    }
+
+#ifdef DEBUG_PBCH
+    LOG_D(PHY,"[PBCH] l=%d, pilots=%d\n",l,pilots);
+#endif
+
+
+    re_offset = frame_parms->ofdm_symbol_size-3*12;
+    symbol_offset = frame_parms->ofdm_symbol_size*l;
+
+    for (rb=0; rb<6; rb++) {
+
+#ifdef DEBUG_PBCH
+      LOG_D(PHY,"RB %d, jj %d, re_offset %d, symbol_offset %d, pilots %d, nushift %d\n",rb,jj,re_offset, symbol_offset, pilots,frame_parms->nushift);
+#endif
+      allocate_pbch_REs_in_RB(frame_parms,
+                              txdataF,
+                              &jj,
+                              re_offset,
+                              symbol_offset,
+                              &eNB_pbch->pbch_e[frame_mod4*(pbch_E>>2)],
+                              pilots,
+#ifdef INTERFERENCE_MITIGATION
+                              (pilots_2==1)?(amp/3):amp,
+#else
+                              amp,
+#endif
+                              &re_allocated);
+
+      re_offset+=12; // go to next RB
+
+      // check if we crossed the symbol boundary and skip DC
+
+      if (re_offset >= frame_parms->ofdm_symbol_size)
+        re_offset=1;
+    }
+
+    //    }
+  }
+
+#ifdef DEBUG_PBCH
+  printf("[PBCH] txdataF=\n");
+
+  for (i=0; i<frame_parms->ofdm_symbol_size; i++) {
+    printf("%d=>(%d,%d)",i,((short*)&txdataF[0][frame_parms->ofdm_symbol_size*(nsymb>>1)+i])[0],
+           ((short*)&txdataF[0][frame_parms->ofdm_symbol_size*(nsymb>>1)+i])[1]);
+
+    if (frame_parms->nb_antenna_ports_eNB!=1) {
+      printf("(%d,%d)\n",((short*)&txdataF[1][frame_parms->ofdm_symbol_size*(nsymb>>1)+i])[0],
+             ((short*)&txdataF[1][frame_parms->ofdm_symbol_size*(nsymb>>1)+i])[1]);
+    } else {
+      printf("\n");
+    }
+  }
+
+#endif
+
+
+  return(0);
+}
+
 void pbch_scrambling(LTE_DL_FRAME_PARMS *frame_parms,
                      uint8_t *pbch_e,
                      uint32_t length)